Journal of Materials Science

Published by Springer Nature
Online ISSN: 1573-4803
Learn more about this page
Recent publications
Article
  • Yong HuangYong Huang
  • Feng ChenFeng Chen
  • Lingyao MengLingyao Meng
  • [...]
  • Wanping ChenWanping Chen
Room temperature gas-sensitive metal oxides have received growing concern over their long-term stability in recent years. Presently, Pt-SnO2 composite nanoceramics of 1 wt% Pt have been prepared, and the time dependence of their room temperature hydrogen sensing capability has been carefully studied. A strong variation with time was observed, with the room temperature response to 1% H2− 20% O2–N2 decreased by a factor of several dozen after only one week. Heat treatments were found highly effective to activate those aged samples. Their room temperature hydrogen sensing capability was almost completely restored through 10 min heat treatments at temperatures as low as 130 °C. It is proposed that impurity gases in air slowly deposit on Pt in Pt–SnO2 composite nanoceramics, and the catalytic role of Pt is deactivated by the deposition and then activated after their desorption through heat treatments. These results suggest that periodic mild heat treatments can be a simple and feasible way for some room temperature gas-sensitive metal oxides to maintain a high long-term stability.
 
Article
The effect of high-dose gamma irradiation on the minority charge carrier lifetime in p-type and n-type single-crystal silicon wafers has been studied using the “Quasi-Static Technique,” Sinton WCT-120. Full computerized measurements are set-up on the lifetime of the minority charge carriers τ for many commercial wafers before/after exposure to gamma rays. It is concluded that there is a linear increase in the Charge Carrier Lifetime CCL till a certain dose, followed by an exponential decrease by increasing the dose at different gamma doses. However, it is suggested that under a certain dose of gamma radiation, the silicon wafers quality can be improved to be used in electronic devices. Graphical abstract
 
Article
  • Jie FanJie Fan
  • Panpan LiPanpan Li
  • Zhijian WangZhijian Wang
  • Jiping YangJiping Yang
The epoxy-based nanocomposites are widely used in the aerospace field, which experience harsh conditions with extremely low and high temperatures. The temperature dependence of the properties of epoxy-based nanocomposites in a wide range of temperatures is of great importance for their application. In this work, we used the molecular dynamics (MD) simulation and experimental methods to comprehensively study the temperature dependence of epoxy-based nanocomposites. Three kinds of nanofillers, prepared by grafting three epoxy monomers with different functionality degrees to graphene oxide (GO), were used. The dynamic behavior, interfacial properties and mechanical properties of the nanocomposites in a wide range of temperatures were investigated by MD simulation. Simulation results showed that as temperature decreased from 600 to 4 K, all the nanocomposites exhibited decreased molecular mobility, increased interfacial interaction energy and increased Young’s modulus. The tensile properties of the nanocomposites at room temperature (RT), liquid nitrogen temperature (LNT) and liquid helium temperature (LHeT) were also experimentally measured, which agreed well with the simulation results. The tensile strength of nanocomposites increased at LNT compared to that at RT, and then decreased at LHeT. Furthermore, the toughening mechanisms of EFGO to epoxy resin at different temperatures were discussed. The results are expected to provide a new insight into the design and preparation of nanocomposites applied at various temperatures.
 
a Schematic diagrams showing the synthesis procedure of the H-TNO@C sample (insets are the corresponding photographs). FESEM images of the b CS, c CS@TNO, d AH-TNO, e H-TNO, f H-TNO@C, and g TNO samples
TEM images and the corresponding SAED patterns of the a CS, b CS@TNO, (c) AH-TNO, and d H-TNO samples. e, f TEM images, g HRTEM image, and h STEM image and the corresponding EDS elemental mapping images of the H-TNO@C sample
a XRD patterns of the CS@TNO, AH-TNO, TNO, H-TNO, and H-TNO@C samples. b Raman spectra of the TNO, H-TNO, and H-TNO@C samples. c TGA curve, d Survey-scan XPS spectrum, e Ti 2p core-level XPS spectrum, f Nb 3d core-level XPS spectrum, g O 1 s core-level XPS spectrum, h C 1 s core-level XPS spectrum, and (i) N 1 s core-level XPS spectrum of the H-TNO@C sample
a Typical CV curves of the TNO, H-TNO, and H-TNO@C electrodes. Initial three GCD curves of the b TNO, c H-TNO, and d H-TNO@C electrodes. e Rate performances, f Nyquist plots, and g cycling performances of the TNO, H-TNO, and H-TNO@C electrodes. h Schematic illustration of the advantages of the H-TNO@C nanoarchitecture for lithium storage
Article
  • Jiao ChenJiao Chen
  • Mingzhu NiMingzhu Ni
  • Wei LiuWei Liu
  • [...]
  • Hui XiaHui Xia
TiNb2O7 (TNO) is regarded as a promising anode candidate for lithium-ion batteries due to its good safety, high theoretical capacity, and good structural stability. However, its application is greatly hindered by its intrinsically poor lithium diffusivity and low conductivity. In this work, N-doped carbon-coated interconnected TNO hollow nanospheres (H-TNO@C) are prepared by a template route followed with carbon coating. Benefiting from the unique hybrid nanoarchitecture, shortened lithium-ion diffusion length, enhanced electronic conductivity, and good structural robustness are obtained by the H-TNO@C electrode. Consequently, the H-TNO@C electrode exhibits a larger specific capacity (271 mAh g⁻¹ at 0.2 C), enhanced rate performance (151 mAh g⁻¹ at 10 C), as well as better cycling durability (91.7% capacity retention after 5000 cycles) than those of the bare TNO particles and the TNO hollow spheres electrodes. Graphical abstract
 
Article
This paper uses the scaleable and commercial in-situ (exhaust) dyeing method to fabricate reduced graphene oxide (rGO)/poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT: PSS) hybrids on knitted cotton fabrics to develop lightweight, flexible, and metal-free knitted cotton fabric for electromagnetic interference shielding (EMI SE) application. The graphene oxide (GO) and PEDOT: PSS solution were directly dyed and reduced through a green reducing agent C6H8O6 (L-ascorbic acid) at a low temperature (60 °C) by a commercially used exhaust dyeing process on cotton fabric. The morphology and elemental analysis, mechanical stability, hydrophobicity, electrical conductivity, and (EMI SE) performance rGO/PEDOT: PSS dyed fabric has been systematically studied. The electrical conductivity of the resultant composite fabric significantly improved up to 4.2 × 10³ Scm⁻¹ due to the higher inter bonding and adhesion of fibers in the yarn, and fabric assembly, with each fiber surface finely coated with composite of rGO and PEDOT: PSS with each other due to less interlayer spacing. The mechanical stability of tensile strength and hydrophobic performance of rGO/PEDOT:PSS composite dyed hybrid (RPD-1) significantly improved up to 49 MPa and 156°, respectively, due to an increase of graphene wt.%. The resultant cotton fabric exhibited outstanding EMI shielding performance up to − 49 dB on 30–1530 MHz and 39 dB on 8–18 GHz (X-band) frequency range which shielded almost 99.99% of incident electromagnetic radiation waves. Graphical abstract
 
