Polyoxometalates (POMs) are a class

Polyoxometalates (POMs) are a class of metal-oxide clusters thatconsist of addenda atoms such as tungsten and molybdenum,hetero atoms such as phosphorus and silicon, and oxygen combined with the addenda atoms and hetero atoms.[1] POMs exhibit fascinating chemical properties, such as high acidity, lowcorrosion, abundant electron storage, high stability againstredox reactions and heating, and a reversible redox colorchange, leading to their application in various fields, i.e., catalytic chemistry, analytical chemistry, biochemistry and materialchemistry.[1,2] In addition, POMs have a variety of structures,although they are based on Keggin- and Wells–Dawson-typestructures in many cases, resulting in an artificial molecular architecture with complicated phases.[3] Moreover, extensive attention has been paid to the synthesis of hybrid POMs withorganic moieties to tune their specific chemical properties.[4]