Strengthen metal-oxygen covalency of CoFe-layered double hydroxide for efficient mild oxygen evolution

Oxygen evolution reaction (OER) is crucial for hydrogen production as well as other energy storage technologies. CoFe-layered double hydroxide (CoFe-OH) has been widely considered as one of the most efficient electrocatalysts for OER in basic aqueous solution. However, it still suffers from low activity in neutral electrolyte. This paper describes partially oxidized CoFe-OH (PO-CoFe-OH) with enhanced covalency of M-O bonds and displays enhanced OER performance under mild condition. Mechanism studies reveal the suitably enhanced M-O covalency in PO-CoFe-OH shifts the OER mechanism to lattice oxygen oxidation mechanism and also promotes the rate-limiting deprotonation, providing superior OER performance. It just requires the overpotentials of 186 and 365 mV to drive the current density densities of 1 and 10 mA.cm(-2) in 0.1 M KHCO3 aqueous solution (pH = 8.3), respectively. It provides a new process for rational design of efficient catalysts for water oxidation in mild conditions.

Automated summary

This paper introduces partially oxidized CoFe-OH with enhanced covalency of M-O bonds as an efficient electrocatalyst for OER in neutral electrolyte. The enhanced M-O covalency shifts the OER mechanism to lattice oxygen oxidation mechanism in PO-CoFe-OH, promoting rate-limiting deprotonation and providing superior OER performance. It only requires overpotentials of 186 and 365 mV to achieve current density densities of 1 and 10 mA.cm(-2) in 0.1 M KHCO3 aqueous solution (pH = 8.3), showing a new approach for designing efficient catalysts for water oxidation in mild conditions.