Structural, Field Emission and Ammonia Gas Sensing Properties of Multiwalled Carbon Nanotube-Graphene Like Hybrid Films Deposited by Microwave Plasma Enhanced Chemical Vapor Deposition Technique

Abstract

This paper reports the direct deposition of multiwalled carbon nanotube (MWCNT)-graphene like hybrid films on nickel substrate using a 2.45 GHz microwave plasma enhanced chemical vapor deposition (MW PECVD) system in the temperature range of 500-700 C at 20 Torr pressure. The films have been characterized by Raman spectra, high resolution transmission electron microscope (HRTEM), scanning electron microscope, high resolution X-ray diffraction and contact angle measurement. Raman spectroscopy and HRTEM reveal the formation of MWCNT and graphene like hybrid carbon sheet structures. The effect of processing temperature on the field emission properties of MWCNT-graphene like hybrid films has been investigated. Field emission measurement reveals that the turn-on field decrease and the emission current density increase with the increase of deposition temperature. The rambutan structure of MWCNT formed at 700 C is responsible for the improvement in the field emission properties. The film deposited at 700 C shows fast response and recovery time of 40 and 96 s, respectively, for ammonia gas sensing due to the high surface area of the film. It has also been found that the hydrophobic surface of the film helps to perform the gas sensing in the humid environment.

Engineering-scale superlubricity of the fingerprint-like carbon films based on high power pulsed plasma enhanced chemical vapor deposition

“…Moreover, for graphene, high growth energy can be reached via heating or high energy excitation and, therefore, involves high temperature (from 500 C to more than 1000 C) or methods such as electron irradiation in the electron cyclotron resonance, mass selected ion beam deposition, arc-discharge, and microwave plasma enhanced chemical vapor deposition. 23,[34][35][36][37][38][39][40][41] This demonstrates that the high energy state can promote the formation of graphene-like sheets. High-power pulsed power supply, exciting ions (near arc discharge) with very high power densities and ion energy, 42,43 could be used to prepare the graphene-like nanostructures.…”

A comprehensive review on the environmental applications of graphene–carbon nanotube hybrids: recent progress, challenges and prospects

“…Another significant factor affecting performance of sensing device is humidity. A hydrophobic sensing material operating at room temperature was developed by depositing hybrid films of MWCNT/graphene on Ni substrate employing microwave plasma enhanced chemical vapour deposition in 500 o C -700 o C at 20 Torr pressure (149). For ammonia sensing, quick response and recovery time, 96 s were observed for film deposited at 700 o C. Additionally, hydrophobic surface of film enables gas sensing even in humid environment.…”

Growth of dense CNT on the multilayer graphene film by the microwave plasma enhanced chemical vapor deposition technique and their field emission properties

“…Earlier single step method to grow CNT rich hybrid material has been reported. 6,7 Nguyen et al 8 have synthesized CNT-graphene hybrid lms on Ni by the low vacuum annealing of cellulose acetate and showed that the hybrid lm exhibited the substantial improvement in the optoelectrical and eld emission properties compared to their individual counterpart. CNT has already been proven as a promising eld emitter.…”