Preparation and photodegradation properties of transition metal ion-poly-o-phenylenediamine/TiO2/fly-ash cenospheres by ion imprinting technology

Transition metal ions have been immobilized on TiO2/fly-ash cenospheres (TiO2/FACs) with poly-o-phenylenediamine (OPD). The as-prepared ion imprinting photocatalyst (M-POPD/TiO2/FACs) has been characterized by SEM, XRD, FT-IR, UV-vis DRS and ICP-AES. The results demonstrated that the polymer and mental ions existed in the M-POPD/TiO2/FACs. The photocatalytic activity of M-POPD/TiO2/FACs was studied by the degradation of tetracycline, oxytetracycline, ciprofloxacin, tetracycline hydrochloride and chloromycetin in simulated wastewater under visible light irradiation. The results showed that the M-POPD/TiO2/FACs could effectively increase the separation rate of photoelectrons and holes in the cycling system and improve the photocatalytic activity for the degradation of antibiotics in solution. Experimental data showed that the as-prepared M-POPD/TiO2/FACs were more suitable for degradation of tetracycline (5 mg L-1), and the photodegradation rate could reach 71.7%. In addition, possible formation and photocatalytic mechanisms were proposed.