Ultrasound-Assisted Green Synthesis of Ag-Decorated ZnO Nanoparticles UsingExcoecaria agallochaLeaf Extract and Evaluation of Their Photocatalytic and Biological Activity

The present study deals with the synthesis of ZnO and Ag-ZnO nanoparticles using Excoecaria agallocha leaf extract under a controlled ultrasound cavitation technique. The characterization of the as-synthesized ZnO and Ag-ZnO nanoparticles (different molar concentration of Ag) were subjected to Fourier transform infrared spectroscopy (FTIR), X-ray diffraction analysis (XRD), UV-Visible Diffuse reflectance spectroscopy (UV-Vis DRS), Thermogravimetric analysis (TGA), N-2 adsorption-desorption isotherm (BET), scanning electron microscopy(SEM) and transmission electron microscopy (TEM). The photocatalytic performance of ZnO and Ag-ZnO nanoparticles as catalysts were studied for hazardous organic dyes such as methylene blue (MB) and rhodamine-B (Rh-B) under solar light irradiation. The degradation study follows pseudo-first-order kinetics. The effective degradation of MB was found to be 56.44 % (ZnO nanoparticles) and 98.44 % Ag-ZnO nanoparticles, respectively at 100 min at the molar ratio (0.25 : 1). Whereas, Rh-B shows 27.50 % (ZnO nanoparticles) and 98.83 % at the same molar ratio of Ag-ZnO nanoparticles at 80 min. Among the as-synthesized nanoparticles, Ag-ZnO at molar ratio 0.25 : 1 shows effective photocatalytic activity. Besides these as-synthesized nanoparticles exhibited good antimicrobial activity with an increase in Ag nanoparticles decorated into ZnO. A similar trend was observed in antioxidant and anti-inflammatory activity.