Photocatalytic CO reduction of Ag/AgS/TiCT heterojunctions with enhanced interfacial charge transfer.

Photocatalytic reduction of CO to produce organic fuels is a promising strategy for addressing carbon reduction and energy scarcity. Transition metal carbides (TiCT ) are of particular interest due to their unique layered structures and excellent electrical conductivity. However, the practical application of TiCT is limited by the poor separation efficiency of photogenerated charge carriers and the low migration ability of photogenerated electrons. Herein, Ag/AgS/TiCT heterojunctions were synthesized by depositing Ag/AgS nanoparticles onto layered TiCT substrates using a combination of co-precipitation and photoreduction methods. Fluorescence spectra, UV diffuse reflection, and photoelectric chemical characterizations demonstrated that Ag/AgS/TiCT heterojunctions provided effective channels for the reverse and synergistic migration of electrons and holes, leading to improved spatial separation. Notably, the Ag component in the composite acts as an electron acceptor and reactive center, significantly enhancing the migration ability of photogenerated electrons. The total alcohol yield over Ag/AgS/TiCT (125.3 μmol g ) was 5.1 times higher than that on AgS (24.7 μmol g ) and 2.1 times higher than on TiCT (60.7 μmol g ). This study offers valuable insights into designing efficient photocatalytic CO reduction catalysts.