MnO2@Co3O4 nanocomposite based electrocatalyst for effective oxygen evolution reaction

Abstract

For large-scale energy applications, conceiving low-cost and simple earth-abundant electrocatalysts are more difficult. By using an aqueous chemical technique, MnO2 was added into Co3O4 with varying concentrations to prepare MnO2@Co3O4 nanocomposite (CM). In an aqueous solution of 1 M KOH, the electrocatalyst with a greater concentration of MnO2 outperforms in terms of OER. To confirm the composition, crystalline structure, and morphology of the electrocatalyst, analytical methods such as X-ray diffraction (XRD) techniques, Fourier transformed infrared spectroscopy (FTIR) and scanning electron microscopy (SEM) were used. At 20 mA/cm2 current density, the electrocatalyst had a lowest overpotential of 310 mV verses Reversible hydrogen electrode (RHE). The CM-0.4 electrocatalyst has a small Tafel slope value and charge transfer resistance of approximately 72 mV/dec and 74 Ω which confirm its high catalytic activity. The electrocatalyst reveals a double layer capacitance (Rct) of 18 µF/cm2 and an electrochemical active surface area (ECSA) of 450 cm2, demonstrating that addition of MnO2 impurities into Co3O4 enhances the active catalyst sites. These findings contribute to the knowledge of these kind of catalysts, that will assist in the development of novel electrocatalysts which are feasible for prospective energy generation technologies.

In-situ growth of nonstoichiometric CrO0.87 and Co3O4 hybrid system for the enhanced electrocatalytic water splitting in alkaline media

“…However, there was only a significant difference observed between O-Co-O and Co-O metal oxide peaks at 667 cm -1 and 577 cm -1 , respectively [58,59]. FTIR studies indicated that higher concentrations of potassium chromate resulted in a decrease in metal oxide peaks, which indicates in situ growth of CrO0.87 and Co3O4.…”

One-pot synthesis of crystalline structure: Nickel-iron phosphide and selenide for hydrogen production in alkaline water splitting

“…In Figure 6c, the morphology of Ni-Fe-P-Se can be seen, which shows a higher amount of prepared material on NF, with varied surface features than both previous samples of Ni-P-Se and Fe-P-Se, respectively. Through the SEM images, we have observed agglomerated surface features of various elements within the as-prepared Ni-Fe-P-Se structure as a potential composite for electrochemical water splitting application [34,35].…”

PdO@CoSe2 composites: efficient electrocatalysts for water oxidation in alkaline media

“…Numerous studies have been conducted to nd low-cost and earthabundant electrocatalysts that foster water oxidation. 17,18 Various transition-metal based oxides, 19,20 suldes, 21,22 phosphides, 23,24 selenides 25 electrocatalysts for water oxidation have been reported. Extensive studies have been performed for the development of efficient, facile, stable and earth abundant electrocatalysts for the hydrogen production due the fact that the complete exploitation of hydrogen fuel from water splitting is restricted by high energy demanding half-cell water oxidation reaction.…”