Sulfate Functionalized Fe2O3 Nanoparticles on TiO2 Nanotube as Efficient Visible Light-Active Photo-Fenton Catalyst

Abstract

Morphology and crystal structure usually play important roles in improving catalytic properties and activity of catalysts. In this study, sulfate functionalized Fe2O3/TiO2 nanotubes as visible light-active heterogeneous photo-Fenton catalysts were synthesized by solvothermal and acid impregnation method. The nanoparticles supported hybrids materials with one-dimensional nanostructures were characterized by Brunauer–Emmett–Teller, X-ray diffraction, transmission electron microscopy, X-ray photoelectron spectroscopy, and Fourier transform infrared spectroscopy, which revealed an intact tubulous morphology structure, high crystallinity, and large surface area. Optical properties were examined by UV spectroscopy and showed a significant reduction in band gap. It was found that the hydrothermal temperature in the synthetic process had an obvious effect on the morphology and structure of prepared samples with transformation from nanotubes to nanowires. The morphology control of support led to Fe2O3 nanoparticles highly dispersed in porous structure of TiO2 nanotubes, which was beneficial to the transfer of photogenerated electrons between (101) planes in anatase TiO2 and (113) planes of α-Fe2O3. After the sulfate groups were introduced into the structure of Fe2O3/TiO2 nanotubes, the photocatalytic performance was enhanced due to the enlargement of light absorption and surface acidity. The prepared sulfated Fe2O3/TiO2 nanotubes with strong synergistic effects had a remarkable catalytic activity in the wide pH range of 4.0–10.0 and exhibited an excellent stability and reusability, which presented a good potentiality for application in environmental and energy fields.