Stability of self-ordered thiol-coated silver nanoparticles: oxidative environment effects

Area of Science:

• Nanotechnology
• Materials Science
• Surface Chemistry

Background:

• Thiol-coated silver nanoparticles (NPs) are used in various applications.
• Understanding the stability of nanoparticle organization is crucial for their practical use.

Purpose of the Study:

• To investigate the stability of 2D-organized thiol-coated silver nanoparticles (NPs) in ambient conditions.
• To compare the stability of silver NPs with gold nanoparticles (AuNPs).

Main Methods:

• Transmission electron microscopy (TEM) was used to observe NP organization.
• Infrared (IR) and energy-dispersive spectroscopies (EDS) were employed to detect excess thiols.

Main Results:

• Silver NPs rapidly corroded within days in laboratory air (O2) but remained stable for weeks under nitrogen.
• Corrosion was exacerbated by air humidity and trapped excess thiols.
• Gold nanoparticles (AuNPs) coated with dodecanethiols demonstrated superior stability in laboratory air.

Conclusions:

• The 2D organization of silver NPs is unstable in air due to oxidation.
• Gold nanoparticles exhibit enhanced stability compared to silver nanoparticles owing to their higher redox potential.
• Environmental factors like humidity and thiol concentration significantly impact NP stability.