Polyhedral magnetite nanoparticles modified with porous bio-templated copper oxide as catalyst for visible-light-driven photodegradation of methylene blue

A visible-light-driven bio-templated magnetic copper oxide (CuO/C/Fe3O4) photocatalyst was prepared via modifying polyhedral magnetite nanoparticles with porous bio-templated copper oxide for the heterogeneous photo-Fenton degradation of methylene blue illuminated by visible light. The synthesized composite was subsequently characterized by X-ray diffraction analysis, thermally gravimetrically analysis, Fourier transform infrared analysis, X-ray photoelectron spectroscopy, Field-emission scanning electron microscopy, energy dispersive spectrometry, and vibrating sample magnetometer techniques to reveal the presence of hybrid particles in the composite matrix and the existence of iron oxide and copper oxide phases. The effects of many parameters, including the initial concentrations of dye and hydrogen peroxide (H2O2), catalyst dosage, initial pH of the solution, and the effect of added electrolytes on the dye's degradation efficiency, have been researched. The findings indicated that the dye could be successfully degraded over a wide pH range within a reaction time of 90 min, corresponding to about 98.5% dye removal and 87% reduction of the initial total organic carbon. The improved hydroxyl radicals (•OH) and superoxide radicals (–•O2) production efficiency and the ferric ions (Fe3+)/Ferrous ions (Fe2+) redox cycle were occasioned by the visible light-assisted heterogeneous Fenton process catalyzed by the synthesized bio-templated magnetic copper oxide (CuO/C/Fe3O4) composite in the high degradation efficiency. In addition, the synthesized bio-templated magnetic copper oxide (CuO/C/Fe3O4) composite was reused consecutively five times with a loss of only 5% of their original degradation efficiency and can be recovered from the aqueous medium by the influence of a magnetic field while maintaining chemical stability.Graphical abstract