Journal of Materials Chemistry A
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2019
·Vol. 7
·期 28
·16969-16978
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IF 10.733
Tianxing Wu,Miaomiao Han,Xiaoguang Zhu,Guozhong Wang,Yunxia Zhang,Haimin Zhang,Huijun Zhao
Deeply understanding the electrochemical activation and inactivation processes of an electrocatalyst is critically important for establishing a high-efficiency nitrogen reduction reaction (NRR) to synthesize an NH3 system. Here we report the utilization of a facile vapor-phase hydrothermal (VPH) method to directly grow ultrafine Nb3O7(OH) nanoparticles on commercial carbon fiber cloth (Nb3O7(OH)/CFC) for the NRR. The results demonstrate that the Nb3O7(OH)/CFC can afford an average NH3 yield rate of 622 μg h−1 mgcat.−1 with a high faradaic efficiency (FE) of 39.9% at −0.4 V versus the reversible hydrogen electrode (RHE) in 0.1 M Na2SO4 electrolyte (pH = 6.1) within 30 min of the NRR, surpassing the performance of most recently reported aqueous-based NRR electrocatalysts. The experimental and theoretical calculation results reveal that the in situ electrochemically converted NbO from Nb3O7(OH) during the NRR is the catalytic active phase with a N2 adsorption free energy of −0.97 eV; however with a reaction time over 30 min, the generated active *N atoms in the *N–NH3 → *N + NH3 hydrogenation step during the NRR are thermodynamically favourable for binding to the oxygen vacancies of NbO to form oxygen-containing NbN0.64 with reduced N2 adsorption free energy (−0.32 eV), resulting in significantly decreased NRR activity. Our studies suggest that although NbO possesses high NRR activity, it may not be a suitable NRR electrocatalyst, owing to easy formation of low active niobium oxynitride during the NRR.
研究领域:
材料科学
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电化学
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DOI
高影响因子
ACS Applied Materials & Interfaces
·
2024
·
IF 8.3
Yongfang Jia,Juan Gao,Feng Yang,Yangmin Diao,Qijun Liu,Yong Zhang,Hongliang Sun,Min Pan,Mei Huang,Min Xu,Xuru Duan,Yong Zhao
Despite the excellent performance of Nb3O7(OH) in dye-sensitized solar cells and catalysis, its charge separation, transport, and structural properties remain poorly understood. Herein, the Nb3O7(OH) nanorods were prepared, and their structural characteristics, optoelectronic properties, and carrier mobility were also analyzed and investigated through a series of complex characterizations. Theoretical prediction suggested that the exciton binding energy of Nb3O7(OH) could be as high as 100.49 meV. The temperature-dependent photoluminescence (PL) of Nb3O7(OH) nanorods revealed two activation energies, and a higher proportion of long-lived components observed in the photoluminescence decay indicated effective electron trapping. That is, two energy states were present, hindering photogenerated charge recombination and promoting photocatalytic action. Current–voltage characteristics of the Nb3O7(OH) nanorod film were analyzed, revealing an ultrahigh carrier mobility of ∼310 cm2/V·s, ensuring fast and efficient electron transfer. Furthermore, Nb3O7(OH) nanorods were employed to reduce CO2, resulting in the effective production of CO and CH4. Overall, considering the presence of hydroxyl pairs on the surface of Nb3O7(OH), which facilitate the formation of the frustrated Lewis acid–base pairs and the activation of CO2, together with its effective electron trapping and charge transport, give Nb3O7(OH) nanorods a promising potential for CO2 reduction.
