Zhiyong Liu

• Doctor of Engineering
• Professor (Associate) at Nanchang Hangkong University

Temperature-stable dielectric properties have been developed in the 0.86 K0.5Na0.5NbO3-0.14SrZrO3 solid solution system. High dielectric permittivity (ε′ = 2310) with low loss sustained in a broad temperature range (−55–201 °C), which was close to that of the commercial BaTiO3-based high-temperature capacitors. Transmission electron microscopy with...

Anti-ferroelectric materials with large saturated polarization, small remnant polarization, and moderate breakdown strength are receiving increasing attention for modern high-power electrical systems. Here we demonstrated that by incorporating CaZrO3 into NaNbO3 ceramics, the antiferroelectricity in NaNbO3-CaZrO3 solid solutions could be stabilized...

Excellent vibration-electricity conversion in various piezoelectric materials is frequently restricted, thus hardly generates high mechanochemical potential eliciting by ferroelectric polarization for advanced catalysis processes. Herein, we propose a phase boundary in Li modified Na0.5K0.5NbO3 (NKN) materials to improve the piezocatalytic activity...

emerging as a promising method for producing renewable green oxidants. However, the low piezoelectricity and limited electron-hole pair separation efficiency significantly hinder its productivity. Here, non-stoichiometric Na1-xNbO3-δ perovskites with lattice strain and ferroelectric enhancement were successfully designed to boost the piezo-catalyti...

The ultra-high piezoelectric activity of K0.5Na0.5NbO3 (KNN)-based single crystals with excellent electromechanical coupling characteristics has attracted great interest. However, the growth of KNN-based single crystals is restricted by their high melting point and harsh equipment conditions. In this work, a large-sized single crystal of (K0.5Na0.5...

Potassium sodium niobate (KNN)-based ceramics exhibit electrical (such as ferroelectric) and photoluminescence (PL) properties and have great application potential in the field of multifunctional optoelectronics. To promote its development in the field of optoelectronics, researchers have been making efforts to improve its photoelectric performance...

Piezo-catalysis is a potently environmental remediation method that converts mechanical vibrations into chemical activity, offering advantages in terms of economy and sustainability. However, the non-polar nature of many materials due...

Dielectric ceramics have attracted significant interest in power electronic systems owing to their high-power density and rapid charge/discharge capabilities. However, achieving excellent capacitive energy storage performance, including high recoverable energy...

Piezocatalysis is an emerging approach for degrading organic dye. However, the limited availability of ultrasonic resources in nature restricts its practical application. Our proposed peak flow kinetic energy piezocatalytic strategy, based on a “waterfall flow” model, aims to simulate the piezocatalytic degradation of pollutants in nature. This inn...

Potassium sodium niobate (KNN)-based ceramics exhibit electrical (such as ferroelectric) and photoluminescence (PL) properties and have great application potential in the field of multifunctional optoelectronics. To promote its development in the field of optoelectronics, researchers have been making efforts to improve its photoelectric performance...

Bismuth sodium titanate (BNT) ceramics exhibit outstanding strain responses but are unfavorable for application in high-sensitivity displacement actuators due to the large negative strain resulting from irreversible changes in their phase transition and domain structure. Here, (1−x)Bi0.50Na0.41K0.09TiO3–xNaNbO3 (BNKT−xNN) solid solutions were prepa...

Dielectric ceramics have attracted significant attention in power electronic systems, owing to their exceptional charging and discharging speeds, as well as their high power density. However, simultaneously achieving a high recoverable energy density (Wrec) and high efficiency (η) in high‐voltage dielectric ceramics remains a challenge for applicat...

Copper calcium titanate (CaCu3Ti4O12, CCTO) ceramics are receiving a great deal of attention for advanced electronic and energy storage device applications owing to their giant permittivity response and good temperature stability. However, the development and real applications of CCTO ceramics are generally restricted by their large dielectric loss...

Sodium bismuth titanate‐based materials are expected to be an alternative candidate to lead‐based ceramic materials due to their excellent electrical properties. However, the low depolarization temperature (Td) limits their practical application. In this work, the phase structure evolution and microstructure of 0.9(0.4Na1/2Bi1/2TiO3–0.6BiFeO3)–0.1B...

