An effective 1.3%CuO-9.2%CeO2/nt-(gray)TiO2 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 CO2 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. CO2 conversion was studied in sodium metaborate solution by optimizing the CO2 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%CeO2/nt-(white)TiO2 and 1.3%CuO-9.2%CeO2/nt-(gray)TiO2 exhibited excellent photocatalytic activity in visible region 7.7 and 9.1 mu mol g(cat)(-1) h(-1), respectively.