A combustion synthesis route for magnetically separable graphene oxide–CuFe2O4–ZnO nanocomposites with enhanced solar light-mediated photocatalytic activity

Abstract

A facile one-step combustion route is used for the synthesis of a magnetically separable GO–CuFe₂O₄–ZnO (GCZ) ternary nanocomposite photocatalyst with varying ZnO contents. Transmission electron microscope (TEM) observations show the exfoliation of graphene oxide sheets and decoration with well-dispersed ZnO and CuFe₂O₄ nanoparticles. The photocatalytic activity of the ternary nanocomposite was tested under solar light irradiation for the photodegradation of several dyes such as rhodamine-B (RhB), methylene blue (MB), methyl orange (MO), and neutral phenol. The evaluation results demonstrate that the ternary GCZ photocatalyst exhibits the best performance compared to GO–CuFe₂O₄ (GC), GO–ZnO (GZ), CuFe₂O₄, ZnO, and CuFe₂O₄–ZnO (CZ) photocatalysts towards the photocatalytic degradation of the dyes. Photoelectrochemical measurements were carried out to provide deep insights into the enhanced photocatalytic activity in the novel ternary nanocomposite. The improved photocatalytic activity of the ternary nanocomposite can be ascribed to the superior light assimilation, proficient charge transfer process, synergistic effects, high surface area, and superior durability of the composite. Furthermore, a possible reaction mechanism has been proposed. Our results have demonstrated that by precisely introducing GO with appropriate metal oxides, a highly efficient photocatalyst can be designed that would assimilate a wider range of visible light. Furthermore, CuFe₂O₄ nanoparticles themselves have excellent magnetic properties, which are largely maintained in the GCZ composite, and can be simply separated from the suspension system by applying a magnetic field.