Electrochemical studies on glassy carbon electrodes

An overview of the electrochemical reduction of oxygen at carbon-based modified electrodes

“…Since the O 2 -adsorption is crucial to increase the rate of reaction (25) and therefore the production of hydrogen peroxide, adsorbates that partially blocked adsorption, like BMB or DNPH, slow down the reaction and shift the oxygen reduction peak potential toward more negative values. The effect of oxidative pre-treatment on the electrocatalytic activity of carbon electrode toward oxygen reduction has been reported by several authors [26,29,57,86,87]. Oxidative pre-treatments lead to an increase of the oxygen reduction rate due to electrocatalysis by oxygen containing surface species [26,29,66].…”

“…Xu et al [29] have proposed a mechanism for several different carbon materials such as electrochemically pretreated GC, laser-treated GC, fractured GC, low defect HOPG basal plane surfaces, and modified GC: [15,[25][26][27]29] are consistent with the experimental data and seem to be logical, they are still not proved. The electroreduction of oxygen on carbon surfaces is much slower than that on 'active' metals such as platinum or gold.…”

“…Therefore carbon is an electrode material suitable for the electrochemical synthesis of hydrogen peroxide. Many different types of carbon have been studied for the oxygen reduction reaction: highly oriented pyrolytic graphite (HOPG) [6], pyrolytic graphite (PG) [6,19], graphite powder, porous graphite, natural graphite, glassy carbon (GC) [20][21][22][23][24][25][26], pyrolytic carbon, active carbon, carbon black [27] and carbon single crystals.…”

“…It is proposed that oxides may enhance adsorption of O 2 -by withdrawing electrons from the surface. It was observed that polarisation curves of glassy carbon and polished pyrolytic carbon show two peaks in oxygen-saturated alkaline solutions [26,57,58] corresponding to the oxygen reduction on two different surface sites. The current of the first peak does not reach the diffusional value and is limited by number of the most active surface catalytic sites.…”

Electrosynthesis of hydrogen peroxide via the reduction of oxygen assisted by power ultrasound

“…less than 12, previous research has mainly focused on electrode materials [9][10][11], influence of the pH [12], use of surfactants [13], mediated electro-reduction using 2-ethyl 9,10-anthraquinone [14,15], and use of electrodes modified with electrocatalytic materials [16][17][18][19][20][21]. Due to the slow kinetics of the oxygen reduction and the low solubility of the oxygen in aqueous solution, three dimensional electrodes with a high ratio of surface area to volume in flow cells, have been commonly used in the electrosynthesis of hydrogen peroxide.…”