A new electrochemical sensor for OH radicals detection.
A new, cheap modified electrode for indirect detection of OH radical is described. A glassy carbon (GC) electrode was modified with a polyphenol film prepared by oxidative potentiostatic electropolymerization of 0.05 M phenol in 1M H2SO4. The film having a thickness of ~10nm perfectly covered the GC surface and inhibited the charge transfer of many redox species. The degradation of the polyphenol film, that was induced by OH radicals generated by Fenton reaction or by H2O2 photolysis, is the analytical signal and it was evaluated by cyclic voltammetry and chronoamperometry using the redox probe Ru(NH3)6(3+). Some simulations of the kinetics of the reactions occurring in the solution bulk and near the electrode surface were carried out to fully understand the processes that lead to the analytical signal. The modified electrode was used to evaluate the performances of different TiO2-based photocatalysts and the results were successfully compared with those obtained from a traditional HPLC method that is based on the determination of the hydroxylation products of salicylic acid.
Dipartimento di Chimica Industriale "Toso Montanari", University of Bologna, INSTM, UdR Bologna, Viale Risorgimento 4, 40136 Bologna, Italy.
Isacco
I
Gualandi
Domenica
D
Tonelli
D002244:Carbon; D055664:Electrochemical Techniques; D004566:Electrodes; D006861:Hydrogen Peroxide / Q000737:chemistry*; D017665:Hydroxyl Radical / Q000032:analysis*; D007700:Kinetics; D053768:Metal Nanoparticles; D010084:Oxidation-Reduction; D019800:Phenol / Q000737:chemistry*; D010782:Photolysis; D058105:Polymerization; D020156:Salicylic Acid / Q000737:chemistry; D013464:Sulfuric Acids / Q000737:chemistry; D014025:Titanium / Q000737:chemistry
D013464:Sulfuric Acids; C009495:titanium dioxide; D017665:Hydroxyl Radical; D019800:Phenol; D002244:Carbon; D006861:Hydrogen Peroxide; D014025:Titanium; C033158:sulfuric acid; D020156:Salicylic Acid
Aromatic hydroxylation; Modified electrodes; OH production; OH radical detection; TiO(2) nanoparticles