Triblock copolymer-mediated synthesis of catalytically active gold nanostructures
The design of nanostructures based on poly(ethylene oxide)-poly(propylene)-poly(ethylene oxide) (PEO-PPO-PEO) and metal nanoparticles is becoming an important research topic due to their multiple functionalities in different fields, including nanomedicine and catalysis. In this work, water-soluble gold nanoparticles have been prepared through a green aqueous synthesis method using Pluronic F127 as both reducing and stabilizing agents. The size dependence (varying from 2 to 70 nm) and stability of gold nanoparticles were systematically studied by varying some parameters of synthesis, which were the polymer concentration, temperature, and exposure to UV-A light, being monitored by UV-Vis spectroscopy and TEM. Also, an elaborated study regarding to the kinetic of formation (nucleation and growth) was presented. Finally, the as-prepared Pluronic-capped gold nanoparticles have shown excellent catalytic activity towards the reduction of 4-nitrophenol to 4-aminophenol with sodium borohydride, in which a higher catalytic performance was exhibited when compared with gold nanoparticles prepared by classical reduction method using sodium citrate.
KeywordsPlasmonic nanoparticles Pluronic Catalysis Reactive surface
The authors are thankful to the CMNano-UFS (Project no. 63) for the TEM analysis, CNPq (Process no. 476674/2013-1), Capes, and Fapitec for financial support. G.R.S.A. received a scholarship from Capes (PNPD/2016).
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Conflict of interest
The authors declare that they have no conflict of interest.
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