Influence of Surface Morphology on Photocatalytic Activity of V2O5 Film Controlled via Applied Voltage and Annealing Temperature by Electrodeposition Method

Abstract V₂O₅ thin films were prepared by electrodeposition method with different applied voltages and different thermal annealed temperatures in the air condition. X-ray diffraction spectrum demonstrated that the film exhibits orthorhombic α-V₂O₅ with a preferential orientation along (001) plane. The V=O stretching and V-O-V bridging vibrations in VO₅ layered structure were shown in the Raman and FTIR spectroscopy. Wide broad emission of PL spectrum exhibits three band transitions at 410 nm, 530 nm, and 710 nm, which confirm the formation of a mid-gap state due to oxygen vacancies. The UV-Vis spectrum displayed a strong, broad absorption optical gap of 2.36 eV. Cross-sectional SEM images and EDS spectrum demonstrated films were uniform and adhered to the FTO substrate with an average thickness of 600 nm and a purity of chemical composition of the thin film. The applied voltage and annealing temperature significantly affected to the surface morphologies of the thin film, leading to the influence of photocatalytic performance. The annealed films achieve higher photocatalytic performance than compared with as-prepared samples of 55 % (k = 0.002 min⁻¹) and 44 % (k = 0.001 min⁻¹), respectively. The results demonstrated that both applied voltage and annealing temperature play an important role in controlling surface morphologies.