Electro-photocatalytic Fenton Decolorization of Orange G Using Mesoporous TiO2/stainless Steel Mesh Photo-Electrode Prepared by the Sol-Gel Dip-Coating Method

Abstract

A photo-electrochemical process is a powerful and eco-friendly method for treating industrial wastewater. Electro-photocatalytic Fenton (EPF) was employed for orange G decolorization using two kinds of photo-electrodes with TiO2 film-coated stainless steel (SS) mesh. These photo-electrodes are prepared by a dip-coating method from the sol-gel-derived TiO2 sols incorporating with various amounts of P25+TiO2 powders (SGDC method). The single dip-coated electrode with the TiO2 sol containing 50 g/L P25 powders possesses similar crystallinity and decolorization performance to the four repetitive dip-coated electrodes with pure TiO2 sol. The kinetics of orange G decolorization using P25+TiO2 film electrode in photocatalytic (PC), electro-Fenton (EF) and EPF processes followed pseudo first-order kinetics model, and the EPF has the highest reaction rate. The efficiency of orange G decolorization achieves 78% via the EPF reaction for 3 h. The SGDC method using the TiO2 sol containing P25 powders not only enhances the TiO2 coating on the SS substrate, but also produces microcracks in the film, that facilitates the in-situ generation of ferrous ions and further induces the EPF reaction for an effective degradation of organic matter in wastewater.