CuS‐Cobalt Porphyrin Organic–Inorganic Heterojunction with a Long‐Lived Charge‐Separated State for Efficient CO ₂ ‐to‐CH ₄ Conversion under Infrared Light

Abstract

ABSTRACT Harnessing infrared (IR) light for the selective reduction of CO 2 remains a significant challenge due to sluggish kinetics and poor carrier dynamics. In this research, a novel organic–inorganic hybrid heterojunction was designed consisting of HKUST‐1‐derived CuS and cobalt porphyrin (CoTPPS), which achieves an exceptional CH 4 generation (178.02 µmol g − 1 h − 1 ) and 96.5% CH 4 selectivity under IR irradiation. Femtosecond transient absorption spectra and synchrotron radiation measurements show that strong interfacial electronic coupling enables a significant charge transfer, creating a robust internal electric field which greatly increases carrier lifetimes (170‐fold). Density functional theory (DFT) calculations further elucidate how the heterojunction lowers the rate‐determining *COOH formation barrier (from 1.43 to 1.07 eV) and stabilizes the critical *CHO intermediate. This effectively steers the eight‐electron pathway towards CH 4 while suppressing CO desorption. The synergy between the porous MOFs‐derived scaffold and the molecular active center provides a versatile paradigm for engineering IR‐responsive photocatalysts with precise intermediate regulation. This work promotes the rational design of hybrid materials for efficient solar‐to‐fuel conversion.