Study on the effect and mechanism of Ag and Bi2MoO6 modification on the CO2 photo-thermal reduction performance of g-C3N4 catalysts with localized surface plasmon resonance

Abstract

As a promising future energy material, g-C₃N₄ as a CO₂ photo-thermal-reduction catalyst can effectively convert CO₂ to renewable fuel, but the low yield and low product selectivity significantly limit its further development and application. Herein, Ag and Bi₂MoO₆ were loaded separately or together on g-C₃N₄ catalysts by photo-deposition and solvothermal synthesis methods, wherein the conversion efficiency of the g-C₃N₄ catalyst co-loaded with 0.5% Ag and 10% Bi₂MoO₆ 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 Bi₂MoO₆ reduces the band gap of g-C₃N₄, improves the light absorption performance, and promotes the photoelectron transfer and CO₂ adsorption, which may be attributed to the LSPR of Ag and the Z-scheme heterojunction between g-C₃N₄ and Bi₂MoO₆. 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-C₃N₄ catalysts.