Materials Today Physics
·
2018
·
IF 0
Y. Zhou,H. Wu,D. Wang,L. Fu,Y. Zhang,J. He,S.J. Pennycook,L.-D. Zhao
The ternary diamond-like compound Cu 2 SnSe 3 is a potential thermoelectric material . Its Cu-Se conducting network leaves Sn as a likely doping site to optimize the carrier concentration without much deterioration to the carrier mobility . Thus, the precise determination on the intricate phase structures of Cu 2 SnSe 3 is critical. Here, we first use the atomically resolved scanning transmission electron microscopy and reveal an unusual phase coexistence (monoclinic and orthorhombic phases) in Ag-doped Cu 2 SnSe 3 . Owing to coexisting phases and the order–disorder transition in the orthorhombic phase, the Ag-doped Cu 2 SnSe 3 shows an unusual three-stage behavior in its temperature-dependent electrical transport properties and achieves record high power factors in this system. The observed three-stage behavior due to the phase coexistence is supported by the first principle calculations, Hall measurements, and optical diffuse reflectance measurements . To fully understand the band structures and the coherent interface between these coexisting phases, a band contact model is proposed that could well explain the three-stage electrical transport behavior. Moreover, the phase coexistence is observed at the nanoscale regime, thus providing a high density of phase boundaries. Such coexisting nanophases play an important role in lowering the lattice thermal conductivity . As a result, the ZT value obtained in Cu 2 Sn 0.93 Ag 0.07 Se 3 is double that of undoped Cu 2 SnSe 3 .
研究领域:
材料科学
·
凝聚态物理
✓ 已验证
产品关联
DOI
Materials Science and Engineering B-Advanced Functional Solid-State Materials
·
2024
·
IF 3.9
Xianzhao Zhang,Qiyi Yin,Hengwen Cheng,Ruihua Zheng,Hui Zhang,Kunhong Hu,Fei Lin,Liping Fang,Shicheng Wang,Zhen Zhang
In this study, new lead-free piezoelectric ceramics (1 − x )(K 0.5 Na 0.5 )NbO 3 (KNN)– x (Bi 0.45 Y 0.05 )Na 0.5 ZrO 3 (BYNZ) were prepared using the conventional solid-state method, and the relation between the doping amount of (Bi 0.45 Y 0.05 )Na 0.5 ZrO 3 and its structural and electrical properties was investigated. Material characterization and structural analyses conducted using X-ray diffraction, scanning electron microscopy, and energy-dispersive spectroscopy revealed that KNN–BYNZ ceramics formed single perovskite structures at 0 ≤ x ≤ 0.05 and a polycrystalline phase boundary (PPB) for the coexisting orthorhombic and tetragonal phases at 0.03 ≤ x ≤ 0.05. The ceramics exhibited desirable electrical properties at x = 0.04 ( d 33 = 305 pC/N, k p = 45.8 %, ε r = 1316, tanδ = 2.4 %, T c = 332 °C, P r = 28.2 μC/cm 2 , and E c = 1.07 kV/mm). These findings reveal that the introduction of BYNZ enables the effective formation of a PPB in the KNN-based ceramics to improve their electrical properties, and they exhibit potential for replacing lead-based piezoelectric ceramics in the market.
研究领域:
材料科学
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物理学
✓ 已验证
DOI
高影响因子
ENERGY & FUELS
·
2023
·
IF 5.3
Ren Hao Xu,Pian Pian Ma,Guan Fu Liu,Yin Qiao,Rui Yang Hu,Li Yuan Liu,Muslum Demir,Guo Hua Jiang
The tetragonal layered transition metal copper–molybdenum sulfide Cu2MoS4 (CMS) possesses a high theoretical electrochemical potential because of its abundant redox properties and large layered surface area, which is favorable for ion adsorption/desorption and transport. Cu2MoS4 contains P and I phases, exhibiting different crystal structures, ion transport characteristics, and electrochemical properties accordingly. In this work, for the first time, Cu2MoS4 electrode materials with dual-phase compositions are designed and prepared for supercapacitor application, providing a synergistic effect with high electron transport efficiency and structural stability. Upon an in-depth optimization process, the optimal CMS-4 sample having P and I phases coexisting yields the optimal electrochemical behavior. The CMS-4@carbon cloth (CC) electrode provides a specific capacity of 33.9 mAh g–1 at 1 A g–1, which is 12.6 and 4.0 times higher than the pure P and I phases, respectively. The assembled MnO2@CC//CMS-4@CC supercapacitor exhibits a high energy density of 16.8 Wh kg–1 at 800 W kg–1 power density. The results demonstrate that two-phase coexistence of Cu2MoS4 significantly enhances the electrochemical activities owing to the synergistic effects of P and I phases and provides a promising material for supercapacitor negative electrodes.
