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Electrochemical and structural characterization of Nafion/Bismuth-Tin nanocomposites stabilized with polyoxyethylene 23 lauryl ether (Brij)

Abstract:

Nafion/Bismuth-Tin nanocomposites stabilized with polyoxyethylene 23 lauryl ether (brij) were produced in a mixture of nafion and brij dissolved in N-N dimethylformamide. Metal salts were reduced in the presence of sodium borohydride assisted by ultrasound. The average hydrodynamic diameter of polymer-metal particles was measured via dynamic light scattering (DLS) and related to the composition of the reactive mixture; growth kinetics were compared with the Liftshitz-Sloyozov-Wagner model, and we found that the polymer-tin system of nanoparticles was time stable and that the size of the nanoparticles, close to 100 nm, is not dependent on brij concentration. The selected nanocomposites with a total metal concentration of 13% w/w were structurally characterized by means of infrared (IR) and X-ray photoelectron spectroscopy (XPS). Furthermore, the morphology and phase-metal distribution was studied via electron microscopy (SEM and TEM). The nanocomposites were used as electrodes for cadmium detection through square-wave anodic stripping voltammetry (SWASV) in a sodium acetate buffer solution. The materials with higher bismuth content allowed obtaining better results in terms of the peak current; however, the addition of tin up to 50% allows producing material with greater resistance to oxidation.