Synthesis of amorphous cobalt-boron alloy/highly ordered mesoporous carbon nanofiber arrays as advanced pseudocapacitor material

Abstract

Mesoporous carbon electrodes have been doped with Co-B nanoparticles via a chemical reduction approach and successfully used for pseudocapacitor application. The morphology is investigated by powder X-ray diffractions (PXRDs), small-angle X-ray scattering (SAXS), inductively coupled plasma (ICP), and transmission electron microscope (TEM). The TEM image displays that the Co-B is highly dispersed along the mesoporous carbon support which are critical for the pseudocapacitor application. Cobalt-boron/ highly ordered mesoporous carbon nanofiber arrays (Co-B/ MCNAs) are investigated by cyclic voltammetry, charge/ discharge test, and electrochemical impedance spectroscopy. The as-synthesized Co-B/MCNAs exhibit remarkable pseudocapacitive activities including high specific capacitance (531 F g −1 at 5 mV s −1 ), good rate capability (315 F g −1 at 50 mV s −1 ), and excellent cycling stability. This value is about 2.7-fold and 1.7-fold higher than MCNAs and Co-B, respectively.

Mesoporous carbons: recent advances in synthesis and typical applications

“…Although the hard-template method has its inherent drawbacks in the sacricial use of hard templates, insufficient stabilities of replicated mesostructures and a complex operational process, it has a wider use in the preparation of MC because it simply allows a carbon source to sediment onto the surface without the need for additional forces at the laboratory level. At the same time, some "hard templates" with similar functions have played important roles in the formation of mesopores and carbon monoliths, such as rigid silicates in composites, which can greatly reduce structural shrinkage during carbonization, creating large mesopores; 39 other novel templates including halloysite, 499 polyurethane foam, 52 cordierite 116,164 and crab shell 195,197,198 also improve this method on different scales. In any case, the method of using natural complex templates to synthesize MC materials has received extensive attention among materials chemists and should be promoted.…”

“…196 Aer that, this crab shell templating method has also been pursued and developed by other researchers. 197,198 To develop a facile template-free method for the preparation of MC nanobers, Li et al reported a novel self-templating method for the preparation of MC nanobers with a 3D interconnected mesoporous structure and large surface area using ethylene glycol as the carbon precursor and Zn(CH 3 COO) 2 as a structure-building agent and porogen. 199 Electrospinning is a mature technology used in the production of ber materials, which has been successfully employed to fabricate MC nanobers.…”