Highly-stable cobalt metal organic framework with sheet-like structure for ultra-efficient water oxidation at high current density

The development of efficient and robust non-precious electrocatalysts for water oxidation at a mild condition is extremely desirable for industrial water splitting. Herein we developed a facile solvothermal strategy to synthesize cobalt metal organic frameworks (Co-MOFs) with sheet-like structure, which showed highly promising performance for electrocatalytic oxygen evolution. The best Co-MOF sample afforded an ultra-high oxygen evolution current density of 63.4 mA cm(-2) at 1.75 V in 1 M KOH with a catalyst loading of only 0.21 mg cm(-2). Notably, its electrochemical performance remained unchanged after 10,000 cyclic voltammograms indicating very promising long-term stability. Detailed study of the mechanism of the oxygen evolution by density functional theory (DFT) indicated that the strong pi-conjugation formed between the central cobalt ion and adjacent aromatic rings favored the high electrocatalytic performance. The solvothermally synthesized MOFs proposed in this paper are expected to inspire the rational design of high-performance electrocatalysts for water oxidation with atomic and molecular level structural control and the exploration of structure-performance relationships to understand the electrocatalytic origin. (C) 2021 Elsevier Inc. All rights reserved.

Automated summary

This study successfully synthesized cobalt metal organic frameworks (Co-MOFs) with excellent oxygen evolution performance using a solvothermal strategy, demonstrating high electrocatalytic activity and long-term stability, which could inspire the rational design of high-performance electrocatalysts for water oxidation.