State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210093, PR China.
J Hazard Mater. 2010 Apr 15;176(1-3):495-502. doi: 10.1016/j.jhazmat.2009.11.057. Epub 2009 Nov 13.
Elongated TiO(2) nanoparticles with high aspect ratio have specific advantages in separation processes. In this study, TiO(2) nanofiber was prepared via a hydrothermal reaction, and TiO(2) nanoparticles with varied structural properties were obtained using hydrothermal and calcination post-treatments. Photocatalytic phenol degradation and Cr(VI) reduction over these catalysts was investigated. Results showed that hydrothermally prepared TiO(2) nanofiber consisted of titanate with high aspect ratio. Calcining the as-prepared TiO(2) nanofiber at 400 and 600 degrees C led to the crystalline phase transformation from titanate to TiO(2)-B and to the presence of mixed crystalline phases composed of TiO(2)-B and anatase. In contrast, hydrothermal post-treatment results in the generation of pure anatase TiO(2) nanoparticles. For photocatalytic phenol degradation, calcining the as-prepared TiO(2) nanofiber resulted in an enhanced catalytic activity, whereas TiO(2) nanoparticles obtained by calcination post-treatment showed lower catalytic activities for photocatalytic Cr(VI) reduction compared to as-prepared TiO(2) nanofiber. TiO(2) nanofiber modified using the hydrothermal post-treatment, however, exhibited the highest catalytic activity among TiO(2) nanoparticles examined for both photocatalytic phenol degradation and Cr(VI) reduction. Furthermore, TiO(2) nanoparticles obtained by hydrothermal post-treatment showed the best sedimentation efficiency, highlighting its prominent potential as a readily separable and recoverable photocatalyst.
具有高纵横比的 TiO(2) 纳米棒在分离过程中具有特定优势。在这项研究中，通过水热反应制备了 TiO(2) 纳米纤维，并通过水热和煅烧后处理获得了具有不同结构特性的 TiO(2) 纳米颗粒。研究了这些催化剂对苯酚的光催化降解和 Cr(VI) 的还原作用。结果表明，水热法制备的 TiO(2) 纳米纤维由具有高纵横比的钛酸盐组成。将所制备的 TiO(2) 纳米纤维在 400 和 600°C 下煅烧，导致从钛酸盐到 TiO(2)-B 的晶相转变和由 TiO(2)-B 和锐钛矿组成的混合晶相的存在。相比之下，水热后处理会生成纯锐钛矿 TiO(2) 纳米颗粒。对于光催化苯酚降解，煅烧所制备的 TiO(2) 纳米纤维会增强催化活性，而通过煅烧后处理获得的 TiO(2) 纳米颗粒在光催化 Cr(VI) 还原方面的催化活性则低于所制备的 TiO(2) 纳米纤维。然而，经过水热后处理修饰的 TiO(2) 纳米纤维在光催化苯酚降解和 Cr(VI) 还原方面表现出最高的催化活性，高于所研究的 TiO(2) 纳米颗粒。此外，通过水热后处理获得的 TiO(2) 纳米颗粒表现出最好的沉降效率，突出了其作为一种易于分离和可回收的光催化剂的突出潜力。
