Application of a Novel Ti/nanoSnO₂-α-Fe₂O₃Anode for the Electro-Catalytic Degradation of Dye Pollutant: Optimization of Operational Parameters by Central Composite Design

Abstract

Electrochemical degradation of Acid Yellow 3 dye (AY3) in aqueous solution was investigated over a novel Ti/nanoSnO 2 -α-Fe 2 O3 electrode ssuccessfully fabricated by the cathodic electrophoretic deposition method. The surface morphology, elemental analysis, crystalline structure, and electrochemical properties of as-prepared nanoSnO 2 -α-Fe 2 O 3 films on titanium substrate surface were characterized by field emission scanning electron microscopy (FE-SEM) with an X-ray spectrometer attached, X-ray diffraction (XRD), linear sweep voltammetry (LSV), cyclic voltammetry (CV), and chrono-potentiometry (CP). The r esults showed that, compared to the traditional nanoSnO 2 electrode, the novel Ti/nanoSnO 2 -α-Fe 2 O 3 electrode with a porous morphology and without voids or cracks on the surface possessed higher electro-catalytic activity and electrochemical stability. To obtain maximum dye removal and to determine the relationship between important operating variables, pH, current density, electrolysis time, and electrolyte concentration were selected for the batch experiments as independent variables in a central composite design (CCD). In the first run, color removal efficiency was 92.73% for the fresh electrode, and 88.40% after 6 consecutive cycles of use under optimized conditions. These results presented here prove that the Ti/nanoSnO 2 -α-Fe 2 O 3 electrode has good electro-catalytic performance and a great potential for efficient degradation of organic pollutants.