Synthesis and characterization of Ti/TiO2-Pt and Ti/TiO2/WO3 photoanodes for application in the degradation of VAT dyes by photoelectro-Fenton process

Abstract

A major challenge of the environmental concerns the development of efficient and environmentally friendly techniques for the removal of pollutants such as persistent, the vat dyes from effluents and surface waters. This project aims to explore the versatility of the technique of photoelectro-Fenton, testing a new type of reactor operating in a single compartment, where in addition to the cathode gas diffusion to be used for peroxide generation and Fe2+ regeneration, after *OH production in solution from the Fenton's reaction, would also be tested using photoanodes Ti/TiO2 of photoanodes doped with Pt or bicomponent Ti/TiO2/WO3 to the additional formation of *OH radicals on the anode surface. Therefore, this system aims to increase the efficiency of photo-Fenton process by using photoanodes irradiated with sunlight, combined with electro-Fenton process. For this, we intend to develop a highly efficient method for the degradation of industrial effluents containing dyes of the type simulated VAT; optimize the degradation process of VAT dyes, using factorial design and response surface methodology for the pilot-scale experiments; investigate the influence of the following operating parameters: temperature, electrolyte, flow rate, pH and initial concentration of Fe2+ as catalyst, kinetic studies for the degradation of selected dyes and determine/quantify the intermediate process of their mineralization, using chromatographic techniques and mass spectrometry; to propose routes of degradation of the dyes selected for the optimized conditions and to compare the efficiency of the Ti/TiO2 photoanodes doped with platinum and the bicomponents Ti/WO3/TiO2 against conventional anodes (Pt).