研究领域:
材料科学
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催化化学
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光电化学
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DOI
高影响因子
JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY A-CHEMISTRY
·
2025
·
IF 4.7
Hezheng Sun,Guoqing Liu,Yi Zhao,Jingcun Shao,Changhui Xin,Yanting Tang,Xin Yu
Bisphenol A is an environmental hormone that shows a significant impact on human health. The removal of bisphenol A substances from the surrounding environment is of great significance for the humanity sustainable development. Current work focuses on synthesizing self-doped Nb 3 O 7 (OH) nanostructure and eosin Y/Nb 3 O 7 (OH) composites with high surface areas through a solvothermal process for bisphenol A degradation under visible-light illumination. The prepared Nb 3 O 7 (OH) sample demonstrated a noticeable photocatalytic performance toward bisphenol A degradation. Notably, the obtained eosin Y/Nb 3 O 7 (OH)-1.0 % composite not only exhibited efficient visible-light harvesting and high surface area but also showed significantly improved charge separation and bisphenol A degradation compared to pristine Nb 3 O 7 (OH) sample. The rate constant of the eosin Y/Nb 3 O 7 (OH)-1.0 % sample for bisphenol A degradation was approximately 0.04252 min −1 , which was 7.85 times that of pristine Nb 3 O 7 (OH) sample. Furthermore, the eosin Y/Nb 3 O 7 (OH)-1.0 % composite achieved approximately 59.76 % mineralization of bisphenol A within 20 min and 75.28 % mineralization within 40 min under visible-light illumination. Additionally, the effects of experimental parameters on bisphenol A degradation and the dye-sensitization mechanism were proposed. The current work suggests the obvious advantages of defective Nb 3 O 7 (OH) nanostructure in fabricating high-performance composite photocatalysts for eliminating emerging pollutants.
研究领域:
环境科学
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纳米技术
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材料科学
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化学工程
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DOI
高影响因子
Nanoscale
·
2014
·Vol. 7
·期 5
·1963-1969
·
IF 6.739
Pei Hu,Dongfang Hou,Yanwei Wen,Bin Shan,Chaoji Chen,Yunhui Huang,Xianluo Hu
Novel three-dimensional (3D) hierarchical Nb3O7(OH) nanostructures with a sheaf-like nanoarchitecture were fabricated for the first time by a hydrothermal process. Interestingly, the nanosheafs are composed of nanorods with an average diameter of about 25 nm. The as-prepared 3D hierarchical nanostructures possess a high surface area of 77 m2 g−1 with pore diameters of ca. 4.2–12.5 nm. A possible growth mechanism based on the combined Ostwald ripening and self-assembly process was proposed. It is found that both the valence-band top and the conduction-band bottom consist of O 2p and Nb 4d orbitals. Importantly, the 3D hierarchical Nb3O7(OH) nanostructures exhibit enhanced photocatalytic activity for the degradation of Rhodamine B (RhB) under UV-visible light, which is attributed to the unusual hierarchical structure, high surface area, and hybridization of energy bands.
研究领域:
材料科学
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环境科学
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DOI
PubMed
高影响因子
APPLIED SURFACE SCIENCE
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2025
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IF 6.9
Hezheng Sun,Yi Zhao,Changhui Xin,Hao Yang,Xin Yu,Yajie Tian
As a well-known endocrine disruptor, bisphenol A can be detected in natural waters, and the exploration of high-performance photocatalytic systems for bisphenol A removal is of significance for the sustainable development. In this work, self-doped Nb 3 O 7 (OH) architecture with abundant oxygen vacancies were synthesized using a controllable solvothermal method, while the Nb 3 O 7 (OH)-supported AgIO 3 /AgCl heterojunctions were fabricated by leveraging the residual Cl − ions over the surface Nb 3 O 7 (OH) architecture for the degradation of organic pollutants. Additionally, the proportion of AgIO 3 to AgCl over the Nb 3 O 7 (OH) architecture was adjusted by controlling the dosage of NaIO 3 , leading to the successful fabrication of the AgIO 3 /AgCl/Nb 3 O 7 (OH) composites. The AgIO 3 /AgCl/Nb 3 O 7 (OH)-25 % composite demonstrated the highest photocatalytic performance for bisphenol A degradation, achieving a rate constant of 0.02445 min −1 , which was 5.57 times that that of AgCl, 5.61 times that of Nb 3 O 7 (OH) and 163 times that of AgIO 3 , respectively. The AgIO 3 /AgCl/Nb 3 O 7 (OH)-25 % composite achieved a total organic carbon removal efficiency of 68.16 % for bisphenol A mineralization within 100 min under visible-light irradiation, which underscored the potential of AgIO 3 /AgCl/Nb 3 O 7 (OH) composites as effective photocatalysts for the efficient mineralization of organic pollutants. Finally, a reasonable charge transfer mechanism of the AgIO 3 /AgCl/Nb 3 O 7 (OH) composites for bisphenol A degradation were proposed.
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DOI
高影响因子
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