Application of Polyoxometalates in Chemiresistive Gas Sensors: A Review

Abstract

Polyoxometalates (POMs) are a series of molecular metal compounds based on W and Mo elements, exhibiting excellent physical and chemical properties. POMs have been widely used in the fields of photoelectric materials, catalytic materials, and coordination chemistry. In recent years, POMs have emerged in the field of chemiresistive gas sensors. They can work as electron acceptors and improve the gas-sensing performance of traditional sensing materials by means of capturing electrons from semiconductors, separating electrons produced by light excitation or thermal excitation and delaying the recombination of electrons and holes. So far, the highest sensing sensitivity response of POMs-based chemiresistive gas sensor is 231 to 1 ppm NO2 gas. In this review, an overview is investigated about how POMs have evolved as sensing materials in gas sensors. First, some POMs and POMs-based sensing materials in recent years are introduced and classified. After that, brief analyses for each kind of sensing materials are provided. Then we compare the reported POMs-based sensors in different sensing parameters. Finally, the future outlooks are discussed on the basis of the current developments. This work is the first comprehensive overview of POMs-based chemiresistive gas sensors. This work can provide valuable information for developing high-performance POMs-based gas sensors.

Review and Perspective: Gas Separation and Discrimination Technologies for Current Gas Sensors in Environmental Applications

“…Both POMs and CQDs can be designed to detect a targeted gas, including VOCs, nitrogen oxides, and carbon monoxide, with high sensitivity and selectivity. Their applications have been reviewed by Tang et al and Song et al, respectively.…”

Polyethylenimine Deposited on Phosphomolybdic-Acid-Loaded Polyacrylonitrile Membranes for Enhanced Dye/Salt Separation

“…Polyoxometalates (POMs) are a class of molecular metal-oxide anions composed of transition metals (mostly W, Mo, and V) and oxygen atoms, possessing eminent redox activity, strong charge property, and bactericidal activity, and have brought brilliant advantages into catalysis, medicine, and sensors. − In addition, due to the flexible coordination ability, hydrophilic POMs are accessible to be assembled to the membrane substrate for better wettability . Meanwhile, the strong negative charge of POMs is also beneficial to prevent the adhesion of negatively charged foulants onto the membrane surface, which is favorable for the antifouling performance of the membrane .…”

PEDOT Films Doped with Titanyl Oxalate as Chemiresistive and Colorimetric Dual-Mode Sensors for the Detection of Hydrogen Peroxide Vapor

“…This is because their response and sensitivity are highly dependent on factors such as the temperature, reactions at the modified surface interface, and micro- or nanostructure regulations, etc. [ 23 , 24 , 25 ]. Therefore, it is necessary to develop direct detection technologies targeting HPV under ambient conditions, relying on nonenzymatic organic probes and simple electric signal models.…”