Donor doping can increase the dielectric constant of a material by several orders of magnitude due to induced space charge causing interfacial polarization. Giant dielectric properties and interface polarization are also both expected to greatly enhance the flexoelectric behavior of a material. In this work, a typical flexoelectric ceramic material...

Dielectric ceramics have garnered significant attention in the realm of pulsed power system applications. Nevertheless, achieving a high recoverable energy density (Wrec) in dielectric ceramics remains challenging. Here, a high...

Flexoelectric effect describes the electromechanical coupling between the strain gradient and its internal polarization in all dielectrics. Despite this universality, the resulting flexoelectric field remains small at the macroscopic level. However, in nanosystems, the size-dependent effect of flexoelectricity becomes increasingly significant, lead...

As the main raw material for ceramics and coatings, black talc contains high contents of organic carbon and quartz, which deteriorates the whiteness and purity of calcined talc. In this work, calcined talc powders with high whiteness and purity have been prepared by the milling and reactive calcination of black talc with magnesium precursors. Black...

The emerging high-entropy oxides (HEOs) have been considered promising candidates in numerous applications due to their unique properties. Yet the dielectric properties of HEOs at high pressure remain to be disclosed. In this work, the dielectric properties of (FeCoCrMnZn)3O4 at high pressures up to ∼20 GPa were systematically investigated. Combine...

The greatest challenge that limits the application of piezo-photocatalytic materials is the low separation efficiency of the generated electron-hole pairs, resulting in poor catalytic activity. Here, the semiconductor n-p heterojunctions BiVO4/BiFeO3 (BVO/BFO) were designed to enhance its piezo-photocatalytic processes. Under the excitation of piez...

The effects of geometric configuration and external force on piezocatalytic properties of BaTiO3 were investigated through experimental and finite element analyses. The simulated results indicate that the piezopotential is linearly related to the sample length of Z-axis of BaTiO3 and the magnitude of applied stress. Then, BaTiO3 single crystal fibe...

In spite of the flexoelectric effect being a universal phenomenon in the ferroelectric perovskites, the current understanding of flexoelectric aging in ferroelectrics is, actually, rather incomplete. In this paper, we have fabricated a series of Mn-doped BaTiO 3 perovskite ceramics (BaTi 1–x Mn x O 3 , x = 0.1% and 1%, BTMO) to systematically inves...

The structural, electronic, and optical properties of pure and Ce-doped BaTiO3 were investigated based on first-principle calculation. Here, we concentrate on understanding the effect of the substitution of Ce for Ba and Ti sites in the equilibrium lattice parameters, DOS, electronic band structure, and optical performance of the materials. The cry...

This work designs a new system (1-x)Na0.5Bi0.5+yTiO3-xNaTaO3 with a nonstoichiometric bismuth ratio, which is used as dielectrics of ceramics capacitors. Phase structure evolution of (1-x)Na0.5Bi0.5+yTiO3-xNaTaO3 is characterized using XRD, Raman and TEM. Dielectric and resistant properties of (1-x)Na0.5Bi0.5+yTiO3-xNaTaO3 are investigated with inc...

Both high strain and low driving electric‐field are important characteristics of the piezoelectric actuators for industrial applications, but they are difficult to achieve together in a single material system. In this work, the layered and inlay‐onlay structures of relaxor/ferroelectric composites were prepared by selecting relaxor phase (0.94Bi0.5...

Dielectric ceramics for electrostatic energy storage suffer from low recoverable-energy-density (Wrec) at a low-electric-field (LEF), constraining their use in downsizing integrated electronic devices and low operating voltage environments. Here, we report a 0.85Bi0.5Na0.5TiO3–0.15(Sr0.7Bi0.2)(Mg1/3Nb2/3)O3 (0.85BNT–0.15SBMN) relaxor ferroelectric...

Piezoelectricity as a physical property has received great attention due to its excellently functional applications, especially in piezoelectric catalysis and mechanical energy harvesting. To take full advantage of the functions of piezoelectric materials, (K0.5Na0.5)0.94Li0.06NbO3 (KNN6L) piezoelectric powders were compounded with polydimethylsilo...

