Journal of Materials Chemistry A
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2021
·Vol. 9
·期 32
·17442-17450
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IF 12.732
Yintong Zhang,Feng Du,Ruyi Wang,Xintong Ling,Xiaoyong Wang,Qing Shen,Yujie Xiong,Tao Li,Yong Zhou,Zhigang Zou
The electrocatalytic nitrogen oxidation reaction (NOR) is a promising alternative to the industrial synthesis of nitrate. However, with the enhancement of NOR activity by modification methods, the competitive oxygen evolution reaction (OER) is always improved simultaneously. Here, a hybrid electrocatalyst composed of Au nanoparticles and oxygen vacancy-enriched niobium oxide nanobelts (Au–Nb2O5−x) was prepared on niobium foil for N2 fixation into NO3−. The results of X-ray photoelectron spectroscopy (XPS) and electron paramagnetic resonance (EPR) demonstrate that electron transfer occurs between Au nanoparticles and the oxygen vacancies in Nb2O5−x nanobelts, which adjusts the electronic structures of oxygen vacancies near the Au/Nb2O5−x interface. Electrochemical and N2 temperature-programmed desorption (TPD) tests indicate that the optimization of the electronic structure suppresses the activity of the competitive OER on oxygen vacancy sites and facilitates nitrogen adsorption on the surface of Au–Nb2O5−x, which significantly enhances the NOR performance of the electrocatalyst.
研究领域:
电化学
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材料科学
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催化化学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF COLLOID AND INTERFACE SCIENCE
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2025
·
IF 9.7
Jiaxin Yao,Feng Gao,Yi Zhao,Yajie Tian,Xin Yu,Yanting Tang
Fabricating semiconductor photocatalysts with abundant oxygen vacancies and porous structures contributes to charge separation and surface photocatalytic degradation reactions. In this work, porous Cl-Nb 2 O 5-x nanostructures were synthesized via a calcination method using NbCl 5 as the niobium and chlorine sources to achieve efficient tetracycline degradation under visible-light irradiation. Porous Nb 2 O 5-x nanostructures were formed during the calcination process accompanied by the generation of oxygen vacancies. The obtained Cl-Nb 2 O 5-x samples demonstrated significantly enhanced photocatalytic performance compared to commercial Nb 2 O 5 . The synthesized Cl-Nb 2 O 5-x -450 sample exhibited the highest photocatalytic performance, achieving a maximal rate constant of 0.03093 min −1 , which markedly surpassed that of commercial Nb 2 O 5 . The remarkable enhancement in tetracycline degradation of the Cl-Nb 2 O 5-x photocatalysts was mainly attributed to the generation of oxygen vacancies and porous structures with large surface areas. Finally, the photodegradation pathways of tetracycline facilitated by the Cl-Nb 2 O 5-x photocatalysts and a plausible photocatalytic mechanism of the Cl-Nb 2 O 5-x photocatalysts were also investigated in this work.
研究领域:
材料科学
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环境科学
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产品关联
DOI
PubMed
高影响因子
APPLIED SURFACE SCIENCE
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2022
·
IF 7.392
Jiamei Lai,Chunhai Jiang,Zhimin Zou
Nanosized oxygen-deficient orthorhombic niobium pentoxide (Nb 2 O 5-x ) that possess high electronic conductivity and stable cycle performance for Li storage are uniformly deposited on the surface of mesophase carbon microspheres (MCMB), which as a whole exhibits very encouraging electrochemical Li ion storage performance, including a high specific capacity of 107 mAh g −1 at 10C (1C = 372 mA g −1 ) and a high capacity retention of 85.4 % after 300 cycles at 3C in the optimized case. The Li + diffusion coefficient of the composite anode as determined by the potentiostatic intermittent titration technique (PITT) is obviously improved as compared to that of pristine MCMB. Ex situ X-ray diffraction characterizations confirm the phase transformation from orthorhombic Nb 2 O 5-x to amorphous Li y Nb 2 O 5-x accompanied by the formation of NbO through a conversion reaction in the first lithiation process. The ultrafast Li + diffusion within the amorphous Li y Nb 2 O 5-x as well as the current-sharing effect of the secondary particles can explain the much enhanced Li ion storage property. The results of this work convincingly demonstrate that designing MCMB/Nb 2 O 5-x composite can be a more practical way to improve the energy and powder densities of Li-ion batteries rather than seeking alternative anode materials with higher capacities.
