Quasi-Two-Dimensional Earth-Abundant Bimetallic Electrocatalysts\nfor Oxygen Evolution Reactions

Abstract

The\nextremely large surface area offered by quasi-two-dimensional\n(2D) nanostructures is a great advantage for catalytic applications.\nWhile bimetallic materials have been discovered as a group of promising\ncatalysts for electrochemical water splitting, a facile and reliable\nsynthesis approach toward 2D morphology to fully release its electrochemical\ncatalytic potential is still lacking. In this work, bimetallic Co–Mo–O\nultrathin nanosheets were synthesized by ionic layer epitaxy with\ncontrolled composition ratio. The Co–Mo–O nanosheets\nexhibited a quadrangle shape with a uniform thickness of ∼2.5\nnm. This 2D morphology largely enriched the surface catalytic active\nsite ratio. Particularly, nanosheets with 2:1 Co-to-Mo ratio showed\na substantially enhanced OER catalytic activity with a 3 orders of\nmagnitude higher mass activity compared to benchmark IrO₂ and RuO₂ in an alkaline environment. This study introduces\na promising possibility for creating high-performance electrocatalysts\nfrom 2D bimetallic materials with a high efficiency for material utilization.