Smart Textile Flexible MnCo 2 O 4 Electrodes: Urea Surface Modification for Improved Electrochemical Functionality.

Surface microstructure modification of metal oxides also improves the electrochemical performance of metal oxide nanoparticles. The present investigation demonstrates how varying the urea molar content during the hydrothermal process altered the surfaces of MnCo 2 O 4 nanoparticles. Successive increases of 0.1 M in urea concentration transformed the surface shape of MnCo 2 O 4 nanoparticles from flower-like to sheet-like microstructures. Excellent electrochemical performance of MnCo 2 O 4 nanoparticles was demonstrated in an aqueous 1 M KOH electrolyte. The improved MnCo 2 O 4 nanoparticles have been employed to develop an asymmetric supercapacitor (ASC). The ASC device exhibits an energy density of 13 Wh/kg at a power density of 553 W/kg and a specific capacitance of 29 F g -1 at a current density of 4 mA/cm 2 . The MnCo 2 O 4 nanoparticle electrode demonstrates remarkable electrocatalytic activity in both HER and OER. The MnCo 2 O 4 electrode shows overpotential for HER and OER at 356 mV and 1.46 V, respectively. The Tafel slopes for HER and OER of the MnCo 2 O 4 electrode are 356 mV/dec and 187 mV/dec, respectively.