Hydrogen-Bond-Regulated Formation of Ultrathin Conjugated Coordination Frameworks with Homogeneous Edge Effect...

The d-π conjugated conductive metal coordination frameworks (c-MCFs) are a type of emerging crystalline porous material. However, due to the interlayer conjugation effect, the clusters tend to assemble into 3D architectures, making it difficult to directly prepare ultrathin 2D structures. Herein, by reasonably regulating the hydrogen-bond network and solvation layer of the reaction solvent environment, the interlayer conjugation effect of the Co-DABDT (DABDT = 2,5-diaminobenzene-1,4-dithiol) layer was effectively inhibited, and ultrathin c-MCFs were efficiently constructed. Using it as a suitable model catalyst, the solvent environment was optimized, and Co-DABDT with different homogenic edge curvatures was synthesized, including bulk Co-DABDT (Co-DABDT-B), layered Co-DABDT (Co-DABDT-L), and Co-DABDT nanosheet (Co-DABDT-NS). Among these, Co-DABDT-NS has the highest homogenic edge curvatures, with the optimal onset potential and half-wave potential of 0.97 and 0.82 V_RHE, respectively. Experimental and theoretical results show that as the layer plate thickness decreases, the homogenic edge curvatures can optimize the interface charge and electric field distribution and enhance the adsorption of oxidation intermediates, thereby achieving efficient oxygen reduction reaction (ORR) catalytic activity. The results indicate that the role of this morphology-induced local field enhances the ORR kinetics and provides a new perspective for the study of catalyst morphology-field effect-catalytic kinetics.