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 (CO 2 ) into methanol on TiO 2 loaded copper ferrite (CuFe 2 O 4 ) photocatalyst under visible light (500 W xenon lamp) irradiation. In this perspective, CuFe 2 O 4 and CuFe 2 O 4 /TiO 2 photocatalysts were synthesized following the sol–gel method from copper(II) nitrate, Cu(NO 3 ) 2 ·3H 2 O (99 %) and iron(III) nitrate, Fe(NO 3 ) 3 ·9H 2 O (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 TiO 2 on CuFe 2 O 4 enhanced the photocatalytic activity in the visible light range. The enhanced photoactivity in CuFe 2 O 4 /TiO 2 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 CuFe 2 O 4 /TiO 2 and the photocatalytic activity of CuFe 2 O 4 /TiO 2 for CO 2 reduction was found to be about three times higher (651 μmol/g cat L) than that of CuFe 2 O 4 photocatalyst which might be due to the modification of band gap through TiO 2 loading.