氮化碳异质结催化剂的制备及光催化还原CO2性能研究OA

Carbon nitride is an ideal catalyst for photocatalytic reduction of CO2,but the recombination of photoelectron-holes has greatly limited the application of carbon nitride.Based on the strategy of heterojunction construction,graphite-phase carbon nitride/nitrogen-rich carbon nitride(C3N4/C3N5)catalysts were synthesized by high-temperature thermal polymerization-thermal reflux method using melamine and 3-amino-1,2,4-triazole as raw materials.The catalysts were characterized by a series of methods.The photocatalytic performance of C3N4/C3N5 catalyst for CO2 reduction was evaluated by introducing high-purity CO2 into the aqueous phase under 300 W xenon lamp irradiation.The results showed that only CH4 was produced during the photocatalytic reduction of CO2 by C3N4/C3N5 catalyst under light irradiation for 5 h,and the yield reached 2.102 8 μmol/(g·h),which was 9.8 times and 5.2 times that of single-component C3N4 and C3N5 catalysts,respectively.The photocatalytic performance was significantly improved.It was not only due to the increases of specific surface area and pore size after the disordered stacking of C3N4 and C3N5,but also due to the construction of Z-scheme heterojunction after the coupling of C3N4 and C3N5,which effectively promoted the separation of photoelectron-holes and promoted the transfer of charges.Active species such as photoelectrons and holes played a key role in the process of photocatalytic CO2 reduction.