Materials Advances

In this work, we investigate the impact of Bi³⁺ doping on the luminescence properties of Eu³⁺-activated NaYb(MoO4)2 phosphors synthesized via the conventional solid-state reaction method. Rietveld refinement of X-ray diffraction data confirmed the tetragonal crystal structure (space group I41/a) for all samples. UV-visible absorption spectroscopy revealed an indirect bandgap of approximately 3.25 eV for the 5% Bi³⁺-doped sample. Under UV excitation, intense red emissions originating from the ⁵D0 → ⁷F transitions of Eu³⁺ ions were observed at 589 nm, 613 nm, 652 nm, and 700 nm, along with near-infrared emission from Yb³⁺ at 997 nm, sensitized by the MoO4²⁻ group. Photoluminescence (PL) analysis demonstrated an enhancement in the Eu³⁺ emission intensity with increasing Bi³⁺ concentration, reaching an optimum at 5% Bi³⁺ doping. Chromaticity coordinates confirmed a significant enhancement in the red emission intensity upon Bi³⁺ incorporation. Judd–Ofelt parameters and crystal field parameters were determined, revealing that Bi³⁺ doping influences the local environment of Eu³⁺ ions, impacting the luminescence properties. Furthermore, we explored the potential of Bi³⁺/Eu³⁺ codoped NaYb(MoO4)2 for optical thermometry based on the fluorescence intensity ratio (FIR) technique, achieving a high relative sensitivity (Sr = 1.14% K⁻¹). This work demonstrates the influence of Bi³⁺ doping on the luminescence properties of Eu³⁺ in NaYb(MoO4)2 and explores its potential for applications in temperature sensing and other optoelectronic devices.

Retraction of ‘Influence of carbon additions on microstructures and mechanical properties in additive manufactured superalloys’ by Mingjun Xie et al., Mater. Adv., 2023, 4, 4897–4911, https://doi.org/10.1039/D3MA00370A.

Correction for ‘White light emission and superior color stability in a single-component host with exceptional eminent color rendering and theoretical calculations on Duv for color quality’ by Wasim Ullah Khan et al., Mater. Adv., 2024, 5, 9851–9861, https://doi.org/10.1039/D4MA00937A.

The rare-earth-free magnetic material α′′-Fe16N2 is known to be a high-performance magnetic material. However, a synthetic route for high-yield α′′-Fe16N2 powder has not yet been established. In this study, a high-yield α′′-Fe16N2 submicron-sized powder was synthesized from Fe3O4via H2 reduction, and subsequent nitridation using a CaH2 drying agent. Here, controlling the crystallite diameter of α-Fe is crucial to promoting nitridation. α-Fe powder with a crystallite diameter of approximately 20 nm was produced by lowering the reduction temperature and water vapor partial pressure. Thus, a high-yield α′′-Fe16N2 phase of 97 wt% could be obtained. Microstructural observations indicated that α′′-Fe16N2 submicron-sized powder with primary particles of 20–30 nm diameter could be synthesized. The α′′-Fe16N2 powder had much higher coercivity than that of the α-Fe powder. Thus, the process suggested in this study is expected to contribute to the development of applications of α′′-Fe16N2 in magnetic materials.

Defect-induced alkali-metal cerium double tungstate compounds, ACe(WO4)2 (where A = Li, Na, K), have been synthesized through a trisodium citrate-based hydrothermal process. The influence of alkali-metal ions on the local structure of ACe(WO4)2 has been explored using various methods, including the Rietveld technique for powder X-ray diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). Although the ACe(WO4)2 compounds exhibit similar transitions, they differ in luminescent intensity. Notably, in the case of the alkali metal Na, the material displays a larger crystal compactness due to its comparable ionic radii with Ce³⁺. This proximity indicates lower distortion. Conversely, Li and K possess significantly different ionic radii from Ce³⁺, leading to pronounced crystal distortion. The ACe(WO4)2 materials show emissions in blue and green spectra, including blue I (439 nm), blue II (462 nm), blue III (487 nm), and green (531 nm). The blue I emission is attributed to the 5d → 4f transition within the CeO8 polyhedra, whereas the blue III emission arises from the same transition within CeO7 polyhedra. The blue II and green emissions result from the formation of CeO6 polyhedra. Additionally, ab initio calculations employing density functional theory reveal that the valence and conduction bands are composed of O 2p and O 2p–Ce 5d hybridization, respectively. Notably, the 5dxy, 5dxz, 5dyz, 5dx²−y², and 5dxz, 5dx²−y² orbitals significantly contribute to the 5d–4f transition within CeO7 and CeO6 polyhedra, respectively. The resulting Commission Internationale de l'Éclairage (CIE) coordinates in the blue region, coupled with a correlated color temperature (CCT) of approximately 7800 K, suggest that ACe(WO4)2 materials hold promise for applications in cold solid-state lighting.

