Synthesis and characterization of composite catalysts comprised of ZnO/MoS2/rGO for photocatalytic decolorization of BR 18 dye

Abstract

In recent years, photocatalysis upon semiconductor-based hybrid materials has received much attention for the improved environmental effects and energy applications. Many good semiconductors such as ZnO have large bandgaps and suffer from fast charge recombination which hinders photocatalytic activity. One possible strategy to overcome this problem is introducing a narrow bandgap co-catalyst. Within the context of this study, triple hybrid nanostructures comprised of ZnO nanorods and MoS2/rGO (MG) co-catalyst were synthesized and characterized by various analytical methods. Accordingly, 25ZnO/75MG and 75ZnO/25MG hybrid materials were synthesized for two different MG co-catalyst comprised of 0.5% (named as 25ZnO/75MG1) and 5% (named as 25ZnO/75MG2) graphene oxide. The photocatalytic activities of the heterostructures and pristine ZnO nanorods were evaluated by the degradation of BR 18 dye, a common water pollutant mainly from the textile industry. When introduced with the co-catalyst, 25ZnO/75MG1 heterostructures achieved 100% degradation for 180 min. Furthermore, when the GO amount in the co-catalyst was increased to 5%, fully degradation of the dye solution was realized by 25ZnO/75MG2 in the first 30 min. These results are indicative of a positive synergistic effect of MoS2-rGO co-catalyst. Also, it is shown that increasing the GO amount is an effective approach to accelerate charge separation and electron transport properties.