Controllable preparation of Ni nanoparticles for catalysis of coiled carbon fibers growth.

Xian Jian,Sixin Wu,Qing Zeng,Lei Chen,Chao Wang,Zuowan Zhou

doi:10.1186/1556-276x-9-370

Abstract

The mass preparation of high-purity coiled carbon fibers (CCFs) remains challenging due to the high complexity and low controllability of reaction. In this work, a controllable growth of Ni particles was fulfilled by liquid phase reduction of nickel sulfate with hydrazine hydrate. The impacts of the reaction temperature, NaOH concentration, and reaction time on the particle size and purity were investigated. The as-deposited Ni particles were characterized by scanning electron microscopy and X-ray diffraction. In addition, these Ni particles were also applied in preparing high-purity CCFs both on graphite and ceramic substrates. The diameter of the as-grown carbon microcoil was about 500 nm, and the related growth mechanism was discussed.

Highlights

Coiled carbon materials exhibit a variety of unique characteristics, such as super-elasticity [1], wide band absorption of electromagnetic waves [2], and hydrogen adsorption [3]
Reaction temperature and pH value were addressed in the following discussion
The analysis suggests that the spherical nickel particles may contain a number of ultra small crystals, which agrees with the observation of morphology

Summary

Introduction

Coiled carbon materials exhibit a variety of unique characteristics, such as super-elasticity [1], wide band absorption of electromagnetic waves [2], and hydrogen adsorption [3]. Artificial coiled structures at the mesoscale usually have simple helical geometries of one-dimensional helical fibers depending on the growth condition such as temperature, flow rate, and carbon source. It was reported that several coiled carbon fibers (CCFs) can be obtained using appropriate catalyst on some substrate or with the help of electric and magnetic field. Chen and Motojima prepared the carbon microcoils by the Ni-catalytic pyrolysis of acetylene containing a small amount of thiophene [19]. Three-dimensional (3D) spring-like carbon nanocoils were obtained in high purity by the catalytic pyrolysis of acetylene at 750°C to 790°C

Methods

Results

Conclusion