resumo
Boron-doped nanocrystalline diamond (B-NCD) films were grown by the hot filament chemical vapor deposition (HFCVD) technique on top of sharp electropolished tungsten substrates, in order to create amperometric microelectrodes (MEs) for detection of Zn2+(aq) and dissolved O-2. The boron source was a B2O3 + ethanol mixture dragged by Argon gas through a bubbler. Different B2O3 concentrations were used to study the doping effect on the electrochemical behavior. The B-NCD MEs exhibited a working potential window of about 3.5 V in 5 mM NaCI, with low background current and good chemical inertness. The best electrochemical kinetics was achieved for the ME with highest boron doping content. The linear relationship between zinc concentration and zinc reduction current was found in a wide concentration interval from 10(-5) M to 10(-2) M of ZnCl2 in a 5 mM NaCI background. Measurements with a Fe-Zn galvanic couple immersed in 5 mM NaCI demonstrate potential applicability of the B-NCD ME for use in localized corrosion studies. (C) 2012 Elsevier Ltd. All rights reserved.
palavras-chave
ANODIC-STRIPPING VOLTAMMETRY; GALVANIC CORROSION; INTERMEDIARY METABOLISM; ZN/STEEL COUPLE; HEAVY-METAL; THIN-FILMS; ZINC; ELECTRODE; KINETICS; ULTRAMICROELECTRODES
categoria
Electrochemistry
autores
Silva, EL; Bastos, AC; Neto, MA; Silva, RF; Zheludkevich, ML; Ferreira, MGS; Oliveira, FJ
nossos autores
António Alexandre Cunha Bastos
Investigador Auxiliar
Eduardo Luís Trindade da Silva
Bolseiro de pós-Doutoramento
Filipe José Alves de Oliveira
Investigador Principal
Mário Guerreiro Silva Ferreira
Professor(a) Jubilado(a)
Miguel Ângelo da Costa Neto
Investigador Principal
Mikhail Zheludkevich
Investigador Principal Convidado
Rui Ramos Ferreira e Silva
Professor associadoagradecimentos
E.L. Silva, A.C. Bastos and M.A. Neto would like to acknowledge FCT (Fundacao para a Ciencia e a Tecnologia) for the grants SFRH/BD/61675/2009, SFRH/BPD/23175/2005 and SFRH/BPD/45610/2008, respectively. This work was supported by project PTDC/CTM-MET/113645/2009, funded by FEDER through COMPETE programmme-Operacional Factors for Competitivity and by national funds through FCT - Portuguese Science and Technology Foundation.