Jia Kangkang, Bai Yajie, Wang Xiaohong, Yang Lili, Yang Pengpeng, Bai Hongye, Xu Guohai, Fan Weiqiang
School of Chemistry and Chemical Engineering, Jiangsu University, Zhenjiang 212013, PR China.
College of New Energy, Ningbo University of Technology, Ningbo 315336, China.
Inorg Chem. 2025 Mar 3;64(8):3959-3968. doi: 10.1021/acs.inorgchem.4c05229. Epub 2025 Feb 21.
Photoelectrochemical nitrate reduction has been a promising method for ammonia (NH) production under normal temperatures and neutral conditions. However, hydrogenation is a key process in the selective production of NH during nitrate reduction; therefore, inducing the active hydrogen for nitrate hydrogenation and inhibiting hydrogen production are a noteworthy problem. In this study, BiVO/CuS (BVO/CS) heterostructure has been constructed for a photoelectrochemical nitrate reduction reaction (PEC NIRR). The introduction of CuS optimizes the electron-transfer ability and enhances the surface catalytic kinetics of BVO/CS. At the same time, the presence of sulfur vacancies on the surface promotes the adsorption and activation of nitrate, realizes the splitting of HO, and successfully generates abundant hydrogen radicals (H*). The generated H* is effectively utilized in the hydrogenation of NIRR. The NH yield and selectivity of optimal BVO/CS reach 30.55 μg h cm and 43.8%, respectively, which are 2.65 and 2.39 times that of bare BVO. Therefore, this work determines the key role of H* for nitrate hydrogenation, providing a novel strategy for boosting PEC NIRR. CuS/BiVO was successfully fabricated for photoelectrochemical nitrate reduction. Sulfur defects enabled the generation of hydrogen radicals, which effectively promoted nitrate hydrogenation and NH production.
光电化学硝酸盐还原一直是在常温中性条件下生产氨（NH₃）的一种很有前景的方法。然而，氢化是硝酸盐还原过程中选择性生产NH₃的关键步骤；因此，诱导用于硝酸盐氢化的活性氢并抑制氢气生成是一个值得关注的问题。在本研究中，构建了BiVO₄/CuS（BVO/CS）异质结构用于光电化学硝酸盐还原反应（PEC NIRR）。CuS的引入优化了电子转移能力并增强了BVO/CS的表面催化动力学。同时，表面硫空位的存在促进了硝酸盐的吸附和活化，实现了H₂O的分解，并成功产生了大量氢自由基（H*）。生成的H有效地用于NIRR的氢化反应。最佳BVO/CS的NH₃产率和选择性分别达到30.55 μg h⁻¹ cm⁻²和43.8%，分别是裸BVO的2.65倍和2.39倍。因此，这项工作确定了H在硝酸盐氢化中的关键作用，为促进PEC NIRR提供了一种新策略。成功制备了用于光电化学硝酸盐还原的CuS/BiVO₄。硫缺陷能够产生氢自由基，有效促进硝酸盐氢化和NH₃生成。
