Preparation of copper oxide-cerium oxide/nanotube-titanium dioxide photocatalyst for CO2 conversion in solar light

An effective 1.3%CuO-9.2%CeO 2 /nt-(gray)TiO 2 photocatalyst was prepared. The nanotubes were obtained by combining interface chemical reaction with hydrothermal reaction and impregnation method was used for active metal oxides loadings for CO 2 conversion. The nanotubes with a diameter about 110 nm was used as a support for monolayer coverage of metal oxides since the loading of cerium oxide on nanotube titanium dioxide was 9.2% and copper oxide loading on cerium oxide-nanotubeTiO 2 was 1.3%. To modify both support and catalyst in color into gray, hydrogen reduction was applied. CO 2 conversion was studied in sodium metaborate solution by optimizing the CO 2 flow rate and sodium metaborate concentration to obtain maximum conversion with the guidance of statistically robust mathematical model with R 2 was 0.8945. Hydrogen reduction process was also applied to color the modified support to enhance the absorption capacity of visible light energy. The photocatalysts 1.3%CuO-9.2%CeO 2 /nt-(white)TiO 2 and 1.3%CuO-9.2%CeO 2 /nt-(gray)TiO 2 exhibited excellent photocatalytic activity in visible region 7.7 and 9.1 µmol g cat −1 h −1 , respectively.