OER activate NixCo(1-x) NPs to NixCo(1-x)(OH)2 on cobalt foam with excellent supercapacitors performance

5-6 nm hydrophilic NixCo(1-x) NPs was synthesized by a cost-effective and scalable method and was coated onto conductive substrates without any binders or additives thanks to its small particle effect and possiblely magnetic effects. Then, the NixCo(1-x) NPs can be transformed into NixCo(1-x)(OH)2 by an OER-activating strategy. Optimized by the composition effect, the Ni0.8Co0.2/CF exhibits best activity for supercapacitors (2124F/g). Underling mechanism of the OER evolution process well studied by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Raman spectrometry, X-ray absorption near-edge spectra (XANES). Density functional theory (DFT) calculations was performed and verify the synergistic effect of nickel and cobalt and the support effect.