Molybdenum doping effects on photochromic properties of WO₃ based composite films

Abstract

Mo-doped tungsten-based photochromic composite films were fabricated using a peroxoisopolytungstic acid methanol solution, peroxoisopolymolybdenum acid methanol solution, and transparent urethane resin. The non-doped composite films showed photochromic properties by UV–Vis light irradiation. The reaction rate constant was 2.68 × 10⁻² min⁻¹. The increasing Mo/W ratio in the film caused a blue shift of the absorption peak of the film. The reaction rate constants k of films with Mo/W rates of 0.1, 0.5, and 1.0 were 3.00, 4.23, and 3.53 × 10⁻² min⁻¹. Those values were larger than that of a non-doped film. All composite films showed a reversible photochromic property, which was the coloring and bleaching property.