Self-Consistent Charge Density Functional Tight-Binding Study of Poly(3,4-ethylenedioxythiophene): Poly(styrenesulfonate) Ammonia Gas Sensor

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• 作者：Ampaiwan Marutaphan ; Yotsarayuth Seekaew&#8230
• 关键词：PEDOT ; PSS ; Conducting polymers ; Ammonia gas sensor ; SCC ; DFTB ; QM/MD simulation
• 刊名：Nanoscale Research Letters
• 出版年：2017
• 出版时间：December 2017
• 年：2017
• 卷：12
• 期：1
• 全文大小：2092KB
• 刊物主题：Nanotechnology; Nanotechnology and Microengineering; Nanoscale Science and Technology; Nanochemistry; Molecular Medicine;
• 出版者：Springer US
• ISSN：1556-276X
• 卷排序：12

文摘

Geometric and electronic properties of 3,4-ethylenedioxythiophene (EDOT), styrene sulfonate (SS), and EDOT: SS oligomers up to 10 repeating units were studied by the self-consistent charge density functional tight-binding (SCC-DFTB) method. An application of PEDOT:PSS for ammonia (NH₃) detection was highlighted and investigated both experimentally and theoretically. The results showed an important role of H-bonds in EDOT:SS oligomers complex conformation. Electrical conductivity of EDOT increased with increasing oligomers and doping SS due to enhancement of π conjugation. Printed PEDOT:PSS gas sensor exhibited relatively high response and selectivity to NH₃. The SCC-DFTB calculation suggested domination of direct charge transfer process in changing of PEDOT:PSS conductivity upon NH₃ exposure at room temperature. The NH₃ molecules preferred to bind with PEDOT:PSS via physisorption. The most favorable adsorption site for PEDOT:PSS-NH₃ interaction was found to be at the nitrogen atom of NH₃ and hydrogen atoms of SS with an average optimal binding distance of 2.00 Å.