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
·
2024
·Vol. 35
·期 36
·1-9
·
IF 2.8
Fu Jinxin,Zhou Changrong,Chen Jun,Yu Dongyan,Wu Di,Li Qingning,Yuan Changlai,Xu Jiwen,Rao Guanghui
The incompatibility of the large piezoelectric response ( d 33 ) and high depolarization temperature ( T d ) in lead-free piezoelectric ceramics limited their practical applications. The most used modification methods for improving d 33 or T d commonly required a delicate control of complex compositions. Here, a strategy for simply changing the sintering temperature is used to defer the T d and increase d 33 simultaneously. The T d and d 33 of unmodified Bi 0.5 Na 0.5 TiO 3 -0.2Bi 0.5 K 0.5 TiO 3 (BNKT20) ceramics increase with increasing sintering temperature until both of them reach the maximum ( d 33 ~ 174pC/N, T d ~ 177 °C) at the sintering temperature of 1100 °C. In-depth analysis unveils the critical role of multiphase coexistence and oxygen vacancies in enhancing T d by optimizing sintering temperature. Meanwhile, increasing sintering temperature promotes large grain size with easy domain orientation, thus, yielding the improved d 33 . This work provides a simple and effective method to broaden the working range of Bi 0.5 Na 0.5 TiO 3 -based (BNT) piezoelectric ceramics at high temperature under the premise of realizing high piezoelectric properties.
研究领域:
材料科学
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物理学
✓ 已验证
DOI
高影响因子
ACS Applied Materials & Interfaces
·
2022
·
IF 10.383
Junhua Li,Xiaowei Wei,Xi-xi Sun,Ruichen Li,Chao Wu,Jiayang Liao,Ting Zheng,Jiagang Wu
Piezocatalysis is regarded as a fascinating technology for water remediation and possible disease treatment. A high piezoelectric coefficient (d33) is one of the most important parameters to determine piezocatalytic performance, which can be manipulated via phase boundary design. Herein, a novel strategy for excellent piezocatalytic activity in lead-free BaTiO3-based materials via manipulating the multiphase coexistence is proposed. The piezocatalyst of 0.82Ba(Ti0.89Sn0.11)O3-0.18(Ba0.7Ca0.3)TiO3 (0.82BTS-0.18BCT) with multiphase coexistence is prepared, and a large d33 can be obtained. As a result, 0.82BTS-0.18BCT exhibits excellent piezocatalytic performance for the degradation of Rhodamine B (RhB). Furthermore, the removal rate of RhB could reach more than 90% after vibration for 30 min, and the reaction rate constant (k) could reach 0.0706 min–1, which is much superior to that of most other representative perovskite-structured piezoelectric materials. Excellent piezocatalytic performance can be attributed to the strong local ferro-/piezoelectric response induced by the multiphase coexistence, as confirmed by the in situ piezoresponse force microscopy (PFM). Finally, the piezocatalytic degradation mechanism is analyzed systemically and proposed. This work not only provides a high-efficiency piezocatalyst but also sheds light on developing efficient BT-based piezocatalysts by manipulating the multiphase coexistence.
研究领域:
材料科学
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环境科学
·
化学工程
✓ 已验证
DOI
PubMed
高影响因子
Journal of Materials Research and Technology-JMR&T
·
2024
·
IF 6.2
Si-Cheng Zhong,Jia Li,Zhe Cui,Guang-Run Tian,Fa-Chang Zhao,Zhong-Hong Zhou,Hong-Fei Jiao,Dan-Yang Liu,Jie-Fu Xiong,Li-Chen Wang,Jun Xiang,Fu-Fa Wu,Rong-Da Zhao
In the field of electrocatalysis, most of the electrodes have the problem of poor mechanical properties, which leads to the electrode can not be used on a large scale. At present, most bulk electrodes are used to study their mechanical properties due to their unique phase composition distribution and facile fabricate methods. But their novel properties in the field of electrocatalysts have not been fully developed. Multi-element bulk electrodes not only diversified the electronic states, but also build complex surface morphology by different dissolution rate between multi-phase distribution. In this paper, we synthesized the FeNiMo bulk electrode for oxygen evolution reaction (OER) with two-phase coexistence of Mo-doped face center cubic phase (FCC) and Mo-rich intermetallic compound (IMC) phase. During cyclic voltammetry activation, the surface reconstruction of Mo-rich IMC phases generated by ion leaching leaves Fe–Ni pore structures with more active area, which enhances OER performance. Meanwhile, the electron states get more diverse on the surface of remaining FCC phases due to Mo doping, which provides more suitable sites for four-step OER process. The FeNiMo electrode shows an ultra-low overpotential of 212 mV and 293.4 mV at a current density of 10 mA cm −2 and 100 mA cm −2 , respectively. Moreover, it can maintain stability at 100 mA cm −2 for up to 72 h. This work provides a strategy for studying the relationship between phase composition and electrochemical performance of alloy bulk electrodes.