The pursuit of effective drug delivery systems is critical in advancing cancer therapies, particularly in the realms of chemotherapy, radiotherapy and immunotherapy. This review focuses on plant-based extracellular vesicles (PBEs) as innovative nanoplatforms for encapsulating and delivering genetic materials, including microRNAs (miRNAs), small interfering RNAs (siRNAs), and mitochondrial DNA (mtDNA). We explore the unique properties of PBEs that enhance the stability and bioavailability of these therapeutic molecules, particularly their resistance to degradation by ribonucleases (RNases) and their ability to withstand gastrointestinal digestion. By improving the stability and facilitating cellular uptake of these genetic particles, PBEs offer a significant enhancement of their therapeutic efficacy through nuclear gene modulation. This review highlights the transformative potential of PBEs in developing novel drug delivery systems for cancer treatment, paving the way for future research and clinical advancements in RNA-based therapies and beyond.

The reaction between volatile platinum and rhodium gas species and bulk materials (alloys or oxides) is of high practical importance in the chemical process industry. Herein, an X-ray photoelectron spectroscopy (XPS) study has been conducted to understand how PtO2(g) and RhO2(g) react with LaNiO3 (LNO) thin films grown via atomic layer deposition (ALD) at elevated temperatures (900 °C). In this study, XPS data for reference powders of La2NiPtO6, LaNi0.95Pt0.05O3, LaNi0.88Rh0.12O3 and LaRhO3 provide a library for the interpretation of oxidation states of platinum and rhodium after reaction with LNO thin films. Upon short exposure to PtO2(g) and RhO2(g), platinum appear as Pt(iii) in the LNO surface, but after prolonged exposure, Pt(iv) appears. Complementary diffraction analysis shows that LaNi1−xMxO3 solid solution forms initially where Ni, Pt and Rh are predominantly +III, however, quickly accompanied by the formation of a La2Ni2−2xM2xO6 (M = Pt, Rh) double perovskite phase with its characteristic (004) peak. Rhodium appears as Rh(iii) and Rh(iv) in both the R3̄c and the double perovskite like phases. Furthermore, platinum and rhodium depth profiles were generated by the combination of XPS and Ar⁺ sputtering. Platinum depth profiles reveal major differences between as-grown ALD films and post-annealed films when exposed to PtO2(g). Pt penetrates faster into the LNO material for films without post annealing, probably due to its smaller grain size and larger surface area and grain boundaries. When exposed to a mixture of PtO2(g) and RhO2(g), the Rh : Pt ratio in LNO increases upon prolonged reaction time. These results may have implications on the use of LNO as platinum and rhodium capture material in the Ostwald process.

The soot oxidation activity of manganese-doped ceria-praseodymium catalysts, synthesized via solution combustion synthesis, was evaluated. The analyses performed with XRD and Raman spectroscopy indicated that the Mn-doped CP catalysts displayed the typical fluorite structure of CeO2. The addition of Mn to CP led to a reduction in crystallite size from 14 nm to below 10 nm. The F2g Raman active mode of fluorite-structured Ce and the oxygen vacancies resulting from the addition of Mn and Pr (bands ∼ 560 cm⁻¹ to 580 cm⁻¹) were consistently observed across all Mn-doped CP catalysts. 15 and 20 Mn-CP exhibited an additional secondary phase identified as Mn2O3. The analysis of BET surface area and BJH pore size revealed that the Mn-doped CP catalysts exhibited both micro and mesoporous characteristics. The H2-TPR and O2-TPD profiles indicated enhanced reducibility resulting from the incorporation of Mn and Pr into CeO2-doped catalysts. The improved T50 (365 ± 1 °C) for the 5 Mn-CP catalytic system is primarily due to its increased specific surface area of 45 m² g⁻¹ and the presence of active surface adsorbed oxygen species identified in the XPS and O2-TPD studies. 5 Mn-CP exhibited the lowest activation energy value compared to all other Mn-doped catalysts.

