CO2 reduction using oxynitrides and nitrides under visible light

Reduction of CO2 using a heterogeneous photocatalyst under visible light has been studied as a potential means to address the problems of global warming and the depletion of fossil fuels. Recently, hybrid photocatalysts constructed with a metal complex and a particulate semiconductor are of particular interest because of the excellent electrochemical (and/or photocatalytic) ability of the metal complexes for CO2 reduction and the high efficiency of the semiconductors for oxidation reactions, where the ultimate target of oxidation reaction is water oxidation to form molecular O2. This review article highlights our recent progress in the development of metal-complex/semiconductor hybrid materials for visible-light CO2 reduction with a focus on oxynitride and nitride materials as the semiconductor component.