Photocatalytic degradation performance of oxytetracycline (OTC) was investigated in aqueous solution using Fe2O3–TiO2 nanopowders under UV and visible light, respectively. Compare with pure TiO2, the Fe2O3–TiO2
nanopowder had improved photocatalytic activity under visible light, while had a bit decrease under UV light. Photoluminescence (PL) spectrum measurement, ·OH radical test and trapping experiments were carried out to investigate the photocatalytic mechanism. Under UV light, photogenerated
electrons–holes can transfer from TiO2 to the conduction band and valence band of Fe2O3, respectively, and further participated in the degradation of OTC, thus both O2·− and holes are the main active species in this case. Under
visible light, Fe2O3 was activated and yield charge carriers, then the photogenerated electrons immigrated to the trapping site of TiO2, the photogenerated holes accumulate in the valence band (VB) of Fe2O3 was the major active species
reacted with OTC.
The degradation behavior of oxytetracycline (OTC) in aqueous solution using Fe2O3–TiO2 nanopowders (Fe2O3–TiO2 NPs) as photocatalysts under UV/visible light was investigated in this paper. Fe2O3–TiO2 NPs photocatalysts synthesized using co-precipitation were characterized by XRD, TEM, FT-IR and UV-vis DRS. Fe2O3–TiO2 NPs with 45 wt% Fe2O3 exhibited higher photocatalytic activity than others. The photocatalytic degradation of OTC shows a maximum efficiency at pH = 5.5 under both UV/visible light due to the surface adsorption. The intermediate products during the photocatalytic degradation of OTC were detected by LC-MS/TOF. Seven main intermediates were formed, and their evolution was discussed. On the basis of the evidence oxidative intermediate formation and a detailed degradation path way of OTC by 45 Fe2O3–TiO2 NPs are proposed.
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