Electrodeposition of Electroactive Co–B and Co–B–C Alloys for Water Splitting Process in 8 M NaOH Solutions

The aim of this work was to determine parameters of obtaining Co–B and Co–B–C alloys characterized by low overpotential in hydrogen evolution reactions. There were tests performed to examine the influence of borax and arginine concentration changes as well as the value of cathodic current intensity on the composition, morphology, synthesis current efficiency, and effectiveness of hydrogen evolution. Carbon was added to Co–B alloys to improve its properties of water decomposition in 8 M NaOH solution at 90 °C. The results of the experiments confirmed a decrease in overpotential values from 48 mV/dec for Co–8.5B alloy to 33 mV/dec for Co–8.2B–9.6C alloy obtained at the highest concentration (0.1 M) of arginine in the electrolyte. It was observed that alloys of good catalytic properties featured an amorphous structure. The coatings were analyzed with the use of a scanning electron microscope (SEM) and X-ray diffraction (XRD). The content of boron was assessed based on the glow discharge spectroscopy (GDS) method, whereas carbon was analyzed with the method of adsorption spectroscopy of infrared radiation.