The preparation and properties study of photocatalytic nanocrystalline/nanoporous WO3 thin films

In this paper, a r.f. magnetron reactive method is used to prepare photocatalytic nanocrystalline/nanoporous WO3 thin films immobilized on glass plates. In order to investigate the effects of film structure and properties on photocatalytic reactivity, the structure, morphology, composition and bond of the thin films are studied with transmission electronic microscope (TEM), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). The light transmission of the films is measured by an UV spectrophotometer. The microstructure, oxygen vacancies and photocatalytic reactivity of the WO3 films have been proved as a function of deposition temperature. The structure of the films is converted from an amorphous state to a basically crystalline state with the increase of substrate temperature. The efficiency of photocatalytic degradation is improved as a result of increasing crystalline content and decreasing oxygen vacancies in the WO3 thin films. (C) 2002 Elsevier Science Ltd. All rights reserved.