Green Fabrication of Ag-Functionalized WO3 Nanostructures: Advancing Visible-Light Photocatalysis and Biodiesel Production

Abstract

In this study, Asystasia gangetica leaf extract was employed as a green precursor for the synthesis of silver-functionalized tungsten trioxide nanoparticles (Ag-WO3 NPs) via the solution combustion method. The synthesized nanoparticles were characterized using X-ray diffraction (XRD), Fourier-transform infrared (FTIR) spectroscopy, UV-visible spectroscopy, and scanning electron microscopy (SEM) to investigate their crystalline structure, functional groups, optical properties and surface morphology, respectively. The visible-light driven photocatalytic performance of Ag-WO3 NPs was evaluated using crystal violet (CV) as a model dye and an effluent sample collected from a silk-dyeing unit. The results demonstrated 88% degradation of CV within 6 h at pH 9.2 and 85% degradation of the effluent within 8 h at pH 6.8 under visible-light irradiation. The synthesized Ag/WO₃ NPs were tested as transesterification catalysts for converting waste sunflower oil into methyl esters, extending their potential use beyond photocatalysis to wastewater treatment and biodiesel production.