Enhanced photocatalytic performance of a two-dimensional BiOIO3/g-C3N4 heterostructured composite with a Z-scheme configuration

The construction of efficient photocatalytic systems has received considerable attention in the fields of water splitting and environmental remediation because of the great potential of these systems to solve the current energy-related and environmental problems. Herein, a two-dimensional BiOIO3/graphitic carbon nitride (g-C3N4) heterostructured composite bearing BiOIO3 nanoplates coupled with g-C3N4 nanosheets has been fabricated through a facile electrostatic self-assembly method. The as-prepared hybrids exhibit significantly improved photocatalytic activities toward 2,4,6-trichlorophenol (2,4,6-TCP) degradation and hydrogen evolution in water splitting under simulated solar light irradiation over those of bare g-C3N4. The apparent rate constant, k, for 2,4,6-TCP degradation (0.97 h(-1)) and the hydrogen evolution rate (56.4 h(-1)) of the BiOIO3/g-C3N4 composites are approximately 4.8 and 3.5 times higher, respectively, than those of g-C3N4. The outstanding activity of the hybrids arises from the Z-scheme charge transfer mode, which imparts a superior photogenerated carrier separation ability and strong redox capability. In this Z-scheme, the I-3(-)/I- redox pairs formed at the contact interface between BiOIO3 and g-C3N4 act as electron mediators. This work provides insight into the rational design of other two-dimensional Z-scheme composites with applications in solar energy conversion and environmental remediation.