Mesoporous TiO2 enhanced by anchoring Mn3O4 for highly efficient photocatalyst toward photo-oxidation of ciprofloxacin

Abstract

We describe the synthesis of mesoporous Mn3O4/TiO2 nanocomposites in the occurrence soft template. TEM images exhibited the Mn3O4/TiO2 nanocomposites homogeneous morphology with a particle size of ∼10–15 nm with close contact between TiO2 anatase and Mn3O4 crystals. The mesoporous Mn3O4/TiO2 nanocomposites were assessed toward degradation of ciprofloxacin (CIP) under visible illumination, which achieved 98.6% CIP degradation within 120 min. The degradation efficiency over porous 3% Mn3O4/TiO2 was greater 18 fold than that bare TiO2. The apparent degradation rate of the optimum 3% Mn3O4/TiO2 photocatalyst was fostered 22 folds higher than that of bare TiO2 NPs. Interestingly, the enhanced photocatalytic ability for Mn3O4/TiO2 heterojunction was significantly referred to the high absorption of visible light, synergistic effect and the unique structure with large surface area, which improved the CIP adsorption on porous Mn3O4/TiO2. Besides, the Mn3O4/TiO2 photocatalysts displayed stability and recyclability toward degradation of CIP for 10 h illumination. The photoelectrochemical and photoluminescence measurements of Mn3O4/TiO2 nanocomposites revealed an enhanced light-harvesting and effective electron-holes separation compared with bare TiO2. The prospective mechanism for degradation of CIP over Mn3O4/TiO2 heterojunction was presented.