Electrochemical corrosion of a glassy carbon electrode

Abstract

Glassy carbon is widely used in electrochemistry due to its properties of high temperature resistance, hardness, low density and low electrical resistance. The present study focuses on the chemical resistance under electrochemical oxidative conditions, which occur under oxygen-involving reactions like oxygen reduction reaction (ORR) and oxygen evolution reaction (OER). The electrochemical performance of glassy carbon investigated in alkaline, neutral and acidic media reveal the same chemical processes during the OER but showing different degradation mechanism. The electrochemical signature of the corrosion in different media could be directly associated with the formation of oxygen functional groups determined by spectroscopic methods like Raman, infrared (IR) and x-ray photoelectron spectroscopy (XPS). The morphology change of the carbon surface caused by carbon oxidation was investigated by microscopy. A rough surface was obtained in the acidic case, whereas dents were seen in alkaline media. It is assumed that the glassy carbon electrode in acidic media degrades by forming surface oxides by acid catalyzed process leading to ring opening in the graphitic structure and therefore oxidation in the bulk. In alkaline media OH radicals preferentially react with alkyl site chains, leading to oxidation of the edges of carbon layers until they become hydrophilic and dissolve

NADH Oxidation onto Different Carbon-Based Sensors: Effect of Structure and Surface-Oxygenated Groups

“…FT-IR spectra obtained for the different carbon-based materials studied are reported in Figure 1. GC (Figure 1(a)) did not exhibit relevant signals; this is in agreement with the literature [11,12]. The low-intensity band in the 3100-3400 cm −1 area can be related to the formation of -OH groups, and the signals at 1500-1700 cm can be attributed to stretching of the carbonyl groups (Figure 1(b)).…”

“…However, the very low absorption indicates the poor content of carbonyl and hydroxyl groups on the GC surface. This is was also obtained by Yi and coworkers [12].…”

“…The structure obtained is generally as randomly intertwined ribbons of graphitic planes not presenting many functional groups at its surface beyond alkyl and aromatic groups, which are characteristic of the graphitic planes [11]. On the other hand, electrochemical oxidation of GC in basic or acidic media has been tested as a surface modification methodology and has been demonstrated that heterogeneous transfer constant and capacitance are increased [12]. Multiwalled carbon nanotubes (MWCNTs) are cylindrical graphite-based molecules which have unusual properties, exploitable in areas like nanotechnology, electronics, optics, and other fields of material science and technology.…”

TiO2-nanowire/MWCNT composite with enhanced performance and durability for polymer electrolyte fuel cells

“…Interestingly, it is observed from CV curves that there is an increase in the capacitive current for PEFC cathode comprising Pt/MWCNT as cathode electrocatalyst during AST as shown in Figure 4S (SI). This increase in the capacitive current in the CV curve may be attributed to the surface roughening initiated by the surface defects [55,56]. Similar increase in capacitive current was already observed in our previous study, were carbon corrosion occurred along with increase in capacitance [57].…”

Analysis of sulfamethoxazole by square wave voltammetry using new carbon paste electrode

“…Also, much lower background current that was obtained for the CPE as compared with the solid glassy carbon, suggests that the proposed CPE electrode could be more sensitive for SMX oxidation [6][7][8][9][10][11][12][13][14][15][16]. The higher background current observed for the glassy carbon electrode in Figure 5B stems from the oxygen evolution [43]. …”