In situ synthesis of Fe-doped NiC2O4 nanorods for efficient oxygen evolution activity and overall water splitting

Abstract

Electrocatalytic water splitting to hydrogen production is a hot research topic in clean energy. However, due to the slow kinetics of oxygen evolution as one of the semi-reactions of water splitting, it is urgent to develop high-performance and cheap bifunctional catalysts. In this paper, we propose an effective one-step hydrothermal method to synthesize Fe doped NiC2O4 nanorods on Ni foam, which exhibit excellent electrocatalytic performance and stability in alkaline electrolytes. The oxygen evolution reaction overpotential is only 231 mV at 50 mA cm−2 and hydrogen evolution reaction overpotential is only 151 mV at 10 mA cm−2, which is superior to that most NiFe-based catalysts. Furthermore, the overall water-splitting device constructed with Fe doped NiC2O4 as anode and cathode achieves a low voltage of 1.60 V at 10 mA cm−2. The contribution of its excellent performance comes from the increase of effective active area and the decrease of electron transportation resistance after Fe doping. This work provides important guidance for the development of NiFe based catalysts.