Cyano group modified g-C₃N₄: Molten salt method achievement and promoted photocatalytic nitrogen fixation activity

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 ([sbnd]C[tbnd]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.