The ability to convert light to higher energies through triplet–triplet annihilation upconversion (TTA-UC) is attractive for a range of applications including solar energy harvesting, bioimaging and anti-counterfeiting. Practical applications require integration of the TTA-UC chromophores within a suitable host, which leads to a compromise between the high upconversion efficiencies achievable in liquids and the durability of solids. Herein, we present a series of methacrylate copolymers as TTA-UC hosts, in which the glass transition temperature (Tg), and hence upconversion efficiency can be tuned by varying the co-monomer ratios (n-hexyl methacrylate (HMA) and 2,2,2-trifluoroethyl methacrylate (TFEMA)). Using the model sensitiser/emitter pair of palladium(ii) octaethylporphyrin (PdOEP) and diphenylanthracene (DPA), the upconversion quantum yield was found to increase with decreasing glass transition temperature, reaching a maximum of 1.6 ± 0.2% in air at room temperature. Kinetic analysis of the upconversion and phosphorescence decays reveal that increased PdOEP aggregation in the glassy polymers leads to a competitive non-radiative relaxation pathway that quenches the triplet state. Notably, the threshold intensity is highly sensitive to the glass transition temperature, ranging from 1250 mW cm⁻² for PHMA90TFEMA10 (Tg = −9.4 °C) to ∼200 mW cm⁻² for more ‘glassy’ hosts, e.g. PHMA33TFEMA67 (Tg = 20.1 °C), suggesting the TTA-UC mechanism switches from diffusion-based collisions to triplet exciton migration at localised sensitiser–emitter pairs.

In geometrically frustrated (GF) magnets, conventional long-range order is suppressed due to the presence of primitive triangular structural units, and the nature of the ensuing ground state remains elusive. One class of candidate states, extensively sought in experiments and vigorously studied theoretically, is the quantum spin liquid (QSL), a magnetically-disordered state in which all spins participate in a quantum-coherent many-body state. Randomly located impurities, present in all materials, may prevent QSL formation and instead lead to the formation of a spin-glass state. In this article, we review available data on the specific heat, magnetic susceptibility, and neutron scattering in GF materials. Such data show that a pure GF magnet possesses a characteristic “hidden energy scale” significantly exceeded by the other microscopic energy scales in the material. When cooled down to a temperature below the hidden energy scale, a GF material develops significant short-range order that dominates its properties and, in particular, dictates the spin-glass transition temperature for experimentally accessible impurity densities. We review the manifestations of short-range order in the commonly observed thermodynamics quantities in GF materials, possible scenarios for the hidden energy scale, and related open questions.

Highly active and stable cathodes play a crucial role in aqueous Zn-organic batteries, enabling them to achieve high capacity, rapid redox kinetics, and an extended lifespan. However, currently reported electrode materials for Zn-organic batteries face challenges such as low capacity and inadequate cycling stability. In this contribution, aiming to overcome the challenges above, we develop a new Zn-organic battery. In this battery, saturated ZnSO4 served as an electrolyte and its cathode is based on dipyrido [3,2-a:2′,3′-c] phenazine (DPPZ). Theoretical calculations and ex situ analyses demonstrate that the Zn//DPPZ batteries mainly undergo an H⁺ uptake/removal process with a highly reversible structural evolution of DPPZ. As a result, the aqueous Zn//DPPZ full cell exhibits a remarkable capacity of 94 mA h g⁻¹ at a mass-loading of 2 mg cm⁻² (achieved at 0.5 A g⁻¹), and rapid kinetics. Moreover, the cell possesses remarkable cycling durability such that at a mass-loading of 2 mg cm⁻², the cell owns a long lifespan of 8000 cycles with a current density of 5 A g⁻¹, and even at a high mass-loading of 8 mg cm⁻², it can still endure 600 cycles with a current density of 0.5 A g⁻¹. These findings pave the way for the development of advanced organic electrodes.

Correction for ‘Study of self-assembly of mixed-ligand metal–organic cages by high-resolution mass spectrometry’ by Jia Jia et al., Materials Adv., 2024, 5, 5394–5397, https://doi.org/10.1039/D4MA00406J.

