| Abstract [eng] |
This master thesis investigates the effectiveness of ternary nickel-iron-phosphorous (NiFeP) coatings as electrocatalysts for water splitting, targeting enhancements in hydrogen and oxygen production efficiencies. This study aligns with the 2020 European Union Hydrogen Strategy, which aims at promoting clean hydrogen technologies to bolster sustainable economic growth, diminish carbon emissions, and enhance energy security. Focused on three distinct electrocatalysts—Ni85Fe4P12, Ni80Fe8P12, Ni75Fe12P12—synthesized via electroless plating, this research employs scanning electron microscopy (SEM) and energy dispersive x-ray spectroscopy (EDS) for structural and compositional characterization. The electrocatalytic activity was assessed through linear sweep voltammetry in an alkaline medium across a temperature range of 25 to 55°C, using potential scan rate of 2 mVs-1. Results demonstrate that the NiFeP coatings, fabricated using sodium hypophosphite as a reducing agent, exhibited crack-free and globular morphology. The electrocatalyst Ni85Fe4P12 showed the highest catalytic efficiency in the hydrogen evolution reaction (HER) with the lowest overpotential of 352 mV at 10 mA cm-2 and a Tafel slope of 79 mV dec-1. In the oxygen evolution reaction (OER), Ni80Fe8P12 and Ni75Fe12P12 demonstrated significant efficiency, correlating the catalytic performance to the iron content within the catalyst. This study underscores the critical influence of Fe concentration on the catalytic efficacy of NiFeP coatings, with reduced Fe content enhancing HER and increased Fe content benefiting OER. These findings contribute valuable insights into the design of cost-effective electrocatalysts for clean hydrogen production. |
