Mn-Co layered double hydroxide (LDH) is a promising electrode material for supercapacitor and oxygen evolution reaction (OER) applications due to its unique layered structure with Mn and Co active sites. However, its full potential for supercapacitor and OER applications is underutilized due to its low conductivity and limited availability of active sites. The challenges related to the super capacitive and OER properties of Mn-Co LDH are overcome by combining it with highly redox-active Co2Mn3O8 and highly conductive rGO to form the Mn-Co LDH/rGO/Co2Mn3O8 composite. The hierarchical rosette- and nanoflower-like Mn-Co LDH/rGO/Co2Mn3O8 composite is prepared using a hydrothermal method followed by calcination. Characterization using FESEM, XRD, XPS, and Raman spectroscopy reveals a unique morphology that enhances conductivity and results in improved performance for supercapacitor and OER applications. As a result, the Mn-Co LDH/rGO/Co2Mn3O8 composite demonstrates a high specific capacitance of 2500 F g-1 at 1 A g-1 in a 3 M KOH electrolyte. Furthermore, the asymmetric supercapacitor (ASC) device employing Mn-Co LDH/rGO/Co2Mn3O8 delivers an energy density of 32 Wh kg-1 at a power density of 600 W kg-1. The zinc-ion supercapacitor based on Mn-Co LDH/rGO/Co2Mn3O8 achieves an impressive energy density of 100 Wh kg-1 at a power density of 780 W kg-1. Additionally, Mn-Co LDH/rGO/Co2Mn3O8 performs well for the OER, exhibiting a low overpotential of 218 mV (at 10 mA cm-2) and a small Tafel slope of 56.03 mV dec-1 in 0.1 M KOH. This study opens promising prospects for the dual utilization of Mn-Co LDH/rGO/Co2Mn3O8 in supercapacitor and OER applications.
MinAllah et al. (Thu,) studied this question.