Preparation of Porous F-WO_(3)/TiO_(2) Films with Visible-Light Photocatalytic Activity by Microarc Oxidation

摘要

Porous F-WO_(3)/TiO_(2) (mTiO_(2)) films are prepared on titanium sheet substrates using microarc oxidation (MAO) technique. The X-ray diffraction patterns show that visible-light (Vis) enabling mTiO_(2) films with a very high content of anatase TiO_(2) and high loading of WO_(3) are successfully synthesized at a low applied voltage of 300 V using electrolyte contenting NaF and Na_(2)WO_(4) without subsequent heat treatment. The cross-sectional transmission electron microscopy micrograph reveals that the mTiO_(2) films feature porous networks connected by many micron pores. The diffused reflection spectrum displays broad absorbance across the UV-Vis regions and a significant red shift in the band gap energy (approx2.23 eV) for the mTiO_(2) film. Owing to the high specific surface area from the porous microstructure, the mTiO_(2) film shows a 61percent and 50percent rate increase in the photocatalytic dye degradation, as compared with the N,C-codoped TiO_(2) films under UV and Vis irradiation, respectively.