Formation of reactive oxygen species upon interaction of Au/ZnO with H2O2 and their activity in methylene blue degradation

The aim of this work was to evaluate the catalytic activity of new Au-Fenton-like catalyst in degradation of methylene blue at ambient conditions. For this purpose gold nanoparticles were deposited on commercial ZnO and the material prepared in this way was characterized with N-2-adsorption and desorption, XRD, XPS and TEM. The catalyst ability to formation of reactive oxygen species (ROS) upon treatment with H2O2 was investigated with the use of o-phenylenediamine (OPD) and nitrotetrazolium blue chloride (NBT) reactants. Degradation of methylene blue was tracked by UV-vis and ESI-MS. The efficiency of dye mineralization was determined by the analysis of total organic carbon (TOC). On the basis of results obtained the role of different types of ROS in dye degradation was demonstrated. It was also demonstrated that the activity of Au/ZnO Fenton-like catalyst can be enhanced by visible light irradiation.