Revisiting Water Oxidation Reaction with Micro Bubble Lithography (MBL) Printed ZIF‐67 MOF Electrocatalysts

Abstract Microbubble‐based micro‐lithographic techniques have developed rapidly over the last ten years and are capable of reproducibly patterning a wide variety of soft materials and colloids, including polymers, metals, and proteins. Zeolitic imidazolate framework (ZIF) materials have attracted a great deal of research and application interest in the field of materials science because of their chemical and thermal stabilities. Furthermore, ZIF‐67 has demonstrated significant potential for applications in gas adsorption, molecule separation, electrochemistry, and catalysis, which when converted into “lab‐on‐a‐chip” platforms might produce remarkable and diverse application‐oriented outcomes. This is due to their highly adjustable nanostructures. Using Co(OAc) 2 .4H 2 O and Co(NO 3 ) 2 .6H 2 O as the metal ion sources and 2‐methylimidazole as the ligand, To design ZIF‐67 (composed of Co 2+ ions and imidazolate ligands) is attempted. Inspired by previous results, the Micro‐Bubble Lithography (MBL) approach is used to successfully demonstrate an instantaneous in situ green synthesis and micro‐patterning of ZIF‐67 MOFs in this work. With reasonable stability and an over‐potential of 440 mV, these micro‐patterns are used as microelectrodes for the electrocatalytic oxygen evolution reaction (OER) in media having different pH.