Laser synthesis of cobalt-doped Ni3S4-NiS/Ni as high-efficiency supercapacitor electrode and urea oxidation electrocatalyst

Abstract

Elemental doping is deemed to enhance the intrinsic conductivity, enrich the redox sites and boost the electrochemical performance in energy storage and conversion fields. However, conventional methods of introducing heterogeneous atoms into nickel sulfides are usually complex multi-step reaction and time consuming or unable to gain satisfactory electrochemical performance. Herein, pulsed laser ablation in liquids, as a simple and fast synthesis technique, was employed to prepare cobalt-doped Ni3S4-NiS/Ni nanomaterials with the composite morphology of nanosheets and nanoparticles. The first-principles calculation and experimental results indicated that cobalt doping into nickel sulfides can modify the electronic structure and morphology of nickel sulfide and thus promote the internal electron transport, enrich the redox sites and boost electrochemical performance. The optimized cobalt-doped Ni3S4-NiS/Ni electrode materials presented an outstanding specific capacity with 1940 F g−1 at 1 A g−1 and UOR catalytic property with a potential of 1.350 V (vs. RHE) at 10 mA cm−2. In addition, the cobalt-doped Ni3S4-NiS/Ni//AC device also exhibited excellent energy and power densities and good cyclic stability of 87.27% after 3000 cycles. This work can provide a simple and availably strategy for exploring other element doping electrode materials with fast electron transport.