Band engineering design of g-C3N4-BiOClxBr1-x direct Z-scheme heterojunctions with remarkable enhancement of photocatalytic performance

A series of g-C3N4-BiOClxBr1-x direct Z-scheme heterojunctions were successfully constructed by direct pyrolysis and solvothermal routes. Direct Z-scheme system not only efficiently separated the charge carriers, but also retained their strong oxidizing and reducing capacity. In addition, the light absorption of BiOClxBr1-x solid solutions extended into the visible light region with the increase of bromine content. Benefiting from the joint utilization of heterojunction construction and solid solution fabrication strategies, g-C3N4-BiOCl0.5Br0.5 (g-C5B5) heterojunction presented notably improved photocatalytic activity with the apparent rate constant of 0.1698 min(-1). The synergistic effects were mainly expounded as the enhanced visible-light response, promoted separation of electron-hole pairs and optimized redox potentials of charge carriers, which was further verified on the basis of photocatalytic experiment and a series of characterization. This work provides a novel insight to design high-efficiency photocatalysts with reasonable structure for removing environmental pollutants and converting solar energy.

Automated summary

A series of g-C3N4-BiOClxBr1-x direct Z-scheme heterojunctions were successfully constructed, leading to enhanced visible-light response and improved photocatalytic activity. This work provides insights for designing high-efficiency photocatalysts with reasonable structure.