Two-Dimensional Semiconducting Covalent Organic Frameworks with Unidirectional Fused-Ring Bands

. Additionally, abundant exposed metal coordination sites within the 2D plane suggest significant potential as high-performance electrocatalysts. CoTAA-COF-1 demonstrates an oxygen reduction reaction (ORR) half-wave potential of 0.84 V in alkaline conditions, among the highest reported for COF-based ORR catalysts. This work provides an effective design strategy for fused-ring COFs while offering new insights for developing narrow-band-gap organic semiconductors and advanced electrocatalysts.