Electrocatalytic evolution of hydrogen on the NiCu/Al2O3/nano-carbon network composite electrode

We present a way to fabricate the NiCu/Al₂O₃/nano-carbon network (NCN) composite electrode by coelectrodepositing NiCu particles, using a novel conductive alumina/NCN composite material as the support. The morphology, crystalline phases, and compositions are characterized by field-emission scanning electron microscope, energy dispersive X-ray spectroscope, X-ray diffraction, and Raman spectroscopy. The electrocatalytic behaviors of this NiCu/Al₂O₃/NCN composite material for hydrogen evolution reaction (HER) in alkaline solution are studied by cathodic polarization curves, electrochemical impedance spectroscopy (EIS), and chronoamperometry. The results show that nickel–copper particles are briefly deposited and uniformly distributed over the carbon layer of the conductive ceramics between alumina grains, in the form of a NiCu solid solution with face-centered cubic structure. The NiCu/Al₂O₃/NCN composite displays a high electrochemical stability in alkaline solution and relatively high electrocatalytic activity for HER due to its relatively high real surface area and high intrinsic electrocatalytic effect of NiCu alloy particles. The associated kinetic parameters of HER are systematically investigated using EIS.