Boosting Reaction Kinetics and Stability of Electrocatalytic Oxygen Evolution with Ir/CoV-LDH/Graphene Heterogeneous...

To address the challenge of low catalytic performance in the electrocatalytic oxygen evolution reaction (OER) caused by slow reaction kinetics, a novel approach is developed utilizing the crystalline properties of iridium (Ir) and hydrogen-related layered double hydroxide (LDH) to enhance corrosion resistance. These materials are integrated into a CoV-LDH structure to design an Ir/CoV-LDH/G heterogeneous electrocatalyst. This innovative heterogeneous structure not only enhances the reaction kinetics but also optimizes the electronic structure of the catalyst through interactions at the heterogeneous interface, leading to excellent electrocatalytic OER performance. Notably, the Ir/CoV-LDH/G catalyst requires overpotentials of merely 203 and 289 mV to achieve current densities of 10 and 100 mA cm^-2, respectively. Furthermore, when utilized in an Ir/CoV-LDH/G||Pt/C electrolytic cell for overall water splitting, it delivers a current density of 10 mA·cm^-2 at a cell voltage of only 1.46 V, surpassing the performance of most commercial IrO₂||Pt/C and previously reported Ir-based and LDH electrocatalysts. The catalyst also exhibits remarkable stability, maintaining a current density of 100 mA·cm^-2 for 100 h without significant degradation.