Magnetic Fe₃O₄@C@Cu₂O composites with bean-like core/shell nanostructures: Synthesis, properties and application in recyclable photocatalytic degradation of dye pollutants

Magnetic Fe₃O₄@C@Cu₂O composites with a bean-like core/shell nanostructure have been successfully synthesized by a self-assembly approach. The synthetic route is feasible, low-cost and green. The size of the as-prepared magnetic composites is about 420 nm and the shells are composed of several nanoparticles in the range of 510 nm. Interestingly, the carbonaceous layer with bound hydrophilic groups inherited from the starting materials acted as both the linker and the stabilizer between Fe₃O₄ and Cu₂O. The Fe₃O₄@C@Cu₂O composites exhibit ferromagnetic behaviour, and good dispersibility in aqueous solution. Importantly, the bean-like core/shell composites show universal and powerful visible-light-photocatalytic activity for the degradation of Rhodamine-B (RhB), methyl orange (MO), and alizarin red (AR) relative to commercial Cu₂O and Degussa P-25 powders. These novel magnetic composites may find applications in dye water treatment, degradation of organic pollutants and environmental cleaning etc.