Harnessing Truxone-Based Electrically Conductive Metal-Organic Framework for Electrochromism

Metal-organic frameworks (MOFs) can exhibit tunable electrochromic properties through redox-active metal nodes or linkers, yet their inherently poor electrical conductivity confines redox activity and requires high operating voltages (>1 V), limiting device integration. Electrically conductive MOFs (c-MOFs) can overcome this but often rely on specific metal-linker combinations, due to the limited redox-active organic functional groups available in c-MOFs. Here, we leverage Cu-truxone, a c-MOF featuring redox-active carbonyl (C═O) groups with a conductivity of 1.9 × 10^-2 S cm^-1 that realizes linker-centric electrochromism. We developed an in situ growth method in which Cu-truxone is directly synthesized on a mercaptobenzoic acid-functionalized fluorine-doped tin oxide (FTO) substrate. This enables pronounced and efficient electrochromic switching at a low voltage range (<1.0 V) with a high coloration efficiency of 193.6 cm² C^-1. Our findings showcase the potential of c-MOFs with redox-active functional groups in linkers for electrochromic applications.