Reactive intermediates during oxindation of water lead dioxide and platinum electrodes

A comparison of electrochemical degradation of phenol on boron doped diamond and lead dioxide anodes

“…Thus, other techniques are needed to destroy this pollutant. Electrochemical techniques which allow reduction of the quantity of organic pollutants in solution are: (a) Separation by electrofloculation [2], (b) Oxidation by electrogenerated Fenton's reagent [3,4], (c) Direct oxidation on a suitable anode material [5][6][7][8][9], where organic molecules are degraded into smaller molecules by successive oxygen atom transfer until complete destruction of the carbon skeleton [10]. The complete oxidation of phenol in aqueous solution by electrochemical means has been carried out on anode materials such as SnO 2 [7,8], PbO 2 [6,11,12], WO 3 [13] and BDD [14,15].…”

Study of electrochemical bleaching of p-nitrosodimethylaniline and its role as hydroxyl radical probe compound

“…However, some discrepancies are found in the literature. RNO has by cyclic voltammetry been showed to be electrochemically inactive at Pt, IrO 2 , SnO 2 , and PbO 2 anodes [3,13], but has as well been reported to be bleached in Ti/Pt and Ti/RuO 2 anode systems [16]. Ti/Pt and Ti/RuO 2 anodes represent types of anodes that according to the generally accepted models developed by Comninellis and co-workers [3,9,17], belongs to the class of active anodes that utilize chemisorbed lattice active oxygen, MO or MO x?1 , and not free hydroxyl radicals for organic oxidation.…”

“…When aqueous solutions are passed through the electrochemical cell, the active oxygen species is produced at the surface of the anode from oxidation of water molecules, and these oxygen species are then capable of organic oxidation leading to either partial oxidation or full mineralization. In electrochemical oxidation studies, the method of RNO bleaching has been adapted from the fields of medical chemistry [10][11][12], cell biology [6] and photobiology [4] as a tool for evaluation of the oxidation performance [3,7,8,[13][14][15][16]. RNO has in the electrochemical oxidation studies been used to obtain evidence for the presence of hydroxyl radicals in the studied systems.…”

Electrochemistry and green chemical processes: electrochemical ozone production

“…Such argument is based on kinetic considerations since the partial coverage by adsorbed O 2 -molecule of the electrode surface acting as an intermediate for EOP directly affects the current efficiency of EOP (fraction of the current leading to ozone production Different electrode mechanisms to describe the OER/EOP processes, taking into account different intermediates, can be found in the literature 30,36,73 . However, these mechanisms do not permit a direct correlation between kinetic, surface adsorbed species and current efficiency for EOP.…”

“…On β-PbO 2 electrodes, depending on electrode morphology, BF 4 -can both act increasing or inhibiting EOP. Advances on the kinetics for EOP were also achieved 4,36,73 . The electrode mechanism recently proposed by Da Silva et al 4 for OER/EOP processes at inert electrodes permits an adequate theoretical interpretation of the influence on Φ EOP of the stability of intermediate oxygenated species adsorbed on the electrode surface (see previous discussion).…”