ZnO flowers and graphene oxide hybridization for efficient photocatalytic degradation of o-xylene in water

Abstract The composition of exhausts from petroleum and paint industry involves xylenes and other components mixed with water. We achieved growth of ZnO particles to flowers through a solution-based method, and then graphene oxide was hybridized with ZnO flowers (GZ-hybrids) via microwave-irradiation. The solid-materials were characterized by the XPS, SEM, TEM, XRD, Raman, TG, UV–vis, and PL analysis. The crystal defects in ZnO were significantly reduced after the graphene oxide hybridization. The origin of better performance was explored by the cyclic voltammetry (CV), photo-electrochemical and electrochemical impedance spectroscopy (EIS) indicating that GZ-15% composite has 4.1 times higher photo-conversion efficiency attributed to the higher photo-current and lower (6.1 Ω) charge transfer resistance ( R CT ). Under UV-light illumination, after 45 min 70% of the initial o -xylene degraded when GZ-15% was used as the photo-catalyst. The comparison of o -xylene photo-degradation by the ZnO flowers and the GZ-15% showed that o -xylene has 3.8 times higher rate constant ( k ) of photo-catalytic-degradation under UV-light. This study provides necessary photo-catalytic oxidation (PCO) degradation details of o -xylene in water.