Ar Plasma Exfoliated Nickel Iron Layered Double Hydroxide Nanosheets into Ultrathin Nanosheets as Highly-Efficient Electrocatalysts for Water Oxidation

Abstract

Layered double hydroxides (LDHs) as a electrocatalyst had exhibited a good oxygen evolution reaction (OER) performance. However, the bulk NiFe LDHs nanosheets with a large lateral size and bulk thickness hindering the exposure of active sites and reducing the electrocatalytic activity of reactive sites. Herein, the bulk NiFe LDHs nanosheets were successfully exfoliated into 2D ultrathin NiFe LDHs nanosheets by one-step Ar plasma. This unique structure of NiFe LDH increased the surface area and the exposure of active sites improving the electrocatalytic performance for OER. Moreover, Ar plasma also further etched the basal planes of 2D crystals leading to production of more edge and corner sites which had much higher catalytic activity than positions in the basal planes. Therefore, this ultrathin NiFe LDHs nanosheets with rich edges and corners as electrocatalyst showed a good OER activity with a low overpotential of 278 mV at 10 mA/cm2.