Boosting N2 photoreduction using a ZnO@HCuxS composite with high activity and easy recovery grown on a copper mesh

Abstract

Accelerating the separation and migration of photogenerated carriers is the key to improve the efficiency of the photocatalytic nitrogen reduction reaction (NRR). Herein, ZnO@HCu_xS-cm (1 < x < 2) with a three-dimensional micro-nanostructure on a copper mesh was constructed, which showed good N₂ photoreduction performance in a liquid membrane reactor. The ammonia yield of the ZnO@HCu_xS-cm sample reached 89.4 μmol cm⁻² h⁻¹ under simulated visible light without any sacrificial reagent, 9.4 and 5.2 times higher than that of the original ZnO-cm and Cu_xS-cm. The characterization results show that the enhancement of the NRR activity of the photocatalyst is due to acid etching assisted vacancy engineering and interface engineering. The synergistic effect of sulfur vacancies (SVs) and p–n heterojunctions provides rich active sites, rapid photogenerated electron–hole transfer and separation paths for photocatalysis. In addition, the perfect match of a liquid membrane reactor and a supported catalyst strengthens the gas–liquid mass transfer and promotes the contact between the reactants and excitons in the reaction process. This study presents a potential guiding method for the design of high-efficiency photocatalyst and photoreaction systems.