Heterostructured TiO₂/SnO₂ fibrillar nanocomposites were synthesized by using electrospinning technology with the setup composed of a syringe pump with two parallel syringes on it and a rotating collector. The heterojunctions were formed between TiO₂ and SnO₂ nanofibers fast and efficiently on a large scale, after the fiberizing carrier polyvinylpyrrolidone (PVP) on the as-spun composite nanofibers was burnt away at 500°C. The samples were characterized by scanning electron microscope (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), UV-vis diffuse reflection spectroscopy (DRS), and photoluminescence spectra (PL), respectively. The results indicated that two kinds of small nanofibers with different diameters were interconnected to form heterojunctions. Photocatalytic tests displayed that the heterostructured TiO₂/SnO₂ nanofibers exhibited a much higher degradation rate of methylene blue (MB), rhodamine B (RhB), and 4-chlorophenol (4-CP) than that of bare TiO₂ nanofibers or Evonik P25 under UV light irradiation. The enhanced photocatalytic activity could be attributed to the effective charge separation derived from the coupling effect of TiO₂ and SnO₂ nanocomposites.

Toluene, as a strong carcinogen, is widely found in the newly renovated rooms, shopping malls, and workshops. Photocatalytic oxidation has great superiority and application prospects for the degradation of toluene. However, low photocatalytic efficiency under visible-light irradiation arising from easy agglomeration of the solid catalysts hinders their photodegradation of toluene gas. In this work, heterostructured TiO₂/WO₃ photocatalysts were fabricated via an electrospinning technology combining the hydrothermal treatment. The special microstructure and composition allowed the photogenerated electrons quickly transfer from the TiO₂ nanofibers to the WO₃ nanorods, and thus effectively reduced the recombination of photogenerated electrons and holes. Coupling TiO₂ with the narrow band-gap WO₃ broadened the spectral response range of TiO₂. The heterostructured TiO₂/WO₃ photocatalysts exhibited a remarkably higher degradation rate of toluene gas than that of the bare TiO₂ nanofibers under visible-light irradiation. The photocatalysts were deposited onto the inner walls of the photoreactor and some nylon meshes. The meshes were also placed in the photoreactor in a direction perpendicular to the air flow. The meshes increased the contact between photocatalysts in solid phase and toluene in gas phase, and about 85.3% of the toluene had been degraded in the experimental conditions.

A hierarchically nanostructured TiO₂/WO₃ photocatalyst was synthesized via the subsequent hydrothermal treatment of electrospun TiO₂ nanofibers in the presence of tungstic acid. With a uniform WO₃ seed layer providing growth sites, the nucleation on the nanofibers was uniform, thus uniform WO₃ nanorods could be grown. The samples were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), UV-vis diffuse reflectance spectroscopy (DRS), photoluminescence spectra (PL), and Brunauer–Emmett–Teller (BET) method. The results indicated that the WO₃ nanorods with a diameter of about 40 nm and an average length of about 150 nm grew perpendicularly on the TiO₂ nanofibers. The crystallite size and specific surface area of the bare TiO₂ nanofibers were about 30 nm and 46.5 m² g⁻¹. The bare nanofibers are anatase phase with the average diameter of about 350 nm. The TiO₂/WO₃ heterostructures provide more accessible sites for both catalysis and adsorption, and the WO₃ nanorods possess a single crystal structure, which facilitates the migration of the photogenerated electrons. Photocatalytic tests show that the TiO₂/WO₃ heterostructures exhibit a remarkably higher degradation rate of organic pollutants than that of the bare TiO₂ nanofibers under visible light irradiation. The enhanced photocatalytic activity is attributed to the extended absorption in the visible light region and the effective charge separation derived from the coupling effect of TiO₂ and WO₃ nanocomposites.

In situ crystallization and growth of TiO₂ nanospheres between MXene layers, which exhibited an intense adsorption capacity and improved visible light photocatalysis.