Article
The inculcation of interlayer spacing sarchitectures between MXene (M-X) sheets is a simplified approach to inhibit restacking of Ti3C2Tx sheets and hinder this inclination. Hence, spacing architectural materials like conductive polymers (CP), carbon, and so on can undergo integration with Ti3C2Tx-M-X in order to benefit from their inherently electrical conductivity as well as elevated energy-storage disposition to attain a synergistic influence on enhanced electrochemical behavior. Furthermore, the intercalation of polymeric architectures into M-X layers presents another prospective pathway to expand the interlayering spacing between Ti3C2Tx-M-X, thereby further enhancing electrochemical capacitance as well as mechanical strength. Metallic oxides, susceptible to benefitting from wide oxidation states, can attain superior pseudocapacitance via redox reactions. Thus, energy-storage capacitance of Ti3C2Tx-M-X can be enhanced through the comingling with metallic oxides. Additionally, Ti3C2Tx-M-X layers restacking can be hindered through inculcation of transitional metallic oxides (TMOs) spacing architectures. Moreover, inclusion of conjugated polymers (CPs), serving as electrochemical materials, can hinder intercalation between Ti3C2Tx sheets. Therefore, this paper elucidates the effects of surface and interfaces on M-X and M-X polymeric nanoarchitectures properties and applications in energy storage devices and structures. Graphical Abstract
 
Article
  • Sri Pragna PendemSri Pragna Pendem
  • Nobufumi UeshimaNobufumi Ueshima
  • Katsunari OikawaKatsunari Oikawa
  • [...]
  • Toshiyuki KoyamaToshiyuki Koyama
The phase equilibria and diffusivity of Co–Fe–Mn system were investigated using alloy equilibrium and the diffusion couple technique. Furthermore, thermodynamic properties and diffusion mobilities were assessed using the CALPHAD approach. Isothermal sections of the ternary phase diagrams of the Co–Fe–Mn alloy at 800, 900, and 1000 °C were obtained. The phase boundaries between face-centered cubic (fcc)/A13 were experimentally determined for the first time, whereas those between fcc/body-centered cubic were similar to those reported in previous studies. The thermodynamic parameters of the A13 phase were assessed based on these results. The phase diagrams obtained using the thermodynamic interaction parameters in this study are in accordance with the experimental results. The diffusion paths of the fcc Co–Fe–Mn ternary systems at 900, 1000, and 1100 °C were experimentally determined, and the interdiffusivities were evaluated from the composition-penetration profiles using the Whittle–Green method. The interdiffusion coefficients and penetration profiles were calculated using the assessed atomic mobility parameters. The calculated interdiffusion coefficients and penetration profiles agreed with the experimental ones, validating the values of the optimized atomic mobility parameters. Graphical abstract
 
Article
  • Yonggang WangYonggang Wang
  • Zhenyu DingZhenyu Ding
  • Zengliang GaoZengliang Gao
  • Xiaogui WangXiaogui Wang
Gradient nanostructured (GNS) metallic materials have the potential to solve the strength-ductility dilemma. In this work, we investigate the depth-dependent microstructures and mechanical properties of the fully austenitic GNS 310S stainless steel fabricated by an adaptive surface mechanical rolling treatment technique. It is of great significance to study the mechanism of gradient nanocrystallization (GNC) and strength-ductility synergy of fully austenitic GNS 310S under the condition that severe plastic deformation does not induce martensitic transformation. Microstructural observations showed that a fully austenitic GNS surface layer is formed at room temperature, with a grain size ranging from ~ 56 nm to tens of microns from surface to the core. The GNC of GNS 310S is dominated by dislocation activities, twins, and shear bands. GNS 310S exhibited excellent mechanical properties and achieved good strength-ductility synergy, which is attributed to a high gradient residual compressive stress and a thicker GNS surface layer. Graphical abstract
 
Article
  • Abhi-Shek JainAbhi-Shek Jain
  • Muhammad Ikhmal MustafaMuhammad Ikhmal Mustafa
  • Mohd Izzat Iskandar Mohd SaziliMohd Izzat Iskandar Mohd Sazili
  • [...]
  • Ming-Xing ZhangMing-Xing Zhang
The components made out of hypereutectic high-chromium cast iron (HCCI), featured with high abrasion resistance and hardness, are usually subjected to destabilization treatment before use, to improve their hardness and wear resistance by destabilizing the retained austenite which transforms to martensite. This study investigates the effects of destabilization and tempering heat treatment on the microstructure and mechanical properties of an HCCI with and without modification of primary carbides. For the unmodified HCCI, the destabilization simultaneously increased both hardness and the transverse rupture strength (TRS). Increasing the destabilization temperature from 970 to 1090 °C led to a marginal decrease in hardness and slight increase in TRS. Destabilization at 1090 °C increased the transverse rupture strength (TRS) by 54% compared to the as-cast HCCI without reduction in wear resistance due to the coarsening of the secondary carbides. In addition, tempering within a temperature range from 200 to 280 °C after destabilization at 1090 °C led to a slight decrease in hardness, but an increase in TRS and wear resistance. Further increasing the tempering temperature to 310, 340 and 400 °C did not vary the properties. Tempering at 280 °C after destabilization at 1090 °C enabled more than 85% increase in TRS compared to the as-cast HCCI. The influence of destabilization temperature on the TiB2-modified HCCI is similar to the unmodified alloy. But, tempering after destabilization at 1090 °C decreased both hardness and TRS without significant variation of wear resistance even though a TRS peak was obtained at 310 °C tempering. Hence, to achieve the best performance an optimized heat treatment for the unmodified HCCI is destabilization at 1090 °C followed by tempering at 280 °C. For the TiB2-modified HCCI, tempering is not needed. Rationalizations of the mechanical properties are also discussed in terms of microstructure. Graphical abstract
 
Article
  • Tao JiangTao Jiang
  • Ying WangYing Wang
  • Shitao ZhangShitao Zhang
  • [...]
  • Jinhong YuJinhong Yu
Simply filling the metal foam as a thermally conductive filler into the polymer matrix can improve the thermal conductivity of the polymer matrix, but it still cannot greatly improve the thermal conductivity of the composites. In this paper, the epoxy resin/copper foam-nickel (EP/CF-Ni) composite thermal conductive material was prepared by a combination of electroplating and vacuum liquid impregnation. The deposition of nickel increases the heat dissipation area of the copper foam and at the same time widens the heat conduction path of the materials. By comparing EP/CF with different pores and EP/CF-Ni with different deposition times, it was found that the thermal conductivity of EP/CF-Ni composites could reach 5.215 W/(mK) at 7.3 wt% nickel deposition, which enhanced 2507% and 75% compared to pure epoxy and copper foam matrix composites, respectively. The deposition of nickel further improves the wear resistance of the composite. This experiment reveals the synergistic effect of thermal conductivity of metallic Ni and 3D copper foam, and provides some reference opinions for the field of thermal conductivity of metallic foam.
 
