Study on the effect and mechanism of Ag and Bi 2 MoO 6 modification on the CO 2 photo-thermal reduction performance of g-C 3 N 4 catalysts with localized surface plasmon resonance

As a promising future energy material, g-C 3 N 4 as a CO 2 photo-thermal-reduction catalyst can effectively convert CO 2 to renewable fuel, but the low yield and low product selectivity significantly limit its further development and application. Herein, Ag and Bi 2 MoO 6 were loaded separately or together on g-C 3 N 4 catalysts by photo-deposition and solvothermal synthesis methods, wherein the conversion efficiency of the g-C 3 N 4 catalyst co-loaded with 0.5% Ag and 10% Bi 2 MoO 6 was the highest (CO yield = 50.77 μmol g −1 h −1 , CO selectivity = 96.98%). Characterization shows that the co-loading of Ag and Bi 2 MoO 6 reduces the band gap of g-C 3 N 4 , improves the light absorption performance, and promotes the photoelectron transfer and CO 2 adsorption, which may be attributed to the LSPR of Ag and the Z-scheme heterojunction between g-C 3 N 4 and Bi 2 MoO 6 . The results of in situ DRIFTS and DFT calculations are consistent with the above conclusion and show that Ag loading effectively reduces the energy barrier of each intermediate state. This thesis aims to provide data support and theoretical guidance for optimal design of g-C 3 N 4 catalysts.