UV-Induced Photocatalytic Reduction of Methylene Blue Dye in the Presence of Photochromic Tungsten Oxide Sols

In spite of the wide application of nanodisperse tungsten oxide (from photo- and electrochromic devices to biomedical materials), its physicochemical properties were studied insufficiently. In this work, we have performed a comparative analysis of photochromic and photocatalytic properties of polyvinylpyrrolidone-stabilized tungsten oxide nanoparticles prepared by ion exchange and precipitation from sodium tungstate solution. Reversible UV-induced reduction of Methylene Blue dye in the presence of photochromic tungsten oxide sol has been shown, the dependence of photochromic properties of tungsten oxide sols on sodium cation concentration in solution has been revealed.