Enhancement of NO2 Gas Sensing Properties of Polypyrrole by Polarization Doping with DBS: Experimental and DFT Studies

Haiying Du; Zhaorui Zhang; Xingang Jiang; Jing Wang; Wencai Yi; Xiaogan Li; Jinkui Chu

doi:10.1021/acsami.3c12154

Enhancement of NO₂ Gas Sensing Properties of Polypyrrole by Polarization Doping with DBS: Experimental and DFT Studies

ACS Appl Mater Interfaces. 2023 Nov 3. doi: 10.1021/acsami.3c12154. Online ahead of print.

Authors

Haiying Du¹, Zhaorui Zhang², Xingang Jiang³, Jing Wang¹, Wencai Yi³, Xiaogan Li⁴, Jinkui Chu²

Affiliations

¹ College of Mechanical and Electronic Engineering, Dalian Minzu University, Dalian 116600, P. R. China.
² School of Mechanical Engineering, Dalian University of Technology, State Key Laboratory of High-performance Precision Manufacturing, Dalian 116024, P. R. China.
³ Laboratory of High-Pressure Physics and Material Science, School of Physics and Physical Engineering, Qufu Normal University, Qufu, 273165, P. R. China.
⁴ School of Microelectronics, Dalian University of Technology, Dalian, Liaoning 116024, P. R. China.

PMID: 37922403
DOI: 10.1021/acsami.3c12154

Abstract

A new technique of polarization doping was adopted to improve NO₂ gas sensing properties of the polypyrrole (PPy) sensor. PPy nanosheets polarization doped with sodium dodecyl benzenesulfonate (SDBS) were synthesized by low-temperature polymerization. The semiagglomerated PPy nanosheets were well-dispersed and a large specific surface areas due to the introduction of dodecyl benzenesulfonate (DBS). The DBS doped PPy sensor shows excellent NO₂ sensing performance. Polarization of sulfonate ions to PPy enhanced the adsorption ability of NO₂ with the synergistic effect of NO₂. The adsorption energy (-0.676 eV) and electron transfer (0.521 |e|) of PPy to NO₂ increased greatly after doping. An unoccupied electron state is observed in the valence band electron structure of PPy/DBS after the adsorption of NO₂ by calculations of Density Functional Theory (DFT). The intermolecular synergy between NO₂ and PPy/DBS causes a strong polarization, resulting in a high polarization potential, which enhances the NO₂ sensing performance of PPy sensor. It is of great significance to develop NO₂ detection device based on PPy that works at room temperature.

Keywords: Density Functional Theory; Electronic transmission; Gas sensing performance; Intermolecular synergy; Polarization.