Journal of Materials Chemistry A
·
2023
·Vol. 12
·期 3
·1753-1763
·
IF 11.9
Yan Zhao,Yan Zhang,Qianqian Xu,Hanyu Gong,Mingyang Yan,Kaiyu Feng,Xiang Zhou,Xuefan Zhou,Dou Zhang
Hydrothermally synthesized Nd-doped bismuth titanate (Bi3.15Nd0.85Ti3O12, BIT-Nd) hierarchical microspheres with assembled nanosheets were developed for water splitting and wastewater purification utilizing the piezo-phototronic effect for the first time. Undoped Bi4Ti3O12 (BIT) microspheres were simultaneously studied for comparison to reveal the role of Nd doping. Under the combined light and ultrasound excitation, the degradation efficiency of RhB (C0 = 10 mg L−1) solution reached 97.5% in 8 minutes in the presence of the BIT-Nd microspheres, leading to an ultrahigh first-order rate constant k of 0.407 min−1, which was 4.9 times higher than that of the BIT microspheres. More impressively, superior piezo-photocatalytic activity in water splitting compared to that of other reported piezo-photocatalysts was achieved in the BIT-Nd microspheres, which showed a H2 evolution rate of 1330.3 μmol g−1 h−1 without any cocatalyst or scavenger. To understand the origins of the excellent piezo-photocatalytic performance, microstructure analysis and piezoelectric and photoelectric characterization, as well as density functional theory calculations were carried out. After Nd doping, the atomic framework of the Ti–O octahedron underwent an apparent distortion, resulting in a stronger ferroelectric polarization, and thus a larger piezoelectric potential output under pressure. Moreover, the thinner nanosheets in the BIT-Nd microspheres were more susceptible to deformation under the ultrasonic effect, which was also beneficial to generate a higher piezoelectric field that inhibited the charge carrier recombination. Additionally, the presence of Nd 4f orbitals in BIT-Nd effectively reduced the band gap and promoted the spectral absorption and production of photogenerated carriers. These merits enabled the BIT-Nd microspheres to exhibit strong piezo-photocatalytic activity.
研究领域:
材料科学
·
环境科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2019
·
IF 3.45
Xiyong Chen,Mingxin Zhou,Junzuo Shi,Tianquan Liang,Jie Zeng,Xia Yan,Nengneng luo,Weizhou Li,Yuezhou Wei
The effect of nominal Na/Bi ratio on the microstructure and electrical conductivity of A-site fully stoichiometric sodium bismuth titanates , Na 0.5+ x Bi 0.5− x TiO 3− δ , was investigated in this study. Bulk samples with x = 0, 0.01, 0.03, 0.05, 0.07, and 0.1 were prepared by conventional solid state reaction method. The as-calcined powders primarily exhibited the perovskite structure, which was identified by X-ray diffraction. Electron microscopic investigation of the sintered samples, however, revealed the presence of secondary phases, the amounts of which were found to increase with increasing Na/Bi ratio. Further elemental analysis by energy dispersive spectroscopy indicated that the secondary phases were mainly composed of sodium titanates with different Na/Ti ratios. The grain bulk and grain boundary conductivities of Na 0.5+ x Bi 0.5− x TiO 3− δ , measured by two-probe AC electrochemical impedance spectroscopy , significantly increased with increasing Na/Bi ratio when x ≤ 0.03, but remained almost constant at higher x . The synergetic effect of oxygen vacancy creation, grain size reduction, and secondary phase formation on the variation in the conductivity upon increasing the nominal Na/Bi ratio in Na 0.5+ x Bi 0.5− x TiO 3− δ was discussed.
研究领域:
材料科学
·
固态化学
✓ 已验证
DOI
高影响因子
JOURNAL OF THE AMERICAN CERAMIC SOCIETY
·
2023
·Vol. 106
·期 5
·2963-2971
·
IF 3.9
Nan Weng,Ji Zhang,Jiajia Wang,Tianze Pan,Jing Wang,Yaojin Wang
Ceramic capacitors with high electrostatic energy storage performances have captured much research interest in latest years. Sodium bismuth titanate (Na 0.5 Bi 0.5 TiO 3 )-based ferroelectric ceramics show great potential due to their environment-friendly composition, high polarization, and excellent relaxor properties. However, the nonergodic relaxor state of Na 0.5 Bi 0.5 TiO 3 -based ceramics hampers the decrement of remanent polarization, leading to poor energy storage performance. Herein, the (1 − x )Na 0.5 Bi 0.5 TiO 3 – x La(Ni 2/3 Ta 1/3 )O 3 ceramics were designed to generate the transformation between nonergodic and ergodic relaxor state. As a result, the ceramics exhibit improved dielectric relaxation, slim polarization–electric field loops, and flattened current–electric field curves due to highly dynamic polar nanoregions. Particularly, the 0.85Na 0.5 Bi 0.5 TiO 3 –0.15La(Ni 2/3 Ta 1/3 )O 3 ceramics show large breakdown electric field E b (345 kV/cm), high recoverable energy density W rec (3.6 J/cm 3 ), and efficiency η (80.6%), revealing potential applications in electrostatic energy storage.
