Structure Design of Ni–Co Hydroxide Nanoarrays with Facet Engineering on Carbon Chainlike Nanofibers for High-Efficiency Oxygen Evolution

Metal hydroxide-based materials have been widely investigated as high efficient electrocatalysts for oxygen evolution reaction (OER) due to their excellent catalytic properties. Herein, we report a multilayered and facet-manipulated Ni–Co hydroxide with controllable flake and acicular-like morphologies, which was grown on self-supported substrates made of in situ grown carbon chainlike nanofibers on carbon cloth (CCNs@CC). The exposed crystal facets were controlled by the synthesis of electrocatalysts with different morphologies. The flake and acicular-like Ni–Co hydroxide on CCNs@CC exhibit the overpotential of 235 and 248 mV at 10 mA cm^–2, and Tafel slope of 69 and 73 mV dec^–1, respectively. The high activity is contributed by the sufficient number of active sites provided by the multidimensional structures, as well as the rapid electron transportation due to the high conductivity of the CCNs. In addition, long-term stability without evident degeneration in 24 h was demonstrated during the OER process.