Hierarchical structured MnO₂@SiO₂ nanofibrous membranes with superb flexibility and enhanced catalytic performance

Constructing nanostructured catalyst-embedded ceramic fibrous membranes would facilitate the remediation or preliminary treatment of dyeing wastewater, however, most of such membranes are brittle with low deformation resistance, thus, restricting their widely applications. Herein, the flexible and hierarchical nanostructured MnO₂-immobilized SiO₂ nanofibrous membranes (MnO₂@SiO₂ NFM) were fabricated by combining the electrospinning technique with hydrothermal method. The morphologies of membranes could be regulated from nanowires and nanoflower to mace-like structure via varying concentration of reactants. The resultant MnO₂@SiO₂ NFM could cooperate with hydrogen peroxide to form a Fenton-like reagent for the degradation of methylene blue (MB). The resultant membrane exhibited prominent catalytic performance towards MB, including high degradation degree of 95% within 40min, fast degradation rate of 0.0865min^-1, and excellent reusability in 5 cycles. Moreover, the membranes could be used in a wide pH range of 0 to 14 and the degradation degree reached 76% during dynamic filtration process with a flux of 490,000Lm^-2h^-1. The successful fabricating of such membrane with extraordinary catalytic performance would provide a platform for preparing high-performance catalysts for remediation of dyeing wastewater.