MATERIALS SCIENCE FORUM
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2015
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IF 0
Wei Cai,Chun Lin Fu,Rong Li Gao,Wei Hai Jiang,Xiao Ling Deng,Gang Chen
Bismuth ferrite is an important material in ferroelectric photovoltaic field, because of its narrow band gap and large polarization. Doping is a common method to further improve the photovoltaic properties of bismuth ferrite. Mn-doped bismuth ferrite thin films were prepared by sol-gel method. The effects of manganese on the crystal structure, ferroelectric and photovoltaic properties have been investigated. The result indicates that Mn-doped bismuth ferrite thin films are single phase and the lattice constant increases with the increase of manganese content. As manganese content increases, the remnant polarization and coercive electric field increase, while the short circuit photocurrent density and power conversion efficiency decrease. The open circuit photovoltage increases first and reaches the maximum and then decreases as manganese content increases. The results indicate that enhanced ferroelectricity caused by addition of manganese doesn’t make improvement on the photovoltaic characteristic.
研究领域:
材料科学
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物理学
✓ 已验证
DOI
APPLIED SURFACE SCIENCE
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2021
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IF 6.707
Yue Wu,Yangwen Chen,Shouqiang Huang,Guobiao Li,Shunping Sun,Yong Jiang,Guobin Liang,Songjian Zhao,Weiqiao Liu
The chloride (Cl − ) ions in wastewater are difficult to remove, since there is a lack of effective and recyclable chloride removal agents. In this study, the bismuth ferrites (BFO) are first explored as chloride removal agents, and their oxidation or precipitation effects on the Cl − removal are studied. In the BFO samples, the crystal phases of BiFeO 3 and Bi 2 FeO 4 have very limited contributions to the Cl − removal, while the enhanced removal ability is exhibited with the increase of Bi 25 FeO 40 . When the mass percentage of Bi 25 FeO 40 reaches 70%, high Cl − removal efficiencies of 80–90% are achieved, which even exceeds 95% for pure Bi 25 FeO 40 . The morphology and structure characterizations reveal that the excellent Cl − removal performance of Bi 25 FeO 40 is determined by its unstable chemical structure due to the sharing of Bi 5+ and Fe 3+ ions in the tetrahedral positions. The density of states and electron localization function of Bi 25 FeO 40 demonstrate that its Fe and O bonding is weaker than those of BiFeO 3 and Bi 2 FeO 4 , resulting in the easier breaking of the Fe 3+ /Bi 5+ -O bonds to release Bi 5+ ions, which have oxidation ability for the formation of OH and Cl radicals to enhance the Cl − removal efficiency.
研究领域:
环境科学
·
材料科学
✓ 已验证
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
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2015
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IF 2.999
Tong Gao,Zhi Chen,Feng Niu,Dantong Zhou,Qiaoli Huang,Yuxiang Zhu,Laishun Qin,Xingguo Sun,Yuexiang Huang
Bismuth ferrite (BiFeO 3 ) has been prepared by hydrothermal method using Fe(NO 3 ) 3 ·9H 2 O and Bi(NO 3 ) 3 ·5H 2 O as the starting materials. The single-phase cube-like BiFeO 3 materials with defined morphologies were successfully synthesized by controlling the experimental parameters. Effects of reaction time, KOH concentration and organic dispersant on the BiFeO 3 particle morphology , size and property were systematically investigated. The prepared BiFeO 3 particles present tunable absorption characters by controlling the particle size and morphology. The prepared samples can degrade methyl orange (MO) under visible light (>420 nm). Cubic BiFeO 3 particles with a size of ca. 1.4 um could be synthesized by using PVP as the dispersant, which shows the highest activity of MO photo-degradation. The photocatalytic mechanism is proposed and active components are further convinced by EPR analysis.
研究领域:
材料科学
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环境科学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2023
·
IF 6.2
Boying Wang,Hao Wang,Jiantao Wang,Chaolong Li,Feng Wang,Chunli Diao,Haiwu Zheng
Dielectric thin film capacitors are expected to be a promising candidate for high-performance energy storage devices due to their high power density, fast charge/discharge speed, and excellent stability. Nevertheless, it remains a challenging endeavor to develop dielectrics with excellent energy storage density comparable to that of commercial batteries. In this work, lead-free 0.8SrTiO 3 -0.2BiFeO 3 (0.8STO-0.2BFO) thin films with coexisting amorphous and nanocrystalline structure were prepared by a sol-gel method. The heat-treatment temperature was adjusted to form polar-nano regions, thereby modulate the breakdown strength and dielectric polarization, and increase the energy storage density. The electric potential, electric field, and current density of the films with different amorphous/crystalline volume fractions were evaluated by the finite element simulation to further verify that the proper crystallization can result in the improved polarization performance and increased breakdown strength of the films, which are beneficial to the enhancement of energy storage performance. Through structural tailoring, the 0.8STO-0.2BFO film annealed at 550 °C demonstrates the optimal energy storage properties with a giant discharge energy storage density of 65 J/cm 3 and high efficiency of 75% at room temperature. Simultaneously, a broad temperature stability (20–160 °C), superb operating frequency stability (20 Hz-2 kHz), and excellent fatigue endurance (6.3 ×10 5 ) are observed without appreciable degradation of the energy storage performance. The excellent energy storage performance indicates a widespread potential of 0.8STO-0.2BFO films in pulse power applications, such as consumer electronics, microelectronics, and medical devices .
研究领域:
材料科学
·
能源存储技术
✓ 已验证
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
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2018
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IF 6.735
Yang Liu,Hongguang Guo,Yongli Zhang,Weihong Tang,Xin Cheng,Wei Li
Sillenite bismuth ferrite (S-BFO) Bi 25 FeO 40 was synthesized by a hydrothermal process and firstly adopted for the activation of peroxymonosulfate (PMS). Multiple characterization was conducted for the morphology and physicochemical features of S-BFO. Degradation of aquatic levofloxacin (LVF) was thoroughly evaluated by using a coupled process for the decontamination of the typical emerging organics. Some crucial parameters for the activation kinetics as well as economic recyclability were examined with the detailed mechanism proposed. For the first time, singlet oxygen ( 1 O 2 ) was identified as the main reactive oxygen species through radical scavenging experiments, electron paramagnetic resonance spectroscopy (EPR) and HPLC-MS determination. Based on the XPS and EPR results, a catalytic mechanism is proposed concerning the parallel generations of 1 O 2 : (i) Bi 5+ is replaced by Bi 3+ , resulting in the formation of an oxygen vacancy in the lattice and an active oxygen (O ∗ ), which could produce 1 O 2 through the reactions with PMS; (ii) direct formation of 1 O 2 from radSO-5 generated by the interaction between Bi 5+ and PMS. This study demonstrates a novel catalyst for heterogeneous activation of PMS via a non-radical mechanism, which could be alternatively adopted in the decontamination in surface/ground water.
研究领域:
环境科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）