High efficiency of graphene/CoFe 2 O 4 nanomaterial in the photocatalytic conversion of CO 2 dissolved in water under solar irradiation simulator

The present work describes the excellent performance of GH–CoFe 2 O 4 photocatalysts based on graphene ferrite, synthesized using water rich in natural organic matter (NOM) as a solvent, for the photocatalytic reduction of CO 2 under artificial visible light, at ambient temperature and pressure. The nano-photocatalysts presented excellent photocatalytic activity, with high selectivity towards the conversion of CO 2 to methanol as the main product, for both semiconductors tested (CoFe 2 O 4 and GH–CoFe 2 O 4 ). The presence of graphene improved photoexcitation under visible light, decreasing the CoFe 2 O 4 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 µmol g −1 h −1 for CoFe 2 O 4 and GH–CoFe 2 O 4 , respectively. The findings reveal the potential of photocatalysts based on ferrite and graphene for use in the conversion of CO 2 dissolved in water without any added chemical into high added-value products.