Photocatalytic CO₂ conversion of W₁₈O₄₉/CdSe-Diethylenetriamine with high charge transfer efficiency: Synergistic effect of LSPR effect and S-scheme heterojunction

Non-stoichiometric W₁₈O₄₉ (WO) prepared by solvothermal method has excellent NIR absorption due to the localized surface plasmon resonance effect caused by oxygen vacancies. This has great potential in the field of using sunlight to convert carbon dioxide into organic fuels. In addition, through the amination of CdSe, the one-dimensional/two-dimensional step-scheme (S-scheme) WO/CdSe-diethylenetriamine (WO/CdSe-D) photocatalyst with electron transmission channels driven by visible light to NIR light is constructed by microwave solvothermal method. The LSPR of WO and the synergistic effect of coupling semiconductors to construct S-scheme heterojunctions can improve light utilization and achieve efficient charge carrier transfer efficiency. The optimized photocatalyst of 35%WO/CdSe-D has the best CO₂ reduction performance compared to WO and CdSe-D, and the yield is 25.37 µmol h^–1 g^–1. X-ray photoelectron spectroscopy was used to verify the charge transfer path of the S-scheme WO/CdSe-D heterojunction. This work provides a possibility for the application of non-stoichiometric oxides rich in oxygen vacancies in the field of photocatalytic CO₂ reduction.