In-situ construction of 2D/2D Bi₂MoO₆/BiOBr Z-scheme heterojunction for efficient photocatalytic CO₂ reduction to CH₃OH

Bi₂MoO₆ has drawn considerable attention in the field of photocatalysis owing to its excellent visible light response and photo-generated carriers transport ability. However, pure Bi₂MoO₆ suffers from the limited surface-active sites and poor photogenerated charge separation efficiency, resulting in unsatisfactory photocatalytic performance. Herein, the 2D/2D Bi₂MoO₆/BiOBr Z-scheme heterojunction photocatalysts were synthesized by in-situ hydrothermal growth of Bi₂MoO₆ on BiOBr. The optimized heterojunction catalyst, Bi₂MoO₆/BiOBr-40 % exhibited a CH₃OH yield of 6.21 μmol·g^-1·h^-1, which was twice that of the pure Bi₂MoO₆. Simultaneously, mechanism study by the band potential estimation and electron spin resonance (ESR) analysis evidenced that the enhanced activity was ascribed to the Z-scheme. This unique structure could enhance the spatial separation of electron-hole pairs, remain the strong redox ability. Moreover, the density functional theory (DFT) calculations were carried out to further expose the charge transfer mechanism of composites. This paper provided a novel approach for the design and manufacture of 2D/2D Z-scheme heterojunctions for energy conversion and environmental remediation.