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

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 150 min 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.