Hydrothermal Synthesis of GO/Pd/ZnO nanocomposite as Photocatalyst for Enhanced Photocatalytic Degradation of Azo Dye under Ultraviolet Light Irradiation

Abstract

The current research focuses on the hydrothermal production of a nanocomposite based on graphene oxide and Pd/ZnO nanorodes (GO/Pd/ZnO) for the photocatalytic degradation of Direct Red 23 (DR23) from textile effluent under UV light irradiation. XRD and SEM analyses revealed that the Pd/ZnO nanorods were anchored onto the crumpled-like characteristics of GO nanosheets in the GO/Pd/ZnO nanocomposite. The optical band gap values for ZnO nanorods, Pd/ZnO nanorods, and GO/Pd/ZnO nanocomposite were found to be 3.10, 3.01, and 2.95 eV, respectively, showing that the GO/Pd/ZnO nanocomposite exhibits a lower band gap than pure ZnO and Pd/ZnO nanorods. EIS measurements revealed a reduction in charge transfer resistance with the addition of Pd and GO nanosheets to the ZnO structure. The photocatalytic performance of photocatalysts for the degradation of 100 ml of 80 mg/l DR23 solution under UV light irradiation revealed that after 60 minutes of UV light irradiation, ZnO nanorods, Pd/ZnO nanorods, and GO/Pd/ZnO nanocomposite achieved 63.0%, 75.9%, and 84.7% DR23 degradation efficiency, respectively. The complete treatment is achieved after 145, 125, and 120 minutes of UV light irradiation on ZnO nanorods, Pd/ZnO nanorods, and GO/Pd/ZnO nanocomposite, respectively, indicating the high photocatalytic efficiency of GO/Pd/ZnO nanocomposite compared to other photocatalysts reported in the literature due to synergetic action between GO, Pd, and ZnO The produced photocatalysts in this study were found to be effective in treating the DR23 pollutant in textile wastewater.