Polyoxometalate-based materials for sustainable and clean energy conversion and storage

In order to relieve current energy crisis and the related environment pollutions arising with fossil fuel, the development and application of sustainable and clean energy, such as solar and hydrogen, is anticipated as a prospective issue. It is urgent and significant to develop and construct various energy storage and conversion technologies and materials for the generation and utilization of clean energy sources. Polyoxometalates (POMs), a class of metal oxide polyanion clusters, can serve as outstanding candidates in energy-related fields like electrocatalysis, rechargeable battery, photocatalysis, and proton conduction, based on their plentiful redox property, semiconductor-like feature and acidity. Here, the selected recent and significant advances in the development of POM-based materials for sustainable and clean energy conversion and storage are reviewed and summarized, and special emphases are shown to the applications of POMs as platforms for hydrogen production, water oxidation, carbon dioxide reduction, Li-ion rechargeable batteries, supercapacitors, proton-exchange membrane fuel cells, dye-sensitized solar cells and so on. The results obtained from different catalytic/energy storage systems have been compared and we try to give a better understanding on catalytic reactivity-catalysts structure correlation as well as to put a picture for the rational design of electrochemical electrodes.