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The Influence of the Capping Agent on the Oxidation of Silver Nanoparticles: Nano‐impacts versus Stripping Voltammetry
Author(s) -
Toh Her Shuang,
Jurkschat Kerstin,
Compton Richard G.
Publication year - 2015
Publication title -
chemistry – a european journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.687
H-Index - 242
eISSN - 1521-3765
pISSN - 0947-6539
DOI - 10.1002/chem.201406278
Subject(s) - coulometry , anodic stripping voltammetry , nanoparticle , silver nanoparticle , polyvinylpyrrolidone , cyclic voltammetry , polyethylene glycol , voltammetry , chemistry , anode , materials science , inorganic chemistry , electrochemistry , nuclear chemistry , chemical engineering , nanotechnology , organic chemistry , electrode , engineering
The influence of capping agents on the oxidation of silver nanoparticles was studied by using the electrochemical techniques of anodic stripping voltammetry and anodic particle coulometry (“nano‐impacts”). Five spherical silver nanoparticles each with a different capping agent (branched polyethylenimine (BPEI), citrate, lipoic acid, polyethylene glycol (PEG) and polyvinylpyrrolidone (PVP)) were used to perform comparative experiments. In all cases, regardless of the capping agent, complete oxidation of the single nanoparticles was seen in anodic particle coulometry. The successful quantitative detection of the silver nanoparticle size displays the potential application of anodic particle coulometry for nanoparticle characterisation. In contrast, for anodic stripping voltammetry using nanoparticles drop casting, it was observed that the capping agent has a very significant effect on the extent of silver oxidation. All five samples gave a low oxidative charge corresponding to partial oxidation. It is concluded that the use of anodic stripping voltammetry to quantify nanoparticles is unreliable, and this is attributed to nanoparticle aggregation.