Correction to: Efficient electrochemical oxidation of reactive dye using a novel Ti/nanoZnO–CuO anode: electrode characterization, modeling, and operational parameters optimization

Abstract

In the current study, electrochemical removal of reactive orange 7 (RO7) dye in aqueous solution was examined over a novel Ti/nanoZnO–CuO electrode prepared through electrophoretic deposition technique. Surface morphology, crystal structure, and elemental investigation of the prepared electrode were done by Field emission scanning electron microscopy, X-ray energy dispersive spectrometry, and X-ray diffraction analysis, which confirmed the presence of CuO nanoparticles along with ZnO nanoparticles in uniform coated layer. Besides, some electrochemical properties of the Ti/nanoZnO–CuO electrode were evaluated applying linear sweep voltammetry, cyclic voltammetry, and electrochemical impedance spectroscopy analysis. Based on these analyses, the Ti/nanoZnO–CuO electrode behaves as a non-active electrode as well as it possessed smaller charge-transfer resistance and higher current density than Ti and Ti/nanoZnO electrodes. Further, chrono-amperometry along with chrono-potentiometry tests were conducted to assess the novel electrode stability and service lifetime. Obtained results indicated the presence of CuO nanoparticles conducive to the enhancement of stability and conductivity properties. To evaluate the prepared electrode performance and optimize the removal process, four independent variables of pH, electrolyte concentration, current, and reaction time as inputs along with RO7 removal efficiency as response function in central composite design were investigated. Under optimal conditions, the RO7 removal efficiency and chemical oxygen demand of 99.16% and 66.66% were obtained after 60 min for Ti/nanoZnO–CuO electrode. According to the obtained results, Ti/nanoZnO–CuO electrode can be used in the electrochemical treatment of organic pollutants as a promising electrode.