Metal-organic framework derived Ni/NiO micro-particles with subtle lattice distortions for high-performance electrocatalyst and supercapacitor

Herein, an effective and novel strategy has been designed to increase electrochemical reaction active sites in Ni/NiO nanoparticles prepared by optimizing the annealing temperature of nickel-based metal organic framework (Ni-MOF). Note that the incorporation of Ni 3+ into the primitive lattice of Ni/NiO nanoparticles will cause a subtle atomic rearrangement, providing a large number of electrochemical reaction active sites. The density functional theory (DFT) simulation results also exhibit that the introduction of Ni 3+ significantly lowers the gibbs free energy of atomic hydrogen absorption on the surface of Ni/NiO, benefiting H 2 gas evolution. On the basis of the above advantages, the as-synthesized Ni/NiO nanoparticles exhibit excellent performance for supercapacitors (SCs, the areal specific capacitance of 684.4 m F cm −2 at 1 mA cm −2 ) and Hydrogen evolution reaction (HER, ultralow overpotential of 41 mV at 10 mA cm −2 ). Significantly, the all-solid-state flexible asymmetric SCs based on Ni/NiO as anode and CNTs-COOH as cathode displays a high energy density of 61.3 W h kg −1 at the power density of 900 W kg −1 . This work highlights the crucial role of the lattice distortion of materials for future applications in the sustainable energy storage and conversion.