Enhanced photocatalytic performance of zinc oxide nanostructures via photoirradiation hybridisation with graphene oxide for the degradation of triclosan under visible light: Synthesis, characterisation and mechanistic study

Abstract

Modification of ZnO nanoparticles with graphene oxide (GO) was carried out, and the obtained hybrid photocatalyst was used for the photodegradation of triclosan (TCS), which is an endocrine disrupting compound. Three different concentrations of GO were used to modify ZnO catalyst using the photoirradiation method and the resultant materials were characterised by SEM, TEM, Zeta Potential, FTIR, Raman, N2 Physisorption, HPLC, XRD and UV–vis spectrophotometry in order to determine their physico-chemical and photocatalytic properties. Regarding the photocatalytic evaluation, the results of the photodegradation process for TCS showed that GO acts as a trap of electrons improving the performance of ZnO even at low TCS concentration (8 mg.L−1) under visible light radiation. The GO-modified composite that contains the highest GO concentration (0.5% w/w) was the material that showed the best photocatalytic performance under visible light degrading up to 45% of the initial concentration of TCS and showed a reaction rate constant two times higher than pristine zinc oxide. This study allowed us to propose the photocatalytic mechanism of ZnO/GO hybrid photocatalysts to degrade TCS. In addition, this research contributes to the understanding of the enhancement of the efficiency of ZnO/GO hybrids and contributes to obtaining a photoactive material with promising use under natural light radiation in an Advance Oxidation Process to eliminate endocrine-disrupting compounds such as triclosan.