Comparative Study Of Electronic Properties In Pristine And Si-Doped Single-Walled Carbon Nanotube As Gas Sensor: A First Principle Study

Farizul Muiz, Alias (2015) Comparative Study Of Electronic Properties In Pristine And Si-Doped Single-Walled Carbon Nanotube As Gas Sensor: A First Principle Study. Project Report. UTeM, Melaka, Malaysia. (Submitted)

Text (24 pages) Comparative Study Of Electronic Properties In Pristine And Si-Doped Single-Walled Carbon Nanotube As Gas Sensor A First Principle Study 24 Pages.pdf - Submitted Version Download (422kB)

Abstract

A pristine single-walled carbon nanotube (SWCNT) and silicon-doped SWCNT have been investigated as materials for gas sensor. The gases that had been chosen were carbon dioxide, oxygen, and methanol due to their widely use and controlled in industrial sector. Adsorption and electronic properties were investigated on the pristine and doped SWCNT upon the gas reacted to SWCNT wall. All the calculation were performed using a first principle study base on density functional theory that has been implemented in CASTEP and DMol3 computer code. For geometry optimization, exchange correlation functional approximations such as Local Density Approximation (LDA) and Generalized Gradient Approximation (GGA) have been utilized in order to get accurate structural information. Using GGA showing improvement in accuracy of data by 80% to 90% in overall calculation. In term of adsorption energy indicates that the O2 and CO2 are weakly adsorbed on the pristine SWCNT but CH3OH with value of -0.61 eV and all other gases attached on Si doped SWCNT showing higher amount of adsorption energy that promote to chemisorptions reaction with value range of -1.6 eV to -3.99 eV. As the electronic properties been calculate, the result indicate there is additional state produce at valance band and reducing the band gap structure in silicon-doped SWCNT of 0.5 eV from the original pristine structure of 0.6 eV while DOS showing a p-type semiconductor properties producing a more sensitive electronic properties upon doping and exposure of gases. Thus, these finding will be able to gear up efforts in optimizing the usage of gas sensor and hence will substantially contribute to the more sensitive gas sensor.

Actions (login required)

View Item