Carbon Dots Decorated Hierarchical NiCo2S4/Ni3S2 Composite for Efficient Water Splitting

Abstract

The decomposition of water into hydrogen and oxygen is an effective method to generate new energy. How to develop highly efficient catalysts with low cost for the hydrolysis of water is a huge challenge. Herein, heterogeneous CDs/NiCo2S4/Ni3S2 nanorods were constructed on nickel foam (CDs/NiCo2S4/Ni3S2/NF) by Co ion exchange on carbon dots (CDs) and sulfur codoped nickel foam (NF). The designed CDs/NiCo2S4/Ni3S2/NF as a self-standing electrocatalyst shows excellent electrocatalytic properties. In the hydrogen evolution reaction process, the current density can reach 10 mA cm–2 only with the overpotential of 0.127 V. During the oxygen evolution reaction process, overpotential of 0.116 V is enough to achieve the same current density. Meanwhile, the CDs/NiCo2S4/Ni3S2/NF electrode can serve as both anode and cathode in alkaline electrolyte, and overpotential of 1.50 V can drive the overall water splitting with superior durability. Such excellent properties are mainly due to (1) a large number of exposed activ...