One-dimensional electrospun nanofibers of p-type NiO/n-type ZnO heterojunctions with different molar ratios of Ni to Zn were successfully synthesized using a facile electrospinning technique. X-ray diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive X-ray (EDX) spectroscopy, transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), UV-vis diffuse reflectance (DR) spectroscopy, resonant Raman spectroscopy, photoluminescence (PL) spectroscopy, and surface photovoltage spectroscopy (SPS) were used to characterize the as-synthesized nanofibers. The results indicated that the p-n heterojunctions formed between the cubic structure NiO and hexangular structure ZnO in the NiO/ZnO nanofibers. Furthermore, the photocatalytic activity of the as-electrospun NiO/ZnO nanofibers for the degradation of rhodamine B (RB) was much higher than that of electrospun NiO and ZnO nanofibers, which could be ascribed to the formation of p-n heterojunctions in the NiO/ZnO nanofibers. In particular, the p-type NiO/n-type ZnO heterojunction nanofibers with the original Ni/Zn molar ratio of 1 exhibited the best catalytic activity, which might be attributed to their high separation efficiency of photogenerated electrons and holes. Notably, the electrospun nanofibers of p-type NiO/n-type ZnO heterojunctions could be easily recycled without a decrease of the photocatalytic activity due to their one-dimensional nanostructural property.

Combining the versatility of the electrospinning technique and hydrothermal growth of nanostructures enabled the fabrication of hierarchical SnO(2)/TiO(2) composite nanostructures. The results revealed that not only were secondary SnO(2) nanostructures successfully grown on primary TiO(2) nanofiber substrates but also the SnO(2) nanostructures were uniformly distributed without aggregation on TiO(2) nanofibers. By adjusting fabrication parameters, the morphology as well as coverage density of secondary SnO(2) nanostructures could be further controlled, and then SnO(2)/TiO(2) heterostructures with SnO(2) nanoparticles or nanorods were facilely fabricated. The photocatalytic studies suggested that the SnO(2)/TiO(2) heterostructures showed enhanced photocatalytic efficiency of photodegradation of Rhodamine B (RB) compared with the bare TiO(2) nanofibers under UV light irradiation.

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.

Heterostructured SrTiO3/TiO2 nanofibers were fabricated by in situ hydrothermal method using TiO2 nanofibers as both template and reactant. The as-fabricated heterostructures composite included SrTiO3 nanocubes or nanoparticles assembled uniformly on the surface of TiO2 nanofibers. Compared with the pure TiO2 nanofibers, SrTiO3/TiO2 nanofibers exhibited enhanced photocatalytic activity in the decomposition of Rhodamine B (RB) under ultraviolet light. The enhanced photocatalytic activity of SrTiO3/TiO2 nanofibers could be attributed to the improvement of charge separation derived from the coupling effect of TiO2 and SrTiO3 nanocomposite.

The tubular nanocomposite with well-dispersed distribution of small gold nanoparticles (AuNPs) assembled on the inside and outside surfaces of silica nanotubes (SNTs) was fabricated by combining the single capillary electrospinning technique and an in situ reduction approach. The AuNPs/SNTs nanocomposite exhibited a good catalytic activity for reduction of 4-nitrophenol (4-NP).