Facile Microwave Production and Photocatalytic Activity of Bismuth Vanadate Nanoparticles over the Acid Orange 7

This work presents the synthesis, characterization, and multifunctional properties of bismuth vanadate (BiVO₄) nanoparticles prepared by a rapid and eco-friendly microwave-assisted method. X-ray diffraction (XRD) confirmed the formation of monoclinic scheelite-type BiVO₄ with an average crystallite size of ~19 nm. Transmission electron microscopy (TEM) revealed nearly uniform nanoscale morphology, while Fourier-transform infrared spectroscopy (FTIR) verified the presence of characteristic Bi–O and V–O vibrational modes. Nitrogen adsorption–desorption analysis (BET) indicated a specific surface area of 7.5 m²/g, consistent with a non-porous or weakly porous material. UV–Vis diffuse reflectance spectroscopy (DRS) determined a band gap of 2.55 eV, confirming visible-light activity. Photocatalytic performance was evaluated through the degradation of Acid Orange 7 (AO7) under visible-light irradiation. Effects of catalyst dosage and the initial concentration of pollutant Acid Orange 7 on photocatalytic degradation efficiency, were explained in details. Catalyst loading and initial dye concentration strongly influenced efficiency, achieving up to 77% removal within 120 minutes and well fitting to pseudo-first-order kinetics. In addition, the BiVO₄ nanoparticles exhibited notable antibacterial activity against Escherichia coli, attributed to synergistic effects of reactive oxygen species generation and direct surface interactions with bacterial membranes. These findings demonstrate that microwave-synthesized BiVO₄ is a multifunctional material with strong potential for integrated wastewater purification and disinfection applications.