Construction of an In 2 O 3 /Bi 2 S 3 Z-Scheme Heterojunction for Enhanced Photocatalytic CO 2 Reduction.

Photocatalytic conversion of CO 2 to hydrocarbon fuel is a potential strategy to solve energy shortage and mitigate the greenhouse effect. Here, direct Z-scheme heterojunction photocatalysts (In 2 O 3 /Bi 2 S 3 ) without an electron mediator are prepared by a simple hydrolysis method. The In 2 O 3 /Bi 2 S 3 composite photocatalysts show greatly boosted photoactivity on CO 2 conversion to CO compared with the pristine In 2 O 3 and Bi 2 S 3 . The highest CO evolution rate of 2.67 μmol·g -1 ·h -1 is achieved by In 2 O 3 /Bi 2 S 3 -3, without any sacrificial agent or cocatalyst, which is about 3.87 times that of In 2 O 3 (0.69 μmol·g -1 ·h -1 ). The boosted photocatalytic performance of In 2 O 3 /Bi 2 S 3 composite catalysts can be ascribed to the establishment of a Z-scheme heterojunction, improving the photoabsorption and facilitating charge separation and transfer. This study provides a reference for designing and fabricating high-efficiency Z-scheme heterojunction photocatalysts for photocatalytic CO 2 reduction.