Triazole-stabilized gold and related noble metal nanoparticles for 4-nitrophenol reduction

Abstract

A series of bifunctional 1,2,3-triazole ligands that contain a polyethylene glycol (PEG) chain and another functional fragment (e.g. phenyl, substituted phenyl, benzyl, and straight-chain alkyl) have been prepared by “click” chemistry. These non-toxic and biocompatible ligands are investigated as stabilizers for gold nanoparticles (AuNPs) via the triazole–Au (trz–AuNPs) bond and provide water-soluble nanocatalysts. All of these AuNPs are fully characterized by UV-Vis spectroscopy, transmission electron microscopy (TEM) and/or energy dispersive X-ray (EDX) spectroscopy. The catalytic activities of these NPs in 4-nitrophenol (4-NP) reduction are evaluated by UV-Vis spectroscopy, and the results illustrate that the size of the AuNPs, the functional groups on the triazole ligands, and the length of PEG chain have great impact on the catalytic activities. Finally, the ligands were extended to stabilize other related metal nanoparticles and their alloys, and the Pd alloys exhibit the best catalytic activity among the noble metal nanoparticles investigated.