Hydrolyzed MOFs-Derived IrOx/Co(OH)2 for Highly Efficient Electrocatalytic Water Splitting.

Abstract

Electrocatalytic water splitting is a promising green energy conversion method. However, the high cost and limited availability of noble metals hinder their large-scale application. To enhance the efficiency of noble metal usage, we developed a facile and mild synthesis method for constructing bifunctional electrocatalysts. By using a metal-organic framework (MOF)-derived strategy, we synthesized IrO _x clusters supported on Co(OH)₂ nanosheets on nickel foam (IrO_x/Co(OH)₂/NF). The mild conditions allowed the in situ loading of IrO_x species without the need for high-temperature treatment. The resulting catalyst exhibits outstanding electrocatalytic performance for both oxygen evolution reaction (OER) and hydrogen evolution reaction (HER), with a low overpotential of 215 and 36.8 mV, respectively, at 10 mA cm^-2. Moreover, it maintains excellent stability, with negligible activity degradation observed over 500 h of OER, 200 h of HER, and 100 h of overall water splitting. This work provides a simple, effective strategy for synthesizing supported cluster catalysts with outstanding catalytic performance and stability in overall water splitting.