Fe2O3 facilitating deeper transformation of Ni-MOF into active NiOOH for enhanced OER performance

Abstract

Due to the large specific surface area and the highly-exposed active metal centers, nickel metal-organic frameworks (MOFs) have recently emerged as one of the excellent functional materials for oxygen evolution reactions (OER). Herein, we have construct uniformly distributed Fe2O3 particles within Ni-MOF nanosheets (Ni-MOF NSs) for enhanced OER performance. This electrocatalyst, prepared by a facile hydrothermal method, provides highly active Fe2O3 particles while preserving the framework structure of Ni-MOF for effective substrates diffusion. The optimal Fe2O3 doped Ni-MOF NSs deliver high stability in alkaline and exhibit striking OER performance with an overpotential of 232 mV at 10 mA cm−2 and a Tafel slope of 49.3 mV dec−1, outperforming the pristine Ni-MOF and most reported non-noble metal based electrocatalysts. The enhance catalytic activity of Fe2O3 doped Ni-MOF NSs is likely due to the introduction of Fe2O3 particles to facilitate the deeper transformation of Ni-MOF into active NiOOH species.