标题: Pt与In2O3之修饰对于TiO2奈米线之光催化性质的影响
Effects of Pt and In2O3 Decorations on the Photocatalytic Properties of Anatase TiO2 Nanowires
作者: 陈宇志
Chen, Yu-Chih
徐雍蓥
Hsu, Yung-Jung
材料科学与工程学系
关键字: 二氧化钛;光催化;氧化铟;铂;TiO2;photocatalysis;In2O3;Pt
公开日期: 2009
摘要: 透过结合不同能带结构的半导体奈米晶体能提供许多的优点,如:更宽广的吸收范围、降低光漂白现象、能够调控的能阶和改善光电的转换效率。在此论文中,我们透过沉积-锻烧的方法成功合成出氧化铟修饰的锐钛矿二氧化钛奈米线 (In2O3-TiO2 NWs)。由于氧化铟和二氧化钛能带结构的差异,使此复合材料能产生载子转移,造成电子电洞对的分离。In2O3-TiO2 奈米线内的载子分离特性,也展现在其降解染料的光催化的特性上。相较于商用的P-25 TiO2粉末和利用物理方式混合的In2O3-loaded TiO2 NWs,In2O3-TiO2 NWs 在紫外光的照射下,展现出更佳的光催化特性。为了更进一步提升其光催化活性,适量的Pt奈米粒子也被用来修饰在In2O3-TiO2 NWs上。这样的提升是来自于在修饰Pt到二氧化钛表面上之后,增加了电子由In2O3传递到TiO2的驱动力。而且在自然阳光的照射下,显示出In2O3-TiO2-Pt NWs 能接收阳光中的能量进行高效率的光催化反应。电子在In2O3, TiO2和Pt的转移现象,我们也透过其相对的光电流量测和时间解析萤光光光谱来探讨分析。
Combination of semiconductor nanocrystal (NCs) with different band structures has been extensively explored since a lot of advantages may be offered by this composite system, for example, the wide absorption profile, the enhanced resistance to photobleaching, the continuous tunability of energetic levels, and the improved photoelectric conversion efficiency. In this thesis, we successfully synthesized In2O3-decorated anatase TiO2 nanowires (In2O3-TiO2 NWs) through a simple precipitation-annealing process. The difference in band structures between In2O3 and TiO2 provided charge carriers with another preferential route for charge transfer, resulting in the separation of photoexcited electrons and holes. The charge carrier separation in In2O3-TiO2 NWs was revealed with their photocatalytic decomposition toward an organic dye. As compared to the commercial P-25 TiO2 powder and In2O3-loaded TiO2 NW samples, the as-synthesized In2O3-TiO2 NWs exhibited superior photocatalytic efficiency under UV illumination, demonstrating their potential as an efficient photocatalyst in relevant redox reactions. A further enhancement in the photocatalytic activity of In2O3-TiO2 NWs can be achieved when Pt nanoparticles of suitable amount were deposited on the surface of TiO2. This improvement is due to the increasing driving force of electron transfer from In2O3 to TiO2 achieved by the decoration of Pt on TiO2 surfaces. Furthermore, the result of performance evaluation under natural sunlight shows that the present In2O3-TiO2-Pt NWs can be used as highly efficient photocatalysts which may practically harvest energy from sunlight. The electron transfer event among In2O3, TiO2 and Pt was also characterized with the corresponding photocurrent measurement and time-resolved PL spectroscopy.
URI: http://140.113.39.130/cdrfb3/record/nctu/#GT079718531
http://hdl.handle.net/11536/44919
显示于类别:Thesis


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