Ultraviolet light induced photocatalytic behavior of hydrothermally synthesized tetragonal zircon type bismuth vanadate nanoparticles.

Abstract

The development of efficient and reusable photocatalyst for removal of azo dyes from wastewater remains challenging. Herein, tetragonal zircon-type BiVO4 nanoparticles were synthesized by hydrothermal route and evaluated for UV-driven degradation of Methyl Red (MR). XRD confirmed the tetragonal zircon phase, with an average crystallite size of 36.99 nm, while SEM-EDAX and HRTEM revealed porous hierarchical morphology and nanoscale particles with a 0.28 nm interplanar spacing corresponding to (112) plane. FTIR and Raman analyses confirmed the characteristics Bi-O and V-O vibrational features, and the optical band gap estimated as 2.70 eV. Under standard experimental conditions, BiVO4 nanoparticles achieved 83.8% degradation of Methyl Red after 120 min UV irradiation. After optimization of the catalyst dose, pH and initial dye concentration, the maximum degradation efficiency increased to approximately 91% at a catalyst dosage of 30 mg. The photocatalytic performance was influenced by solution pH, with maximum degradation observed at pH 3. The catalyst retained substantial activity over four consecutive cycles, demonstrating good reusability. These findings highlight hydrothermally synthesized BiVO4 nanoparticles as a promising reusable photocatalyst for UV-assisted degradation of azo dye contaminants.