Application of TiO2-nanotubes/PbO2 as an anode for the electrochemical elimination of Acid Red 1 dye

• Published in: Journal of solid state electrochemistry Vol. 23; no. 2; pp. 351 - 360
• Main Authors: Santos, José Eudes L., de Moura, Dayanne Chianca, da Silva, Djalma Ribeiro, Panizza, Marco, Martínez-Huitle, Carlos A.
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 12.02.2019; Springer Nature B.V
• Subjects: Analytical Chemistry; Anodes; Characterization and Evaluation of Materials; Chemical evolution; Chemical oxygen demand; Chemistry; Chemistry and Materials Science; Condensed Matter Physics; Current efficiency; Dyes; Electrochemical cells; Electrochemistry; Electrodes; Electrolysis; Electron transfer; Energy consumption; Energy conversion efficiency; Energy Storage; Lead oxides; Nanotubes; Organic chemistry; Original Paper; Oxidation; Oxidation rate; Oxidizing agents; Physical Chemistry; Platinum; Sodium sulfate; Titanium dioxide; Dye; Anodic oxidation; Water treatment, strong oxidants; PbO; Titanium oxide nanotubes
• ISSN: 1432-8488; 1433-0768
• DOI: 10.1007/s10008-018-4134-5

In this study, galvanostatic electrolysis, through the use of the platinum supported on Ti (Ti/Pt) and Ti/TiO 2 -nanotubes/PbO 2 anodes, was conducted in an electrochemical cell with 0.2 L of solution containing 100 mg dm −3 of the textile dye Acid Red 1 (AR1) using Na 2 SO 4 as supporting electrolyte, applying 7.5 and 60 mA cm −2 . From the voltammetric curves, it was possible to understand that Ti/TiO 2 -nanotubes/PbO 2 electrode has high oxygen evolution overpotential than Ti/Pt anode. A direct electron transfer reaction is attained between the dye molecules and Ti/Pt surface, at lower currents. Conversely, the AR1 oxidation involves water decomposition intermediates, mainly · OH radicals at Ti/TiO 2 -nanotubes/PbO 2 anode. The electrolytic process was monitored by the UV–visible spectrometry and the chemical oxygen demand (COD). Results clearly show that Ti/TiO 2 -nanotubes/PbO 2 anode performs better than Ti/TiO 2 in removing ARI due to the electrosynthesis of strong oxidants on its surface ( · OH and persulfates), achieving a higher oxidation rate, higher current efficiency, and less energy consumption than Ti/Pt electrode.