Redox Molecular Junction Metal‐Covalent Organic Frameworks for Light‐assisted CO2 Energy Storage

Abstract Visible‐light sensitive and bi‐functionally favored CO 2 reduction (CRR)/evolution (CER) photocathode catalysts that can get rid of the utilization of ultraviolet light and improve sluggish kinetics is demanded to conquer the current technique‐barrier of traditional Li‐CO 2 battery. Here, a kind of redox molecular junction sp 2 c metal‐covalent organic framework (i.e. Cu 3 ‐BTDE‐COF) has been prepared through the connection between Cu 3 and BTDE and can serve as efficient photocathode catalyst in light‐assisted Li‐CO 2 battery. Cu 3 ‐BTDE‐COF with redox‐ability, visible‐light‐adsorption region, electron‐hole separation ability and endows the photocathode with excellent round‐trip efficiency (95.2 %) and an ultralow voltage hysteresis (0.18 V), outperforming the Schiff base COFs (i.e. Cu 3 ‐BTDA‐COF and Cu 3 ‐DT‐COF) and majority of the reported photocathode catalysts. Combined theoretical calculations with characterizations, Cu 3 ‐BTDE‐COF with the integration of Cu 3 centers, thiazole and cyano groups possess strong CO 2 adsorption/activation and Li + interaction/diffusion ability to boost the CRR/CER kinetics and related battery property.