Utilizing sunlight to split water into hydrogen and oxygen is an ideal way to convert solar energy into chemical energy and solve energy and environmental problems. In general, water splitting is hindered by the oxidation of water to oxygen which involves transfer processes of four electrons and four protons. To overcome this obstacle, an effective, robust and low-cost water oxidation catalysts (WOCs), and the anodes and photoanodes that perform fast oxygen evolution at low onset potentials, as well as benign conditions are highly desired. In this article we review recent advances in molecular water oxidation catalysts based on the first-row transition metal elements and advances in commonly used semiconductor materials such as α-Fe₂O₃, WO₃, and BiVO₄. Finally, we briefly discuss the assembly methods (covalent link, π-π stack, etc.) of molecular catalysts to electrodes and the classic examples of anode in catalytic oxidation of water.

molecular water oxidation catalysts  /  semiconductor  /  photoanode