Cabrera Julieta, Alarcón Hugo, López Alcides, Candal Roberto, Acosta Dwight, Rodriguez Juan
Universidad Nacional de Ingeniería, Lima, Perú E-mail:
INQUIMAE, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Argentina.
Water Sci Technol. 2014;70(6):972-9. doi: 10.2166/wst.2014.312.
Nanowire/nanorod TiO(2) structures of approximately 8 nm in diameter and around 1,000 nm long were synthesized by alkaline hydrothermal treatment of two different TiO(2) nanopowders. The first precursor was TiO(2) obtained by the sol-gel process (SG-TiO(2)); the second was the well-known commercial TiO(2) P-25 (P25-TiO(2)). Anatase-like 1D TiO(2) nanostructures were obtained in both cases. The one-dimensional (1D) nanostructures synthesized from SG-TiO(2) powders turned into rod-like nanostructures after annealing at 400 °C for 2 h. Conversely, the nanostructures synthesized from P25-TiO(2) preserved the tubular structure after annealing, displaying a higher Brunauer-Emmett-Teller surface area than the first system (279 and 97 m²/g, respectively). Despite the higher surface area shown by the 1D nanostructures, in both cases the photocatalytic activity was lower than for the P25-TiO(2) powder. However, the rod-like nanostructures obtained from SG-TiO(2) displayed slightly higher efficiency than the sol-gel prepared powders. The lower photocatalytic activity of the nanostructures with respect to P-25 can be associated with the lower crystallinity of 1D TiO(2) in both materials.
通过对两种不同的二氧化钛纳米粉末进行碱性水热处理，合成了直径约8纳米、长度约1000纳米的纳米线/纳米棒二氧化钛结构。第一种前驱体是通过溶胶-凝胶法获得的二氧化钛（SG-TiO₂）；第二种是著名的商用二氧化钛P-25（P25-TiO₂）。在这两种情况下均获得了类锐钛矿型一维二氧化钛纳米结构。由SG-TiO₂粉末合成的一维纳米结构在400℃退火2小时后转变为棒状纳米结构。相反，由P25-TiO₂合成的纳米结构在退火后保留了管状结构，其比表面积高于第一个体系（分别为279和97平方米/克）。尽管一维纳米结构具有较高的比表面积，但在这两种情况下，其光催化活性均低于P25-TiO₂粉末。然而，由SG-TiO₂获得的棒状纳米结构显示出比溶胶-凝胶法制备的粉末略高的效率。纳米结构相对于P-25较低的光催化活性可能与两种材料中一维二氧化钛的较低结晶度有关。
