Enhanced Photocatalytic Degradation of Organic Pollutants and Anticorrosion of Mild Steel by Vanadium Modified Titanate Nanotubes (X%V‐TiNTs)

Abstract

The present work aims to study the anticorrosion and the photodegradation properties of titanate nanotubes (TiNTs) and vanadium doped-titanate nanotubes (V-TiNTs). Moreover, this article seeks to investigate the effect of doping TiNTs by vanadium species at different amount (2, 5 and 10 wt %). The raw materials (i.e:TiO 2 and V 2 O 5-TiO 2) are obtained by a sol gel process, while the hydrothermal treatment is chosen to achieve the hollow structure. The structural evolutions and morphological characteristics of materials have performed using various techniques such as: Scanning Electron Microscopy and Energy Dispersive X-ray (MEB/EDS), X-ray diffraction (XRD), UV-Visible in Reflection Diffuse spectroscopy (RD/UV-Vis) and Fourier Transform InfraRed spectroscopy (FTIR) analysis. However , the anticorrosion properties of the synthesized nanotubes are evaluated on mild steel corrosion in 1 N HCl using a weight loss method. All materials showed a potential inhibitor effect (up to 90 %) depending on the vanadium percentage and the inhibitor concentration. The photodegradation activity of the prepared materials is evaluated in the photodegradation of two organic pollutants: Methylene Blue (MB) and Malachite Green (MG) under UV-Visible irradiation. The obtained results underlined the improvement of photocatalytic activity of TiNTs by vanadium species. A conversion rate up to 96 % is achieved at reduced time. Therefore, the prepared materials could be suitable for the anticorrosion of mild steel and the photodegradation of organic pollutants.

WITHDRAWN: Application of doped-titanate nanotubes in (1) the photodegradation of Tannic Acid, Methyl Orange and Malachite Green and (2) the inhibition of bacteria and fungus .

“…XRD analysis of the prepared materials. The d-spacing (d100)of various materials are shown in Table 3.The values obtained for these materials are in good agreement with those found in the literature (between 0.77 and 1.7 nm) [8,38,39]. The changes in the value of interlayer spaces are due to the exchange of Na + ions by different dopants.…”

“…This confirms the presence of the crystalline phase of metals [45][46][47][48][49]. The bands detected around 850 cm -1 after doping TiNTs indicate the existence of the interaction between M-O-Ti which confirms the strong attraction between the different metals and Ti [26]. The intense band located at 1631 cm -1 in the case of Zr-TiNTs indicates that the materials have absorbed moisture [48].…”

“…iii. The presence of Ti-O-dopant bonds (As confirmed by FTIR and RD/UV-Vis deconvoluted spectra) enhances the photodegradation of doped materials [39,53].…”

“…However, TiNTs also have similar disadvantages to ordinary titanium oxide, that is, the low separation efficiency of (e -/h + ) pairs [15], as well as a narrow range of light absorption only under UV radiation [16,17]. It was reported that TiNTs band gap energy (Eg)(3.34 eV) is higher than that of ordinary TiO2 anatase (3.20 eV) due to the quantum size effect which is probably due to the decrease in crystallite sizes as well as the transition from a 3D crystal structure to a 1D crystal structure [8,18].Doping of TiNTs by metals such as, Au, Ag, V, Ce, Zn, Fe, Zn and Zr will decrease their Eg and improve their absorption in the visible region [8,19,20].Sekino et al [21] evoked anEgvalue around 3.40 eV for TiNTs. In the same concept, Qu et al [22] calculated the Eg of ZrO2/TiNTs and found it equal to 3.22 eV while that of the TiNTs was 3.13 eV.…”

“…Methyl orange (MO) and Malachite green (MG) are anionic and cationic dyes which present an azo group (N=N) in their chemical structure [25,26]. They are used in the textile, printing, paper, pharmaceuticals, food industries [25], and the dyeing of cotton, leather and silk [26]. In addition, MG is found to be mainly a useful fungicide to combats aprolegia (a very current disease in aquaculture) [26].However, tannic acid (TA) is a neutral organic substance which presents many functional groups, like hydroxyl and phenolic hydroxyl [27] constituted by the decomposition of a natural organic matter (NOM) which are detected in natural water sources, industrial and domestic waste-waters [28].…”