School of Materials Science and Engineering, China University of Petroleum (East China), Qingdao 266580, China.
Offshore Oil Engineering Co. Ltd, Tianjin 300451, China.
An Acad Bras Cienc. 2023 Aug 11;95(2):e20201164. doi: 10.1590/0001-3765202320201164. eCollection 2023.
The TiO2 nanotube arrays were prepared by anodization, and the crystal structure was changed by calcination at different temperatures. The photocatalytic performance of the samples was measured by the degradation of rhodamine B under visible light. The TiO2 nanotubes calcined at 600 °C showed higher photocatalytic activity than other samples. The prepared catalyst is characterized by a variety of techniques, including X-ray diffraction, scanning electron microscopy, ultraviolet-visible diffuse reflectance spectroscopy, Raman, photoluminescence spectroscopy and electrochemical testing. The reasons for improving the catalytic activity were studied from the aspects of crystal structure, surface morphology, and photoelectric properties, and the catalytic mechanism was studied. The results show that the TiO2 nanotubes calcined at 600°C contain two phases of anatase and rutile. Compared with pure phase TiO2, the charge transfer resistance is reduced and the electron-hole reorganization is well suppressed. In addition, it affects the band structure and improves the absorption of visible light. At the same time, studies have found that the main active substances in the catalytic process are h+ and •OH.
TiO2 纳米管阵列通过阳极氧化法制备，并通过在不同温度下煅烧来改变晶体结构。通过在可见光下降解罗丹明 B 来测量样品的光催化性能。在 600°C 下煅烧的 TiO2 纳米管比其他样品表现出更高的光催化活性。通过多种技术对所制备的催化剂进行了表征，包括 X 射线衍射、扫描电子显微镜、紫外-可见漫反射光谱、拉曼、光致发光光谱和电化学测试。从晶体结构、表面形貌和光电性能等方面研究了提高催化活性的原因，并研究了催化机制。结果表明，在 600°C 下煅烧的 TiO2 纳米管包含锐钛矿和金红石两种相。与纯相 TiO2 相比，电荷转移电阻降低，电子-空穴重组得到了很好的抑制。此外，它还影响了能带结构，提高了可见光的吸收。同时，研究发现催化过程中的主要活性物质是 h+和•OH。