研究领域:
材料科学
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电化学
✓ 已验证
DOI
高影响因子
Journal of Materials Chemistry C
·
2023
·Vol. 11
·期 35
·11895-11904
·
IF 6.4
Mengdi Cheng,Yangxi Yan,Zhimin Li,Pangpang Wang,Ri-ichi Murakami,Dongyan Zhang
Modern electronic devices are highly in demand for high-performance piezoelectric materials. Herein, Pb(Ni, Nb)O3–Pb(Lu, Nb)O3–PbTiO3 piezoelectric ceramics are investigated, among which the 0.52PNN–0.16PLN–0.32PT ceramic shows the best performance (d33 = 850 pC N−1, d33* = 1139 pm V−1). Excellent piezoelectricity can be explained by multiphase coexistence, as well as an enhanced local heterogeneous structure. Polar nanoregions that promote polarization rotation are an important cause of high piezoelectricity according to characterization using SEM and PFM. TEM also confirmed a heterogeneous domain configuration with two coexisting phases. In addition, a large signal piezoelectricity of 1000 pm V−1 is maintained in the temperature range of 20–90 °C. This work presents an excellent example of achieving both high piezoelectric properties and a good temperature range in relaxor ferroelectric ceramics.
研究领域:
材料科学
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电子工程
✓ 已验证
DOI
高影响因子
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
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2016
·
IF 3.205
Lin Chen,Hao Hua,Qi Yang,Muhammad Sufyan Javed,Chenguo Hu,Cuiling Zhang
TiO 2 microflowers assembled by nanosheets are prepared by a one-step solvothermal process. The anatase-TiO 2 (B) dual-phase coexistence or anatase single phase is obtained under different annealing temperatures. Pt nanoparticles supported on the anatase-TiO 2 (B) microflowers are first applied to alcohol electrooxidation . The electrocatalytic performances of Pt/anatase-TiO 2 (B), Pt/anatase and Pt/carbon-black (Pt/C) on graphite substrates are systematically investigated. The Pt/anatase-TiO 2 (B) catalyst exhibits superior electrocatalytic activity and stability compared with that of Pt/anatase and Pt/C catalysts for methanol and ethanol in acidic and alkaline media , which is attributed to the large specific surface area, the porous channels to reduce the liquid sealing effect, the enhanced electronic conductivity by dual-phase coexistence and quick electron transfer from anatase phase to TiO 2 (B).
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF APPLIED PHYSICS
·
2024
·Vol. 136
·期 7
·
IF 2.7
Zha Jielin,Yang Yulong,Liu Jiaxun,Lu Xiaomei,Hu Xueli,Yan Shuo,Wu Zijing,Zhou Min,Huang Fengzhen,Ying Xuenong,Zhu Jinsong
Although K 0.5 Na 0.5 NbO 3 (KNN) possesses large maximum polarization and relatively high breakdown strength, the large remnant polarization constrains their practical applications as energy storage materials. In this work, through multi-element doping, (K 0.5−0.5 x Na 0.5−0.5 x Bi x )(Nb 1− x Sn 0.2 x Zn 0.6 x Ta 0.2 x )O 3 relaxor ferroelectrics were prepared. As the superparaelectric states (SPE) were adjusted to room temperature, orthorhombic, tetragonal, and cubic phases coexisted, accompanied by the highly dynamic polar nanoregions (PNRs). In particular, a high recoverable energy storage density of 4.5 J/cm 3 and an energy storage efficiency of 83% were achieved for the x = 0.125 ceramic, with the variations less than 11% and 4%, respectively, in the wide temperature range of 20–180 °C. These results demonstrate that the multiphase PNRs in the SPE state is an effective strategy for improving the energy storage performance of KNN-based ceramics.
