▎ 摘　　要

Electrochemical N-2 reduction is developing as an appealing carbon-neutral strategy for NH3 artificial synthesis but seriously influenced by requiring high-efficiency electmcatalysts for the N-2 activation at ambient conditions. Here, we reported that defective-rich ZnS nanoparticles supported on reduced graphene oxide (DR ZnS-rGO) acts as a high-efficiency electmcatalyst for ambient N-2-to-NH3 conversion with excellent selectivity. In 0.1 M HCl, such DR ZnS-rGO presents a large NH3 yield of 51.2 mu g h(-1) mg(cat)(-1). (-0.15 V vs. reversible hydrogen electrode, RHE) and a high faradic efficiency of 28.2 % (-0.10 V vs. RHE), as well as high electrochemical and structure stability. Isotopic labelling samples experiments reveal that the synthetic NH3 directly arise from the supplied N-2. Density functional theory calculations demonstrated that the engineering S vacancies in DR ZnS-rGO not only provide reaction sites for N-2-to-NH3 conversion but activate of N-2 molecules.