The stability of gold nanoparticles (AuNPs) determined

structure–activity relationships are fundamental topics that have

garnered significant interest and attention. AuNPs were treated with

small molecules containing sulfur (S) and nitrogen (N) to regrow and

were filtered into thin films with heat treatment for the first time.

The results indicate that small molecules with S or N significantly

improve the stability of AuNPs, leading to enhanced electrical

conductivity and catalytic performance, especially in conversion of

2-nitrophenol. TEM images show that AuNPs regrew into larger

nanoparticles which were confirmed by the results of UV spectra. The

electrical conductivity was enhanced variously after treated small

molecules. Among them, the AuNPs film treated with thioacetamide

exhibited the highest conductivity at 4.6 Ω/sq. The time for catalytic

conversion of 2-nitrophenol was reduced after treated with small

molecules, with the AuNPs film treated with thiourea showing the

shortest time of 150 s, which is a significant reduction compared to the

other small molecules treated AuNPs film. At last, X-ray

photon-electron spectroscopy shows that the small molecules do not

obviously change chemical valence of AuNPs after treatment. This study

underscores the role of small molecules containing S and N in

stabilizing AuNPs, with significant potent for nanochemistry, materials

science, energy, and environment fields.

https://doi.org/10.1016/j.cej.2025.161086