摘要
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-free electrode consisting of nickel cobalt diselenide （NiCoSe2） nanobrush arrays on Ni foam （NF） through the initial hydrothermal reaction and subsequent thermal selenization process. Introducing ammonium fluoride as surface controller, different NiCoSe2 hierarchical architecture can be modulated from nanorods, nanobrush to nanosheets. The unique brush-like NiCoSe2 possesses high surface area for mass transfer, rough surface with rich active sites, 3D nanostructure preventing the accumulation of 02 bubbles. Compared to NiCoSe2 nanorods/NF, NiCoSe2 nanosheets/NF and commercial RuO2, NiCoSe2 nanobrush/NF exhibits an enhanced OER performance in alkaline media to reach a low overpotential of 274 mV at the current density of 10 mA/cm^2, 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,
基金
supported by the National Natural Science Foundation of China (21475007 and 21675009)
the Fundamental Research Funds for the Central Universities (buctrc201608 and buctrc201720)
