Development of nickel-cobalt-zinc oxide/manganese-nickel hydroxide/reduced graphene oxide on nickel foam for efficient supercapacitors and oxygen evolution reaction applications

Incorporating carbon materials with transition metal compounds (TMC) to form the hierarchical heterostructure is a valid strategy for creating advanced electrode materials in developing supercapacitors and oxygen evolution reactions (OER). Herein, this work presents a hierarchical heterostructure, denoted as NCZO/Mn–Ni(OH)2/rGO/NF, where manganese-nickel hydroxide (Mn–Ni(OH)2) is anchored on nickelcobalt-zinc oxide (NCZO) and grown on reduced graphene oxide/nickel foam (rGO/NF). The hierarchical heterostructure of NCZO/Mn–Ni(OH)2/rGO/NF provides abundant reaction sites and enhances ion transport rates, effectively addressing the weak conductivity and restacking issue of Mn–Ni(OH)2. Electrochemical investigations concluded that the NCZO/Mn–Ni(OH)2/rGO/NF demonstrates an exceptional specific capacitance of 3344.44 F g−1 (1505 C g−1 or 418.1 mAh g−1) and excellent cycling stability (75.6 % at 10000 cycles). Moreover, the NCZO/Mn–Ni(OH)2/rGO/NF//AC recombination exhibits excellent energy density (72.22 Wh kg−1 at 799.87W kg−1) and excellent cycling stability (88.6 % at 8000 cycles). In the meantime, the overpotential of the NCZO/Mn–Ni(OH)2/rGO/NF material at 50 mA cm−2 was 407 mV for the OER. These results show that NCZO/Mn–Ni(OH)2/rGO/NF proposes an effective strategy for designing bifunctional electrode materials suitable for use in both supercapacitors and oxygen evolution reactions.