Preparation of highly dispersed Ce–Fe bimetallic oxides on graphene and their superior adsorption ability for Congo red

Abstract

The well-defined structure and favorable surface properties of adsorbent materials are essential for the adsorption of pollutants in water. Highly dispersed Ce–Fe/graphene hybrid materials with the size of about 1–2 nm nanoparticles (NPs) and the high specific surface area of 322 m² g⁻¹ are synthesized by using reduced graphene oxide (RGO). The small particle size is due to the inhibition of different species on crystal growth and the high specific surface area is due to the monolayer dispersive action of reduced graphene. The obtained Ce–Fe/RGO hybrid material exhibits the superior adsorption ability for Congo red (CR) in water. Research results suggest that the driving force for the adsorption is the electrostatic action between adsorbent materials with positive electricity and CR with negative electricity. The Fe doping modifies the electronegativity of adsorbent materials and the CR molecule was firmly adsorbed on the hybrid material by the bidirectional force. The new hybrid material displays the high adsorption capacity of 179.5 mg g⁻¹ for the CR in water, suggesting the potential use of Ce–Fe/RGO hybrid materials in water treatment.