Electrospun Nanofibers of ZnO-SnO2 Heterojunction with High Photocatalytic Activity

One-dimensional ZnO-SnO2 nanofibers with high photocatalytic activity have been successfully synthesized by a simple combination method of sol-gel process and electrospinning technique. X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy-dispersive X-ray (EDX) spectroscopy, nitrogen adsorption-desorption isotherm analysis, UV-vis diffuse reflectance (DR), and photoluminescence (PL) spectroscopy were used to characterize the as-synthesized nanofibers. The results indicated that the ZnO-SnO2 nanofibers with diameters of 100-150 nm consisted of wurtzite ZnO and rutile SnO2. The photocatalytic activity of the ZnO-SnO2 nanofibers for the degradation of rhodamine B (RB) was much higher than that of electrospun ZnO and SnO2 nanofibers, which could be attributed to the formation of a ZnO-SnO2 heterojunction in the ZnO-SnO2 nanofibers and the high specific surface area of the ZnO-SnO2 nanofibers. Notably, the ZnO-SnO2 nanofibers could be easily recycled without the decrease of the photocatalytic activity due to their one-dimensional nanostructural property.