Hydroxyl radical induced from hydrogen peroxide by cobalt manganese oxides for ciprofloxacin degradation

Abstract

Advanced oxidation processes (AOPs) are promising technology to remove organic pollutant in water. However, the main problem in the AOPs is the low generation of hydroxyl radical (•OH) owing to the low decomposition efficiency of hydrogen peroxide (H2O2). Herein, the spinel type cobalt acid manganese (MnCo2O4) with flower morphology was fabricated through a co-precipitation method. In situ Fourier transform infrared spectroscopy confirms that the MnCo2O4 with the optimal molar ratio of Co and Mn precursors (CM3, Co:Mn = 3) has more Lewis acid sites compared with single metal oxide catalysts (Co3O4 and Mn2O3), leading to the excellent performances for H2O2 decomposition rate constant on CM3, which is about 15.03 and 4.21 times higher than those of Co3O4 and Mn2O3, respectively. As a result, the obtained CM3 shows a higher ciprofloxacin degradation ratio than that of Co3O4 and Mn2O3. Furthermore, CM3 shows an excellent stability during several cycles. This work proposes effective catalysts for ciprofloxacin decomposition and provides feasible route for treating practical environmental problems.