Preparation of g-C3N4 doped Cu/black TiO2 and its high photocatalytic reduction performance of CO2

Series g-C 3 N 4 /Cu/B-TiO 2 (x) composites with different mass ratio of g-C 3 N 4 to Cu/B-TiO 2 were prepared and tested for photocatalytic reduction of CO 2 . The structure–function relationship of the photocatalysts was investigated through various characterization methods and photocatalytic experiments. The results show that g-C 3 N 4 can be uniformly distributed on the surface of Cu/B-TiO 2 and formed a stable heterojunction structure, which effectively reduced the band gap width of the catalyst, thus significantly improving the visible light absorption capacity of the catalyst. The modulation of the composite material properties can be realized by regulating the composite ratio of g-C3N4 and Cu/B-TiO 2 . The rate and selectivity of photocatalytic reduction of CO 2 to produce CO reached the maximum when the mass ratio of g-C 3 N 4 to Cu/B-TiO 2 was 3:7, and the rate of CO production was as high as 32.65 μmol∙g −1 ∙h −1 , which was about 12.87 percentage points higher than that of Cu/B-TiO 2 .