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/nanoparticles prepared by optimizing the annealing temperature of nickel-based metal organic framework (Ni-MOF). Note that the incorporation of Ni3+ 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 Ni3+ 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 900W kg(-1). This work highlights the crucial role of the lattice distortion of materials for future applications in the sustainable energy storage and conversion.