Tribological and electrochemical properties of graphene

Abstract

The report comprises the author’s research on a new method to synthesize graphene from amorphous carbon through annealing and its applications. The fabrication was done together with the fellow student mate, in which a series of experiments was carried out on nickel / diamond like carbon (DLC) bi layer coated in silicon (Si) & silicon dioxide (SiO2) /Si samples to find the optimum annealing parameters like temperature and time. At each stage, the samples were examined using Raman spectroscopy, particularly in terms of G & D peak positions and peak intensity.

Studies were carried out on 14 samples to achieve the best graphene sample. Seven composite (C-Ni) samples on Si & SiO2/Si substrate were used. All the samples went through roughness check after heat treatment using atomic force microscope and Raman spectroscopy.

The tribological properties of the samples were studied with aid of a ball on disc micro tribometer and the wear profiles were examined using Talyscan, which give the cross sectional area and wear depths of the wear tracks. The hardness of the annealed samples were determined using a Nanoindentor. The wear rate and friction coefficient values were used to find the best graphene sample.

Square wave anodic stripping voltammetry (SWASV) test was performed on the annealed samples to find out their sensitivity to detect toxic lead ions (Pb2+) mixed in acedic buffer solution. Bismuth (Bi3+) was added to the solutions in order to enhance the sensitivity and stability of the SWASV experiments. . The effect of deposition potential and deposition time on the graphene sample was observed from the stripping peak of Pb2+ & Bi3+ present in the buffer solution. By means of SWASV test it is able to understand the effect of Pb2+ alone and in the presence of Bi3+ for different graphene samples. Corrosion tests as well as real life experiment was also conducted with the best graphene sample to check the presence of heavy metals both in tap and lake water.