To address food waste and promote sustainable food packaging, pH-sensitive edible films were developed using Opuntia ficus-indica mucilage (OM) and cellulose nanofibers (CNFs) incorporated with varying concentrations of the encapsulated beetroot waste extract (EB) (0.5%, 1%, 1.5%, and 2%). Based on the percentages of EB, the films were labelled as OM/CNF/EB (2%), OM/CNF/EB (1.5%), OM/CNF/EB (1%), OM/CNF/EB (0.5%), and OM/CNF (control). The films were prepared using the solvent casting method, and the impact of EB on the films’ mechanical properties, physical characteristics, and pH sensitivity was subsequently evaluated. The physicochemical properties of the film were analyzed using X-ray diffraction (XRD), scanning electron microscopy (SEM), and Fourier transform infrared (FTIR) spectroscopy to confirm the successful integration of EB into the OM polymer matrix. Furthermore, the incorporation of EB at varying concentrations significantly enhanced the film properties, including moisture content (28.20–57.77%), water solubility (11.52–56.15%), swelling test (80.12–83.18%), antioxidant activity (14.33–21.53%) and water vapor permeability (0.39–0.89 g m⁻¹ s⁻¹ Pa⁻¹). The films exhibited pH-sensitive color changes, transitioning from red to yellow within a pH range of 1 to 13, making them suitable for intelligent packaging applications. Notably, the 2% EB film effectively monitored the freshness of hake medallions, with a distinct color change correlating with spoilage indicators by day 4. These findings underscore the potential of OM/EB films for enhancing postharvest preservation.

Recent advancements in the field of conductive hydrogels have made the hydrogels promising candidates for the development of human motion sensors, as well as for energy storage in soft and flexible electronic devices, owing to their excellent mechanical properties such as flexibility, bioavailability, and biocompatibility. However, limitations such as resilience, resistance to fatigue, toughness, flexibility, and stretchability have hampered their sensing capabilities and long-term operation. To address these limitations, we introduced an ionically and electronically conductive hydrogel composite, which is aimed at enhancing mechanical performance and responsiveness to human motion, ranging from finger bending to epidermal motion sensing. This hydrogel was synthesized by incorporating an unmodified electroactive material, carbon nanotubes (CNTs), stabilized by the biopolymer gum arabic (GA) within the hydrophobically associated hydrogels of lauryl methacrylate (LM) and polyacrylamide (p(Am)). The dispersion of both LM and CNTs was facilitated by the anionic surfactant sodium dodecyl sulfate (SDS). The introduction of CNTs and varying the concentration of GA highly enhanced the mechanical property of the synthesized hydrogel, which in turn brilliantly improved its stretchability up to 1380%, with an antifatigue character and a toughness of 661.5 kJ m⁻³. The high tensile strain sensitivity of the hydrogel material, with a gauge factor (GF) of 9.45 at 1000% strain, demonstrated its remarkable sensitivity. The composite hydrogels exhibited impressive sensing capabilities, including differentiation in language, response to high and low pitches and stresses, drawing various shapes, writing different words, and detection of various human actions. The critical strain study of the present materials underscored their excellent rheological properties. The hydrogels with CNT addition and higher concentrations of GA demonstrated specific capacitance (Cs) values of 171.25 F g⁻¹ from CV at 20 mV s⁻¹, 113.7 F g⁻¹ from GCD at a current density of 0.3 A g⁻¹, and a resistance of 7.656 Ω measured via EIS at a frequency of 5 mV. These electrochemical properties highlight the potential use of hydrogels for energy storage in soft wearable electronic devices.

The escalating environmental challenges posed by different waste sources, including agricultural residues and industrial byproducts, necessitate innovative solutions for waste utilization. Converting waste into valuable resources offers a sustainable approach to mitigating pollution and conserving natural resources. Driven by the urgent need for eco-friendly packaging solutions, this review explores the potential of waste-generated fillers to enhance bioplastic performance. The integration of waste-derived fillers, including nanofillers, into bioplastic matrices significantly improves the mechanical, thermal, and barrier properties, promoting the principles of circular economy and industrial symbiosis. This approach also contributes significantly to reducing carbon footprints by minimizing waste and promoting the reuse of byproducts for sustainable bioplastic production. Addressing the growing concern over the potential toxicity of commercial fillers, specifically metal and metal oxide-based nanofillers, bio-based fillers have emerged as a promising alternative, offering a safer and more eco-friendly solution. An in-depth analysis of recent advancements in processing, production, utilization, challenges, and future prospects would serve as a valuable guide for researchers, industry professionals, and policymakers. The key findings of this review emphasize the necessity of modifying or pre-treating waste fillers to optimize the properties of bioplastic composites. According to the literature, corn processing residues, coffee waste, eggshell waste, and sugarcane bagasse-based fillers are particularly notable among the most studied materials for green composites. Polylactic acid is the most commonly used biopolymer for experimentation with waste-derived fillers. This review underscores the transformative potential of waste valorization in enhancing bioplastic performance, stressing the need for continued research, innovation, and supportive policies to drive sustainable development in this field.