Electrode selection and its effects are extremely crucial to characterize the electrical properties and understand the colossal permittivity response of CaCu3Ti4O12 (CCTO) ceramics. However, the specifical correlation between metal electrode and electrical performances of CCTO ceramics are not clear so far. In this study, we have systematically inv...

Polymer-based nanocomposites embedded high dielectric-constant (high-εr) ceramic fillers in high breakdown-strength (high-Eb) polymer matrix are extensively studied as the flexible dielectrics for high discharged-energy-density (high-Ue) film capacitors. Ferroelectric ceramics composition lying on the morphotropic phase boundary (MPB) show ultrahig...

The development of excellent performances polymer-based nanocomposite films with high discharge energy density and high discharge efficiency are eagerly desirable for promoting their electric energy storage applications. However, the high discharge energy density and efficiency of polymer-based nanocomposite films are usually not compatible above m...

Quarrying and processing of granite produce large amounts of waste residues. Besides being a loss of resources, improper disposal of these wastes results in pollution of the soil, water and air around the dumpsites. The main components of granite waste are quartz, feldspars and a small amount of biotite. Due to its hard and dense texture, high stre...

Ceramic-based dielectrics are considered as the best candidates for high temperature capacitors because of their outstanding mechanical and electrical properties. Nevertheless, conventional barium titanate-based capacitors show narrow operating temperature ranges owing to the low tetragonal-cubic phase transition temperature. In order to increase t...

Piezoelectric catalysis is the catalytic action driven by the force-electrical conversion of piezoelectric materials. In this paper, the piezoelectric activity of K 0.5 Na 0.5 NbO 3 (KNN) was thoroughly investigated by annealing KNN at a series of temperatures and poling KNN under different electric-fields. With the application of an ultra-sonifica...

Relaxor-ferroelectric (RFE) ceramics possess slender ferroelectric hysteresis loop and low remnant polarization (Pr). They have great potential to provide excellent energy-storage performance as dielectric energy-storage materials. Herein, a lead-free 0.8Ba0.4Sr0.6TiO3–0.2Sr0.7Bi0.2TiO3 (0.8BST–0.2SBT) RFE ceramic with high energy-storage performan...

High-entropy oxides with complex compositions can be designed as new ferroelectric materials with interesting physical consequences. Here, a series of high-entropy perovskite ceramics (Bi0.2Na0.2Ba0.2Sr0.2Ca0.2TiO3, Bi0.2Li0.2Ba0.2Sr0.2Pb0.2TiO3, Bi0.2Na0.2Ba0.2Sr0.2Pb0.2TiO3, Bi0.2K0.2Ba0.2Sr0.2Pb0.2TiO3, and Bi0.2Ag0.2Ba0.2Sr0.2Pb0.2TiO3) was pro...

Dielectric energy storage materials have a high power density, which has attracted much attention in many fields, such as pulsed power generation and electric vehicles. As a typical and traditional energy storage material, barium strontium titanate (Ba1-xSrxTiO3) has been widely used in this field. However, its energy storage density is low. In thi...

Calcite powders were prepared from black marble waste by milling and alkaline hydrothermal processes. Crystal modifiers including two sulfates and an organophosphate chelator were used to study their effects on the crystallinity and particle morphology of calcite powders. Compared with control experiments without crystal modifiers, the Na2SO4 modif...

Different alumina sources (Al(OH)3, Al2O3, and boehmite) were used to prepare mullite-based ceramics from milled coal fly ash. The effect of alumina source and sintering temperature on the densification and phase evolution of these ceramics was investigated. Among the three alumina sources, boehmite yielded the greatest densification and crystalliz...

Piezoelectric catalysis is the catalytic action driven by the force-electrical conversion of piezoelectric materials. In this paper, the piezoelectric activity of K0.5Na0.5NbO3 (KNN) was thoroughly investigated by annealing KNN at a series of temperatures and poling KNN under different electric-fields. With the application of an ultrasonification,...

Ceramic-based dielectrics are considered as the best candidates for high temperature capacitors because of their outstanding mechanical and electrical properties. Nevertheless, conventional barium titanate-based capacitors show narrow operating temperature ranges owing to the low tetragonal-cubic phase transition temperature. In order to increase t...

