A vanadium-nickel oxynitride layer for enhanced electrocatalytic nitrogen fixation in neutral media

The application of transition-metal oxides (TMOs) in electrocatalytic nitrogen fixation still is hindered by their sluggish reaction kinetics and weak stabilization. In this work, a vanadium-nickel oxynitride (VNiON) layer is designed and synthesized on the corresponding oxide nanosheets to solve the above crucial issues. The first-principles kinetics analyses theoretically prove that the delocalized electron environment of VNiON enhanced pi backdonation, which is conducive to nitrogen absorption and activation. Experimentally, both the ammonia production rate (similar to 6.78 mu g h(-1) cm(cat.)(-2)) and faradaic efficiency (similar to 5.57%) of VNiON are enhanced by 2-fold relative to those of its corresponding oxide under neutral conditions. Meanwhile, the stability of oxide is enormously improved by introducing a VNiON layer. The mechanism of improving the nitrogen fixation performance of oxides is investigated. This work provides a novel strategy of constructing oxides with advantageous structures for extensive electrochemical applications.