NiMn₂O₄ spinel binary nanostructure decorated on three-dimensional reduced graphene oxide hydrogel for bifunctional...

Nickel-manganese spinel oxide (NiMn₂O₄) was hybridized with reduced graphene oxide hydrogel (rGOH) via a facile solvothermal process and a highly porous three-dimensional (3D) structure was constructed. NiMn₂O₄/rGOH exhibited excellent electrochemical performance due to the high specific surface area, excellent electrocatalytic activity, and enhanced electrical conductivity due to the synergetic effects between the two components. The NiMn₂O₄/rGOH exhibited excellent glucose sensing performance with high sensitivity (1310.8 μA mM^-1 cm^-2), a wide linear range (2 μM-20 mM), rapid response time (<3.5 s), and anti-interference properties. Furthermore, it also showed excellent supercapacitor performance with a high capacitance (396.85 F g^-1) and excellent energy and power density on account of the large surface area and pseudo-capacitor behavior of NiMn₂O₄. A self-powered glucose sensor can be fabricated with NiMn₂O₄/rGOH as both supercapacitor and glucose sensing electrodes.