研究领域:
材料科学
·
能源存储
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF COLLOID AND INTERFACE SCIENCE
·
2023
·
IF 9.9
Zihan Kang,Mengshi Chen,Jiang Wu,Ni Qin,Dinghua Bao
Piezocatalytic technology with controllable generation of reactive oxygen species (ROS) is emerging in wastewater treatment. This study employed the synergetic regulation of functional surface and phase interface modification to effectively accelerate redox reaction in piezocatalytic process. We anchored the conductive polydopamine (PDA) onto Bi 2 WO 6 (BWO) using template method, in which a small amount of Bi precipitation to induce partial phase transition of BWO from tetragonal to orthorhombic (t/o) in virtue of simple calcination. ROS traceability studies have identified the synergistic relationship between charge separation and transfer. Polarization in two-phase coexistence is intimately modulated by the orthorhombic relative central cation displacement. The orthorhombic phase with large electric dipole moment significantly promotes the generation of piezoresistive effect of intrinsic tetragonal BWO and optimizes the charge distribution. PDA further overcomes the obstruction of carrier migration at the phases interface to accelerate the generation rate of free radicals. Consequently, the superior rhodamine B (RhB) piezocatalytic degradation rate of 0.10 and 0.32 min −1 were delivered by t/o-BWO and t/o-BWO@PDA, respectively. This work reveals a feasible polarization enhancement strategy for the phase coexistence, and flexibly introduces the in-situ synthesized economical polymer conductive unit into the piezocatalysts.
研究领域:
环境科学
·
材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Journal of Materials Chemistry A
·
2025
·
IF 9.5
Yingzhi Meng,Zhaojie Wang,Xiang Niu,Yuleng Jiang,Peng Nong,Silin Tang,Jiyang Xie,Wanbiao Hu,Dingyuan Wang,Biaolin Peng,Shengguo Lu,Laijun Liu
The development of high-performance electrocaloric effect (ECE) is of great importance for local refrigeration (such as chip and wearable electronics cooling, etc.). However, how to simultaneously achieving both a large ECE and a wide working temperature range near the room temperature are long-term challenges for lead-free ceramics. Herein, we report a novel lead-free ceramic with a high-performance ECE. Phase coexistence and optimized ferroelectric domain configuration and ultra-fine grains were constructed by {Nb 5+ , In 3+ } co-doping in B 0.9 Ca 0.1 TiO 3 ceramics near the room temperature. Ultimately, an ultrahigh ECE of 3.0 K and a wide working temperature range of 97 K are obtained near the room temperature in the composition (B 0.9 Ca 0.1 Ti 0.89 (Nb 0.5 In 0.5 ) 0.11 O 3 ). Furthermore, the origin of the high ECE performance was elucidated by the microstructures characterized using piezoresponse force microscopy (PFM) and atomic-resolution HAADF-STEM, and the dielectric and ferroelectric properties. This work provides an innovative approach for achieving high-performance ECE.
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产品关联
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2022
·Vol. 49
·期 2
·1846-1854
·
IF 5.532
Xinkun Liu,Ying Dai,Xinmei Pei,Wen Chen
The electrocaloric (EC) effect cooling technique of environmentally friendly lead-free thin film materials driven by electric fields has recently gained tremendous attention due to the urgent demand for microelectronic and integrated circuit refrigeration devices. However, the widespread use of lead-free materials in EC devices is seriously hindered due to the small electrocaloric temperature change (ΔT) within a narrow operation temperature span (T span ) near room temperature. Here, lead-free Ba 0.85 Ca 0.15 Zr 0.1 Ti 0.9-x Sn x O 3 (BCZT-xSn, 0 ≤ x ≤ 0.03) thin films were prepared on substrates (Pt/Ti/SiO 2 /Si) via a sol-gel route. The BCZT-0.02Sn thin film presents an excellent EC effect (ΔT = 32.74 K, ΔS = 37.18 J kg −1 K −1 ) and large EC strength (ΔT/ΔE = 0.033 K cm kV −1 , ΔS/ΔE = 0.037 J cm K −1 kg −1 kV −1 ) over a wide T span (∼26 K) under 1000 kV cm −1 near room temperature. The giant ΔT is mainly attributed to the emergence of an intermediate O phase and the formation of a multiphase (R, O and T phases) coexistence structure at room temperature, while the diffuse phase transition behavior is responsible for the wide T span . Our study provides a new idea for developing environment-friendly EC materials with an excellent room-temperature ΔT over a broad operational temperature region.
研究领域:
材料科学
·
功能材料
·
固态物理
·
环境友好材料
·
制冷技术
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）