The Effect Of Ni And Cu Catalysts On The Growth Of Graphene Under Different Ethanol Flow Rates Using Atmospheric Pressure Chemical Vapor Deposition

Graphene was grown on both nickel (Ni) and copper (Cu) catalysts by atmospheric pressure chemical vapor deposition (APCVD) technique at various ethanol flow rates. Raman spectroscopy and field emission scanning electron microscopy (FESEM) were used to study morphological and structural properties of APCVD grown graphene. The crystallite size, defect intensity, distance between defects and the graphene thickness were estimated based on Raman spectra analysis. For the same growth conditions, Ni catalyst promote the formation of more graphene layers as compare to Cu. This because of the higher carbon solubility in Ni as compared to Cu which leads to different growth mechanisms

An Alternative Method for Estimating the Phase Fraction of Multiphase Nanomaterials: Analysis from X-ray Diffraction

The presence of multiple phases/ components within a nanocomposite material impacts the properties of a nanomaterial. Therefore, there is a need to estimate the phase fraction of each component present in a sample. Spurr-Myers proposed a valuable formula for estimating the rutile and anatase phase fraction of a TiO2 sample from X-ray diffraction. However, this formula is dedicated to TiO2 and is inapplicable to samples that contains more than two phases. The present research work proposed a simple method for quantifying the phase fraction of all types of nanomaterials that consist of two or more phases. Precision/ accuracy test carried out by multiplying the grand total intensity of all the diffraction peaks present in a sample with the value of the phase fraction of individual components showed that the proposed method gave precision values that were equivalent to the sum of the intensity of the peaks of each component. Whereas the S-M gave precision values that were significantly inconsistent with the sum of the intensity of the peaks of each component. The study showed that the proposed method was valid for a wide range of 2  values and can be deployed to obtain reasonable and reliable values of phase fraction that could assist to understand the material phase fraction-properties relationship