Siam Physics Congress 2017

Theoretical Study on Structural and Electronic Properties of Polypyrrole: Ammonia Gas Sensor

25 May 2017, 17:00

1h

Rayong Marriott Resort & Spa

Poster Material Physics and Functional Materials Poster Presentation II

Speaker

Ampaiwan Marutaphan (Rajamangala University of Technology Suvarnabhumi)

Description

Polypyrrole (PPy) have been considered as one of the most promising conducting polymers for gas sensor application due to it can operate efficiently at room temperature, light weight, thermal stability and high sensibility. In this research, we have been reported the geometric and electronic structure of PPy based on B3LYP/3-21G${}^{\ast }$, B3LYP/6-31G${}^{\ast }$ and SCC-DFTB methods. The effects of polymer chain length of PPy on structural and electronic properties including bond length, bond angle, torsion angle, the highest occupied orbital (HOMO), the lowest unoccupied molecular orbital (LUMO) and energy gap have been studied from the optimized PPy oligomers (n=1-10). The results show that the bond length, bond angle and torsion angle from SCC-DFTB method are C-N = 1.38 Å, N-H = 1.04 Å, C-C = 1.45 Å, N-C-C = 122 ${}^o$, C-C-C = 131${}^o$, N-C-C-C = 179${}^o$ and C=C-C=C = 179${}^o$, respectively. The HOMO and LUMO are ranging from -5.49 to -4.23 eV and -0.078 to -1.92 eV, respectively. The energy gap decreased with increasing polymer chain length from 5.41 to 2.31 eV. Furthermore, the results based on B3LYP/3-21G${}^{\ast }$, B3LYP/6-31G${}^{\ast }$ and effects of PPy ammonia gas sensor have been investigated and discussed in more detail.

Peer reviewing

Paper

Accepted on 24 Jun 2017 by Papichaya Chaisakul

Paper files:

• Response_to_Reviewer.pdf
• SCC-DFTB_Study_on_Structure_Electronic_and_Sensing_Properties_of_Polypyrrole-revised.pdf
• Supplementary_Data_Table_S1.pdf