Article
Upgrading low-quality wood with less consumption of modifier is demanded in sustainable development of wood industry. In this study, multi-interfacial furfurylation combined with densification was proposed to improve performances of wood. Different from traditional furfurylation, the multi-interfacial furfurylation comprised internal impregnation with 10% concentration furfuryl alcohol (FA) and surface coating with reused FA. After combined treatments, FA polymerized on wood surface, and also penetrated into cell lumina and cell walls. Some cell walls became closer and almost attached together. Wood mass increased by 12.6% and density reached 860 kg m⁻³. The set recovery of densified wood decreased by over 92% due to multi-interfacial furfurylation. On account of density increase and multi-interfacial interactions among FA from wood surface to inner parts principally, the mechanical properties were significantly improved with over 260% increase of flexural strength and 50% enhancement of impact toughness. Physical properties were improved indicated by reduction of surface wettability, dynamic moisture sorption and water absorption mainly due to hydrophobicity increase, accessible sorption site decrease, water-path block and accommodation reduction for water molecules. The results can help facilitate better application of low-quality wood for building more efficient and environmentally friendly material industry. Graphical Abstract
 
Article
When polyoxymethylene (POM)—a common polymer used in metal injection moulding feedstock—is exposed to heat and oxygen during compounding, it can be easily decomposed, releasing undesired gaseous formaldehyde products. In order to reduce the formaldehyde emission from POM, amine treatment was performed. The effectiveness of propylamine at different concentrations and its role as a formaldehyde scavenger was studied via the UV–vis Spectrophotometry, Fourier Transform Infra-red, Thermogravimetric Analysis, Scanning Electron Microscopy, and melt flow index. The results proved that a simple amine, such as propylamine, is a promising candidate for scavenging formaldehyde in POM. It is also demonstrated that the best concentration of propylamine is 2 wt.% (POM-PA2) with a minimum formaldehyde emission of 1.44 mg/L. Further, when used in formulating metal injection moulding feedstock (MIM), the POM-PA2 reveals good rheological properties and high green strength. These advantages make the modified polyoxymethylene (POM-PA2) a promising binder system for MIM feedstock.
 
Article
The fretting wear behaviors and mechanism of a high Nb–TiAl alloy with full lamellar microstructure at ambient temperature were investigated. The fretting wear mechanism of the alloy under different loads and displacement amplitudes was revealed using experiments and molecular dynamics simulations. The results showed that the load and displacement amplitude significantly affected fretting wear behaviors and the mechanism of the Ti–45Al–9Nb alloy. Higher load and lower displacement amplitude could effectively reduce the fretting wear of the alloy. Molecular dynamics simulation results showed that the order-twin lamellar interface hindered the deformation and dislocation movement of twins, improved the mechanical properties of the material, and improved the wear resistance of such alloy. The wear mechanism of Ti–45Al–9Nb alloy was adhesive wear and surface fatigue wear.
 
a X-ray diffraction profiles recorded on the ceramic at various temperatures from 520 to 620 °C, b Rietveld refinement on the powder XRD data collected on the cracked ceramics (sintered at 580 °C) using Fullprof software; the schematic crystal structure of Li1.6Mn2.2(MoO4)3 is shown in the inset. c Raman spectra of the sample at 580 °C
SEM micrographs of the sintered ceramics at different temperatures. a 520 °C; b 540 °C; c 560 °C; d 580 °C; e 600 °C; f 620 °C
a Bulk density and relative density of the sintered Li1.6Mn2.2(MoO4)3 ceramics at various temperatures from 520 to 620 °C, b Measured and corrected permittivity of the samples sintered at 520–620 °C, c Q × f and τf values of the ceramics sintered at 520–620 °C for 4 h
XRD patterns, SEM images of the as-fired surface and EDS analysis result of Li1.6Mn2.2(MoO4)3 ceramic co-fired with 20 wt% Ag and 20 wt% Al powders at 580 °C for 1 h, respectively
Article
A new type of ternary molybdate ceramic Li1.6Mn2.2(MoO4)3 was manufactured through solid-state reaction. The experimental results exhibit that the changes in microstructure and dielectric property of the ceramic samples depend on sintering temperatures. At microwave frequency of 13.4 GHz, Li1.6Mn2.2(MoO4)3 ceramics sintered at 580 °C possess a supreme density of 3.88 g/cm³ together with the best comprehensive properties of εr = 4.75, Q × f = 30,434 GHz and τf = − 54 ppm/°C, and the prepared ceramic can be co-fired with Al and Ag metal electrodes, which is suitable for ultralow temperature co-fired ceramics (ULTCC) technology.
 
Article
Graphene nanosheets (GNSs) modified Sn58Bi and Cu-core Sn58Bi solder joints were manufactured in this work. The evolution of microstructure and growth of intermetallic compounds (IMCs) under current stressing were carefully investigated. The results show that the addition of GNSs aggravates the electromigration behavior in Sn58Bi solder joints, while it inhibits the mass transfer in Cu-core Sn58Bi solder joints. The effects of GNSs on the Bi migration were well discussed with the assistance of the finite element simulation. Furthermore, the local current density was calculated, considering the influence of microstructure, to analyze the formation of IMC particles existing in the solder matrix.
 
Article
Sr2MgSi2O7:Eu²⁺, Dy³⁺(SMSED) is a common persistent luminescence (PersL) material with excellent performance. In this work, the cubic SMSED phosphor with porous structure was prepared by employing a template-assisted high temperature solid-phase(THT) method. THT method can lower the calcination temperature, improve the performance, and form a good pore structure. This is conducive to the subsequent recombination with the photocatalyst. Then, Ag3PO4(APO) is compounded in situ in the pore structure of SMSED PersL material. And the cubic porous SMSED/APO composite device possesses an obvious catalytic function regardless of the presence of light or not. The good adsorption of porous materials and photocatalysis can synergistically adsorb organic pollutants to obtain faster degradation efficiency. Moreover, the SMSED PersL material with porous structure can be reused, reducing secondary pollution. This work will help reduce the energy consumption of industrial production of PersL material and promote the further application of photocatalytic technology. Graphical abstract
 
Article
The manufacturability of metallic alloys using laser-based additive manufacturing methods such as laser powder bed fusion has substantially improved within the last decade. However, local melting and solidification cause hierarchically structured and crystallographically textured microstructures possessing large residual stress. Such microstructures are not only the origin of mechanical anisotropy but also pose metrological challenges for the diffraction-based residual stress determination. Here we demonstrate the influence of the build orientation and the texture on the microstructure and consequently the mechanical anisotropy of as-built Inconel 718. For this purpose, we manufactured specimens with [001]/[011]-, [001]- and [011]/[1¯11]-type textures along their loading direction. In addition to changes in the Young’s moduli, the differences in the crystallographic textures result in variations of the yield and ultimate tensile strengths. With this in mind, we studied the anisotropy on the micromechanical scale by subjecting the specimens to tensile loads along the different texture directions during in situ neutron diffraction experiments. In this context, the response of multiple lattice planes up to a tensile strain of 10% displayed differences in the load partitioning and the residual strain accumulation for the specimen with [011]/[1¯11]-type texture. However, the relative behavior of the specimens possessing an [001]/[011]- and [001]-type texture remained qualitatively similar. The consequences on the metrology of residual stress determination methods are discussed.
 
