Ultrahigh density defects of Mn₃O₄ boosting oxygen evolution reaction

College of Chemistry and Chemical engineering, China University of Petroleum (East China), Qingdao 266580, China

Abstract

Surface defects have a positive effect on the improvement of electrocatalytic performance due to the ability to introduce half-metallicity into selected semiconductors. Herein, we prepare a defect-rich Ni-doped Mn3O4 (Ni-Mn3O4) material by a simple hydrothermal and impregnation method. Ni-Mn3O4 exhibits a unique morphology consisting of ultrathin nanoarrays and nanoflowers embellished at the top, which endows the material with large specific surface area and reactive sites and contributes to enhanced oxygen evolution reaction (OER). The obtained Ni-Mn3O4 shows improved OER activity with the overpotential of 290 mV at the current density of 20 mA cm^-2. This remarkable OER performance can be attributed to the multi-dimensional interface and ultra-high density defects, leading to the formation of abundant active sites, thereby inducing half-metallicity properties and suitable intermediate adsorption energies. This work is expected to provide reference and guidance for the design and synthesis of high-performance electrocatalysts.