Instituto de Materiales de Misiones, IMAM (CONICET-UNaM), Félix de Azara 1552, 3300, Posadas, Misiones, Argentina.
IIIA (CONICET-UNSAM), Instituto de Investigación e Ingeniería Ambiental, Escuela de Hábitat y Sostenibilidad, Universidad Nacional de General San Martín, Campus Miguelete, Av. 25 de Mayo y Francia, 1650, San Martín, Buenos Aires, Argentina.
Photochem Photobiol Sci. 2022 Oct;21(10):1793-1806. doi: 10.1007/s43630-022-00257-5. Epub 2022 Jul 4.
The photocatalytic and mechanical performance of TiO nanotubular coatings obtained by anodic oxidation of commercial titanium, using an NHF and 3.5% v/v water in ethylene glycol solution as electrolyte was investigated. After the anodization, the coatings were thermally treated at 450 °C for 2 h. The effects of the anodizing voltage (40-80 V) and NHF concentration (0.06, 0.15, 0.27 M) on the formation of the nanotube arrays were evaluated. Nanotube diameters (57 to 114 nm), wall thicknesses (4 to 13 nm), and lengths (5 to 17 µm) increased with the anodizing voltage and the NHF concentration. The photocatalysts were characterized by scanning electron microscopy, glancing incidence X-ray diffraction, and UV-Vis diffuse reflectance spectroscopy. The mechanical properties of the photocatalysts were determined: adhesion using the tape test (ASTM D3359) and erosion resistance through a 3 h accelerated test. The photocatalytic activity of the nanotubes under UV irradiation was evaluated using hexavalent chromium (Cr(VI)) in the presence of ethylenediaminetetraacetic acid (EDTA), using a 1.25 EDTA/Cr(VI) molar ratio solution at pH 2. A complete Cr(VI) transformation after 3 h of irradiation was obtained for all samples, with a better performance than that of an immobilized P25 sample. The photocatalyst obtained with 0.27 M NHF at 40 V presented a good behavior in adherence and erosion resistance, together with a very good photocatalytic activity. This novel analysis, combining photocatalytic and mechanical tests, proved that the new TiO nanotubular coatings could be successfully used as immobilized photocatalysts in photoreactors for water treatment.
采用 NHF 和 3.5%（体积比）水在乙二醇溶液作为电解液对商业钛进行阳极氧化，研究了所得 TiO 纳米管涂层的光催化和机械性能。阳极氧化后，将涂层在 450°C 下热处理 2 小时。评估了阳极氧化电压（40-80V）和 NHF 浓度（0.06、0.15、0.27M）对纳米管阵列形成的影响。纳米管直径（57 至 114nm）、壁厚（4 至 13nm）和长度（5 至 17μm）随阳极氧化电压和 NHF 浓度的增加而增加。使用扫描电子显微镜、掠入射 X 射线衍射和 UV-Vis 漫反射光谱对光催化剂进行了表征。通过胶带测试（ASTM D3359）和 3 小时加速试验测定光催化剂的机械性能。在 pH 2 下使用 1.25 EDTA/Cr(VI)摩尔比溶液，评估了纳米管在紫外光照射下对六价铬（Cr(VI)）的光催化活性。所有样品在照射 3 小时后均实现了 Cr(VI)的完全转化，其性能优于固定化 P25 样品。在 40V 下使用 0.27M NHF 获得的光催化剂在附着力和耐侵蚀性方面表现良好，同时具有非常好的光催化活性。这种结合光催化和机械测试的新分析证明，新型 TiO 纳米管涂层可成功用作水净化光反应器中的固定化光催化剂。
