In situ synthesis of long tubular water-dispersible polyaniline with core/shell gold and silver@graphene oxide nanoparticles for gas sensor application

Zahra Babaei; Bahareh Rezaei; Ehsan Gholami; Faramarz Afshar Taromi; Amir Hossein Haghighi

doi:10.1016/j.heliyon.2024.e26662

In situ synthesis of long tubular water-dispersible polyaniline with core/shell gold and silver@graphene oxide nanoparticles for gas sensor application

Heliyon. 2024 Feb 18;10(4):e26662. doi: 10.1016/j.heliyon.2024.e26662. eCollection 2024 Feb 29.

Authors

Zahra Babaei¹, Bahareh Rezaei², Ehsan Gholami³, Faramarz Afshar Taromi¹, Amir Hossein Haghighi⁴

Affiliations

¹ Department of Polymer Engineering, Amirkabir University of Technology, Tehran, Iran.
² Department of Chemistry, Amirkabir University of Technology, Tehran, Iran.
³ Department of Engineering, Persian Gulf University, Bushehr, Iran.
⁴ Department of Polymer Engineering, Shiraz Branch, Islamic Azad University, Shiraz, Iran.

Abstract

Gold nanoparticles (Au NPs) with graphene oxide (GO) shell (Au@GO), silver nanoparticles (Ag NPs) with GO shell (Ag@GO), and gold silver nanoparticles (AuAgNPs) with GO shell (AuAg@GO) were synthesized employing a cationic surfactant. The prepared core@shell structures were used for in situ synthesis of long tubular polyaniline structures employing cetyl trimethyl ammonium bromide (CTAB) as a soft template. This process led to a notable enhancement in the tubular nanostructure of PANI, extending its length beyond 10 μm, in the case of using core/shell Au@GO, Ag@GO, and AuAg@GO structures. To evaluate their applicability and compatibility, the dispersibility of these nanocomposites was assessed in three distinct solvents: water, dimethyl sulfoxide (DMSO), and N-Methyl-2-pyrrolidone (NMP). Subsequently, the dedoping of PANI within the prepared nanocomposites was scrutinized using UV-Visible (UV-Vis) spectroscopy, which revealed a reduction in the I₇₅₀/I₃₁₅ ratio from 1.00 to 0.66 when subjected to water and NMP solvents, respectively. Notably, the dedoping of the AuAg@GO/PANI nanocomposite was predominantly observed in NMP, attributable to the presence of hydrogen bonding interactions and the basic properties of NMP. In terms of ionic conductivity, it was observed that the prepared nanocomposite exhibited its highest conductivity in a water-based medium, registering at 1982 μs. Furthermore, the AuAg@GO/PANI nanocomposite exhibited superior sensing capabilities in comparison to PANI-based gas sensor devices, particularly when exposed to acetone, CO₂, NO₂, and H₂S. Remarkably, at room temperature (25 °C), the AuAg@GO/PANI nanocomposite displayed rapid response and recovery times, with values of 279 s, 431 s, 335 s, and 509 s for 1 ppm concentrations of CO₂, NO₂, H₂S, and acetone, respectively. The sensitivity of these sensors towards acetone, CO₂, NO₂, and H₂S, was quantified by analyzing the slope of the response versus the target gas concentration, revealing the AuAg@GO/PANI nanocomposite to exhibit the highest sensitivity, particularly towards NO₂.

Keywords: Core/shell; Gas sensor; Gold and silver nanoparticles; Graphene oxide; Polyaniline; Tubular structure.