Large amounts of marble wastes have been generated annually from the marble processing industry, which pose serious hazards to the environment and healthcare. In this work, high brightness calcite powders were recycled from marble powder by the alkaline hydrothermal treatment. The ball milling pretreatment had a prominent effect on the brightness o...

Huge amounts of granite wastes have been generated in the granite-processing industry and should be properly disposed to reduce the negative impacts on the environment and health care. In this work, waste granite powder was modified and sintered to prepare high-strength and tough glass–ceramics. The heating rate was studied to clarify its effects o...

Large amounts of granite wastes in the stone processing industry should be recycled to prevent the environmental pollution and health hazards. In this work, the sintered glass-ceramics have been prepared from granite powder by the sintering-crystallization method. The sintering additives were investigated to reveal their influence on the densificat...

Coal fly ash generated from thermal power plants is the largest single solid waste, and its reutilization is indispensable for the environmental protection and resource sustainability. In this work, mullite powders have been prepared from coal fly ash by the mullitization and hydrothermal processes. In the mullitization process, the milled fly ash...

(1-x)(K0.49Na0.49Li0.02)(Nb0.8Ta0.2)O3-xCaZrO3 (x=0, 0.025, 0.05 and 0.075, abbreviated as KNLNT-1000xCZ) ceramics were prepared by a solid state method. The correlations between phase constitution, domain configuration and tunable dielectric properties are investigated. Due to the combined effects of multi-phase coexisting and nanoscaled domain, K...

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High dielectric tunability, low loss and an appropriate level of dielectric permittivity are basic requirements of ferroelectric materials for tunable microwave devices. In this study, 0.96NaNbO3-0.04CaZrO3/0.88(K0.5Na0.5)NbO3-0.12SrZrO3, antiferroelectric/relaxor-ferroelectric composites were designed to tailor dielectric tunability. By tailoring...

The humidity property of the lithium stabilized Na-β"-alumina (LSBA) sensing material was investigated in detail on a resistivity-type sensor prepared by pasting LSBA powder on a ceramic substrate with Ag interdigitated electrodes through ac and dc analysis. Results from ac complex impedance analysis suggested that LSBA powder based sensor was high...

In this work, well-aligned ZnO nanorods were grown on the substrate of exfoliated g-C3N4 nanosheets via a microwave-assisted hydrothermal synthesis, and then Pt/ZnO/g-C3N4 nanostructures were obtained after the deposition of Pt nanoparticles. The growth of vertically ordered ZnO nanorods was occurred on g-C3N4 nanosheets through the bonding interac...

The ZnTiO3 ceramics with pure phase were successfully synthesized for the first time by solid state reaction method. The corresponding synthesis temperature was higher than the phase transition temperature, wherein the ZnO nano particles act as inhibitor to prevent the formation of secondary phase: Zn2TiO4, which was inevitable by conventional prep...

Lead-free piezoceramics (Na(1+x)/2Bi(1-x)/2)0.94Ba0.06Ti1-xNbxO3 (BTN100x) were prepared using conventional solid-state reaction method. The structures, field- induced strain, AC impedance of sintered ceramics were investigated. The pure perovskite solid solution BTN3 exhibited giant electric-field-induced strain of 0.478% under an electric field o...

xSrTiO3–(1−x)LaAlO3 ceramics with ZnO–B2O3 sintering aid were prepared by solid‐state reaction method leading to a significant decrease in sintering temperature from 1550°C to 1050°C. The structure, microwave dielectric properties, and low‐temperature sintering behavior were systematically investigated. The results revealed the relationships among...

Highly transparent ferroelectric ceramics based on 0.9K0.5Na0.5NbO3–0.1SrTiO3 were prepared using a pressure-less solid-state sintering method without using hot isostatic pressing and spark plasma sintering. An independence electromechanical response of bipolar switching cycles (S33 only degraded 3.2 % up to 107 cycles) was presented in this transp...

Perovskite ferroelectric BiFeO3 has been extensively researched in many application fields, but which have rarely been used for the conversion of tiny mechanical motion into electricity, in spite of its large theoretical remnant polarization. Here we demonstrate the fabrication of a flexible piezoelectric nanogenerator (PNG) based on a composite fil...

