Riboflavin Immobilized CeO2-RGO Nanohybrid as a Potential Photo-redox Catalyst for Enhanced Removal of Organic Pollutants under Visible Light

We report a facile immobilization of riboflavin (RF) over in situ synthesized CeO2–RGO nanohybrid surface synthesized through a simple wet-chemical approach for photocatalytic degradation of organic pollutants under the visible light (λ ≥ 420 nm). The hybrid containing 3%, w/w RGO shows an excellent photocatalytic activity under the visible light. The UV–Visible diffuse reflectance spectra, PL analysis and transient photocurrent measurements corroborate the hybrid RF@CeO2-RGO significantly absorbs the visible light, and exhibits lower recombination of charge carriers in comparison to RF@CeO2. The catalyst, RF@CeO2-RGO, offers enhancement in photocatalytic rate, i.e. 2.8 fold increase for methyl orange (MO) and 3.5 fold for p-nitrotoluene (PNT) in comparison to RF@CeO2 under the visible light (2 h). The enhancement could be attributed to the synergistic effect among CeO2, RF (broadens visible light absorption region) and RGO (an electron-shuttling agent), which lead efficient separation of charge carriers....