Synthesis of ultra-small gold nanoparticles by polyphenol extracted from <i>Salvia officinalis</i> and efficiency for catalytic reduction of p-nitrophenol and methylene blue
Mohamed Habib Oueslati, Lotfi Ben Tahar, Abdel Halim Harrath
Abstract
The present research work reports an eco-friendly route for preparing gold nanoparticles (AuNPs) with high catalytic activity using polyphenol extracted from salvia officinalis. In both alkaline (pH ∼ 11) and acidic media (pH ∼ 5), the polyphenol induced rapid reduction of the Au (III) salt and lead to the formation of highly monodisperse and spherical small (S) and larger (L) AuNPs, respectively. The average particle size was found to be ∼ 6 nm for S and ∼ 27 nm for L AuNPs, respectively. FT-IR revealed that polyphenol species are capped onto the nanoparticles surface favorizing a high aqueous colloidal stability of the AuNPs in a wide pH range. In addition, the produced AuNPs exhibited significant size-dependent degradation rate of p-nitrophenol (p-NP) and methylene blue (MB) to p-aminophenol (p-AP) and leucomethylene blue (LMB), respectively.