Facile synthesis of Se/BiVO4 heterojunction composite and evaluation of synergetic reaction mechanism for efficient photocatalytic staining of organic dye pollutants in wastewater under visible light

Abstract

The novel Se/BiVO4 heterojunction nanocomposites were successfully synthesized by facile hydrothermal method. The physical and chemical properties of photocatalyst samples were characterized by XRD, SEM, EDS, FTIR, XPS, BET, UV–Vis DRS, PL, EIS, and EPR techniques. The photocatalytic activity of Se/BiVO4 was measured for the degradation of pollutant, Crystal Violet (CV) organic dye. It was observed that Se/BiVO4 photocatalyst with mole ratio 2:1 exhibited superior degradation of 98.69% of CV dye within 50 min using visible light. The electron paramagnetic resonance spectra show that OH· radical being strong oxidizing agent is a major active agent species in the degradation of CV over Se/BiVO4@(2:1). The tremendous photo memory and stable nature of the Se/BiVO4 photocatalysts endorsed their usage as cost-effective photocatalysts for practical applications. Based on these results, the enhanced photocatalytic activities could be owed to the improved optical absorption and efficient separation and migration of photo-created charge carriers with the decreased recombination of electrons–holes resulting from composite effect. The possible photocatalytic mechanism of Se/BiVO4 was critically discussed based on the experimental results.