Photocatalytic reduction of CO2 into methanol over CuFe2O4/TiO2 under visible light irradiation

The present study aims to focus the photocatalytic reduction of carbon dioxide (CO2) into methanol on TiO2 loaded copper ferrite (CuFe2O4) photocatalyst under visible light (500 W xenon lamp) irradiation. In this perspective, CuFe2O4 and CuFe2O4/TiO2 photocatalysts were synthesized following the sol–gel method from copper(II) nitrate, Cu(NO3)2·3H2O (99 %) and iron(III) nitrate, Fe(NO3)3·9H2O (99 %) as precursors. The phases and crystallite size of the photocatalysts were characterized by X-ray diffraction (XRD), morphology by scanning electron microscopy (SEM), absorption spectrum by ultraviolet–visible spectroscopy (UV–Vis), electron–hole (e−/h+) recombination process by photoluminescence spectrophotometer, and elemental compositions by energy dispersive X-ray spectroscopy (EDX) instruments. The loading of TiO2 on CuFe2O4 enhanced the photocatalytic activity in the visible light range. The enhanced photoactivity in CuFe2O4/TiO2 semiconductor catalyst can be attributed to interfacial transfer of photogenerated charges, which led to effective charge separation and inhibited the recombination of photogenerated electron–hole (e−/h+) pairs. Methanol was observed as the main product over CuFe2O4/TiO2 and the photocatalytic activity of CuFe2O4/TiO2 for CO2 reduction was found to be about three times higher (651 μmol/gcat L) than that of CuFe2O4 photocatalyst which might be due to the modification of band gap through TiO2 loading.