Continuous high-efficient degradation of organic pollutants based on sea urchin-like Fe3O4/ZnO/ZnSe heterostructures in photocatalytic magnetically fixed bed reactor

Abstract

In this study, a sea urchin-like Fe3O4/ZnO/ZnSe hierarchical heterostructured photocatalyst was successfully prepared via a convenient synthetic strategy and combined with a newly designed photocatalytic magnetically fixed bed reactor (PMFBR) to continuously photodegrade pollutants under simulated solar light irradiation. In the experiment, ZnO nanorods were first grafted onto the surfaces of hollow Fe3O4 nanoparticles, and then ZnSe nanoparticles were uniformly distributed on the ZnO nanorods, the obtained Fe3O4/ZnO/ZnSe composite exhibited three-dimensional structure and excellent magnetic response. Through citing PMFBR, a stable and homogeneously distributed heterogeneous catalyst, efficient light distribution, and good mass transfer of reactants were achieved. As a result, the Fe3O4/ZnO/ZnSe composite in the PMFBR showed excellent photocatalytic capacity with a continuous process. The combination of the magnetic photocatalyst and PMFBR transformed the reaction mode from cumbersome intermittent operation to a simple continuous-flow photocatalytic style. It is hoped that this continuous photocatalytic system could provide a new idea for large-scale wastewater treatment.