BiVO4/TiO2 heterojunction with rich oxygen vacancies for enhanced electrocatalytic nitrogen reduction reaction

Abstract

The large-scale production of ammonia mainly depends on the Haber-Bosch process, which will lead to the problems of high energy consumption and carbon dioxide emission. Electrochemical nitrogen fixation is considered to be an environmental friendly and sustainable process, but its efficiency largely depends on the activity and stability of the catalyst. Therefore, it is imperative to develop high-efficient electrocatalysts in the field of nitrogen reduction reaction (NRR). In this paper, we developed a BiVO4/TiO2 nanotube (BiVO4/TNT) heterojunction composite with rich oxygen vacancies as an electrocatalytic NRR catalyst. The heterojunction interface and oxygen vacancy of BiVO4/TNT can be the active site of N2 dynamic activation and proton transition. The synergistic effect of TiO2 and BiVO4 shortens the proton transport path and reduces the over potential of chemical reaction. BiVO4/TNT has high ammonia yield of 8.54 µg·h−1·cm−2 and high Faraday efficiency of 7.70% in −0.8 V vs. RHE in 0.1 M Na2SO4 solution.