Precursor-mediated synthesis of interconnected ultrathin NiFe-layered double hydroxides nanosheets for efficient oxygen evolution electrocatalysis

Abstract

Developing two-dimensional layered double hydroxides (LDHs) electrocatalysts with high efficiency for oxygen evolution reaction (OER) is crucial to the electrocatalytic water splitting. However, the large thickness of the bulk LDHs electrocatalysts greatly limit the OER activity. Hereby, a simple precursor-mediated strategy for synthesis of interconnected ultrathin NiFe-layered double hydroxides (NiFe-LDHs) nanosheets is first proposed, taking the “pre-synthesized” Ni-Fe alkoxides as precursors. The electrochemical studies illustrate that Ni2Fe1-LDHs catalyst with the optimum Ni/Fe ratio shows excellent low overpotential of 245 mV at 10 mA cm−2 and the Tafel slope of 57 mV dec−1, superior to commercial IrO2 and most reported the Ni, Fe based LDH OER electrocatalysts previously, indicating its enormous potential as a low-cost and efficient electrocatalyst for OER. We anticipated that the precursor-mediated synthetic strategy would open a new avenue to offer ultrathin LDHs based electrocatalysts for water splitting.