The synthesis of a self-doped TiO₂ nanotubes (SD-TNT) electrode and its potential applicability as a sensing platform electrode for voltammetric determination of methylene blue (MB) dye is reported. Highly ordered TiO₂ nanotubes vertically oriented to the titanium surface were grown and the electrochemical doping did not change the morphology of the TNT. Raman spectroscopy demonstrated that the electrochemical doping of TNT promoted a blue shift of the E_g¹ mode (from 152 to 158 cm⁻¹) which results in an increased conductivity due to the phonon confinement resultant from the formation of non-stoichiometry Ti³⁺ donor states. The structural changes allowed the application of SD-TNT as a voltammetric sensor of MB without any UV irradiation. The SD-TNT electrode allowed an efficient quantification of MB, with a limit of detection of 0.48 and 0.90 μmol L⁻¹ when considered the oxidation and reduction peak, respectively. Then, SD-TNT electrode was applied to the monitoring of MB concentration during electro-Fenton oxidation. MB removal fitted well with pseudo-first-order kinetics, suggesting a constant formation of ^•OH radicals and oxidation of MB. These results revealed that the SD-TNT is a versatile, simple, and promising material for the voltammetric determination of synthetic dyes.

报道了自掺杂TiO ₂纳米管（SD-TNT）电极的合成及其作为伏安法测定亚甲基蓝（MB）染料的传感平台电极的潜在适用性。生长垂直于钛表面的高度有序的TiO ₂纳米管，并且电化学掺杂不会改变TNT的形态。拉曼光谱表明，TNT的电化学掺杂促进了E _g ¹模式的蓝移（从152 cm至158 cm ^-1），这由于非化学计量的Ti ³⁺的形成而导致的声子约束导致电导率提高。捐助国。结构上的变化允许将SD-TNT用作MB的伏安传感器，而无需任何紫外线照射。SD-TNT电极可实现MB的高效定量，当分别考虑氧化峰和还原峰时，检出限分别为0.48和0.90μmolL ^-1。然后，将SD-TNT电极应用于电子芬顿氧化过程中的MB浓度监测。MB去除与拟一级动力学非常吻合，表明^• OH自由基的不断形成和MB的氧化。这些结果表明，SD-TNT是一种用于伏安法测定合成染料的通用，简单且有希望的材料。