Photocatalytic film prepared by Electrophoretic Sol-Gel Deposition - Challenges for the visible light activity

摘要

Electrophoretic sol-gel deposition was introduced to immobilize the TiO_2 photocatalyst. The raw solution for the deposition consisted of titanium tetra-isopropoxide, isopropyl alcohol and water. For the purpose of hydrolysis concentrated nitric acid was poured to this solution. Finally thus prepared solution was diluted at a constant ratio. The electrodeposition was performed by constant voltage mode. The working electrode, cathode, was made of stainless steel. Applied voltage between the cathode and anode was varied from 10V to 40V. The deposition could be terminated within few mins. Photocatalytic activity was evaluated by the decomposition rate for acetaldehyde gas. Coated films prepared in this way showed quite high photocatalytic activities without successive heat treatment. Moreover, the photocatalytic activity for visible light was confirmed for the film prepared by the electrophoretic sol-gel deposition by use of the solution containing boric acid. And similar photocatalytic activity for visible light was confirmed in the case of the prepared film on active carbon substrate.