Browsing by Author "del Rio, Rodrigo"

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    An electrochemical deposition route for obtaining alpha-Fe2O3 thin films - II. EQCM study and semiconductor properties
    (ELECTROCHEMICAL SOC INC, 2007) Schrebler, Ricardo; Llewelyn, Cynthia; Vera, Francisca; Cury, Paula; Munoz, Eduardo; del Rio, Rodrigo; Meier, Humberto Gomez; Cordova, Ricardo; Dalchiele, Enrique A.
    The electrochemical formation of hematite (alpha-Fe2O3) precursor thin films (oxyhydroxide iron compounds), onto gold substrates in an aqueous solution of Fe (III) + KF + H2O2 was investigated in situ using an electrochemical quartz crystal microbalance (EQCM) and voltammetric techniques. Nanostructured alpha-Fe2O3 obtained after annealing of oxyhydroxide iron compounds thin films have been prepared onto SnO2/F covered glass substrates through a potential cycling procedure in this electrolytic bath. Photoelectrochemical measurements, carried out in 0.1 M NaOH + 0.05 M KI electrolyte at pH 13, show an n-type behavior, a flatband potential of -1.08 V vs saturated mercury/mercury sulfate reference electrode, and an apparent donor density of 1.26 X 10(19) cm(-3) at 1 kHz. (C) 2007 The Electrochemical Society.
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    Corrosion inhibition of copper in chloride media by 1,5-bis(4-dithiocarboxylate-1-dodecyl-5-hydroxy-3-methylpyrazolyl)pentane
    (PERGAMON-ELSEVIER SCIENCE LTD, 2008) Vera, Rosa; Bastidas, Francisco; Villarroel, Maria; Oliva, Alfonso; Molinari, Aurora; Ramirez, Daniel; del Rio, Rodrigo
    The efficiency of 1,5-bis(4-dithiocarboxylate-1-dodecyl-5-hydroxy-3-methyl-pyrazolyl)pentane (BDTCPP) as copper corrosion inhibitor in 3.5% NaCl solutions was studied by electrochemical polarization methods (Tafel extrapolation and polarization resistance method), electrochemical impedance spectroscopy and immersion assays. Results obtained in this study reveal that BDTCPP is a good inhibitor and the potentiodynamic polarization studies clearly show that BDTCPP is a mixed-type inhibitor for copper in chloride solutions. It decreases the anodic reaction rate more strongly than the cathodic reaction rate and it renders the open circuit potential of copper more positive in 3.5% NaCl solutions. The UV analysis of the protective layer of BDTCPP after corrosion experiments shows that the inhibitor prevents copper corrosion by physisorption on the metal surface, followed by chemisorption of a protective Cu(II)-complex. This Cu(II) is generated by oxidation of the Cu(I) ion formed at the beginning of the corrosion process in the aerated solution of NaCl. (C) 2007 Elsevier Ltd. All rights reserved.
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    Effect of the Dispersing Agent on the Electrochemical Response of Glassy Carbon Electrodes Modified with Dispersions of Carbon Nanotubes
    (WILEY-V C H VERLAG GMBH, 2012) Gonzalez Segura, Karina; Canete Rosales, Paulina; del Rio, Rodrigo; Yanez, Claudia; Ferreyra, Nancy F.; Rivas, Gustavo A.; Bollo, Soledad
    The electrochemical response of a glassy carbon electrode modified with carbon nanotubes (CNT) dispersed in two solvents, water and DMF, and two polymers, chitosan and Nafion is reported. The films were homogeneous when the dispersing agent was water or DMF. In the case of polymers, the surfaces present areas with different density of CNTs. A more sensitive electrochemical response was obtained when CNTs are dispersed in the solvents. In the case of CNT dispersed with polymers, the nature of the polymer demonstrated to be a critical parameter not only for dispersing the nanotubes but also for the electrochemical activity of the resulting electrodes.
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    Electrochemical Conversion of Carbon Dioxide into CHO-Containing Compounds on Multimetallic Porphyrins
    (2017) Calfuman, K.; Honores Sotelo, Jessica Scarlet; Guzmán Ángel, Daniela; Ohlbaum, M.; Armijo Mancilla, Juan Francisco; del Rio, Rodrigo; Isaacs Casanova, Mauricio
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    Understanding the loss of electrochemical activity of nanosized limn2o4 particles: a combined experimental and ab initio DFT study
    (2018) Velasquez, Ever A.; Silva, Daiane P. B.; Falqueto, Juliana B.; Mejía López, José Félix; Bocchi, Nerilso; del Rio, Rodrigo; Mazo-Zuluaga, Johan; Rocha-Filho, Romeu C.; Biaggio, Sonia R.