Healable multilayered photocatalysts promote durability and productivity of solar-driven CO₂ conversion

Numerous studies have focused on efficient CO₂ photoreduction on short notice. However, more hours of efficient and selective CO₂ and pure water photoconversion without precious metals or sacrificing reagents should be emphasized. Herein, a multilayer (SrTiO₃/Ce:CaF₂/CuNi/Ce:CaF₂/TiN) is utilized with a high selectivity of 87 % for healable photocatalytic CO₂ and pure water conversion without sacrificial reagents and the longest service life for the Cu nanolayers, to the best of our knowledge. Meanwhile, the photocatalytic activity, optical absorption, and charge separation ability of SrTiO₃/Ce:CaF₂/CuNi/Ce:CaF₂/TiN can be recovered after regeneration. The deactivation and healable mechanism are illuminated that the adsorption of CO₂ molecules at the photocatalyst surface is changed from M-CO₂ to MO-CO₂, due to the oxidation of active sites, resulting in the deactivation of CO₂ reduction. The Ce:CaF₂ nanolayers can accommodate oxygen atoms effectively to heal the photocatalyst. The article proposes a feasible way for commercial CO₂ and pure water photoconversion.