Effect of TiO2 Nanoparticles on Photochromism of WO3 Colloids1

WO3 and TiO2 colloids were synthesized by the hydrolysis technique and part of the TiO2 colloid was treated by means of the hydrothermal method. The photochromic performances of the resulting materials obtained via combining the WO3 colloid with the treated TiO2 colloid and the non-treated TiO2 colloid, respectively, are very different. The TiO2 colloid without hydrothermal treatment can effectively improve the photochromic performance of the WO3 colloid. The TiO2 nanoparticles were investigated in detail by XRD, TEM, surface photovoltage spectra (SPS) and field-induced surface photovoltage spectrometry (FISPS). The photochromism mechanism of WO3 colloid is discussed.