研究领域:
材料科学
·
能源存储
✓ 已验证
DOI
高影响因子
Results in Chemistry
·
2024
·
IF 2.5
Mohammed N. Alabdulsalam,Abdulaziz A. Bagabas
Photocatalysis is a recognized approach in the detoxification of pollutants and in water splitting. Such process is more appealing when it is driven by visible or solar light. In this context, we synthesized bismuth titanate perovskite oxide (Bi 4 Ti 3 O 12 , BTO) photocatalyst by sol–gel hydrothermal process. The resulting BTO materials was affected by the titania source and by the synthesis medium pH parameter. Titanium butoxide [Ti( n - BuO) 4 ] was much better than titanium isopropoxide [Ti( i - PrO) 4 ] in producing regular nanosheets with higher surface area, while 75 ml of 5.0 M sodium hydroxide was the optimum concentration for the synthesis of regular, thin, porous, almost equal size nanosheets. The photocatalytic activity of BTO was improved by loading silver nanoparticles (AgNPs) by photo-assisted reduction. The optimum weight percent of loading AgNPs was found to be 1.5 % because it led to the highest light absorbance, the smallest band gap energy, the minimum rate of electron-hole recombination. The photocatalytic degradation efficiency of 1.5 wt% Ag/BTO reached as high as 99.0 % of rhodamine B (RhB, 100 ml, 6 ppm of initial concentration) under 70 min of irradiating visible light (>420 nm). Moreover, pH had a strong influence on the photocatalytic activity of 1.5 wt% Ag/BTO, with pH=3.0 was the optimum, owing to its impact on the interaction between the positively-charged photocatalyst surface and the negatively-charged RhB molecules. It was found that superoxide radicals played key role in the photocatalytic activity.
研究领域:
环境科学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF THE AMERICAN CERAMIC SOCIETY
·
2020
·Vol. 104
·期 2
·936-947
·
IF 3.502
Shuaishuai Bian,Zhenxing Yue,Yunzhou Shi,Jie Zhang,Wei Feng
Lead-free ferroelectric ceramics are very suitable for electrostatic energy storage capacitors due to their outstanding characteristics of high charge-discharge speed, high power density, and environmental friendliness. Herein, a novel material system as (1− x )Na 0.5 Bi 0.5 TiO 3 - x CaZr 0.5 Ti 0.5 O 3 (NBT-CZT, x = 0, 0.05, 0.10, 0.12, 0.15, and 0.20) was designed and prepared for dielectric energy storage ceramics. It demonstrated that the CZT additives induced a phase transition for the NBT ceramics, from ferroelectric to relaxor ferroelectric. In particular, extremely high stored energy storage density (6.92 and 5.37 J/cm 3 ), high recoverable energy storage density (4.77 and 4.37 J/cm 3 ), and moderate efficiency (69.0% and 81.4%) were achieved in both the samples of x = 0.12 and x = 0.15, respectively. The ceramics exhibited excellent stability of energy storage performance covering a wide temperature (25°C–200°C) and frequency (0.5–50 Hz) range, and also fatigue cycles up to 10 5 . Additionally, the NBT-CZT ceramics had a fast discharge speed ( t 0.9 < 100 ns) and high power density (24.2 MW/cm 3 , E = 100 kV/cm, x = 0.15), and the charge-discharge process remained stable even when the measured temperature was up to 160°C. Therefore, the NBT-CZT ceramics have the potential to be utilized in electrostatic energy storage applications.
研究领域:
材料科学
·
能源存储
✓ 已验证
DOI
高影响因子
JOURNAL OF MATERIALS SCIENCE
·
2019
·Vol. 54
·期 21
·13740-13752
·
IF 3.442
Wang Juan,Liu Wenwen,Zhong Dongling,Ma Yongjin,Ma Quanyin,Wang Ziyu,Pan Jun
The synergism between different surface facets of semiconductor with optimal ratios can contribute to obtain enhanced photocatalytic degradation performance. Herein, a bismuth-based material Bi 4 Ti 3 O 12 exposed with {001} top facets and {010}/{100} lateral facets was prepared by the molten-salt method.
More importantly, the ratio of different exposed facets could be controlled by adjusting the synthesis temperature of molten-salt synthesis process. The as-prepared Bi 4 Ti 3 O 12 exposed with the optimal ratio of {001} top facets to {010}/{100} lateral facets exhibited the enhanced degradation activity of tetracycline hydrochloride (TC-HCl) under irradiation. The rate constant of optimal sample reached 0.904% min −1 , over 3.3 times as compared with that of the counterpart with higher proportion of {001} facets. Besides, active species trapping experiments, photoelectrochemical measurements and selective photodeposition tests were used to illuminate the photocatalytic degradation mechanism. According to that, the enhanced degradation activity could be ascribed to crystal facet synergism which can promote photoinduced carrier separation. This work can give insights into designing and constructing other two-dimensional (2D) bismuth-based materials with the aim of enhancing photocatalytic degradation performance.
研究领域:
材料科学
·
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）