Comparison of graphene oxide titania catalysts for their use in photocatalytic ozonation of water contaminants: Application to oxalic acid removal

Abstract In this work, three catalysts constituted by graphene oxide on titania prepared from different methods for their use in photocatalytic ozonation (PhOz) have been compared through their properties determined from well known characterization techniques (SBET, XRD, Raman, TEM, UVVisDRS, XPS, etc) and efficiency to remove oxalic acid as model end product of ozone processes. Comparison has also been made for transfer ozone demand and RCT and RHO,O3 parameters. By considering the reacting system as one irreversible gas–liquid-solid catalytic reaction, a kinetic study has been developed and activation energies of these reactions calculated for two out of three catalysts. Finally, kinetic modelling was also proposed and solved to calculate TOC and ozone concentrations in the gas leaving the reactor and dissolved in water for the three PhOz processes.