Activation of a Ni electrocatalyst through spontaneous transformation of nickel sulfide to nickel hydroxide in an oxygen evolution reaction

• Published in: Applied catalysis. B, Environmental Environmental, 2018-10, Vol.233, p.130-135
• Main Authors: Lee, Minoh, Oh, Hyung-Suk, Cho, Min Kyung, Ahn, Jae-Pyoung, Hwang, Yun Jeong, Min, Byoung Koun
• Format: Article
• Language: English
• Subjects: Catalysts; Chemical synthesis; Electrocatalysis; Electrocatalyst; Electrocatalysts; Metal foams; Metal-chalcogenide; Nickel; Nickel compounds; Nickel hydroxide; Nickel sulfide; Nitrogen; Oxidation; Oxygen; Oxygen evolution reaction; Oxygen evolution reactions; Sulfide; Sulfide compounds; Sulfides; Sulfur; Sulfurization
• ISSN: 0926-3373; 1873-3883
• DOI: 10.1016/j.apcatb.2018.03.083

[Display omitted] •Electro-oxidation treatment on Ni-sulfide/Ni foam highly improves its OER activity.•Sulfurization of Ni facilitates the formation of Ni-(oxy)hydroxide layer on the surface.•Ni3S2 derived amorphous/crystalline Ni-(oxy)hydroxide mixtures with Fe are active for OER.•Sulfur in Ni3S2 activates to form nanoparticle embedded layered structures in amorphous matrix. Ni-sulfide compounds synthesized on Ni foam by simple thermal sulfurization are employed as electrocatalysts for water oxidation, resulting in superior activity in alkaline electrolyte media. The role of sulfur in Ni-sulfide was found to be an activator that transformed sulfide into hydroxide, which was eventually transformed into (oxy)hydroxide. The Ni-(oxy)hydroxide phase was also found to be layered and/or amorphous. This activated catalyst showed significant enhancement in water oxidation performance with a low overpotential value of 256 mV at current density of 10 mA cm−2. Our observation could offer important insight into metal-chalcogenide electrocatalyst for water oxidation.