Article
To manufacture micro-drawn cups featuring high CH/CD (cup height/cup diameter ratios) and high quality, a three-stage micro-deep drawing (MDD) system was designed and studied. TA1 pure titanium (Ti) foils with the thickness of 50 μm were annealed at 600–700 °C for 1 h to obtain different grain sizes. Then, the effects of different grain sizes on the deformation behavior of multi-stage MDD and the quality of the formed cups were analyzed. The results show that the as-received pure Ti has a poor formability, suffering a slight fracture problem and significant wrinkling problem of the final drawn cup. At the optimal annealing temperature of 600 °C, the drawn cups show very few wrinkles and a good shape profile. Besides, high CH/CD ratios can be produced for the final drawn cups. Moreover, with the increase in drawing stage, the wrinkling of the cup is significantly reduced due to the "ironing effect" in the multi-stage MDD process. The research can provide a basis for forming high-quality and high CH/CD ratios micro-parts by multi-stage MDD and enrich the knowledge from behavior deformation behavior and product quality assurance. Graphical abstract
 
Article
Exploring novel and efficient photocatalysts to accelerate CO2 photoreduction into useful chemicals or fuels is of great significance. In this work, we developed the three-dimensional (3D) structural heterojunction photocatalysts composed of ReS2 and Cu2O by a drop-casting approach. The ReS2 microspheres with nanosheets were deposited on the 3D structure of Cu2O/Cu foams. The analysis of UV–Vis absorption and PL spectra showed that the ReS2@Cu2O/Cu heterostructure delivered enhanced visible light absorption and improved charge carrier separation. The resulting ReS2@Cu2O/Cu-180 exhibited the CO yield of 14.3 µmol g⁻¹ under the visible light irradiation. The realized S-scheme heterostructure not only promoted the separation of the photogenerated electron and hole pairs, but also enhanced the visible light absorption. Furthermore, the enriched electrons with high reducing abilities aggregated into the conduction band and diffused to the surface of Cu2O for favoring the CO2 reduction and CO formation. This study is expected to provide a strategy to prepare high-performance S-scheme photocatalysts to perform efficient photocatalytic CO2 reduction.
 
Article
Transition metal oxides are considered as promising anode materials of high-performance lithium-ion batteries because of their higher specific capacities than that of commercial graphite. However, they still suffer from huge volume expansion/contraction during cycling, leading to fast decay of the reversible capacity and poor cycle stability. In this work, a graded porous carbon matrix has been in situ constructed successfully to strengthen structural stability of NiFe2O4 nanoparticles via a facile and green low-temperature combustion method. The calcination temperature has a significant effect on the purity and electrochemical performances of the final NiFe2O4/C composites. NiFe2O4/C prepared at 350 °C shows a high first discharge capacity of 1385.8 mAh g⁻¹ at 200 mA g⁻¹, excellent cycle stability, and good rate capability. This excellent electrochemical performance may be attributed to its favorable graded porous structure. The carbon matrix can effectively protect the NiFe2O4 nanoparticles, buffer the surface stress caused by volume expansion/contraction, and facilitate the transmission of electrons and Li⁺ ions. The symbiotic relationship between NiFe2O4 active nanoparticles and graded porous carbon matrix strengthens the structural stability of the electrode, which expands the way of designing high-performance electrode materials for secondary rechargeable batteries.
 
Article
It is vital to reveal the effect of microstructure features on the corrosion behavior of pure aluminum anode in alkaline electrolyte for Al-air batteries. In this paper, we extensively studied the influence of mechanical deformation on the corrosion microstructure and then corrosion features of pure aluminum anode. The results demonstrate that the cold-rolling deformation could facilitate the grain size refinement of pure aluminum. Surprisingly, the aluminum anodes with smaller grain sizes and larger grain boundary areas could effectively improve the corrosion resistance. The further characterization of the microstructure indicates that the deformation is capable of causing the fracture of the cathodic secondary phase precipitate clusters thus weakening the galvanic corrosion effects. The results of this paper could gain insights into the design and processing of pure aluminum for Al-air battery.
 
Article
Studies have shown that semiconductor compound photocatalysts have a wide range of promising applications in the treatment of environmental pollution. Meanwhile, in nature, the leaves of green plants are almost always lamellar, and photosynthesis in leaves is the most common solar energy conversion system, which involves the process of light absorption and conversion. In this paper, CuS/CuO nanorod arrays with plant-like structures were prepared on Cu mesh by in situ oxidation and successive ion layer adsorption and reaction (SILAR) method. The effects of oxidation temperature, annealing time and SILAR cycle on the structure and properties of CuS/CuO/Cu Mesh were investigated, and the mechanism of photothermal effect and photocatalysis was further analyzed. The experimental results show that the layered nanostructure and porous morphology of CuS/CuO/Cu mesh can reduce photon spillage and have better photothermal, wettability and photocatalytic properties. CuS/CuO/Cu mesh degraded MB and MO up to 92.7% and 86% in 180 min, while it still has good stability after 8 cycles. Compared with powder and microbial catalyst, CuS/CuO/Cu mesh has the advantages of brief preparation time, good stability, reusable, and no secondary pollution, which can bring greater economic benefits and better sewage treatment effect. Graphical abstract
 
Article
Based on depth-sensing indentation measurements, the relationship between microstructure and mechanical behavior of plasma-sprayed amorphous Al2O3–YAG ceramic coating was investigated. The Al2O3 and Al2O3–Y2O3 coatings were also deposited for performance comparison and mechanism discussion. In nanoindentation tests, the load-control mode was selected. Constant loading rate/load (P′/P) method was applied to obtain the steady-state indentation process by control loading. Scanning electron microscope, electron backscatter diffraction, depth-sensing indentation method of Oliver and Pharr, Weertman–Dorn equation and elastic–viscoelastic–viscous (EVEV) model were combined to analyze microstructural features, phase distribution and nanomechanical behavior of the coatings. The results revealed that amorphous Al2O3–YAG coating possessed excellent microstructure/mechanical performance uniformity, larger recovery resistance Rs, higher fraction of energy dissipation rd and better creep performance. Compared with the Al2O3 and Al2O3–Y2O3 coatings, the Al2O3–YAG coating showed a significant increase in creep compliance, which denoted corresponding decrease in coating elastic modulus and reflected more pronounced relaxation phenomenon.
 
Article
As nanotechnology floods application areas like medicine, electronics, water remediation, space and textiles, just to name a few, some nanomaterials remain in the spotlight due to their fantastic properties and their incredible potential. Such is the case of the 2D, transparent, flexible, strong, carbon-based nanomaterial called graphene. Graphene consists of sp2 hybridized carbon arranged in a flat network packed in a honey-comb pattern, having thus mono-atomic thickness. Its isolation in 2004 opened the door to numerous investigations and its research is funded each year by governments, industries and academia worldwide. Due to its non-hydrophilic nature, some applications represent a challenge (particularly biological and medical applications), thus an oxygen/hydrogen-functionalized hydrophilic version of it has lately gained popularity, its name is graphene oxide. This document aims to review the synthesis methods of graphene, graphene oxide and reduced graphene oxide. A revision of the most important top-down and bottom-up methods is presented, focusing on chemical vapor deposition for the growth of graphene and the wet-chemical methods for the synthesis of graphene oxide and the reduction techniques available for reduced graphene oxide. We conclude by analyzing the current situation of graphene and graphene oxide production and the challenges that need to be tackled in order to meet the short-term demand of these nanomaterials for the promised applications.
 
