Electrochemical degradation of aromatic compounds at modified SnO2 anodes [articol]

Abstract

The purpose of this study was the electrochemical degradation of a mixture of Reactive Black 5 (RB5) azo dye and nonylphenol ethoxylate with 9 ethoxy units (NP9EO) at modified SnO2 anodes. Ti/RuO2/SnO2-Sb2O5-RuO2 and Ti/RuO2/SnO2-Sb2O5-Bi2O3 anodes were prepared by thermal decomposition of appropriate precursors. Both NP9EO and RB5 concentrations were 0.1 g/L in 0.1 M Na2SO4 as supporting electrolyte. The electrolysis were conducted under galvanostatic regime at applied current densities of 50, 75 and 100 A/m2 and electrolysis time of 30, 60 and 120 minutes. The electrolysed solutions were characterised by UV-VIS spectroscopy. The spectral data revealed the aromatic ring opening and they were also used to assess the colour removal efficiency. Based on the spectral data, it was assessed the colour efficiency and some aspects of oxidation process were discussed.