Ir-doped Co3O4 as efficient electrocatalyst for acidic oxygen evolution reaction

Abstract

Oxygen evolution reaction (OER) is an important bottleneck for large-scale acidic water splitting applications due to its sluggish reaction kinetics. Therefore, the development of highly active, stable, and inexpensive electrocatalysts for OER remains a challenge. Herein, we develop the iridium doped Co3O4 (Ir–Co3O4) with low Ir content of 2.88 wt% for efficient acidic OER. Considering systemic characterizations, it is probably concluded that Ir can be uniformly doped into the lattice of Co3O4 and induce a certain distortion. The electrochemical results reveal that Ir–Co3O4 nanoparticles demonstrate significantly enhanced electrocatalytic OER activity and stability in 0.5 M H2SO4 solution compared with pure Co3O4, in which the overpotential at the current density of 10 mA cm−2 decreases from 382 mV to 225 mV and the value of Tafel slope decreases from 101.7 mV dec−1 to 64.1 mV dec−1. Besides, Ir–Co3O4 exhibits excellent electrocatalytic durability for continuous 130 h's test without any activity attenuation. Moreover, this work provides a kind of high-performance acidic OER electrocatalyst for the development of hydrogen energy.