Photocatalytic overall water splitting by Z-scheme g-C3N4/BiFeO3 heterojunction

Solar water splitting by photocatalysis in the absence of sacrificial agent has been identified as a promising approach to produce green hydrogen. Increasing photocatalytic efficiency is the core issue in this process. Forming heterojunctions is one potential solution to improve photoactivity. Herein, we successfully synthesized several g-C3N4/BiFeO3 composites containing different mass ratio of g-C3N4 by an uncomplicated and cost-effective method. The composite samples exhibited remarkably enhanced photocatalytic performance compared with the bare BiFeO3 and g-C3N4. The highest hydrogen production rate obtained is similar to 160.75 mu mol h(-1) .g(-1) under UV irradiation and similar to 23.31 mu mol h(-1).g(-1) under visible light irradiation. This enhanced photocatalytic activity is attributed to the synergistic effect of the junction and Z-scheme charge transfer mechanism between BiFeO3 and g-C3N4 , which can effectively accelerate the separation of photogenerated electron-hole pairs and also capability of carrying out redox reaction. (C) 2019 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.