Abstract
A nitroso compound (R-NO) known as a "spin trap" was used to study the production of hydroxyl radicals (OH·) on a Ti/SnO2-Sb2O5 anode. A linear voltammetry study was conducted on this anode in the presence of this compound, using the rotating disk electrode technique. The results showed that the electrode started to produce (OH·) at 0.7V vs. Ag/AgCl reference electrode. The current was limited by the mass-transport of RNO in the electrolyte. When the voltage increased to 1.4V and higher, significant oxygen evolution took place. Further investigation was conducted by constant voltage electrolysis and spectroscopic measurement of the RNO concentration. The change in the RNO was interpreted as the evolution of (OH·), and the current efficiency was calculated based on the assumed stoichiometry. The results showed that the efficiency was optimal within the potential range 0.7-1.4V, and the highest efficiency could reach 30%. This was in agreement with the RDE experiment.