Synergistic enhancement in photocatalytic performance of Ce (IV) and Cr (III) co-substituted magnetite nanoparticles loaded on reduced graphene oxide sheets

Effective utilization of visible-light by a photocatalyst is of great significance in photocatalytic processes. Herein, magnetite structure was modified by co-incorporation of Ce⁴⁺ and Cr³⁺ cations, and deposition on reduced graphene oxide sheets. The as-prepared Fe_2.8Cr_0.2O₄#rGO and Fe_2.5Cr_0.2Ce_0.3O₄#rGO nanocomposites were characterized by XRD, SEM, X-ray Dot mapping, EDX, BET, DRS, XPS, FT-IR and VSM techniques and assessed for their photocatalytic performance under visible light irradiation for treatment of methylene blue. The results confirmed the central role of the incorporated Cr and Ce in improving the photocatalytic performance of magnetite through enhanced light harvesting, and the role of Ce³⁺/Ce⁴⁺ redox pair, and rGO sheets in extending the life span of photo-induced e⁻/h⁺. Moreover, the influence of enhancers and scavengers were evaluated and oxidation path and generated byproducts were estimated. The results established the Fe_2.5Cr_0.2Ce_0.3O₄#rGO nanocomposite as a visible-light-driven photocatalyst for effective degradation of recalcitrant compounds.