Self-templating synthesis of nickel-iron hydroxide for highly efficient oxygen evolution reaction

초록

As the importance of research and development of alternative energy for fossil is highlighted due to the depletion of fossil fuels and generation of greenhouse gases, hydrogen, which has excellent energy conversion efficiency and environmental advantage, is attracting attention as a next-generation alternative energy. However, noble metal catalysts (Pt, Ru, Ir) with good water electrolysis performance are hindering commercialization due to their high price. To overcome this bottleneck, many studies on alkaline water electrolysis systems that can use transition metal-based catalysts that are relatively inexpensive and have abundant reserves are being conducted. However, the transition metal catalyst has disadvantages of having high overpotential and low stability. Among the transition metal catalysts, it is known that iron acts as a co-catalyst for generating oxygen in a nickel-iron binary catalyst, showing superior performance than a single catalyst. Therefore, since nickel-iron binary catalysts show excellent performance, studies on water electrolysis performance in various structures such as oxides, chalcogen compounds, and hydroxides are being conducted. In this experiment, a large-area nickel foam was supported in a solution of ferric chloride and oxalate without special equipment at room temperature to form a nickel-iron composite nanostructured metal oxalate in various ratios on the surface. It was confirmed that the electrochemically active surface area and electrical conductivity changes according to the nickel and iron ratios, and the oxygen generation performance changes accordingly, and that the catalyst in the optimum condition shows excellent stability.