Tailoring the surface in copper manganese oxide materials and enhanced redox nature by graphitic carbon nitride sheets with ultra-long life for electrochemical applications

Designing different micro/nanostructured materials with high electrical conductivity and porosity has attracted significant attention, making their extraordinary electrochemical properties available in the field of energy storage. Herein, we report the preparation of copper manganese oxide (CMO) nanoparticles supported by graphitic carbon nitride (gC₃N₄) sheets (i.e.gCN-CMO) by a facile silicone oil-bath method. The surface of the CMO nanoparticles was optimized by changing the temperature conditions. Furthermore, the gCN-CMO material exhibits a high specific capacity of 250 mA h g⁻¹at a current density of 1.5 A g⁻¹. For comparison, the electrochemical properties of CMO electrodes were also investigated at different temperatures. The fabricated pouch-type asymmetric supercapacitor (ASC) device reveals good energy density (29.3 W h kg⁻¹) and power density (2018 W kg⁻¹) with enhanced rate capability. Additionally, the ASC device exhibits an ultra-long cycling stability with a capacity retention of 84% after 100 000 cycles at a current density of 20 mA cm⁻²with a corresponding coulombic efficiency of 99%. Moreover, a green light-emitting diode is powered using the ASCs to test real-world applications. On the other hand, the oxygen reduction reaction activity of the gCN-CMO material is also studied. The obtained results strongly suggest that the gCN-CMO-based electrode materials with desirable characteristics are very promising in the field of energy storage.