Synthesis of multi-walled carbon nanotubes by thermal CVD technique on Pt–W–MgO catalyst

Tarun Sharda,K. Sreenivas,Khurshed A. Shah,Feroz A. Najar

doi:10.1080/16583655.2018.1451114

Abstract

ABSTRACTBoth tungsten (W) and platinum (Pt) are materials of interest in modern science and technology. Here, in this paper, we report the growth of multi-walled carbon nanotubes (MWCNTs) by thermal chemical vapour deposition (CVD) on Pt–W catalyst with MgO as a support material. The XRD studies were used to determine the structural characteristic of the as-prepared catalyst. Raman spectroscopy studies confirm the growth of MWCNTs with less structural defects and non-crystalline carbonaceous products. The images of field scanning electron microscope (FESEM) show that the grown network of carbon nanotubes (CNTs) contains less impurities, whereas the high-resolution transmission electron microscope (HRTEM) images indicate that the grown MWCNTs have good crystallinity with no lateral carbon deposit. TGA of the unpurified CNT product shows the addition of catalyst particles with the sample. This study will pave way for the new research area in the synthesis of CNTs and their applications in the electronic industry. Moreover, the results were compared with the previously reported results in the literature.

Highlights

The discovery of the carbon nanotubes (CNTs) by Lijima [1] has been the breakthrough in nanotechnology keeping in view their potential applications in different fields
Rh–Pt catalyst produced narrow diameter distribution of CNTs [15], Fe–Mo catalyst produced the highest crystallinity CNTs [16], Ni–Al produced a positive change in the yield of multi-walled carbon nanotubes (MWCNTs) [17], Ni–Co catalysts supported on TiO2 for use in chemical vapour deposition (CVD) depicted a positive response in growth process of nanotubes [18], whereas a synergistic effect was observed on the growth of CNTs using Fe–Co catalyst [19]
The RBM mode (120– 300 cm−1) is absent in our spectra which confirms that the grown CNTs are MWCNTs and not SWCNTs

Summary

Introduction

The discovery of the carbon nanotubes (CNTs) by Lijima [1] has been the breakthrough in nanotechnology keeping in view their potential applications in different fields. For the preparation of CNTs by CVD, the initial step involves the thermal decomposition of hydro-carbons (in our case methane) so as to liberate the carbon which deposits over the catalyst. All the above-cited papers [13,14,15,16,17,18,19,20] along with other studies [20,21,22,23,24,25] report the use of bi-metallic catalysts for synthesizing nanotubes for the better reason of improved quality, yield and at the same time keeping in view the potential applications of the as-prepared nanotubes.

Results

Conclusion