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

In this study, a low-cost and high-performance MoS/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 Fe. The reaction was initiated by Fe which was derived from the cyclic redox reaction between MoS and Fe and produced large quantities of ·OH to degrade the MB. The effect of MoS concentration, FeCl·6HO concentration, HO dosage, solution pH, and light on the degradation was systematically studied. The MoS concentration of 0.5 mg/ mL, FeCl·6HO concentration of 0.25 g/mL, 50 μL HO, 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 HO 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.