Cyano group modified g-C_3N_4: Molten salt method achievement and promoted photocatalytic nitrogen fixation activity

摘要

Photocatalytic nitrogen fixation is one of the most green and sustainable methods for NH3 production under ambient conditions. Exploration of high-efficiency photocatalysts paves the way for realizing ammonia synthesis under ambient conditions. In this study, through the molten salt method retreatment approach, we design a cyano group modified g-C3N4 (CG-CN), which enables high-efficiency visible-light-driven nitrogen fixation in the absence of any organic scavengers and precious-metal cocatalysts. The cyano group (-C N) can promote the separation of photogenerated electron-hole pairs and simultaneously induce the nitrogen activation based on the strong electron-withdrawing character. The introduction of the cyano group results in a 12.8 times improved photocatalytic nitrogen fixation activity in sharp contrast to that of pristine g-C3N4 (CN). This work provides a feasible route to modify photocatalysts with functional surface group for nitrogen fixation.