One-step synthesis of silver nanoparticles in self-assembled multilayered films based on a Keggin structure compound

Abstract

Ag nanoparticles (NPs) formed in situ by the photochemical reduction of phosphotungstic acid (H 3 PW 12 O 40 , PTA) under UV-irradiation in polyelectrolyte multilayer nanoreactors composed of poly(ethyleneimine)-silver ions (PEI-Ag + ) and PTA fabricated on solid substrates by alternating adsorption, wherein the PTA plays the role of a UV-switchable reducing agent and an assembly reagent. Transmission electron microscopy (TEM) images show the formation of sphere-like silver NPs with sizes smaller than 12 nm in the multilayer films. Atomic force microscopy (AFM) and field emission scanning microscopy (FESEM) imply a film with a rough surface. The UV-vis characteristic absorbances of PTA and Ag NPs increase almost linearly with the number of bilayers, suggesting that the deposition process was regular and highly reproducible from layer to layer. X-Ray photoelectron spectroscopy (XPS) and Fourier transform infrared spectroscopy (FTIR) confirm the incorporation of PEI-Ag and PTA into the films. The multilayer films also exhibit good electrocatalytic activity for the oxidation of uric acid, which may be used in electrochemical biosensors.

Chemical, electrical and electrochemical characterization of hybrid organic/inorganic polypyrrole/PW12O403− coating deposited on polyester fabrics

“…P2p analyses showed the presence of a band to P at 133.7 eV (figure not shown). This band has been observed in other studies of polyoxometalates [45][46][47][48].…”

Electroreductions on Silver‐Based Electrocatalysts: The Use of Ag Nanoparticles for CHCl3 to CH4 Conversion

“…Depending on the substrate and the working conditions (solvent, supporting electrolyte, electrode material and potential), a second ET reaction (4) leads to the organic anion. Both anion and/or radical can react with solvent, hydrogen/proton donors and/or other RX molecules (or their organic moieties) to give propagation reaction prod- ucts like dimers and hydrodehalogenated species, as in reactions (5)- (7).…”

“…Although, Ag_NP are used in a large variety of applications that range from biosensors [7][8][9] to oxygen reduction electrocatalysts [10][11][12], to antimicrobial agents [13], to the best of our knowledge, this is the first time that these Ag_NP composites have been synthesised and applied to the electrochemical reduction of organic halides.…”

Advances in self-assembled ultrathin polyoxomolybdates multilayers

“…Our group [27] has reported the synthesis of organicinorganic nanocomposite films consisting of poly (ethyleneimine)-silver (PEI-Ag) and phosphotungstate acid (PTA) by means of a LbL self-assembly technique. Ag nanoparticles (NPs) formed in situ by the photochemical reduction of PTA under UV-irradiation in the polyelectrolyte multilayer nanoreactors.…”

“…A very versatile technique, known as electrostatic LbL self-assembly [3,23,26,27,29], has been explored to form well-defined layered architectures of polyoxomolybdates. Layer formation is based on the rather unspecific electrostatic attraction between the negatively-charged Fig.…”