Abstract
This study demonstrates a new model for the treatment of azo dye wastewater by means of a heterogeneous photocatalytic degradation coupled with the homogeneous electrochemical Fenton reaction, and is called electrochemical photocatalytic (ECPC) degradation. Titanium dioxide-coated stainless steel (P 25 -TiO 2 /SS) mesh was employed as a photo-anode, covered with a uniform layer of P 25 -TiO 2 using electrophoretic deposition (EPD) in a 2-propanol suspension with 10 -4 M Zn(NO 3 ) 2 , at a deposition time of 1min. After annealing in air at 350°C for 1h, a crack-free, porous P25-TiO 2 layer of ca. 2.14μm was obtained. Potential bias was used to enhance the photocatalytic degradation of P25-TiO 2 /SS towards the target pollutant, azo dye orange G, in an undivided cell under ultraviolet light irradiation. Heterogeneous photocatalytic degradation and a homogeneous electro-Fenton reaction occurred in the system simultaneously when H 2 O 2 and Fe 2+ were electrochemically generated on the graphite cathode and photo-anode, respectively, under a suitable potential bias, enhancing the de-colorization and removal of total organic carbon. © 2013 Elsevier B.V.