2014 Volume 83 Issue 2 Pages 112-115
In order to realize the efficient conversion of solar light, the development of water-splitting systems that can efficiently use visible light have had major challenges for many years. Recently, a new type of photocatalysis system that can split water into H2 and O2 under visible light irradiation has been developed, by mimicking the two-step photoexcitation (Z-scheme) mechanism of natural photosynthesis in green plants. In this system, the water splitting reaction is broken up into two stages: one for H2 evolution and the other for O2 evolution; these are combined by using a shuttle redox couple (Ox/Red) in the solution. The introduction of a Z-scheme mechanism reduces the energy required to drive each photocatalysis process, extending the usable wavelengths significantly from that of conventional water splitting systems.
