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

This work reports the rapid aqueous microwave-assisted synthesis of monoclinic scheelite BiVO4 nanoparticles and their behavior under visible light. X-ray diffraction (XRD) confirms phase-pure BiVO4 with an average crystallite size of ~19 nm, consistent with transmission electron microscopy (TEM) observations, while N2 sorption yields a BET surface area of 7.5 m2/g. UV–Vis diffuse reflectance spectroscopy (DRS) indicates a direct band gap of 2.55 eV. We evaluated the effects of catalyst dosage and initial Acid Orange 7 (AO7) concentration on visible-light degradation efficiency. Up to 77% removal was achieved within 120 min, with kinetics following a pseudo-first-order model (R2 ≈ 0.970–0.996). Under the tested conditions, BiVO4 also exhibited a modest antibacterial effect against Escherichia coli (~0.5 log reduction). These findings demonstrate that microwave-synthesized BiVO4 is a multifunctional material and provides a quantitative baseline for practical wastewater treatment studies under visible light.