RAPID CHEMICAL DECOLORIZATION REACTION OF HXWO3 THIN-FILMS AND REVERSIBLE OPERATION OF PHOTOCHROMISM OF WO3

Colored WO3 films were decolorized by the immersion in aqueous solutio ns containing oxidizing reagents such as Fe-2(SO4)(3) and H2O2. The ki netics of this reaction were examined by solving the diffusion equatio ns using numerical methods. The rate-determining step of the decoloriz ation reaction was found to be a surface reaction, not the diffusion o f the color center in the film.