电荷掺杂聚苯胺气体传感器的理论研究  

Theoretical Study of Charge Doped Polyaniline Gas Sensor

作　　者：黄永祥 刘悦灵 王妤婕 周健 钟欣欣 张干兵[1] HUANG Yong-xiang;LIU Yue-ling;WANG Yu-jie;ZHOU Jian;ZHONG Xin-xin;ZHANG Gan-bing(Ministry-of-Education Key Laboratory for the Synthesis and Application of Organic Functional Molecules,College of Chemistry and Chemical Engineering,Hubei University,Wuhan 430062)

机构地区：[1]有机功能分子合成与应用教育部重点实验室湖北大学化学化工学院,武汉430062

出　　处：《胶体与聚合物》2021年第1期21-25,共5页Chinese Journal of Colloid & Polymer

摘　　要：为了对质子酸掺杂聚苯胺的传感机理进行详细的理论研究,本文设计了电荷掺杂模型来模拟质子酸掺杂聚苯胺气体传感器,运用Uωb97xd和TD-Uωb97xd密度泛函理论方法在6-31G(d,p)基组下从几何结构、电子性质、自然键轨道、HOMO-LUMO能隙和第一激发能等方面对其吸附二氧化碳、甲醇和氨的传感机理进行了探究。结果表明,电荷掺杂导致共轭链失去电子被氧化,表现出一定的导电性,小分子与电荷掺杂聚苯胺之间的电子转移导致了共轭链得到电子被还原,进而表现出导电性的差异。此外,电荷掺杂聚苯胺及其吸附二氧化碳、甲醇和氨的复合物外推到无限长链时HOMO-LUMO能隙分别为2.0233 eV、2.2458 eV、2.2552 eV和2.2191 eV,而第一激发能分别为1.1584 eV、1.3312 eV、1.5503 eV和1.6506 eV,进一步确证了质子酸掺杂聚苯胺的氨敏感性。In order to demonstrate the detailed theoretical description of the sensing mechanism existing in charge doped polyaniline sensor,density functional theory method(Uωb97 xd and TD-Uωb97 xd)study,performed at 6-31 G(d,p)basis set,has been accomplished to optimize the structure of charge doped polyaniline from 2 to 10 phenyl units towards carbon dioxide、methanol and ammonia.At the same time,the charge transfer,natural bond orbital,HOMO-LUMO gap and first excitation energy are studied revealing the sensing mechanism of the fully optimized structure towards above gases.The finding indicates that charge doping leads to the loss of electrons and oxidation of theπ-conjugated chain,which shows certain conductivity,and then the electron migrate from adsorbent toπ-conjugated system contributing to that conjugated chains are reduced to show difference in conductivity.Furthermore,the extrapolated HOMO-LUMO Gap of charge doped polyaniline and its complex adsorbing carbon dioxide、methanol and ammonia are about 2.0233、2.2458、2.2552 and 2.2191 eV,and the extrapolated first excitation energy are about 1.1584、1.3312、1.5503 and 1.6506 e V,confirming the excellent sensitivity of charge doped polyaniline towards ammonia.

关 键 词：电荷掺杂聚苯胺 电子转移 HOMO-LUMO能隙 第一激发能 

分 类 号：O649.5[理学—物理化学]