Well-defined hierarchical teddy bear sunflower-like NiCo2O4 electrocatalyst for superior water oxidation. Issue 24 (14th November 2022)

• Record Type: Journal Article
• Authors: Bodhankar, Pradnya M.; Dhawale, Dattatray S.; Giddey, Sarbjit; Kumar, Ravi; Sarawade, Pradip B.
• Is Part Of: Sustainable energy & fuels. Volume 6:Issue 24(2022)
• Page Start: 5491
• Page End: 5502
• Publication Date: 2022-11-14
• Subjects: Renewable energy sources -- Periodicals; Fuel cells -- Periodicals; Electric batteries -- Periodicals; Electrochemistry -- Periodicals; 660.297
• DOI: 10.1039/d2se01111e
• Languages: English
• ISSNs: 2398-4902

Abstract

Abstract : Transition metal oxides were fabricated by a facile solvothermal route. The hierarchical NiCo2 O4 electrocatalyst exhibited enhanced water oxidation performance due to the unique teddy bear sunflower-like morphology. Abstract : The development of a robust and efficient electrocatalyst for water oxidation is challenging due to the large overpotential requirement to transfer four electrons. Herein, a novel spinel-type hierarchical teddy bear sunflower-like NiCo2 O4 electrocatalyst was synthesized through the facile solvothermal process and evaluated for the challenging and demanding oxygen evolution reaction (OER) in the water electrolysis process. The teddy bear sunflower-like NiCo2 O4 supported on nickel foam (NF) delivers a current density of 50 mA cm −2 at a small water oxidation overpotential ( η 50 = 319 mV) which is significantly lower than that of the corresponding spherical NiO/NF ( η 50 = 338 mV), and sea-urchin like Co3 O4 /NF ( η 50 = 357 mV). A large specific and electroactive surface area, as well as a high TOF value exhibited by the hierarchical teddy bear sunflower-like NiCo2 O4 electrocatalyst, demonstrates the potential of NiCo2 O4 to catalyze the water oxidation reaction efficiently. The impact of the near-Fermi-level d-orbital states in NiCo2 O4 electrocatalyst for boosting OER activity was unveiled by the density functional theory calculation. The stable performance even after 16 h and high catalyst utilization of the hierarchical teddy bear sunflower-like NiCo2 O4 through the OER indicates that the catalyst is highly suitable for the large-scale water oxidation process.