Photocatalytic performance evaluation of visible active α-SnWO4 under different wavelengths

Abstract

In current scenario, researches on visible light driven metal oxide semiconductor photocatalysts have much attention due to its better photocatalytic performance under solar radiation. The commercialized mixed phase TiO2 (Degussa P25) with anatase and rutile phase shows enhanced photocatalytic performance under UV light irradiation compared to its pristine phases. However, the performance of Degussa P25 is limited to UV region due to wide band gap. Among various metal oxide semiconductor photocatalysts, stannous tungstate (SnWO4) has attained much attention due to its favorable band gap and polymorphs nature. In this study, SnWO4 in α-phase was prepared via solvothermal synthesis. The structural analysis confirms the high crystalline nature of the sample with crystallite size distribution in nano scale in α-phase. The photocatalytic performance of the sample was performed under different wavelengths such as red light (700–635 nm), green light (560–520 nm), blue light (490–450 nm) of visible irradiation and in white light (700–400 nm). The sample showed enhanced photocatalytical performance in all the wavelengths compared to DP 25. The sample out performed in 490–450 nm (blue light) compared to white and other wavelength irradiation. The enhancement in the photocatalytic performance of the sample under blue light may be ascribed to the synergetic effect of the absorption of the sample and the light source.