Microwave synthesis of a novel magnetic imprinted TiO2 photocatalyst with excellent transparency for selective photodegradation of enrofloxacin hydrochloride residues solution

Magnetic imprinted TiO2 photocatalyst (MITP) with excellent transparency was prepared via a microwave heating method based on enrofloxacin hydrochloride (ENRH) as the template molecule, methyl methacrylate (MMA) as the functional monomer, and TiO2@SiO2@Fe3O4 (TSF) as the matrix material. TSF was synthesized by a mild sal-gel method. The results indicated that MITP possessed hierarchical spherical structure, good monodispersity, superior magnetic properties (Ms = 11.59 emu/g), the average diameter was approximately 410 nm, and the surface-imprinted layer was composed of the imprinted polymer and poly (methyl methacrylate). Moreover, MITP was proved to exhibit an excellent photochemical stability and a higher photocatalytic efficiency than other photocatalysts, the apparent rate constant (k) for degradation of ENRH with MITP in 90 min under the visible light irradiation was 1.08min(-1). The coefficient of selectivity (k(seiecovity)) of MITP relative to TSF and magnetic non-imprinted TiO2 photocatalyst (MNITP) was 2.14 and 2.08, respectively, indicating that MITP also possessed the strong ability to selective recognition and photodegradation of ENRH in the binary antibiotic residues solution containing ENRH and tetracycline (TC). In addition, the mechanism and intermediate products of selective photodegradation of the binary antibiotic residues solution with MITP were further discussed. (C) 2014 Elsevier B.V. All rights reserved.