Influence of Post Plasma Treatment on the Photocatalytic Activity of BiVO₄ Synthesized by Surfactant-Assisted Hydrothermal Method

Monoclinic bismuth vanadium oxide (BiVO4) has been synthesized by solvothermal method with the assistance of surfactant, and the prepared sample was treated with cold plasma in argon atmosphere. The hydrothermal temperature has been controlled at $80~^{\circ }$ C for 3 h in hot air oven. Four different surfactants were used, i.e., hexamine, PEG, PVA, and PVP. The prepared samples were subjected to argon plasma treatment for 20 min with glow discharge (GD) plasma technique. The morphology and structural properties have been analyzed with SEM and XRD, respectively. The optical property has been evaluated and showed higher absorbance in UV-visible light region. Photocatalytic activity of PEG added BiVO4 showed higher degradation for methylene blue dye, i.e., 56% in 180 min under visible light illumination. The result has been further supported by PL and Raman analyses. The BET analysis was used to detect the pore size and specific surface area of the samples. Furthermore, the reusability of the photocatalyst was evaluated by the stability test. The XPS and TEM analyses analyze the composition and crystalline nature of the prepared sample. The GCMS analysis of MB dye degradation has inferred the stability of the sample after dye degradation. The GCMS analysis and reusability test confirm the stability of PG after the photocatalysis process and confirm that the plasma treatment has helped in the stability of PG.