Fe-Doped Ni3 C Nanodots in N-Doped Carbon Nanosheets for Efficient Hydrogen-Evolution and Oxygen-Evolution Electrocatalysis

Abstract

Uniform Ni₃ C nanodots dispersed in ultrathin N-doped carbon nanosheets were successfully prepared by carburization of the two dimensional (2D) nickel cyanide coordination polymer precursors. The Ni₃ C based nanosheets have lateral length of about 200 nm and thickness of 10 nm. When doped with Fe, the Ni₃ C based nanosheets exhibited outstanding electrocatalytic properties for both the hydrogen evolution reaction (HER) and oxygen evolution reaction (OER). For example, 2 at % Fe (atomic percent) doped Ni₃ C nanosheets depict a low overpotential (292 mV) and a small Tafel slope (41.3 mV dec^-1 ) for HER in KOH solution. An outstanding OER catalytic property is also achieved with a low overpotential of 275 mV and a small Tafel slope of 62 mV dec^-1 in KOH solution. Such nanodot-incorporated 2D hybrid structures can serve as an efficient bifunctional electrocatalyst for overall water splitting.

Keywords: HER; Ni3C nanodots; OER; bifunctional electrocatalysts; nanosheets.