Activated g-C3N4 Photocatalyst with Defect Engineering for Efficient Reduction of CO2 in Water

The conversion and utilization of CO2 intohydrocarbonfuel using solar energy is an attractive way to reduce CO2 emissions. In the photocatalytic CO2 conversion process,a synergistic enhancement of both photoreaction and chemical reactionis quite important for promoting the conversion. Here, we presenta facile method for preparing a defective and activated graphiticcarbon nitride (g-C3N4) photocatalyst, whichexhibits a superior CO2-to-CO production of 32.06 mu molg(-1) without sacrificial agent or noble metal. Thisis about 9.1 times higher than that of the defect containing g-C3N4 (3.51 mu mol g(-1)). Theactivated g-C3N4, in which the TiO2 species coexist, not only improved the CO production to 54.03 umolg(-1) but also reduced CO2 into CH4 with 2.50 umol g(-1) in 5 h. This is becausethe coexistence of TiO2 species in activated g-C3N4 promotes molecule and electron transfer, as observedthrough experimental characterization techniques. Therefore, thiswork provides a novel insight into the synthesis of multifunctionalg-C3N4 for efficient photocatalytic CO2 reduction with H2O.