BACKGROUNDSynthetic dyes are present in the wastewater from many industrial processes and they cause serious problems to human and aquatic life. The development of a novel and effective peroxymonosulfate (PMS) activator is proposed to eliminate dyes pollution. A new magnetic nanocomposite, Fe3O4@C/MnCo2O4, was prepared and characterized. The activity of Fe3O4@C/MnCo2O4 as heterogeneous catalyst for PMS activation was evaluated by the decolorization of Acid Orange II (AO II). RESULTSWith a Fe3O4@C/MnCo2O4 + PMS' system, the dye solution could be nearly completely decolorized in about 25 min over a wide pH range (pH 4.1-8.1), and 98% removal could be achieved in 15 min without pH adjustment (pH = 6.38). The influence of solution pH, dosage of catalyst and PMS, reaction temperature, and PMS activation mechanism were studied. It was found that sulfate radicals were the primary species responsible for the oxidation of AO II. The catalyst was magnetically separable and displayed good stability and reusability, giving six cycles of use without deterioration in its performance. CONCLUSIONThis study demonstrated the simple recycling and high activity of Fe3O4@C/MnCo2O4 composite in PMS activation for the decolorization of AO II solution. It provides a promising way for the decontamination of organic pollutants. (c) 2016 Society of Chemical Industry