Preparation of Ni-NiO/N-C electrocatalyst and its performance for water splitting into hydrogen

The hydrogen production from hydrogen evolution reaction (HER) in electrochemical water splitting is considered to be one of the most promising energy conversion methods, which can simultaneously obtain high purity hydrogen and realize energy storage and conversion. The key depends on the development of HER electrocatalysts with high efficiency, high stability and low price. A series of NiOOH/polyaniline (NiOOH/PANI) catalyst precursors were prepared via one-pot hydrothermal method. After pyrolysis at 800°C, the Ni-NiO/N-C electrocatalysts were obtained and applied to HER. The XRD, SEM, TEM, BET, XPS and Raman spectroscopy were conducted to analyze the physical and chemical properties of the catalysts. Results show that the catalysts are present in the nanosheet morphology, the nickel and nickel oxide are coexisted and highly dispersed in the carbon support. The results of HER tests demonstrate that the catalytic performance is closely related with the content of nickel in the catalyst, and the Ni-NiO/N-C-0.6 catalyst with the aniline addition of 0.6 mL exhibits the best performance for HER, which has an overpotential of only 168 mV at a current density of 10 mA·cm⁻². Besides, the catalyst also has good catalytic stability with almost no detectable activity decay after 16 h HER test or 1000 times of cyclic voltammetry measurements, demonstrating broad application prospects.