Thermal Synthesis of Au-ZnO Nanoparticles for Application in Photocatalytic Degradation of Reactive blue 4 Dye in Aqueous Solution

Abstract

In the present study, zinc oxide (ZnO), gold (Au) and gold doped zinc oxide (Au-ZnO) nanoparticles (NPs) were successfully synthesized through thermal decomposition of [Au(L)Cl]Cl.H2O and [Zn(L)2].H2O complexes, where L is 7-[2-(BenzImidazolyl) Azo]-8-Hydroxy Quinoline (BIAHQ). Several characterization techniques such as XRD, FT-IR), UV–Vis DRS, SEM, TEM, AFM) were employed to investigate the phase structure, crystallite size, chemical structure, optical features, particles morphology and surface topography of as synthesized nanomaterials. The visible light photocatalytic activities of undoped ZnO and Au-ZnO NPs were compared for the decolorization of reactive blue 4 dye (RB4) aqueous solution. Factors influencing the photocatalytic degradation process including irradiation time, catalyst dosage, initial RB4 concentration and initial pH have been evaluated. The photocatalytic degradation results showed that the Au-ZnO NPs exhibited excellent photodecolorization efficiency towards cationic RB4 dye decolorization with 97.36 removal efficiency under visible light illumination for 160 min