Article
A novel polydopamine/reduced graphene oxide/MOF-5 (PDA/RGO/MOF-5) composite membrane with high flux, outstanding dye separation performance and anti-fouling ability was prepared by synthesizing the polydopamine-modified GO/MOF-5 composite material and aggregating it on a commercial cellulose acetate (CA) membrane substrate through the vacuum filtration process. The prepared samples were characterized by X-ray diffraction, Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy. Besides, scanning electron microscopy, transmission electron microscopy and atomic force microscopy were used to explore the structural characteristics of the membrane. The results showed that the permeation performance of the hybrid membrane was greatly enhanced due to the increase in the spacing between RGO layers. The flux for methylene blue (MB, cationic dye) and Congo red (CR, anionic dye) could reach 3439 ± 208 L·m⁻²·h⁻¹ and 2484 ± 52 L·m⁻²·h⁻¹, respectively, which were much higher than those of other polymer membranes reported so far. Moreover, the membrane material also exhibited an ideal dye rejection rate (99 ± 0.07% for MB and 97 ± 0.3% for CR). After three fouling-washing cycle experiments, the composite membrane still maintained an excellent flux recovery rate (FRR) of more than 85 ± 2%. Overall, it can be predicted that the PDA/RGO/MOF-5 membrane prepared by us has great potential in wastewater purification. Graphical abstract
 
Article
Magnesium alloy has excellent physical and mechanical properties and is expected to become a new generation of medical degradable materials. In this paper, the blood compatibility analysis of Graphene Oxide(GO)/Hydroxyapatite(HA)-AZ91D was carried out to improve the blood compatibility of magnesium alloy materials. AZ91D was used as the control group and GO/HA-AZ91D was used as the experimental group. The two samples were studied in vitro by hemolysis rate test, cell proliferation test, NO release and T-AOC test. The results combined with the work of the research group showed that the blood compatibility and cell compatibility of the GO/HA-AZ91D group were significantly improved, providing an effective idea for future corrosion resistant coatings on magnesium alloys.
 
Article
Fabrication of guided rotary tools requires perfectly levelled thin plates having an excellent combination of high strength and toughness. Uniformity of the mechanical properties is another challenge in the manufacturing process of these tools. The present research studies the influence of cross-rolling and austempering–tempering heat treatment on the microstructure, texture, levelness, and mechanical properties of the AISI 8670 steel used for making circular cutting tools. Actual size saw blades were produced with the new method, and the results were compared with those of commercial saws made with the conventional approach out of the same material. Cross-rolling homogenized the tensile properties of the rolled and heat-treated sheets due to the development of an intense and uniform {100} < 110 > components of α and ε fibers along in-plane directions. The distinctive uniform texture induced by cross-rolling notably increased the material’s resistance against the neutralization of the as-rolled texture and softening during heat treatment. Post-deformation austempering–tempering resulted in a microstructure of lower bainite that helped minimize distortion while achieving excellent flexural (~ 3.4 GPa) and tensile (~ 1.74 GPa) strength. Alongside high strength, the austempered–tempered plates showed significant elongation in both tensile (8%) and bending (7%) modes.
 
Article
Biomimetic scaffolds that induce bone growth in defects have always been the main focus of bone regeneration research. This study was to develop biomineralization scaffolds using eggshell membranes as the bio-template. The structural and mineralizing characteristics of the inner and outer eggshell membrane (IM and OM) before and after alkaline protease and sodium sulfite treatments were investigated. Electron microscopy showed that both the IM and OM had a core-mantel structure. IM had a thinner mantel layer and more uniform fiber network structure than OM, exhibiting small average pore size and high specific surface area. The mineralization of IM and OM only occurred on the fibers surface. However, enzymatic treatment caused partial destruction of the mantel layer, which allowed the formation of mineral crystals. Specifically, the IM and enzyme-treated IM (EIM) fibers had better mineralization potentials than OM and the enzyme-treated OM (EOM), respectively. Hydroxyapatite-accumulated EIM (EIMHA) showed stronger hydrophilicity, higher BSA fixation ability, and simulated tissue fluid absorption ability. Moreover, the EIMHA facilitated the cell adhesion of the MC3T3-E1 cells and showed a strong cell proliferation activity. In summary, eggshell membranes treated with alkaline protease and sodium sulfite has a high potential to be used as a biomimetic mineralization scaffold. Graphical abstract
 
Article
TiAl alloys are regarded as ideal lightweight structural materials above 600 °C and show remarkable application prospects in the field of aerospace materials. However, many potential TiAl alloy engineering applications have been limited by their low room-temperature tensile plasticity and insufficient high-temperature capability. Composite technology is an effective method for enhancing the comprehensive properties of TiAl alloys. In this paper, recent research progress in TiAl matrix composites is reviewed to highlight the scientific and technological investigation of TiAl matrix composites with excellent properties. The content includes four aspects of TiAl matrix composites: reinforcement selection, configuration design, interfacial microstructure, and processing technology. The aim of this work is to provide a reference for the preparation and research of TiAl matrix composites and open up a novel design direction for TiAl matrix composites with excellent comprehensive properties.
 
Article
Layered double hydroxide (LDH) films have attracted extensive attention in Mg alloy anti-corrosion due to their unique physical barrier function and ion exchange performance. However, most of the LDH films on Mg alloy have problems of harsh preparation conditions, poor anti-corrosion stability, and poor adhesion. In this paper, a typical Li–Al-alanine (Ala) LDH film has been successfully prepared on AZ91D Mg alloy surface under milder conditions using multi-arc ion plating and in-situ dipping for the first time. Then an improved vacuum impregnation further modified the Li–Al-Ala LDH film in an ethanol solution of stearic acid (SA) to improve its protective stability. The potentiodynamic polarization curves and electrochemical impedance spectra (EIS) showed that the Li–Al-Ala LDH/SA film's corrosion resistance is more than three orders of magnitude higher than that of the blank Mg alloy in 3.5 wt% NaCl, showing a highly increased corrosion resistance. The long-term immersion experiments found that the surface structure and corrosion resistance of the Li–Al-Ala LDH/SA film did not change much after immersion in 3.5 wt% NaCl for 432 h. The bonding force between the film and the Mg alloy substrate can reach grade 0 based on the standard from International Standardization Organization (ISO). And the hydrophobicity of the film can remain stable with the water contact angle (WCA) being steady at about 140° after a certain distance of external abrasion, showing excellent mechanical wear resistance. The study provides a new milder approach to fabricating superhydrophobic LDH films with durable anti-corrosion resistance, good adhesion, and mechanical stability on Mg alloy surface. Graphical abstract
 
Article
Hexagonal boron nitride (hBN) is a graphite-like crystal that possesses high potential in two-dimensional (2D) heterojunction devices, nano-electronic devices and deep ultraviolet photoelectronic devices. Unfortunately, a highly efficient atmospheric-pressure method for fabricating bulk hBN crystals with low defect density is not yet developed. The addition of carbon into the growing alloy in the metal-flux-based fusion synthesis of hBN was found dramatically improved the hBN single crystal sizes but gave rise to a large number of random-shaped cracks. In this work, these cracks were confirmed to contain highly separated graphene formed from the aggregation of carbon impurities. However, the crack density was remarkably reduced by adding gold into the Ni–Cr alloy for the additional gold improves the dispersion of carbon in the alloy. Carbon control and removal of cracks suppressed the fast non-radiative recombination process, thus enhancing the photoluminescence efficiency. This work provided the guidance to improve the quality of bulk hBN crystals and control their defect-related emission properties by using an atmospheric-pressure technique, which is essential for device fabrication in the future. Graphical abstract
 