Humans are surrounded by harmful non-visible electromagnetic (EM) waves. Application and production of microwaves have become integral to technology, but it is essential to mitigate their adverse effects while maintaining accessibility to devices. In this study, engineered nitrogen-doping and etching were employed using urea, ball milling, KOH, and reflux treatments to develop optimized microwave-absorbing and shielding composites. Peanut shells were selected as a sustainable carbon source, and nitrogen-doping was enhanced by urea as a dopant, while nitrogen elimination was conducted using HCl and NaNO2. Additionally, polymethyl methacrylate (PMMA) was utilized as a polymeric matrix, fabricated via in situ polymerization to create microwave-absorbing composites. The total shielding performance (SET = SEA + SER), absorption shielding value (SEA), and reflection shielding parameter (SER) were evaluated. The pyrolized, KOH-refluxed, and nitrogen-doped PMMA composite achieved a reflection loss (RL) of −81.34 dB at 25.61 GHz, with an efficient bandwidth (EBW) of 8.50 GHz (RL ≤ −20 dB) at a thickness of 0.55 mm. Nitrogen elimination led to a maximum RL of −92.38 dB at 23.32 GHz, covering the entire K-band (RL ≤ −20 dB) with a narrow thickness of 0.60 mm. Both samples camouflaged the K-band (RL ≤ −10 dB) at thicknesses between 0.40 and 0.85 mm. Our innovative nitrogen-doping and defect engineering resulted in exceptional microwave absorption and moderate shielding of EM waves, paving the way for practical applications in affordable and sustainable materials.

Climate and demographic changes necessitate new paradigms to ensure equitable access to safe drinking water, limiting health, economic, and social damage from poor water management. Nanomaterials present promising opportunities in this area. This work addresses two relevant issues for safe water access: potable water monitoring and disinfection by leveraging plasmonic nanoparticles' biorecognition and photothermal properties. Colloidal gold nanorods (AuNRs), known for their sensitivity to local refractive index changes and light-to-heat conversion ability, are used to create AuNR arrays with optimal morphological and optical characteristics. We demonstrate that these biofunctionalized AuNR arrays, mimicking a logic-OR gate, can detect multiple bacterial strains in water, specifically recognizing two bacterial strains often monitored to guarantee safe access to potable water: Escherichia coli and Salmonella typhimurium (10³ CFU per mL). The two strains are recognized separately or simultaneously, highlighting the multiplexing capability of the AuNR array. Furthermore, the exceptional light-to-heat conversion of AuNR arrays in a ‘cascade-like’ configuration, validated by a custom theoretical model, is utilized for photothermal disinfection. In a customized thermo-optical setup, this system effectively reduces pathogen viability by five orders of magnitude within 30 minutes under NIR laser irradiation. The bioactivated AuNR arrays, with their selective pathogen recognition and robust disinfection capabilities, represent a powerful multifunctional technology for monitoring and purifying potable water.

Solid lipid nanoparticles are appealing to the scientific community owing to their expedient and versatile nature as systems for drug delivery and therefore are being used to treat variety of...

Calcium ion plays a vital role in skeletal growth, muscle action and neural signalling. Thus level of calcium in body is a crucial parameter in the diagnosis of muscle weakness...

The increasing demand for advanced materials with multifunctional magnetic properties has sparked growing interest in rare-earth and transition metal-based double perovskites. In this study, we comprehensively investigate disordered Y ² CoCrO ⁶ (YCCO),...

In this study, we developed a novel Gd2O3/Fe3O4 composite nanoparticles (GFO CNPs) via a simple one-step thermal decomposition of Fe(III) actylacetonate and Gd(III) acetate in octadecene solvent, with oleic acid...

In this work, optical nonlinearity of PVD grown Cr2Te3 thin film of 33 and 100 nm thickness with huge thermal optical effect was investigated. By removing the thermally-induced background signal,...

We present a simple method for bonding an elastomer substrates using a stretchable, low-molecular-weight adhesive. By mixing 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide (EDC) and gallic acid on an aminated surface, EDC is converted into...

Cancer, a major health challenge worldwide, is accountable for large percentage of disease-related deaths. Annually, new cancer diagnosis reaches over 10 million with a record of about 9.6 million deaths....

Antibiotic pollution poses a significant threat to global health and ecosystems. It is highly demanding to detect the trace amounts of antibiotics in food and biological samples. Thus, there is...