Effect of Multi-Walled Carbon Nanotubes Incorporation on the Structure, Optical and Electrochemical Properties of Diamond-Like Carbon Thin Films

Abstract

We report the effect of incorporation of multi-walled carbon nanotubes (MWCNT) on the mechanical, structural, optical and electrochemical properties of diamond-like carbon (DLC) thin films. The DLC/MWCNT hybrid composite was deposited onto stainless steel and quartz substrates by plasma enhanced chemical vapor deposition at low temperature (∼100°C). Raman spectra of DLC/MWCNT film have characteristics from both DLC and MWCNT. The optical bandgap energy decreases with the incorporation of nanotubes. Scanning electron microscopy images confirm the presence of the MWCNT within the DLC film, forming a large interconnected conducting mesh. Tribological tests confirm there was slight adherence loss with incorporating MWCNT into the DLC films, while improving their electrical conductivity. Electrochemical assays show the incorporation of MWCNT converts DLC from an insulating material into a reversible electrode with fast charge transfer. This novel hybrid composite is shown to be mechanically robust, chemically inert and exhibits fast charge-transfer kinetics, which is very promising for several new applications.