Colloidal synthesis of NiMn₂O₄ nanodisks decorated reduced graphene oxide for electrochemical applications

This work describes the preparation of spinel NiMn₂O₄ nanodisks decorated reduced graphene oxide (rGO) via low-temperature colloidal solution method and analyzes their performances as electro-active electrode for electrochemical sensor and supercapacitors. The morphological analysis revealed the well-decorated spinel NiMn₂O₄ nanodiks over the rGO surfaces. The crystalline, structure, and composition of spinel NiMn₂O₄nanodisks decorated rGO was studied and extensively used as electrode materials for electrochemical applications. For sensing measurements, the NiMn₂O₄/rGO composite modified GCE expressed the high sensitivity of 78.56 mA.mM⁻¹·cm⁻² with an excellent linear dynamic range of 1.0 μM–500.0 μM towards the acetylacetone chemical. The electrode prepared by NiMn₂O₄/rGO composite was applied to fabricate the double layer electrochemical supercapacitors. NiMn₂O₄/rGO electrode showed a reasonably high specific capacitance of 356 F g⁻¹ at a current density of 0.5 Ag⁻¹ in 1 M Na₂SO₄ electrolyte. The fabricated supercapacitor exhibited the admirable rate capability by maintaining 86% from initial capacity after 5000 cycles. The prepared NiMn₂O₄/rGO composite and obtained results are the promising electrode materials for achieving high-performance sensing and supercapacitors.