Theoretical approach to evaluate graphene/PANI composite as highly selective ammonia sensor

• DOI: 10.1016/j.apsusc.2018.05.108
• Publication Date: 2018-05-16T06:55:23Z
• Authors: Zhi Guo; Ningbo Liao; Miao Zhang; Wei Xue
• Keywords: 02 engineering and technology; 0210 nano-technology

Abstract The incorporation of graphene is an effective way to enhance the sensitivity of polyaniline (PANI) gas sensors, while the interaction mechanism between gas and graphene/PANI composite system is still not clear. In this work, the interaction between NH3, NO, CO, H2 and graphene/PANI are investigated by density functional theory and molecular dynamics simulations. Based on the obtained adsorption energy, Mulliken charge and band gap, graphene/PANI exhibits much higher sensitivity towards NH3 gas than the other three gases. The adsorption of NH3 on graphene/PANI causes a clear increase of the DOS above the Fermi level, thus changing the conductivity of graphene/PANI and making the sensing feasible. The further comparative research on gases diffusion properties demonstrates that the composite show excellent adsorption capacity towards NH3 gas molecules. Our results show graphene/PANI system can detect NH3 gas with high sensitivity and selectivity, enabling it to be a promising sensing material of NH3.