Article
Calcium silicate ceramics have excellent bioactivity and biomineralization performance. In this work, we investigated the effect of different mineralization environments of one time and five times simulated body fluids (× 1 and × 5 SBF) on the apatite mineralization behavior of CaSiO3 ceramic and explored the mineralization mechanism by soaking them in the × 1 SBF. The CaSiO3 ceramics were found to release Ca²⁺ and SiO3²⁻ ions firstly. The process of ions exchange resulted in the pH increased and the ≡Si–OH groups formed. H⁺ ions released from the ≡Si–OH groups due to the pH variation, which thereby caused that the surface was negatively charged to recombine with the Ca²⁺. Meanwhile, the calcium silicate surface layer reformed above the original CaSiO3 ceramic surface. The calcium phosphate layer with different mineral morphologies was induced to be deposited on the reformed calcium silicate surface layer. Importantly, the cytological response results also indicated that a thicker calcium phosphate minerals layer with lamellar-like morphology covered on the CaSiO3 ceramic surface played a more prominent role in up-regulating the expressions of osteogenesis-related genes. Graphical Abstract
 
Article
Epoxy resins (ERs) are one of the main types of resins used as structural adhesives; however, they present some weakness, which are mostly related to their highly cross-linked network after the curing process. Low electrical and thermal conductivity and low fracture toughness are the major drawbacks of these type of materials, and several efforts have been made over the past few years to overcome them. A critical survey regarding the use of different fillers in ERs systems and the outcome is highlighted and discussed in the present review. The incorporation of fillers into ERs matrix is one of the most successfully explored alternatives to improve the properties of ERs. It is worth to mention that even though ER composites are a widely explored topic, few reports have been focused on a compilation of the most relevant fillers and the main changes on ERs composites performance. Therefore, the present review gives an overview of a vast selection of fillers—natural, metallic, carbon fillers—incorporated in ER matrices to enhance or to meet the requirements for a desired application, such as the increase in the final adhesive toughness. The combination of the top characteristics of fillers and polymers is accomplished, leading to high-performance composites. Among the most promising fillers, carbon nanomaterials, fiber-reinforced polymers, carbon fiber-reinforced polymers, biofillers and metallic and ceramic fillers are described which have the ones having higher application potential. The influence of the addition of these different types of fillers in ERs system properties such as flame retardancy, mechanical and thermal and electrical performance is discussed and reviewed in detail.
 
Article
Nano zirconia/zeolite molecular sieve was synthesized by using sodium alginate and FeCl3 as cross-linking agents to produce a bead type adsorbent (Fe@nano ZrO2/ZMS) with improved usability and applicability for nitrate removal. Optimal preparation parameters via mass ratio of nano ZrO2 to ZMS and FeCl3 concentration were determined by batch tests. Best adsorption performance was determined by varying operational adsorption parameters, such as dose (1.0–8.0 g/L), solution pH (3.0–10.0) and co-existing ions (K⁺, Mg²⁺, Ca²⁺, NH4⁺, Cl⁻, F⁻, SO4²⁻, HCO3⁻). The effect of contact time (10–100 min) and the kinetics of adsorption process were studied using pseudo-first-order, pseudo-second-order, Power and Elovich models starting from different initial concentrations of NO3– ions (20, 30, 50 mg/L, respectively). The Langmuir, Freundlich, Sips and Temkin adsorption models were utilized to describe the equilibrium isotherms. Influence of solution temperature (10–40 °C) and thermodynamics results indicated adsorption was an exothermic and spontaneous process. Maximum removal efficiency of 79.8% occurred at 10 °C which was in line with the actual groundwater temperature. The structural properties were tested by SEM, BET, BJH and N2 adsorption–desorption isotherm. Adsorption mechanism of elements and functional groups on Fe@nano ZrO2/ZMS were studied by EDS, XRD and FTIR. The proposed adsorption mechanism included mostly hydrogen bonding, electrostatic attractions, and ion exchange. After 5 times repeated regeneration by 0.5 mol/L NaHCO3 solution, the beads still showed higher nitrate removal ability. The results showed that Fe@nano ZrO2/ZMS beads can be considered a potentially efficient adsorbent for the removal of nitrate ions from water. Graphical abstract
 
Article
Two fly ash glasses were synthesized and dissolved in KOH at a water/solid ratio of ≤ 0.3. We measured reaction kinetics, gel formation, and compressive strength. Mathematical modeling revealed that two consecutive solid-state diffusion processes controlled the reaction progress. A fast diffusion process determined the rate at which gel formed on the glass surface. Formation of gel in the interstices between glass particles slowed the reaction progress. The mixtures set and hardened. Compressive strength increased. A slower diffusion process took over as soon as most of the interstices were filled with gel. This diffusion process controlled the growth of compressive strength in the longer term. Compressive strength and its growth rate depended on Si/Al in the glass and on macro-porosity of the geopolymer, much less so on the mass of gel. The higher Si/Al supported the formation of a more compact gel, leading to higher and more rapidly growing compressive strength than at the lower Si/Al.
 
Article
A fine-tuned mordenite was prepared to overcome the low selectivity of tert-amyl anthracene production in the direct alkylation of anthracene. Herein, a series of boric acid-modified Fe-Zr mordenite materials were prepared, and tert-amyl anthracene was smoothly and efficiently obtained over these catalysts. The boron sites in modified catalyst promoted the alcohol dehydrogenation, which benefited the reaction conversion. Moreover, the existence of Brønsted and Lewis acid sites was the key in alkylation reaction, making 1.0B-Fe-Zr/MOR good reactivity (Conv. 47.8%, Sel. 91.4%). Calculated results correlated the products properties with catalyst structures, verifying that boric acid-modified Fe-Zr/MOR was a successful shape-selective catalyst. The present work opens a new frontier for a sustainable and high-selective method to process anthracene alkylation. Graphical abstract
 
Article
The simple preparation of porous carbons with highly-dispersed metal particles and no additional activation by gelating iron alum and carboxymethylcellulose sodium (CMC-Na) was investigated. Various porous carbons with different pore structures were prepared by varying the mass ratio of iron alum to CMC-Na. In carbonizing the gels, Na2CO3 by-product acted as an activator and promoted pores formation by decomposing over 700 °C. Carbonization of the CMC-Na xerogels with more Fe content resulted in the formation of α-iron (iron(cI2)) nanocrystals in porous carbons. Because the carbons exhibited typical ferromagnetic behavior, they could be collected by a neodymium magnet in water. The porous carbons which include other sodium compounds that improved adoption for volatile organic compound (VOC) demonstrated good VOC removal abilities compared to a commercial activated carbon. Their developed pores would facilitate accessing of VOC adsorbates to the carbon. Graphical abstract
 
Article
Magnetic properties of a Kagome-like nanoparticle with a ferromagnetic exchange coupling described by the mixed-spin (5/2, 3/2) Ising model were studied, and unique magnetic behavior was found by effective-field theory with correlations. Exchange coupling, transverse magnetic field, and anisotropies were displayed to have major influences on the magnetization, the specific heat and in turn, magnetization plateaus. Magnetization reversal, in terms of magnetization plateaus, is shown on magnetization curves. Through the influence of various parameters, magnetic susceptibility and specific heat curves appear interesting two-peak behavior. In addition, possible situations for depressed saturation magnetization in the Kagome-like nanoparticle are examined.
 
