Impact of reaction temperatures on the particle size of V2O5 synthesized by facile hydrothermal technique and photocatalytic efficacy in dye degradation

In this study, the influence of hydrothermal reaction temperatures on V2O5synthesized via a green facile mild hydrothermal method at six different reaction temperatures ranging from 100 to 200 °C, at steps of 20 °C and the physical properties the synthesized samples have been investigated. The x-ray diffraction pattern confirms the stable orthorhombic crystal structure of the synthesized samples at all reaction temperatures. The scanning electron microscopy and transmission electron microscopy images demonstrate the particle-like morphology, and these characterizations affirmed that the particles’ size became larger with the increase in the reaction temperatures. To study the functional groups, Fourier-transform infrared investigation has been employed. The bandgap of the synthesized samples has been estimated using UV-vis diffuse reflectance spectra and was found to vary from 2.08 to 2.15 eV, which implies their suitability for absorbing a significant amount of visible light. The photocatalysis of methylene blue with synthesized samples has been carried out to investigate the photocatalytic efficiency. Pure V2O5 synthesized at a lower reaction temperature (100 °C) possesses a lower bandgap and, accordingly, higher photocatalytic efficiency.