Cobalt carbonate hydroxide assisted formation of self-supported CoNi-based Metal-Organic framework nanostrips as efficient electrocatalysts for oxygen evolution reaction

The development of efficient and low-cost electrocatalysts is crucial for improving the efficiency of electrochemical oxygen evolution reaction (OER). Herein, self-supported CoNi-based metal-organic framework (MOF) nanostrips grown on Ni foam (NF) were synthesized with cobalt carbonate hydroxide (CoCH) nanoneedles as a sacrificial template and demonstrated to be highly efficient electrocatalysts for OER. In this approach, the CoCH nanoneedles play a key role in modulating the morphology of CoNi-MOF with reduced thickness and sizes through affording Co source and slowing down the leaching of Ni ions from the NF substrate. The resultant CoNi-MOF/CoCH/NF electrode possesses higher catalytically active surface area and smaller electrochemical impedance than CoCH template-free electrodes, which enable rapid mass transport and charge transfer during OER, thus showing enhanced electrocatalytic activity for OER. In alkaline media (1.0 M KOH), it needs a low overpotential of 251 mV to deliver a current density of 10 mA cm-2 and exhibits a small Tafel slope of 40.7 mV dec-1 as well as excellent durability. The developed approach may inspire further capability on constructing more promising catalysts for energy related applications. (c) 2023 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.

Automated summary

The synthesis of self-supported CoNi-based metal-organic framework (MOF) nanostrips on Ni foam using CoCH nanoneedles as a template shows promising electrocatalytic activity for oxygen evolution reaction (OER). The CoCH nanoneedles modulate the morphology of CoNi-MOF, resulting in higher catalytically active surface area and faster mass transport and charge transfer, leading to enhanced OER performance. The developed approach holds potential for constructing more efficient catalysts for energy applications.