Cost-Effective Fabrication of Biomorphic Mesoporous Ni-NiO Microtube for Pseudocapacitors

Abstract

In this paper, a biomorphic mesoporous Ni-NiO microtube was successfully prepared by a facile and cost-effective synthesis strategy using cotton as a biotemplate. The morphology and textural characterization of as-obtained Ni-NiO materials were analyzed by X-ray diffraction patterns, scanning electron microscopy and nitrogen adsorption–desorption technology. The results suggested the as-prepared Ni-NiO samples owned uniform micro-tubular morphology and prominent mesoporous structure. Meanwhile, the effect of annealing temperature on morphology and porosity of Ni-NiO was also investigated. The optimal sample, Ni-NiO-4, exhibited a uniform microtube morphology with an ideal mesoporous structure of a high surface area (15.8 m2 g[Formula: see text]) and suitable mesopore size (9.28 nm). Furthermore, these as-obtained Ni-NiO materials showed enhanced electrochemical property as electrodes for pseudocapacitors. Especially, the Ni-NiO-4 electrode displayed the outstanding capacitive performance, including a high specific capacitance of 98.7 F g[Formula: see text] at 0.5 A g[Formula: see text] and satisfactory rate capacity. More importantly, Ni-NiO-4 electrode owned an excellently long-term cycling stability.