Advancing Oxygen Evolution Catalysis with Dual-Phase Nickel Sulfide Nanostructures

• Published in: Energy & fuels 2025-01, Vol.39 (2), p.1375-1383
• Main Authors: M Santhosh, Neelakandan, Gupta, Suraj, Shvalya, Vasyl, Košiček, Martin, Zavašnik, Janez, Cvelbar, Uroš
• Format: Article
• Language: English
• Subjects: Catalysis and Kinetics
• ISSN: 0887-0624; 1520-5029
• DOI: 10.1021/acs.energyfuels.4c05182

The production, conversion and storage of energy based on electrocatalysis, mainly assisted by oxygen evolution reaction (OER), plays a crucial role in alkaline water electrolyzers (AWEs) and fuel cells. Nevertheless, the insufficient availability of highly efficient catalyst materials at a reasonable cost that overcome the sluggish electrochemical kinetics of the OER is one of the significant obstacles. Herein, we report a fast and facile synthesis of vapor phase deposition of dual-phase nickel sulfide (Ni-sulfide) using low-temperature annealing in the presence of H2S and demonstrated as an efficient catalyst for OER to address the issues with sluggish electrochemical kinetics. The dual-phase Ni-sulfide structures consist of densely packed 10–50 μm microcrystals with 40–50 individual dual-phase layers, such as NiS and Ni7S6. As an electrocatalyst, the dual-phase Ni-sulfide exhibits excellent OER activity by achieving a current density of 10 mA/cm2 at an overpotential (η10) of 0.29 V and excellent electrochemical stability over 50 h. Besides, the Ni-sulfide displays considerable electrochemical robustness in alkaline conditions and forms OER-active Ni-oxide/hydroxide species during the process. Using an energy-efficient synthesis method, the fabricated unique crystalline nanodesign of dual-phase Ni-sulfide could open new pathways for the controlled synthesis of a high-efficiency group of electrocatalysts for a long-time stable electrochemical catalytic activity.