Yeredla Rakesh R, Xu Huifang
Department of Geology and Geophysics, and Materials Science Program, University of Wisconsin, 1215 W Dayton Street, Madison, WI 53706, USA.
Nanotechnology. 2008 Feb 6;19(5):055706. doi: 10.1088/0957-4484/19/05/055706. Epub 2008 Jan 14.
Developing new semiconductor materials for improving photocatalytic reactivity is important for solving the challenging environmental and energy problems we are facing today. This work focuses on increasing the quantum efficiency in titania photocatalysts for photocatalytic (oxidation of acetaldehyde) and photosynthetic (photosplitting of water) reactions by synthesizing pure phase rutile and anatase nanostructures with well defined morphologies and investigating their photocatalytic performance compared to a commercial titania photocatalyst (Degussa P25). Nanostructured anatase is dominated by {100} surfaces with a small amount of {101} surfaces, whereas the rutile nanoplates consist of nanorods dominated by {110} and {111} crystal surfaces. In accordance with the signals from electron spin resonance (ESR) spectra, both nanostructured anatase and rutile phases have high photocatalytic activity for photosplitting of water compared to P25 titania. The anatase phase shows a high activity for photocatalytic oxidation (PCO) of acetaldehyde whereas the rutile phase shows a lower activity. The results of these experiments basically agree with previously published works that reported that the oxidation and reduction sites on rutile particles are on the {011} and {110} faces respectively, and on {001} and {011} faces respectively for anatase particles. The results have important implications for enhancing the photocatalytic activity of titania for environmental remediation, increasing the quantum efficiency in photo-voltaic (PV) solar cells and other photo-assisted processes.
开发新型半导体材料以提高光催化反应活性对于解决我们当前面临的具有挑战性的环境和能源问题至关重要。这项工作的重点是通过合成具有明确形态的纯相金红石和锐钛矿纳米结构，并将其光催化性能与商用二氧化钛光催化剂（德固赛P25）进行比较，来提高二氧化钛光催化剂在光催化（乙醛氧化）和光合（水的光解）反应中的量子效率。纳米结构的锐钛矿以{100}面为主，含有少量{101}面，而金红石纳米板由以{110}和{111}晶面为主的纳米棒组成。根据电子自旋共振（ESR）光谱的信号，与P25二氧化钛相比，纳米结构的锐钛矿相和金红石相在水的光解方面都具有高光催化活性。锐钛矿相对乙醛的光催化氧化（PCO）表现出高活性，而金红石相表现出较低的活性。这些实验结果基本上与先前发表的研究结果一致，即先前的研究报道金红石颗粒上的氧化和还原位点分别在{011}面和{110}面上，而锐钛矿颗粒上的氧化和还原位点分别在{001}面和{011}面上。这些结果对于提高二氧化钛用于环境修复的光催化活性、提高光伏（PV）太阳能电池和其他光辅助过程中的量子效率具有重要意义。
