Immobilization of Fe2O3 on perlite for photo-Fenton degradation of methylene blue

Abstract Photo-Fenton catalysts with floating features based on the immobilization of Fe2O3 particles on the surface of perlite granules were synthesized by a simple precipitation-annealing method. The effects of annealing temperature on the crystal structure, phase composition, morphology, surface area, surface functional groups, and surface atomic composition of the prepared catalysts were investigated by powder X-ray diffraction, field emission scanning electron microscope, nitrogen adsorption-desorption, Fourier transform infrared spectroscopy, and low voltage energy-dispersive X-ray spectroscopy. The catalytic activity was evaluated via the degradation of methylene blue in the presence of oxalic acid under UVA light and visible light. Immobilization of Fe2O3 on the perlite surface resulted in photo-Fenton catalytic activity for all samples, attributable to the formation of the hematite phase and the presence of surface Fe species. Owing to the low density of perlite, all catalysts float on the surface of the solution, which allows them to be easily separated. GRAPHICAL ABSTRACT