Electrosynthesis of a Nickel-Based Conductive Metal-Organic Framework with Controlled Morphology for Enhanced Capacitance

Electrically conductive metal-organic frameworks (EC-MOFs) are highly sought-after materials for electrocatalysis and energy storage because of their unique combination of intrinsic porosity and electrical conductivity. However, it is challenging to incorporate these exciting materials into functional devices because of the difficulty in synthesizing the frameworks directly on desired substrates and at a scale suitable for mass distribution with a controlled morphology. Electrosynthesis can provide a means that is both scalable and synthetically controllable by which metal-organic frameworks can be grown directly on targeted substrates for use in electronic devices. In this work, we demonstrate the electrosynthesis of an EC-MOF constructed with nickel and 2,3,6,7,10,11-hexahydroxytriphenylene, namely Ni-HHTP, with distinct disc and flower-like morphologies (Ni-HHTP-Disc and Ni-HHTP-Flower) by varying the ligand concentrations. The electrochemical performance of Ni-HHTP-Flower greatly exceeds that of bulk Ni-HHTP, boasting gravimetric capacitances and electrochemically active surface areas up to 10 times that of the bulk material because of mesoporous features absent in the bulk, showcasing electrosynthesis as a promising method for preparing future EC-MOF-based devices.