Biocompatible nanogenerators (NGs) are of vital importance for in vivo applications. In this work, Bi5-xLaxTi3FeO15 (x = 0, 1) nanofibers (NFs) toward wool keratin-based biocompatible piezoelectric NGs are demonstrated. The refined structure of Bi4LaTi3FeO15 (BLTF) NFs by the Rietveld method was confirmed to be a four-layer Aurivillius oxide with a...

Niobium and aluminum co-doped TiO2 ceramics, i.e., (Nb0.5Al0.5)xTi1-xO2 (x = 0, 0.01, 0.05, 0.1, 0.15, abbreviated as NAT100x) were synthesized via a solid-state reaction route. As could be seen from X-ray diffraction (XRD) patterns, all samples were in pure rutile phases. A colossal permittivity (CP) over 105 with relatively low dielectric loss co...

Aurivillius Bi5Ti3FeO15 (BTF) multiferroic (MF) nanofibers (NFs) of about 400 nm were fabricated by electrospinning and calcination. The BTF NFs exhibit an effective micro-piezoelectric coefficient of 35 pm/V and benign micro-ferroelectricity. Macro-ferroelectric and magnetoelectric coupling behavior were investigated in detail by non-sintering and...

(B1/3/Nb2/3) (B=Mg, Zn, Cu) co-substituting for Ti4+ in B-site of Bi4Ti3O12-based Aurivillius ceramics were prepared to improve the piezoelectric properties. The electrical properties and conduction mechanisms of them were investigated. The activation energy related with the electrical relaxation determined from the electric modulus spectra was 0.7...

Large energy-storage density is observed in BaZrO3 (BZ)-modified 0.80Bi0.5Na0.5TiO3-0.20Bi0.5K0.5TiO3 (BNBK) lead-free ferroelectric (FE) ceramics synthesized by conventional solid-state reaction. The energy-storage property of (1 − x)BNBK–xBZ has been investigated. Certain content of BZ can enhance the energy-storage property of BNBK by enhancing...

Transparent relaxor ferroelectrics, (K0.5Na0.5)0.9Sr0.1Nb0.9Ti0.1O3–x%Bi2O3 (x = 0, 0.5, 1.0, 1.5, and 2, abbreviated as KNSNT-10x), were fabricated using a pressureless sintering method. With the modification of Bi2O3, the crystal phase of KNSNT ceramics transformed from tetragonal to cubic-like symmetry, and dielectric behaviors became more relax...

xCeO2-doped Bi0.487Na0.427K0.06Ba0.026TiO3 lead-free piezoelectric ceramics (BNTC1000x, x=0, 0.3, 0.6, 0.8, 1.0, 1.2, 1.4 wt%), were synthesized by the solid-state reaction method. XRD patterns showed that all BNTC1000x ceramics exhibit pure single perovskite phase. At the critical composition BNTC12, a large electric-field-induced strain of 0.39%...

Pure perovskite K0.5Na0.5NbO3–xSrTiO3 (x = 0.16, 0.17, 0.18, and 0.19) ceramics were prepared by using a solid-state reaction process. The ceramics were optically transparent for visible and near-infrared wavelengths. Then, high tunability (24.1%) and low dielectric loss (0.016) for the x = 0.18 sample indicated the transparent ceramics could be us...

New high temperature ceramic capacitors (K0.5Na0.5)(1-x)BixNb(1-2x/3)Cu2x/3O3 ( x = 0-0.03) with Bi substitution for A site and Cu substitution for B site were synthesized using a solid state reaction process. Owning to its inhomogeneous microstructure and diffuse phase transition, (K0.5Na0.5)0.985Bi0.015Nb0.99Cu0.01O3 shows a stable permittivity n...

K0.5Na0.5NbO3–xSrTiO3(x = 0, 0.1 and 0.2) ceramics were prepared using the solid-state method. The phase transition behaviors, electrical properties, and electric field-induced dielectric nonlinearity behaviors were investigated as a function of the SrTiO3 content. The electrical properties of the investigated compositions exhibited a significant d...