γ-Graphyne-modulated g-C3N4 nanostructures for boosted photocatalytic ammonia production

Abstract

Photocatalytic nitrogen reduction is a promising route for sustainable ammonia production, yet its efficiency remains limited by poor charge separation and sluggish N₂ activation. Herein, a two-dimensional g-C₃N₄ nanosheet/γ-graphyne (CNNS/GY) heterostructure is designed to modulate interfacial charge dynamics and strengthen nitrogen binding under illumination. The CNNS/GY interface delivers markedly improved charge separation and accelerates electron transfer, enabling an NH₄⁺ production rate of 803.67 µmol g⁻¹ h⁻¹, which is 2.45 times higher than that of pristine CNNS. DFT calculations reveal strong electronic coupling and rapid charge migration across the heterojunction, providing a mechanistic basis for the enhanced activity. This work demonstrates the effectiveness of γ-graphyne in tuning the interfacial electronic structure and highlights CNNS/GY heterostructures as a promising platform for advancing photocatalytic ammonia production.