Ultrafine Ir Nanocluster-Modified Nickel-Vanadium Phosphide Nanosheet Arrays for Efficient Alkaline Oxygen Evolution Reaction

Abstract Designing noble metal electrocatalysts with ultralow metal loadings for alkaline oxygen evolution reaction (OER) has attracted tremendous attention, since such catalysts can greatly improve noble-metal utilization and cut material expenditure. Herein, we synthesize a high-performance and durable OER electrocatalyst (Ir−NiVP). In this material, ultrafine Ir nanoclusters (∼2 nm) are homogeneously immobilized on nickel-vanadium phosphide nanosheet arrays grown on carbon cloth. The low-loading Ir nanoclusters (3.4 wt %) regulate the electronic configuration of the NiVP substrate, endowing the catalyst with high OER activity under alkaline conditions. The Ir−NiVP catalyst delivers a small overpotential of 291 mV at 50 mA cm−2 and maintains stable electrocatalytic behavior over a 120 h multi-step chronopotentiometry test. Moreover, we assemble an alkaline electrolyzer using Ir−NiVP as the anode and Pt/C as the cathode. This electrolyzer achieves 50 mA cm−2 at a cell voltage of 1.61 V and exhibits favorable electrochemical durability. This work puts forward a feasible strategy to construct low-cost yet high-efficiency electrocatalysts and provides experimental support for green hydrogen production technology by exploiting the synergy between noble metals and transition metal substrates.