Tungsten trioxide powder with the novel morphology was prepared via the hydrothermal method with oxalic acid as the organic inducer, the structure and shape of which were detected by X-ray diffraction (XRD), scanning electron microscopy (SEM) and BET. Furthermore, photochromic properties of the as-prepared powder samples were tested by an ultraviolet-visible spectrophotometer combined with a color difference meter. The corresponding results indicated that the induced product was still hexagonal WO3, made up of regularly spindle particles with 200-300 nm in length and 30-50 nm in width. The ratio of the length and width was from 4 to 10. Moreover, the special morphology improved its absorptive capacity to the excitation light source, resulting in its high photochromic properties.
SHEN Yi1, ZHU Hua1, HUANG Rong1, ZHAO Li2 & YAN ShaNing1 1 Faculty of Material Science and Chemical Engineering, China University of Geosciences, Wuhan 430074, China