Regulating surface state of WO3 nanosheets by gamma irradiation for suppressing hydrogen evolution reaction in electrochemical N2 fixation

Realizing the reduction of N-2 to NH3 at low temperature and pressure is always the unremitting pursuit of scientists and then electrochemical nitrogen reduction reaction offers an intriguing alternative. Here, we develop a feasible way, gamma irradiation, for constructing defective structure on the surface of WO3 nanosheets, which is clearly observed at the atomic scale by high-angle annular dark field scanning transmission electron microscopy (HAADF-STEM) The abundant oxygen vacancies ensure WO3 nanosheets with a Faradaic efficiency of 23% at -0.3 V vs. RHE. Moreover, we start from the regulation of the surface state to suppress proton availability towards hydrogen evolution reaction (HER) on the active site and thus boost the selectivity of nitrogen reduction.