Nickel and cobalt co-doped MnCO3 nanostructures for water oxidation reaction

Nowadays, electrochemical water splitting is a securing alternative for clean-energy production and also an efficient expertise for oxygen and hydrogen production. Compared to single metal-based electrocatalyst, multi metal-based electrocatalyst offers more active sites, high surface area, and distinctive nanostructure for effective water oxidation. In this work, nickel and cobalt co-doped MnCO₃ was successfully synthesized via a facile co-precipitation technique. Rhombohedral crystal phase of MnCO₃ nanostructures and its crystallite sizes were thoroughly analyzed by the XRD spectra. Incorporation of doping element such as Ni and Co in MnCO₃ nanostructures exhibited two different morphologies which enhanced the catalytic performance of the prepared samples. Large surface area and porosity of the nanomaterials improved the stability and activity of the prepared MnCO₃ nanostructures. EDX analysis confirmed Mn, C, O, Ni and Co elements in stoichometric ratio. Moreover, the specific capacitance of (Ni, Co) co-doped MnCO₃ nanostructures attained 581 F/g while the other electrodes attained only 207, 332 and 175 F/g respectively. A small Tafel slope with low overpotential of Ni, Co co-doped MnCO₃ nanostructures was 20.2 mV/dec and 293 mV respectively. Therefore, the prepared electrocatalysts of Ni, Co co-doped MnCO₃ nanostructure is one of the attractive anode material for high performance energy conversion applications.