Liu Enzhou, Kang Limin, Yang Yuhao, Sun Tao, Hu Xiaoyun, Zhu Changjun, Liu Hanchen, Wang Qiuping, Li Xinghua, Fan Jun
School of Chemical Engineering, Northwest University, No 229 Taibai North Road, Xi'an, Shaanxi 710069, People's Republic of China.
Nanotechnology. 2014 Apr 25;25(16):165401. doi: 10.1088/0957-4484/25/16/165401. Epub 2014 Mar 26.
TiO2 nano-sheet film (TiO2 NSF) was prepared by a hydrothermal method. Ag nanoparticles (NPs) were then deposited on the surface of TiO2 NSF (Ag/TiO2 NSF) under microwave-assisted chemical reduction. The prepared samples were characterized by x-ray diffraction (XRD), scanning electron microscopy (SEM), UV-visible (UV-vis) absorption spectroscopy, x-ray photoelectron spectroscopy (XPS), photoluminescence (PL) spectroscopy, and Raman scattering spectroscopy. The results revealed that the Ag NPs were well dispersed on the anatase/rutile mixed-phase TiO2 nano-sheet surface with a metallic state. The visible light absorption and Raman scattering of TiO2 were enhanced by Ag NPs based on its surface plasmon resonance effect. Besides, Ag NPs could also effectively restrain the recombination of photogenerated electrons and holes. Photocatalytic water splitting was conducted on the films to obtain hydrogen, and the experimental results indicated that plasmonic Ag NPs could greatly enhance the photocatalytic activity of TiO2 due to the synergistic effect between electron transfer and surface plasmon resonance enhanced absorption. The hydrogen yield obtained from the optimal sample reached 8.1 μmol cm(-2) and the corresponding energy efficiency was about 0.47%, which was 8.5 times higher than that of pure TiO2 film. Additionally, the formation mechanism of TiO2 nano-sheet film is preliminarily discussed.
采用水热法制备了TiO₂纳米片薄膜（TiO₂ NSF）。然后在微波辅助化学还原条件下，将银纳米颗粒（NPs）沉积在TiO₂ NSF表面（Ag/TiO₂ NSF）。通过X射线衍射（XRD）、扫描电子显微镜（SEM）、紫外可见（UV-vis）吸收光谱、X射线光电子能谱（XPS）、光致发光（PL）光谱和拉曼散射光谱对制备的样品进行了表征。结果表明，Ag NPs以金属态良好地分散在锐钛矿/金红石混合相TiO₂纳米片表面。基于其表面等离子体共振效应，Ag NPs增强了TiO₂的可见光吸收和拉曼散射。此外，Ag NPs还能有效抑制光生电子和空穴的复合。对薄膜进行光催化水分解以获取氢气，实验结果表明，由于电子转移与表面等离子体共振增强吸收之间的协同效应，等离子体Ag NPs可大大提高TiO₂的光催化活性。最佳样品的产氢量达到8.1 μmol cm⁻²，相应的能量效率约为0.47%，比纯TiO₂薄膜高8.5倍。此外，还初步探讨了TiO₂纳米片薄膜的形成机理。
