Supercritical CO₂-Directed Semi-Metallic (010) Plane on CaTiO₃ for Enhanced Photocatalytic CO₂ Reduction

Photocatalytic CO₂ reduction offers a promising route for carbon recycling and solar energy conversion. Here, we develop a supercritical CO₂ surface reconstruction strategy to engineer (010)-faceted CaTiO₃ nanosheets with semi-metallic properties and H₂O-assisted surface stabilization. The optimized catalyst exhibits significantly enhanced CO₂ photoreduction, with CO and CH₄ yields of 16.93 and 9.76 µmol/g/h, respectively. Mechanistic studies reveal that the enhanced performance arises from multiple synergistic effects. The electron-rich (010) plane promotes CO₂ adsorption and activation. Incorporated H₂O molecules stabilize the structure and provide proton sources. The semi-metallic nature facilitates charge separation while an upshifted d-band center lowers energy barriers for key reaction steps (*CO → *COH, *CH → *CH₂). This work provides atomic-level insights into facet-engineered perovskite photocatalysts and offers a rational design strategy for high-performance CO₂ reduction materials.