Effect of Calcination Temperature on Photocatalytic Degradation Performance of Electrospun β-Ga₂O₃ Nanofibers.

In the present work, Ga₂O₃ nanofibers were successfully synthesized by electrospinning a solution of polyvinylpyrrolidone (PVP) and gallium nitrate, followed by temperature-controlled calcination treatment of the as-spun PVP and gallium nitrate composite nanofibers. The crystallinity and crystallite size of the Ga₂O₃ nanofibers can be readily controlled by varying the calcination temperature. From the physicochemical analysis results of the synthesized nanofiber, it was found that the nanofiber calcined at a higher temperature showed a higher crystallinity and a larger crystallite size. The photocatalytic degradation results on rhodamine-B (Rho B) revealed that the photocatalytic activity of the Ga₂O₃ nanofibers can be improved by optimizing the conflicting characteristics, crystallinity and crystallite size, through the control of the calcination temperature. The photocatalytic activity of a nanofiber calcined at 800 °C for the degradation of Rho B under ultraviolet irradiation exhibits 2.39 and 1.16 times higher than that of nanofibers synthesized at 700 °C and 900 °C, respectively, which is ascribed to relatively efficient charge transfer and dye molecule adsorption by its proper crystallinity and crystallite size.