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Abstract: Nanostructures based on copper (CuNSs) are promising materials in different fields of application. To this end, in this work we have studied a simple one-step electrosynthesis of CuNSs directly onto ITO electrode surface starting from an aqueous solution of copper sulphate. We have investigated the effects of the presence of electrolyte salts such as K2SO4, Na2SO4 and (NH4)2SO4 and we have found that they gave rise to the formation of a number of remarkably different forms of nanostructures. In particular, when the electrodeposition was conducted in presence of K2SO4 fractal-like or dendritic structures consisting of a long central backbone and sharp side branches were observed. The resulting CuNSs were characterized by SEM, XRD and by electrochemical techniques. Studies on the electrocatalytic behaviour of dendritic CuNSs modified electrodes towards the oxidation of L-tyrosine in 0.05M NaOH solution showed a 1.0 10−6 ÷ 7.0 10−5 M linear range and a detection limit of ca. 6.0 10−7 M. [Copyright &y& Elsevier]

The electrochemical deposition of silver nanodendrites (AgNDs) on pure graphite sheet (PGS) electrodes, both in the absence of surfactant/templates and in the presence of 1-nonanesulfonic acid (NS) or polyvinylpyrrolidone (PVP) additives, is reported. The synthesis carried out without additives and with NS produced a bigger amount of large size AgNDs (dimension of 1-5 μm), with scarce influence played by NS, while the deposition with PVP favoured the formation of smaller spherical particles (with average diameter below 150 nm). The performances of the electrodes towards the electroreduction of HO were investigated by chronoamperometry at −0.4 V and at more cathodic applied potentials (−0.6 and −0.8 V). The electrodes fabricated without additives and in the presence of NS displayed similar performances, while those fabricated with PVP exhibited significantly lower sensitivity. This suggests that AgNDs present enhanced electrocatalytic activity in respect to the spherical aggregates, since the Ag amount deposited on PGS was practically the same. The best amperometric responses among those recorded at −0.4 V in PBS (pH 6.7) exhibited a linear range extending from 0.1 to 3.5 mM, a detection limit of about 20 μM and a sensitivity close to 200 mA M cm. The proposed electrodes display sensitivities which are markedly better than those reported in the literature for similar Ag-based sensors. [ABSTRACT FROM AUTHOR]

Abstract: Bimetallic Au–Pt nanoparticles (Au–PtNPs) have been synthesized using an electrochemical reduction approach. The effects of the addition of different additives in the electrodeposition bath namely KI, 1-nonanesulfonic acid sodium salt and Triton X-100 have been investigated. The structural characterization of the bimetallic nanoparticles has been carried out using scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), UV–vis spectroscopy, X-ray diffraction (XRD) and cyclic voltammetry (CV). The Au–PtNPs prepared in the presence of KI and Triton X-100 characterized by a relatively narrow size distribution as well as a higher particle density and surface coverage whereas no changes in the morphology were observed. These results suggest a dependence of the size and distribution of the bimetallic nanoparticles from the type and concentration of the additives employed. [ABSTRACT FROM AUTHOR]