High efficiency of graphene/CoFe2O4 nanomaterial in the photocatalytic conversion of CO2 dissolved in water under solar irradiation simulator

The present work describes the excellent performance of GH-CoFe2O4 photocatalysts based on graphene ferrite, synthesized using water rich in natural organic matter (NOM) as a solvent, for the photocatalytic reduction of CO2 under artificial visible light, at ambient temperature and pressure. The nano-photocatalysts presented excellent photocatalytic activity, with high selectivity towards the conversion of CO2 to methanol as the main product, for both semiconductors tested (CoFe2O4 and GH-CoFe2O4). The presence of graphene improved photoexcitation under visible light, decreasing the CoFe2O4 band gap value from 1.47 to 1.25 eV, resulting in decreased recombination of the e-/h+ pairs. The rates of formation of methanol were 1105.7 and 1389.9 mu mol g(-1) h(-1) for CoFe2O4 and GH-CoFe2O4, respectively. The findings reveal the potential of photocatalysts based on ferrite and graphene for use in the conversion of CO2 dissolved in water without any added chemical into high added-value products.