abstract
The present work reports on a novel needle type oxygen microsensor based on boron doped diamond (BDD) with tailored surface aiming in better electrochemical performance. The microelectrodes are produced by growing diamond films using HFCVD (hot filament chemical vapor deposition) on top of electrochemically sharpened tungsten filaments. The diamond is functionalized using CF4 RF-plasma post-treatments resulting in fluorine termination of the surface. The quantitative detection of the dissolved oxygen (DO) is demonstrated and supported with successful fitting to the theoretical values calculated for diffusion limited current on hemicylinder shape electrode. The developed MEs were calibrated and tested as probes for microamperometric mapping of dissolved oxygen in a Zn-Fe wire-electrode model galvanic couple immersed in 50 mM NaCl. Modified diamond MEs show a fast and stable response towards oxygen mapping, as well as stability for several days of measurements. (C) 2014 Elsevier B.V. All rights reserved.
keywords
BORON-DOPED DIAMOND; ELECTROCHEMICAL-BEHAVIOR; TERMINATED DIAMOND; SINGLE-CRYSTAL; ELECTRODES; CORROSION; SURFACE; SVET; POLYCRYSTALLINE; PERFORMANCE
subject category
Chemistry; Electrochemistry; Instruments & Instrumentation
authors
Silva, E; Bastos, AC; Neto, M; Fernandes, AJ; Silva, R; Ferreira, MGS; Zheludkevich, M; Oliveira, F
our authors
Projects
Enhancing Scanning Ion-Selective Electrode Technique - SISET (SISET)
PROAIR - Active PROtection of multi-material assemblies for AIRcrafts (PROAIR)
Corrosion adn corrosion protection in multi-material systems (PTDC/CTM/108446/2008)
acknowledgements
E.L. Silva, M.A. Neto would like to acknowledge FCT (Fundacao para a Ciencia e a Tecnologia) for the grants SFRH/BD/61675/2009, and SFRH/BPD/45610/2008, respectively. This work was supported by projects PTDC/CTM/108446/2008, PTDC/CTMMET/113645/2009, funded by FEDER through COMPETE programmme-Operacional Factors for Competitivity and by national funds through FCT - Portuguese Science and Technology Foundation. The FP7 Marie-Curie Programe is also gratefully acknowledged for the support provided in frame of SISET (FP7-PEOPLE-2010-IRSES Reference 269282) and PROAIR (FP7-PEOPLE-2013-IAPP Reference 612415) projects.