Degradation of methylene blue through Fenton-like reaction catalyzed by MoS2-doped sodium alginate/Fe hydrogel

Abstract

In this study, a low-cost and high-performance MoS2/sodium alginate (SA)/Fe (MSF) hydrogel catalyst was prepared. It was found that the MSF hydrogel could efficiently catalyze the degradation of methylene blue (MB) through the Fenton reaction without the addition of Fe2+. The reaction was initiated by Fe2+ which was derived from the cyclic redox reaction between MoS2 and Fe3+ and produced large quantities of ·OH to degrade the MB. The effect of MoS2 concentration, FeCl3·6H2O concentration, H2O2 dosage, solution pH, and light on the degradation was systematically studied. The MoS2 concentration of 0.5 mg/ mL, FeCl3·6H2O concentration of 0.25 g/mL, 50 μL H2O2, and the pH of 4.0 were the optimized parameters. Moreover, it was found that the MB degraded faster under the infrared radiation. The MB removal rate reached as high as 98% within 15 min in the presence of a low concentration of H2O2 and the procedure could be repeated 5 times. The MSF hydrogel provided an effective and simple strategy for the sustainable degradation of organic pollutants in wastewater.