Visible-light-driven photocatalytic properties of self assembled cauliflower-like AgCl/ZnO hierarchical nanostructures

Abstract

Self assembled cauliflower-like AgCl/ZnO hierarchical nanostructures were successfully synthesized using template-free chemical method. The as-synthesized materials were characterized by X-ray powder diffraction (XRD), field emission scanning electron microscope (FESEM), transmission electron microscopy (TEM), high resolution transmission electron microscopy (HRTEM), Fourier transform infrared (FTIR) spectroscopy, X-ray photoelectron spectroscopy (XPS), diffuse reflectance spectroscopy (DRS) and photoluminescence (PL). The characterization results revealed the formation of hierarchical AgCl/ZnO nanostructures with cauliflower-like morphology from the self assembly of 1D-nanorods. The photocatalytic activity of these hierarchical nanostructures was evaluated by the degradation of malachite green (MG) dye under visible light. As compared to other AgCl/ZnO nanostructures and bare ZnO, cauliflower like AgCl/ZnO hierarchical nanostructures (i.e., 30% AgCl/ZnO) exhibited higher photocatalytic activity upto 85% in 150min for the degradation of MG dye under visible light. Furthermore, the efficiency of 30% AgCl/ZnO was also investigated for the degradation of simulated dyebath effluent under solar light. A terephthalic acid-photoluminescence technique was used to detect OH radicals present in the photocatalytic process. LC–MS technique was also employed to identify the major intermediates in the photodegradation process of MG dye and the reaction pathway based on them was proposed.