Nanostructured Fe-Doped Ni<sub>3</sub>S<sub>2</sub> Electrocatalyst for the Oxygen Evolution Reaction with High Stability at an Industrially-Relevant Current Density
Jiahui Zhu, Wei Chen, Stefano Poli, Tao Jiang, D Gerlach, João R. C. Junqueira, Marc C. A. Stuart, Vasileios Kyriakou, Marta C. Figueiredo, Petra Rudolf, Matteo Miola, Dulce M. Morales, Paolo P. Pescarmona
Abstract
High Resolution Image Download MS PowerPoint Slide A novel oxygen evolution reaction (OER) electrocatalyst was prepared by a synthesis strategy consisting of the solvothermal growth of Ni 3 S 2 nanostructures on Ni foam, followed by hydrothermal incorporation of Fe species (Fe–Ni 3 S 2 /Ni foam). This electrocatalyst displayed a low OER overpotential of 230 mV at 100 mA·cm –2, a low Tafel slope of 43 mV·dec –1, and constant performance at an industrially relevant current density (500 mA·cm –2 ) over 100 h in a 1.0 M KOH electrolyte, despite a minor loss of Fe in the process. Based on a detailed characterization by (in situ) Raman spectroscopy, (quasi-in situ) XPS, SEM, TEM, XRD, ICP-AES, EIS, and C dl analysis, the high OER activity and stability of Fe–Ni 3 S 2 /Ni foam were attributed to the nanostructuring of the surface in the form of stable nanosheets and to the combination of Ni 3 S 2 granting suitable electrical conductivity with newly formed NiFe-based (oxy)hydroxides at the surface of the material providing the active sites for OER.