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.