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Active, stable and low-cost oxygen evolution reaction(OER) catalyst for electrochemical water splitting is key to efficient energy conversion and storage. Here, we report a three-dimensional(3D) nanonetwork as noble-metal-free electrode consisting of nickel cobalt diselenide(NiCoSe_2) nanobrush arrays on Ni foam(NF) through the initial hydrothermal reaction and subsequent thermal selenization process. Introducing ammonium fluoride as surface controller, different NiCoSe_2 hierarchical architecture can be modulated from nanorods, nanobrush to nanosheets. The unique brush-like NiCoSe_2 possesses high surface area for mass transfer, rough surface with rich active sites, 3D nanostructure preventing the accumulation of O2 bubbles. Compared to NiCoSe_2 nanorods/NF, NiCoSe_2 nanosheets/NF and commercial Ru O2,NiCoSe_2 nanobrush/NF exhibits an enhanced OER performance in alkaline media to reach a low overpotential of 274 m V at the current density of 10 m A/cm2, small Tafel slope and a long-term stability. The developed 3D nanonetwork highlights the nanoscale engineering and offers a promising alternative to noble metal catalysts for electrochemical water oxidation.
Active, stable and low-cost oxygen evolution reaction (OER) catalyst for electrochemical water splitting is key to efficient energy conversion and storage. Here, we report a three-dimensional (3D) nanonetwork as noble-metal- diselenide (NiCoSe_2) nanobrush arrays on Ni foam (NF) through the initial hydrothermal reaction and subsequent thermal selenization process. The unique NiCoSe_2 hierarchical architecture can be modulated from nanorods, nanobrush to nanosheets. The unique brush-like NiCoSe_2 Compared to NiCoSe_2 nanorods / NF, NiCoSe_2 nanosheets / NF and commercial Ru O2, NiCoSe_2 nanobrush / NF exhibits an enhanced OER performance in alkaline media to reach a low overpotential of 274 m V at the current density of 10 m A / cm 2, small Tafel slope and a long-te rm stability. The developed 3D nanonetwork highlights the nanoscale engineering and offers a promising alternative to noble metal catalysts for electrochemical water oxidation.