Cobalt-doped g-C₃N₄/CoO S-scheme heterojunction enabling efficient photothermal CO₂ conversion via synergistic charge...

Photothermal co-catalyzed CO₂ conversion technology has attracted much attention for its potential to synthesize high-value-added chemicals under mild conditions. However, the complex charge transfer mechanisms and reaction pathways in heterogeneous material systems still constrain the development of this technology. To address this challenge, this study constructed a cobalt-doped g-C₃N₄/CoO (dCN/CoO) S-scheme heterojunction catalyst using a solid-state grinding and stepwise pyrolysis strategy. Experimental characterization combined with DFT calculations indicates that cobalt doping not only induces the formation of face-centered cubic (FCC) CoO crystals but also significantly enhances the material's adsorption energy for CO₂ molecules. Furthermore, the formation of S-scheme heterojunction facilitates the establishment of an internal electric field, which not only enhances the efficiency of separation for photogenerated charge carriers within the material，but also maintains a high reduction potential in the conduction band of dCN. Further in situ DRIFTS characterization reveals that light can promote the rapid conversion of the key active intermediate *COOH, facilitating the generation of CO. This study synergistically regulates charge transfer and reaction pathways through interface engineering, providing theoretical and foundational support for the application of S-scheme heterojunctions in photothermal cooperative CO₂ conversion technology.