研究领域:
材料科学
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电化学
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能源存储
✓ 已验证
产品关联
DOI
高影响因子
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
·
2025
·
IF 8.3
Guoxiang Wang,Taipu Chen,Dahui Fang,Jinkai Hao,Zhigang Shao
The development of highly active and stable catalysts of oxygen evolution reaction (OER) plays a crucial role in proton-exchange-membrane water electrolysis (PEMWE). Herein, an electronic modulate was used to fabricate oxygen defect-rich and supported metal catalysts AuIr/Nb 2 O 5-x , and it promoted the sluggish kinetics and low efficiencies of OER with the interaction between oxygen defects and the active sites. The Nb–O defect with an electron redistribution and manipulated active electronic state tailored the OER performance. The Ir actively exposed the AuIr/Nb 2 O 5-x -500 catalyst, which exhibited a low overpotential of 230 mV and maintained an excellent stability for 200 h at the current density of 10 mA cm −2 in 0.5 M H 2 SO 4 electrolyte. Furthermore, the PEMWE using AuIr/Nb 2 O 5-x -500 as the anode revealed a high water-splitting performance (1.61 V @ 0.5 A cm −2 & 1.70 V @ 1 A cm −2 ). In-situ Raman spectra and theoretical calculations revealed the electronic structure of AuIr/Nb 2 O 5-x -500 and the mechanism of OER processes, which rationalized the improved performance through the synergistic effect of metal–support interaction and defect effect.
研究领域:
电化学
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催化
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材料科学
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能量转换
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表面科学
✓ 已验证
产品关联
DOI
高影响因子
ACS Applied Materials & Interfaces
·
2022
·
IF 10.383
Piaoyun Yang,Yijing Fan,Keyang Hu,Lei Jiang,Lun Tan,Zhao Wang,Ang Li,Shulin Yang,Yongming Hu,Haoshuang Gu
The research and development of low-power-consumption and room-temperature hydrogen sensors are of great significance for the safe application of hydrogen energy. Herein, orthorhombic Nb2O5–x nanobelts are prepared through a combined procedure of hydrothermal, ion exchange, and annealing treatment in Ar. The topological transformation process results in the formation of abundant surface defects including chemical defects such as Nb4+, oxygen vacancies, and disordered microregions, which lead to the abnormal p-type conducting and hydrogen sensing behavior. Moreover, the orthorhombic Nb2O5–x nanobelts exhibit fast and sensitive room-temperature hydrogen sensing performance, which shows greater advancement than the monoclinic, tetragonal, and hexagonal Nb2O5 one-dimensional (1D) nanostructures. The response time and lowest limit of detection of the as-fabricated room-temperature sensor decrease to 28 s and 3.5 ppm, respectively. The sensor also exhibits a highly selective hydrogen response against CO, CH4, ethanol, H2S, and NH3. The hydrogen response of the Nb2O5–x nanobelts can be attributed to the redox reaction between hydrogen and preadsorbed oxygens. The defective surface structure and the prolonged dimension of the nanobelts give rise to the highly reactive surface and the suppression of the negative nanojunction effect, which greatly improves the sensing performance. The orthorhombic lattice structure can also promote gas adsorption and diffusion behavior due to its specific catalytic and pathway effect. The results of this work can be helpful for the rational design and defect engineering of the Nb2O5-based 1D nanostructures for room-temperature hydrogen sensing applications.
研究领域:
材料科学
·
传感器技术
✓ 已验证
DOI
PubMed
高影响因子
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