In Situ Exsolved Cu/Cu‐TCPP Heterojunction With Lowered Schottky‐Barrier and Switched Photo‐Thermal Electrons Pathway for CO ₂ Reduction and Water Evaporation

ABSTRACT

The performance of the photocatalysts is typically limited by high charge‐carrier recombination and low CO ₂ activation. While metal–semiconductor heterostructures can enhance charge carrier separation, a significant fraction of the hot charge carriers is dissipated upon traversing the Schottky barrier. By temperature and PVP etching, enriched oxygen vacancies and Cu/Cu‐TCPP Schottky junction (Cu‐x) with lowered barrier are exploited via an in situ Jahn‐Teller distortion methodology. This leads to a high rate of separation of photogenerated charge carriers and facilitates unidirectional electron flow from Cu‐TCPP to metallic Cu. Meanwhile, Cu nanocrystals (Cu NCs) act as plasmons to inject more hot electrons, which provides enrichment of electron enrichment at metallic Cu active sites. Therefore, the Cu/Cu‐TCPP junction exhibited excellent photothermal conversion and photocatalytic property in water evaporation and CO ₂ RR. Typically, the synthesized Cu‐170 hydrogel exhibited good water evaporation rate of 1.94 kg m ⁻²  h ⁻¹ and 92.6% evaporation efficiency, and displayed noticeably improved CO ₂ reduction performance, attaining an optimum rate of 290.18 µmol g ⁻¹  h ⁻¹ of CO. DFT calculations and in situ spectroscopic investigations unveil that photo/hot electrons concentrated in the implanted Cu facilitate the production of *COOH and *CO. This study offer an effective paradigm to construct the heterojunction in manipulating the photo‐thermal electrons transfer toward CO ₂ reduction.