Aqueous exfoliated 2D cobalt-iron-layered double hydroxide nanosheets: Effect of Co:Fe ratio on electrocatalytic oxygen evolution reaction

• Published in: Colloids and surfaces. A, Physicochemical and engineering aspects Physicochemical and engineering aspects, 2025-02, Vol.706, p.135793, Article 135793
• Main Authors: Pawar, Shraddha A., Talekar, Shweta V., Sawant, Prashant D., Magdum, Vikas V., Kulkarni, Shirin P., Chitare, Yogesh M., Lokhande, Chandrakant D., Yadav, Hemraj M., Gunjakar, Jayavant L.
• Format: Article
• Language: English
• Subjects: Co-precipitation; Layered double hydroxide; Oxygen evolution reaction; Water exfoliation
• ISSN: 0927-7757
• DOI: 10.1016/j.colsurfa.2024.135793

The water exfoliation strategy is utilized to synthesize ultrathin monolayers of 2-dimensional cobalt-iron-layered double hydroxide nanosheets (CFL-NS) for application in the electrocatalytic oxygen evolution reaction (OER). These nanosheets exhibit a hexagonal crystal structure, and their zeta potential varies between +30 mV and +36 mV, depending on the Co:Fe ratio. The electron microscopy analysis reveals aggregated ultrathin nanosheets with a lateral size of ∼75 nm and the formation of very small nanoparticles due to the tearing of CFL-NS. The bulk CFL and CFL-NS with Co:Fe ratio of 3:1 demonstrate outstanding OER performance, with an overpotential of 305 and 299 mV at a current density of 10 and 25 mA cm−2, respectively. Additionally, they exhibit a high electrochemical active surface area (ECSA) of 8.5 cm2, a Tafel slope of 47 mV dec−1, and excellent electrocatalytic stability during a chronoamperometric test of 24 h. This study underscores the benefits of an aqueous LDH exfoliation strategy for achieving enhanced electrocatalytic performance of CFL-NS. [Display omitted]