Sulfur-Rich N-Doped Co₉S₈ Catalyst for Highly Efficient and Durable Overall Water Electrolysis Application

Figure 1

Schematic illustration of the experimental process for the fabrication of the CoS, N-Co₉S₈, and S,N-Co₉S₈ catalysts. (a) Autoclave containing the mixed solution and precleaned NF substrate. The CoS phase was obtained at 150°C with a deposition time of 6 h. (b) The proposed S,N-Co₉S₈ catalyst electrode was obtained under an N₂ environment (3 h at 700 K; N-Co₉S₈), and (c) the subsequent anion-exchange process was conducted in 0.1 M CH₄N₂S at 120°C for 10 h. (d) Experimental three-electrode setup for electrocatalytic OER and HER activities. (e) Typical electrocatalytic OER and HER reaction mechanisms in 1.0 M KOH electrolyte.