Effect of W concentration in the organized Ti-W alloy oxide nanotubes array on the photoelectrocatalytic properties and its application in the removal of endocrine disruptors using real water matrix

• Published in: Journal of environmental chemical engineering 2022-06, Vol.10 (3), p.107830, Article 107830
• Main Authors: de Almeida, Juliana, Kaminagakura, Verena Mandorino, Felez, Marissol Rodrigues, de Léon, Carlos Ponce, Bertazzoli, Rodnei, de Arruda Rodrigues, Christiane
• Format: Article
• Language: English
• Subjects: Hormones; Nanotubes; Photoelectrocatalytic degradation; Real water matrix; Ti-W alloy; Tungsten oxide
• ISSN: 2213-3437; 2213-3437
• DOI: 10.1016/j.jece.2022.107830

To evaluate the tungsten content on the photoelectrocatalytic properties of self-organized nanotubes grown by anodization on Ti-xW (wt%) alloys, where x is 0.5, 2.5 or 5.0, this work investigated the phase transformation of TiO2, the tungsten oxidation states in the oxide layers and their photoelectrocatalytic performance in the degradation of estrone (E1) and 17α-ethinylestradiol (EE2). These films were employed in photocatalytic and photoelectrocatalytic removals of hormones from synthetic and real water matrices. In synthetic water, E1 and EE2 removals, reached efficiencies of 92% and 71%, respectively, after 2 min under UV–Vis photoelectrocatalysis using NT/Ti-5.0W as catalyst. About 30 times longer was needed to degrade 77% of both hormones from the real water matrix due to the presence of other high organic charge. The high performance of the NT/Ti-5.0W was associated with the combination of doping (W-doped TiO2) and WO3 (W6+) heterojunction. However, this electrode had its stability compromised under long degradation times, mainly under visible light, due to a WO3 leaching process. As for NT/Ti-0.5W, the substitutional W-doped TiO2 contributed to its greater stability and efficiency for a long time. The low performance of NT/Ti-2.5W was justified by high density of oxygen vacancy and unfavorable position of its adsorption bands. [Display omitted] •The nanotubes (NT) with high W content showed higher degradation efficiency for both hormones.•E1 (100%) and EE2 (78%) degradation from real matrix water in 60 min on NT/Ti-5.0W (wt%) and photoelectrocatalytic process.•The high performance of the NT/Ti-5.0W was associated with the combination of doping (W-doped TiO2) and WO3 (W6+).