2D boron nitride supported Cu2O promotes photocatalytic nitrogen fixation at normal temperature and pressure

Abstract

Boron nitride (BN) semiconductors, as graphene analogues, have attracted extensive attention in the field of photocatalysis due to their unique physical and chemical properties. In this study, a low-cost visible light responsive semiconductor photocatalyst, Cu₂O/BN, was used to form a unique heterostructure. The optimum ammonia yield of 20 wt% Cu₂O/BN (BNC2) under ambient conditions and in pure aqueous solution without a sacrificial agent is 62.2 μmol g⁻¹ h⁻¹, which is 9 times that of pure Cu₂O and 6 times that of pure BN. Photoluminescence (PL) spectra show that the Cu₂O/BN heterojunction is favorable for photogenerated electron hole separation. Electron spin resonance (ESR) results show that Cu₂O/BN has a higher oxygen vacancy content than pure Cu₂O. The mechanism of nitrogen reduction was explained using in situ infrared spectroscopy. This study provides a new research prospect for the photocatalytic nitrogen fixation of BN and Cu₂O materials.