Robust route to photocatalytic nitrogen fixation mediated by capitalizing on defect-tailored InVO4 nanosheets

作者：Yao, Shan; Liu, Jiawen; Liu, Fangyan; Wang, Biao; Ding, Ying; Li, Li^*; Liu, Chuan; Huang, Feng; Fang, Jingyun; Lin, Zhang; Wang, Mengye^*

来源：Environmental Science-Nano, 2022, 9(6): 1996-2005.

DOI：10.1039/d2en00205a

• OXYGEN VACANCIES
• WATER
• CONVERSION

Ammonia (NH3) is one of the fundamental pillars of the chemical industry nowadays. Compared with the traditional Haber-Bosch process that requires high energy consumption, the photocatalytic conversion of N-2 to NH3 under mild conditions is recognized as a sustainable and environmentally-friendly technology. However, the photocatalytic breakage of the N N bond in nitrogen (N-2) is a kinetically difficult process. Here, based on density functional theory (DFT) calculations, we report a novel and viable strategy to markedly boost the photocatalytic nitrogen fixation efficiency of InVO4 by tailoring its oxygen vacancies (V-O). InVO4 containing constructed V-O (V-O-InVO4) shows enhanced ammonia production rate, which can be attributed to the promoted N-2 adsorption, improved N-2 activation and decreased reaction barriers on the InVO4 surface, as evidenced by DFT simulations. Remarkably, the NH3 yield rate of the optimal V-O-InVO4 achieves up to 139.03 mu mol g(cat)(-1) h(-1), which is 5.33 times higher than that of InVO4 without additional V-O fabrication. The introduction of V-O largely suppresses the photogenerated charge carrier recombination and enhances visible light utilization, as revealed by photoluminescence and UV-vis absorption spectra, respectively, which correlate well with simulations. Notably, the low-valence V-4(+) induced by V-O is a more favorable active reaction site for N-2 adsorption, as revealed by the simulation results. This study not only provides a simple yet robust strategy to craft catalysts of high efficiency for photocatalysis, but also expands the mechanistic understanding about defect-mediated catalysis.

• 单位
  中山大学