Redox Molecular Junction Metal-Covalent Organic Frameworks for Light-assisted CO Energy Storage.

Visible-light sensitive and bi-functionally favored CO 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 battery. Here, a kind of redox molecular junction spc metal-covalent organic framework (i.e. Cu-BTDE-COF) has been prepared through the connection between Cu and BTDE and can serve as efficient photocathode catalyst in light-assisted Li-CO battery. Cu-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-BTDA-COF and Cu-DT-COF) and majority of the reported photocathode catalysts. Combined theoretical calculations with characterizations, Cu-BTDE-COF with the integration of Cu centers, thiazole and cyano groups possess strong CO adsorption/activation and Li interaction/diffusion ability to boost the CRR/CER kinetics and related battery property.