Electrocatalytic and antifouling properties of CeO2-glassy carbon electrodes

Abstract

Binary metal oxides with different degrees of covalent/ionic character of the oxygen-metal bond are tested as a partial coating of glassy carbon electrode surfaces. The electrocatalytic and antifouling properties of the resulting bicomponent electrode systems are analysed in view of possible applications in different fields of electrochemistry, such as electroremediation and electroanalysis. Based on the performance with respect to oxidation of ascorbic acid, as to sensitivity, repeatability of the responses, and activation of electrocatalytic oxidation, CeO2 has been preferred. This same electrode system has been further studied in respect to a trickier electrochemical process, namely the anodic oxidation of a chlorophenol derivative, which induces massive passivation of bare electrode surfaces. The effectiveness of the bicomponent electrode system in anodic oxidation of 2,4,6-trichlorophenol has been ascertained, over a wide range of concentrations, by comparison with pure glassy carbon surfaces

Multiple Pulse Amperometry—An Antifouling Approach for Nitrite Determination Using Carbon Fiber Microelectrodes

“…Although electrochemical detection via oxidation is usually preferred, the use of bare electrodes is limited by surface poisoning and passivation [ 22 , 23 ]. Some strategies can be employed to overcome these limitations, such as electrode surface modification, pretreatment [ 24 ], and pre-stabilizing the electrode signal before the analysis. The modification of the electrode surface has been shown to enhance the signal stability significantly, even though the mechanism associated with the antifouling effect still needs to be fully elucidated [ 25 , 26 ].…”

“…An emblematic example is the WPI electrodes (World Precision Instruments Inc., Sarasota, FL, USA) for nitric oxide detection, which require a stabilization time of about two hours before usage [ 27 ]. Another common strategy is the pretreatment of the electrode surface by polarizing the electrode at positive or negative potentials over a few minutes before the measurements [ 24 , 28 ].…”

Electrodeposition of Cobalt Oxides on Carbon Nanotubes for Sensitive Bromhexine Sensing

“…A major obstacle in electrochemical sensing is the need for large overpotentials to detect an analyte and the consequent electrode fouling, which can deteriorate its performance and stability [11]. Many surface modifications have been proposed to reduce fouling accretion on electrodes [12]; a promising approach is based on coating the electrode surface with metal-oxide nanoparticles, which reduces the overpotentials required [13]. Cobalt oxide nanoparticles are particularly interesting due to their unique properties, including large surface area, high dispersion (fraction of atoms on the surface), and great chemical stability [14].…”

A Flexible Platform of Electrochemically Functionalized Carbon Nanotubes for NADH Sensors

“…The performance of the electrode material was improved here by functionalizing SWCNTs with catechol residues. To such a purpose, SWCNTs have been electrochemically oxidized in strong acidic medium [20,28,29] and the resulting SWCNT ox film has been further modified by performing a voltammetric treatment in a caffeic acid (CFA) solution. The effectiveness of the resulting SWCNT CFA surface in activating electrocatalytic processes in charge of NADH oxidation has been ascertained by performing both electrochemical and spectroelectrochemical experiments in absence and in presence of NADH.…”