Facile Synthesis of Nickel Manganese Composite Oxide Nanomesh for Efficient Oxygen Evolution Reaction and Supercapacitors

•The unique NiMnO nanomesh is firstly synthesized for OER and supercapacitors.•The NiMnO nanomesh possesses special 2D porous structure.•The catalytic properties of NiMnO nanomesh are significantly enhanced.•The NiMnO nanomesh exhibits excellent capacitive properties.

Herein, we introduce a facile two-step means to generate the unique (NiO)0.25(MnO)0.75 nanomesh (NiMnO NM) by employing NiMn3O7.H2O nanosheet as precursor. The characteristics of abundant pores, high specific surface area and decreased ion diffusion distance for meshy NiMnO nanomaterial play a major role in both oxygen evolution reaction (OER) and supercapacitors. For OER, the porous NiMnO NM demonstrates enhanced catalytic properties, such as modest onset overpotential of ∼270 mV as well as Tafel slope of 41 mV dec−1, large Cdl of 22.5 mF cm−2, attractive durability for at least 3000 cycles and improved stability over 80 h at different temperatures in 0.1 M KOH. Meanwhile, the excellent capacitive properties in supercapacitors, including intriguing specific capacitance of 371 F g−1 at a high current density of 10 A g−1, admirable rate capability and eminent cycling stability for 5000 cycles at 10 A g−1, are also displayed by NiMnO NM tested in 0.5 M Na2SO4. This work gives an example to prepare 2D meshy transition metal composite oxide as highly active electrocatalyst for OER and high-performance electrode material for supercapacitor through a feasible means.