In the present study, degradation of Reactive Orange 7 dye was investigated using a new designed titanium electrode, in which a plate of Ti was coated with multi-walled carbon nanotubes (Ti/MWCNT) via electrophoretic deposition technique. A series of characterizations including field scanning electron microscopy, X-ray diffraction, cyclic voltammetry, scanning electrochemical impedance spectroscopy and chronoamperometric analysis were performed to investigate MWCNT impact on the microstructure and electrochemical properties of Ti electrode. Furthermore, the effect of main operating parameters as independent variables (current density, electrolyte concentration, initial pH, and electrolysis time) on color removal efficiency as response variable were investigated and optimized by central composite design under response surface methodology. The maximum color removal efficiency of 89.1% and chemical oxygen demand removal efficiency of 55% were obtained, under the optimum condition. These results indicate that the presence of MWCNT on the Ti substrate noticeably promoted the electrochemical activity and the electrodes’ property for treatment of dye in aqueous solution.

中文翻译：

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中心复合设计在Ti / MWCNT电极上活性染料电化学氧化的应用

在本研究中，使用新型设计的钛电极研究了活性橙7染料的降解，其中钛板通过电泳沉积技术涂有多壁碳纳米管（Ti / MWCNT）。进行了一系列表征，包括场扫描电子显微镜，X射线衍射，循环伏安法，扫描电化学阻抗谱和计时电流分析，以研究MWCNT对Ti电极的微观结构和电化学性能的影响。此外，在响应面方法下，通过中心复合设计研究并优化了主要操作参数作为自变量（电流密度，电解质浓度，初始pH和电解时间）对作为响应变量的脱色效率的影响。在最佳条件下，获得的最大脱色效率为89.1％，化学需氧量去除率为55％。这些结果表明，在Ti基体上MWCNT的存在显着提高了电化学活性和电极在水溶液中处理染料的性能。