From Co-MOF to CoNi-MOF to Ni-MOF: A Facile Synthesis of 1D Micro-/Nanomaterials

Abstract

Controlling the growth of metal-organic frameworks (MOFs) at the micro-/nanoscopic scale will result in new physical properties and novel functions into the materials without changing the chemical identities and the characteristic features of the MOFs themselves. Herein, we report a facile approach to synthesize a series of MOFs [Co-MOF, Co_<i>x</i>Ni_<i>y</i>-MOFs (<i>x</i> and <i>y</i> represent the molar ratio of Co²⁺ and Ni²⁺ and <i>x</i>/<i>y</i> = 1:1, 1:5, 1:10, 1:15, and 1:20), and Ni-MOF] with a one-dimensional micro-/nanoscaled rod-like architecture. From Co-MOF to Co_<i>x</i>Ni_<i>y</i>-MOFs to Ni-MOF, the diameters of the rods turn to be spindly with the increase of Ni²⁺ content which will facilitate the supercapacitor performances. Interestingly, Co₁Ni₂₀-MOF exhibits a highest specific capacity of 597 F g^-1 at 0.5 A g^-1 and excellent cycle performance (retained 93.59% after 4000 cycles) among these MOF materials owing to its micro-/nanorod structure with a smaller diameter and the synergy effect between the optimum molar ratio of Co²⁺ and Ni²⁺.