Article
The effects of SiC (20–30 vol. %) and MgO (1–3 vol. %) on sinterability, phase evolution, microstructures, mechanical and ablation characteristics of spark plasma sintered ZrB2-based composites were investigated in the present study. The analytically estimated residual stresses decreased with SiC and MgO addition. The highest relative density of 98.29 ± 0.36% and microhardness of 16.13 ± 2.91 GPa were observed for the composite containing 2 vol. % MgO owing to uniform dispersion of SiC and MgO in the ZrB2 matrix. The highest fracture toughness and critical energy release rate of 6.15 ± 0.41 MPa.m0.5 and 88.53 ± 11.73 J/m² were observed for the composite containing 3 vol. % MgO due to the invigoration of toughening mechanisms (SiC particle pull-out, crack deflection and bridging). The ablation resistance was enhanced with MgO addition and the highest ablation resistance was observed for the composite containing 2 vol. % MgO. The composites retained maximum hardness and fracture toughness of 14.17 ± 3.03 GPa and 5.91 ± 0.4 MPa.m0.5 after ablation test, which were 87.85% and 96.09% of maximum hardness and fracture toughness before ablation test. Graphical abstract
 
Article
Nanostructured Ti–Fe alloys were fabricated by cryomilling and spark plasma sintering (SPS). Cryomilling was performed for 8 h in a liquid N2 atmosphere, and densification of the alloyed mixture was performed at different SPS temperatures (800, 1000, and 1200 °C). The phase and structure of the Ti–Fe alloyed powder were studied by X-ray diffraction analysis. The morphologies of the cryomilled powders and SPS-treated compacts were investigated by scanning and transmission electron microscopic analyses. The results showed that alloying did not occur completely in the powder mixture after cryomilling and pure Ti and Fe phases were found. However, SPS treatment of cryomilled Ti–Fe powder resulted in a different phase evolution with temperature. Intermetallic compounds were formed in small amounts in the Fe-rich region; however, β-Ti phases were mostly present. The absorption energies of these alloys showed small changes from 460, 452, and 430 MJ/m³ when the SPS temperatures were 800, 1000, and 1200 °C, respectively. The compressive strength values of these Ti–Fe alloys improved with increasing SPS temperature owing to the diffusion of Fe in the Ti matrix, which promoted the dispersion hardening of these alloys.
 
Article
This paper reports the synthesis and the performance of polymer-derived ceramic filters for molten metal filtration. Two different filter types were studied: foam filters produced from flexible polyurethane (PU) foams and additive manufacturing (AM) filters produced from thermoplastic polyurethane (TPU) cellular structure, and the results from all filter types were compared with that of the commercially used SiC foam filters. In both cases, the urethane-based polymeric template was impregnated with the preceramic solution, followed by pyrolysis. The produced ceramic components were then used to filter a molten Al alloy (A357), and the resulting Al samples were characterized for their mechanical properties. When filters were used, more reproducible and reliable mechanical properties were achieved compared to the samples obtained without any filtration. Among the different filters tested, the foam filters demonstrated better performance in comparison with the AM ceramic filters due probably to the three-dimensional interconnected porosity compared with the unidirectional cellular structure of the AM ceramic filters. Graphical abstract
 
Article
We synthesize mesoporous WO3/carbon composites with PS-PVP-PEO polymeric template. The molecularly dissolved polymer in THF self-assembles in positively charged spherical micelles upon the addition of HCl. The negatively charged tungsten source (WO4²⁻) binds strongly with positively charged polymeric micelles. Glucose, WO4²⁻, and micelles are assembled as a mesostructure during solvent evaporation. The carbonization of composites leads to mesoporous WO3/carbon nanocomposites. A polymeric micelle having unique blocks for porogen (polystyrene), reaction site (polyvinyl pyridine), and stabilizer (ethylene oxide) makes the system exceptional to synthesize mesoporous nanocomposites in a one-pot method. The nanocomposites were characterized by dynamic light scattering, scanning electron microscopy, transmission electron microscopy, Fourier transforms infrared spectroscopy, X-ray photoelectron spectroscopy, and Raman spectroscopy. The electrochemical studies reveal that the composites deliver 381 F.g⁻¹ capacitance with 96% retention in 1 M H2SO4.
 
Article
In recent years, the utilization of Al as a grain refiner in Mg–RE alloys has gained widespread attention because of its advantages such as low cost. In this study, Mg–5Y–4Sm–xAl (x = 0, 0.6, 1.2 and 1.8 wt.%) alloys were fabricated, and high grain refinement efficiency of Al addition was obtained. Subsequently, the effect of different Al addition on the grain refinement was investigated and the refinement mechanism was discussed deeply in two major aspects. Firstly, Al2RE particles were formed in the solidification process and acted as the nucleation sites of α-Mg. The numerical density and diameter of those particles were obviously increased by increasing Al addition. Secondly, the addition of Al reduced the solute elements content in the α-Mg melt, resulting in a decrease in the grain growth restriction factor (Q value). Furthermore, the synergistic effect of solute elements and nucleation particles on grain refinement was described by the interdependent theory. Finally, the Al addition is beneficial to improve the mechanical properties of alloy. When the Al addition was 1.8%, the room temperature tensile strength of the alloy reached a maximum of 221 MPa and the maximum elongation was 9.2%. When the Al addition was 1.2%, the yield strength of the alloy reached a maximum of 142 MPa.
 
a XRD patterns and b Raman spectra of Ti3C2Tx, TiO2/Ti3C2Tx and P-Ti3C2Tx, c nitrogen adsorption/desorption isotherms with pore size distribution and d EPR spectra of Ti3C2Tx and P-Ti3C2Tx.
a Full XPS survey spectra, b Ti 2p, c O 1s and d C 1s spectrum of P-Ti3C2Tx and Ti3C2Tx.
SEM images of a Ti3C2Tx, b TiO2/Ti3C2Tx and c P-Ti3C2Tx, d, e TEM images of P-Ti3C2Tx, f EDS elemental mapping of P-Ti3C2Tx.
a CV curves, b EIS, c cycling performance at 100 mA g⁻¹ and d rate capability of Ti3C2Tx and P-Ti3C2Tx electrode, e GCD curves at different cycles and f long-term circulation at 0.5 A g⁻¹ of P-Ti3C2Tx electrode.
CV curves of a Ti3C2Tx and e P-Ti3C2Tx electrode at scan rates ranging from 0.1 to 2.0 mV s⁻¹, log (i) versus log (v) plots of b Ti3C2Tx and f P-Ti3C2Tx electrode, the capacitive contribution of c Ti3C2Tx and g P-Ti3C2Tx electrode at 0.1 mV s⁻¹, normalized 5contribution ratios of capacitive and diffusion-controlled capacity of d Ti3C2Tx and h P-Ti3C2Tx electrode at different scan rates, GITT profiles of the i Ti3C2Tx and h P-Ti3C2Tx electrode at 0.05 A g⁻¹, k the zoomed-in voltage corresponding to box in i , l the measured diffusivities D versus state of charge.
Article
In this work, a facile “in situ etching” approach is proposed to prepare porous Ti3C2Tx (P-Ti3C2Tx) anode for durable sodium-ion battery (SIB). The P-Ti3C2Tx which inherits the accordion-like structure of Ti3C2Tx possesses massive mesopores on the layered plane. Remarkably, abundant oxygen vacancies are introduced in P-Ti3C2Tx as well. Benefiting from the novel 3D architecture, the P-Ti3C2Tx demonstrates the improved specific surface area, improved active sites and electrochemical performance. As anode for SIB, the P-Ti3C2Tx and Ti3C2Tx electrode delivers 140 mAh g⁻¹ and 99.4 mAh g⁻¹ after 150 cycles at 100 mA g⁻¹, respectively. The charge storage mechanism analysis proves that the capacity of both anodes is dominated by the capacitive-controlled process and the capacitive contribution of P-Ti3C2Tx is higher than that of Ti3C2Tx at any scan rate. Moreover, the Na⁺ diffusion coefficient of P-Ti3C2Tx varies from 1.42 × 10⁻¹⁰ to 1.19 × 10⁻⁸ cm² s⁻¹, while it changes from 1.16 × 10⁻¹⁰ to 8.78 × 10⁻⁹ cm² s⁻¹ for Ti3C2Tx electrode, highlighting the significance of porous engineering on Ti3C2Tx.
 
