Polyoxometalates-based functional materials in chemiresistive gas sensors and electrochemical sensors

The construction of chemiresistive gas sensors and electrochemical sensors for various application scenarios has greatly facilitated human progress and altered the course of history. Sensitive material design is crucial but difficult since it affects the sensitivity, detection limit, and selectivity of the various sensing systems. POMs with distinctive physical and chemical properties have been frequently used to construct functional materials in sensing systems. Particularly, the large-scale electron delocalization of POMs cluster-based constructions with natural nanometer size enables incomparable catalytic properties in efficient sensing. This review focuses on the design and synthesis of POMs-based functional materials in accordance with the remarkable properties of POMs for various sensing application scenarios, such as VOC sensing, humidity sensing, and the electrochemical sensing of inorganic anions/heavy metal cations, and biomolecules. Moreover, the relationship between the properties of POMs and various sensing mechanisms is emphatically discussed.