Design and Development of Sustainable Cu2 (II)- and Mn2 (III)-Embedded Bifunctional Electrocatalysts: Enhanced Hydrogen and Oxygen Generation

Niteesh Kumar; Lalita Wagh; Sajid Mehmood; Apurba K Das; Tanmay Kumar Ghorai

doi:10.1021/acs.inorgchem.3c04271

Design and Development of Sustainable Cu₂ (II)- and Mn₂ (III)-Embedded Bifunctional Electrocatalysts: Enhanced Hydrogen and Oxygen Generation

Inorg Chem. 2024 Apr 26. doi: 10.1021/acs.inorgchem.3c04271. Online ahead of print.

Authors

Niteesh Kumar¹, Lalita Wagh², Sajid Mehmood¹, Apurba K Das², Tanmay Kumar Ghorai¹

Affiliations

¹ Nanomaterials and Crystal Design Laboratory, Department of Chemistry, Indira Gandhi National Tribal University, Amarkantak, Anuppur, Madhya Pradesh 484887, India.
² Department of Chemistry, Indian Institute of Technology Indore, Khandwa Road, Simrol, Indore 453552, India.

PMID: 38668850
DOI: 10.1021/acs.inorgchem.3c04271

Abstract

Nowadays, environmentally friendly, low-cost-effective, and sustainable electrocatalysts used widely for hydrogen and oxygen evolution reactions have come into the limelight as a new research topic for scientists. This study highlights the preparation of two unique and symmetrical dinuclear Cu (II) and Mn (III) bifunctional catalysts by a facile simple slow evaporation and diffusion route. [C₃₂H₂₄Cu₂F₄N₄O₄] (1) and [C₃₂H₂₄Mn₂F₄N₄O₄] (2) both have monoclinic (C2/c (15)) crystal systems, with oxidation states +2 and +3, respectively. Prominent SPR peaks at 372 and 412 nm indicate an M-L charge transfer transition in both complexes. The synthesized electrocatalysts display exceptional catalytic activity for the hydrogen evolution reaction (HER) and oxygen evolution reaction (OER). Complex 1 exhibits enhanced hydrogen generation in 0.5 M H₂SO₄ with a small overpotential of 216 mV at -10 mA cm^-2 along with a significantly lower Tafel value of 97 mV/dec compared to Complex 2. Moreover, Complex 1 is highly active for the OER in 1 M KOH with a small Tafel slope of 103 mV/dec and a low overpotential of 340 mV to acquire 10 mA cm^-2 current density, compared to Complex 2. Complex 1 and Complex 2 remain stable up to 20 h in acidic electrolyte and up to 36 h and 20 h in the basic electrolyte, respectively.