Constructing direct Z-scheme heterojunction g-C3N5/BiOBr for efficient photocatalytic CO2 reduction with H2O

Abstract

Photocatalytic CO2 reduction with H2O into hydrocarbon fuels represented an appealing approach to mitigate the energy crisis and greenhouse effect. However, isolated BiOBr (BOB) usually possessed rapid recombination of photogenerated carriers and low solar energy utilization, which restricted the elevation of photocatalytic performance. Herein, a direct Z-scheme porous N-rich g-C3N5/BiOBr (pCN/BOB) photocatalyst was fabricated through in situ hydrothermal approach. Furthermore, benefiting from Z-scheme heterojunction and tight surface contact, the pCN/BOB exhibited remarkably enhanced photoreduction ability of CO2 under visible light. Specially, 10% pCN/BOB exhibited the optimized photocatalytic performance for CH3OH production (3.08 μmol·g−1·h−1), approximately four times that of isolated BOB, whose improved photocatalytic performance was ascribed to the separation of photoinduced carriers by Z-scheme heterojunction and intimate interface contact. Meanwhile, the photogenerated charge transfer mechanism was calculated by work function calculation. Moreover, pCN/BOB exhibited good reusability for photocatalytic CO2 reduction. This work provided an efficient strategy for designing and preparing the high-efficiency photocatalysts for converting solar energy.