Efficient photocatalytic CO2 reduction achieved by constructing Bi4O5Br2/Bi-MOF Z-scheme heterojunction

Building efficient catalysts is an urgent issue in the field of photocatalytic CO2 reduction, and Z-scheme heterojunction structures can availably suppress the recombination of photo generated carriers and improve photocatalytic performance. This study successfully prepared a new type of Bi4O5Br2/Bi-MOF composite photocatalyst through self-assembly method. After 5 h of simulated sunlight exposure, the optimized sample 50-Bi4O5Br2/Bi-MOF photocatalytic reduction of CO2 to CO efficiency (23.78 μmol·g−1·h−1) was 5.09 times higher than pure Bi4O5Br2, and the CH4 yield (5.39 μmol·g−1·h−1) was 2.52 times that of pure Bi-MOF. In addition, in the cyclic experiment, the catalyst had high stability and reusability. The Z-scheme charge transfer mechanism was confirmed through band structure analysis, Electron spin resonance (ESR), Ultraviolet photoelectron spectroscopy (UPS) and other related characterizations. This work provided an important strategy for designing efficient Z-scheme heterojunction photocatalysts.