Article
In the growing application field of electrowetting (EW), reliable control of the wetting behavior by an applied voltage is required over a wide temperature range. Despite the rising interest of EW, only few data are reported in the literature on the EW behavior as a function of temperature. In this paper, we investigate the quasi-static EW response on one of the most widely used hydrophobic materials, Teflon AF1600, in a temperature range from 25 to 70∘C\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\,^{\circ }\mathrm{C}$$\end{document}. The contact angle versus voltage is analyzed to illustrate the EW behavior. The results are in good agreement with the friction-adsorption model, which explains the contact angle (CA) hysteresis by a temperature-independent friction-like force and a temperature-dependent contribution of liquid adsorption onto a dielectric surface. The EW-CAs show a small asymmetry with respect to the polarity of the applied voltage, which might be due to the temporary and reversible charge trapping on the dielectric layer. The results underline that the different effects of the temperature-independent friction force and the temperature-dependent adsorption need to be taken into account to predict and control the CA in any EW-based application scenario. Graphical abstract
 
Article
Hematite is an ideal photoanode candidate for its appropriate energy band position, small band gap and good stability. However, sluggish charge carriers transport process and severe recombination reaction caused by surface and interface flaws always leads to inferior photoelectrochemical performance. In this study, we synthesized a SnO2 passivation layer with several-nanometer thickness on Fe2O3 nanorod arrays by a facile sonochemical method. And such passivated Fe2O3 was labeled as T-Fe2O3. After ultrasonic treatment, the surface chemical state of Fe2O3 was availably adjusted by SnO2 layer, the as-prepared T-Fe2O3 photoanode exhibits a 28-fold increase in photocurrent density compared with pristine Fe2O3 photoanode under simulated solar illumination. Based on systematic investigations, it is found that SnO2 layer efficiently compensates the surface states on Fe2O3, prolonging charge carrier lifetime and promoting charge separation greatly. As a result, the remarkably improved photoelectrochemical water splitting performance of T-Fe2O3 is attributed to unrestrained and fast hole transport way provided by SnO2 mediated photoanode/electrolyte interface.
 
Article
We develop several inference methods to estimate the position of dislocations from images generated using dark-field X-ray microscopy (DFXM)—achieving superresolution accuracy and principled uncertainty quantification. Using the framework of Bayesian inference, we incorporate models of the DFXM contrast mechanism and detector measurement noise, along with initial position estimates, into a statistical model coupling DFXM images with the dislocation position of interest. We motivate several position estimation and uncertainty quantification algorithms based on this model. We then demonstrate the accuracy of our primary estimation algorithm on synthetic realistic DFXM images of edge dislocations in single-crystal aluminum. We conclude with a discussion of our methods’ impact on future dislocation studies and possible future research avenues.
 
Article
The loosening of the fixed interface between inactive artificial joint material and human bone seriously affects the rehabilitation of patients after artificial joint replacement. Therefore, increasing the bonding strength of the fixed interface is the key direction to prolong the service life of the joint prosthesis. In this paper, active rat bone tissue and inactive titanium alloy coated with titanium beads were used as the research objects. The growth promoting mechanism of bone tissue on the surface of titanium bead coating under fretting mechanical stimulation was explored on a self-made mechanical fretting stimulation test device. The results showed that, compared with the static control group, the interface bonding force between bone tissue and titanium bead coating improved, and the distribution range and volume of bone tissue on the surface of titanium bead coating increased. In addition, the section staining results showed that a quantity of collagen fibers and calcium salt particles were generated in bone tissue, and the proliferation and differentiation activity of chondrocytes was higher as well. This study provides an important theoretical and experimental basis for promoting the biological fixation of artificial joints through mechanical stimulation. Graphical abstract
 
Article
Herein, materials with pH-regulated near-infrared (NIR) photothermal effect are utilized to realize the efficient, safe, and synergistic antibacterial treatment. Polymeric multilayers were prepared through layer-by-layer assembly and ultraviolet (UV) crosslinking, and the key factors affecting the surface charge and isoelectric point (IEP) of the multilayers were discussed. When the pH-responsive multilayers were obtained, gold nanoparticles (AuNPs) having photothermal effect were further assembled into them. The pH responsibility, photothermal effect and antibacterial performance of the multilayers were further studied. The AuNP-composited multilayers can be heated up to 60 °C in 5 min under NIR irradiation, showing a good photothermal property. The multilayers swell and become negatively charged in pH 7.4, whereas they shrink and become positively charged in pH 5.0. Meanwhile, due to the volume shrinkage of multilayers and thereby the aggregation of AuNPs, the photothermal effect is enhanced. Under the synergism effect of pH-regulated photothermal effect and cationic polymer, the bacteria are killed by the multilayer efficiently under NIR and acidic conditions. This study provided a new idea and method for adaptive and intelligent antibacterial treatment.
 
Article
Short hemp fibers, an agricultural waste, were used for producing biochar by pyrolysis at 1000 °C. The so-obtained hemp-derived carbon fibers (HFB) were used as filler for improving the properties of an epoxy resin using a simple casting and curing process. The addition of HFB in the epoxy matrix increases the storage modulus while damping factor is lowered. Also, the incorporation of HFB induces a remarkable increment of electrical conductivity reaching up to 6 mS/m with 10 wt% of loading. A similar trend is also observed during high-frequency measurements. Furthermore, for the first time wear of these composites has been studied. The use of HFB is an efficient method for reducing the wear rate resistance and the friction coefficient (COF) of the epoxy resin. Excellent results are obtained for the composite containing 2.5 wt% of HFB, for which COF and wear rate decrease by 21% and 80%, respectively, as compared with those of the unfilled epoxy resin. The overall results prove how a common waste carbon source can significantly wide epoxy resin applications by a proper modulation of its electrical and wear properties. Graphical abstract
 
Top-cited authors
Anthony J. Kinloch
  • Imperial College London
Togay Ozbakkaloglu
  • Texas State University
Ambrose C Taylor
  • Imperial College London
Darshil U Shah
  • University of Cambridge
Kamal Sharma
  • GLA University