Photocatalytic overall water splitting with dual-bed system under visible light irradiation

Photocatalytic overall water splitting has been demonstrated with WO₃ for oxygen producing photocatalyst (OPC), and Rh-doped SrTiO₃ for hydrogen producing photocatalyst (HPC) in a simulated dual-bed system under visible light irradiation (λ ≥ 400 nm). The Fe³⁺/Fe²⁺ redox couple was chosen as the most effective electron mediator between OPC and HPC. The overall performance of the dual-bed system was limited by the low activity of HPC, and thus the activity of HPC should be increased to improve the overall performance. For overall water splitting reaction in a dual-bed system, the conduction band of OPC must be more negative than the redox potential of the electron acceptors and the valence band of HPC must be more positive than the redox potential of the electron donors.