Growth temperature dependence of partially Fe filled MWCNT using chemical vapor deposition

TL;DR

This study examines how growth temperature affects the synthesis and properties of Fe-filled multiwalled carbon nanotubes produced via chemical vapor deposition, highlighting optimal conditions and structural characteristics.

Contribution

It provides new insights into the temperature-dependent growth behavior and structural features of Fe-filled MWCNTs, including a proposed growth model.

Findings

Increased temperature leads to larger nanotube diameters and lower density.

Fe-filled MWCNTs are multi-walled with partial Fe filling across temperatures.

Optimal growth temperature for quality Fe-filled CNTs is 850°C.

Abstract

This investigation deals with the effect of growth temperature on the growth behavior of Fe filled multiwalled carbon nanotubes (MWCNTs). Carbon nanotube (CNT) synthesis was carried out in a thermal chemical vapor deposition (CVD) reactor in the temperature range 650 to 950 1C using propane as the carbon source, Fe as the catalyst material, and Si as the catalyst support. Atomic force microscopy (AFM) analysis of the catalyst exhibits that at elevated temperature clusters of catalyst coalesce and form macroscopic islands. Field emission scanning electron microscopy (FESEM) results show that with increased growth temperature the average diameter of the nanotubes increases but their density decreases. High-resolution transmission electron microscopy (HRTEM) studies suggest that the nanotubes have multi-walled structure with partial Fe filling for all growth temperatures. The X-ray diffraction (XRD) pattern of the grown materials indicates that they are graphitic in nature. The characterization of nanotubes by Raman spectroscopy reveals that the optimized growth temperature for Fe filled CNTs is 850 1C, in terms of quality. A simple model for the growth of Fe filled carbon nanotubes is proposed.