Investigation on the photoconductivity of polyoxometalates

Abstract

Polyoxometalates (POMs), a class of molecular metal-oxo cluster compounds based mainly on Mo, W, and V elements, have shown superior physicochemical properties and various applications. In this study, we investigate the photoconductivity of Keggin-type tungsten-series POMs, H₃PW₁₂O₄₀, Na₃SiW₁₂O₄₀, Na₃GeW₁₂O₄₀ and Na₆H₂W₁₂O₄₀, considering that photoconductivity can be closely related to the potential applications in sensors, photodetectors, photovoltaics, and photocatalysis. The results from the photoconductivity measurements demonstrate that the photoconductive performance of the POM is clearly dependent on the type of POM. Moreover, H₃PW₁₂O₄₀ exhibited a much higher photocurrent than the others; this may be due to the different photogenerated electron–hole recombination rate and photogeneration efficiency of the POMs. Furthermore, H₃PW₁₂O₄₀ exhibited a good sensing performance for ethanol gas.