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Updated: May 13, 2025
Thermochemical Studies of NiII and ZnII Ternary Complexes Using Ion Mobility-Mass Spectrometry
Published on: June 8, 2022
A Tetranuclear NiII 4O4 Cubane Molecular Complex as an Efficient Electrocatalyst for Oxygen Evolution Reaction: From
Joshi Ankitkumar Bharatbhai1, Soumalya Roy2, Atanu Dey3
1Department of Basic Sciences, Chemistry Discipline Institute of Infrastructure Technology Research and Management, Near Khokhra Circle Maninagar East, Ahmedabad, Gujarat, 380026, India.
Abstract:
The oxygen evolution reaction (OER) is integral to electrochemical energy systems; however, its intrinsic sluggish kinetics necessitate the design of high-performance electrocatalysts to minimize overpotential, enhance the durability, and optimize the efficiency. Significant efforts have been dedicated to developing OER catalysts based on earth-abundant transition-metal complexes. Here, the efficacy of a tetranuclear cubane-cored Ni(II) complex, [Ni₄(LH)₄(MeOH)]·CHCl₃ (1), in OER is demonstrated. The complex is synthesized using a tetradentate Schiff-base ligand, [2-{(E)-(2-hydroxyphenylimino)methyl)-6-(hydroxymethyl)-4-methylphenol}], and characterized by single-crystal X-ray diffraction. The redox properties of complex 1 are evaluated by cyclic voltammetry in the solid state, which emphasize the quasireversible oxidation state of the Ni(II) metal center. The complex 1 is immobilized on activated carbon cloth (CC), referred as CC-1, which demonstrates efficient OER catalysis, subsequently activating to form the Ni(O)OH catalyst. The postreaction analysis including UV-vis, FTIR, scanning electron microscopy-energy-dispersive X-ray spectroscopy, and X-ray photoelectron spectroscopy confirm the stability of molecular complex 1. The results demonstrate efficient OER catalysis with a low overpotential of 330 mV versus reversible hydrogen electrode and a Tafel slope of 64 mV dec-1, confirming an effective OER catalyst in alkaline medium with a deep understanding of the core reaction mechanisms.
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