Synthesis of gold nanoparticles using phenolic acids and its application in catalysis

The potentiality of different phenolic compounds, belonging to both hydroxycinamic (caffeic, sinapinic and ferulic acids) and hydroxybenzoic (protocatechuic, syringic and vanillic acids) families to generate different gold nanoparticles (AuNPs) has been investigated. The synthesized AuNPs were characterized by transmission electron microscopy (TEM) andUV-Vis absorption spectroscopy. The influence of different experimental parameters, such as pH, ionic strength, buffer concentration, temperature and presence or absence of a stabilizer agent in AuNP synthesis has been studied. In all cases, the addition of a stabilizer has influence in both the amount of AuNP synthesized and in their size. On the other hand, different UV-vis spectra were obtained depending on the phenolic acid used as reducing agent, which was attributed to the different reducing power and stabilization capacity of the different phenolic acids. Finally, the prepared AuNPs showed good catalytic activity for the reduction of 4-nitrophenol to 4-aminophenol by an excess of NaBH4.