Water coordinated Co-MOFs with 1D/2D network structure and highly enhanced electrocatalytic OER activity

Abstract

The versatility of metal coordination geometry and organic linkers is used to derive metal–organic frameworks (MOFs) with an intriguing network structure in the solid-state, exerting significant control over its functional application. In this study, we prepared Co-benzene dicarboxylic acid based MOFs with 1D and 2D network structures with similar coordination environment and studied their electrocatalytic OER activity in alkaline medium. The use of bidentate amines (2,2′-bipyridine and DABCO) controlled the dimensionality and produced water coordinated 1D (Co-MOF-1D) and 2D (Co-MOF-2D) network structures. Although both Co-MOFs showed strong electrocatalytic OER activity, Co-MOF-2D exhibited relatively strong OER activity (required overpotential (η) of 211 mV to produce 10 mA cm⁻² current density) compared to Co-MOF-1D (η₁₀ = 237 mV). Co-MOF-2D exhibited excellent stability with a low Tafel slope, charge transfer resistance, and high electrochemical surface area that further supported the enhanced OER activity.