Approach to a pulse photoelectrocatalytic process for the degradation of organic pollutants

Ag-TiO2 composite film was supported on indium-tin oxide glass (ITO) by a dip-coating and subsequent photodeposition procedure. The composite film was employed as the photoanode for photoelectrocatalytic (PEC) degradation of Acid Orange II. The degradation efficiency for the PEC process on the Ag-TiO2/ITO electrode with a 0.8V anodic bias is significantly higher than that for a photocatalytic process on Ag-TiO2/ITO film or for a PEC process on a neat TiO2/ITO photoanode. A new PEC technology with a pulse anodic bias was also proposed in order to solve the problem of the loss of deposited Ag from the Ag-TiO2/ITO. It was found that the PEC process with a 4.2 V pulse anodic bias could much more efficiently degrade Acid Orange II than that with a constant anodic bias of 0.8 V or 4.2 V. Moreover, when the duration of the open and close circuit time was identical, the treatment efficiency was observed to be optimal. (C) 2003 Society of Chemical Industry.