Tuning porous nanostructures of MnCo2O4 for application in supercapacitors and catalysis

Abstract

It is shown that spinel type MnCo₂O₄ can be used as a pure negative electrode in supercapacitors. The electrochemical response can be significantly tuned by forming and modulating the mesoporous structures of these materials. With varying formation temperature, the nature of particle growth mechanism moves from Oswald ripening type to digestive ripening. This leads to increased surface area, porosity and charged states on the particles surface. Thus, making this material useful from application ranging from supercapacitors to catalysis. As a function of changing porosity, specific capacitance could be tuned in the range ∼290 F g⁻¹. Added functionality of the material could be established by proving its excellent catalytic response for reducing p-nitrophenol, a common pollutant found in industrial waste streams. The sample calcined at 800 °C reduced p-nitrophenol in 8 min at 1 mg mL⁻¹ catalyst concentration, while the sample obtained at 400 °C could complete the task only after 16 min. The superior catalytic response have been explained by analyzing the change in zeta potential, which develops on the surface of different porous structures.