鈷鋯共摻雜二氧化鈦奈米粒子對提高可見光吸收之研究

Enhanced visible light absorption in cobalt and zirconium co-doped titanium dioxide nanoparticles

許稜侑(Syu, Leng You)

指導教授 ： 蘇雲良

國立清華大學/理學院/物理學系/碩士(2016年)

摘要

二氧化鈦在光觸媒的應用上相當重要，本研究探討雜質與鍛燒溫度對二氧化鈦在可見光吸收率的影響。使用溶膠凝膠法製備鈷摻雜、鋯摻雜以及鈷鋯共摻雜的二氧化鈦奈米粒子，並經過攝氏500度和攝氏800度鍛燒。從X光粉末繞射以及拉曼光譜確認樣品的結構，X光吸收精細結構的結果顯示摻雜的原子是取代二氧化鈦中鈦原子的位置，之後利用紫外光至可見光光譜儀測量材料的吸收率與能隙大小。我們發現鈷鋯共摻雜二氧化鈦在攝氏500度鍛燒條件下存在較多的缺陷，加上摻雜鈷所形成的雜質能帶，使樣品在可見光波段的吸收率增加。

關鍵字

X光吸收光譜 ； 二氧化鈦 ； 溶膠凝膠法

並列摘要

Titanium dioxide(TiO2) is an important materials for photocatalytic applications.In this thesis,we have investigated the effects of impurity doping and thermal annealing on visible-light absorption of TiO2.
Nanoparticles of Cobalt- and Zirconium-doped titanium dioxide, as well as (Co, Zr) co-doped TiO2, were synthesized by sol-gel method followed by thermal annealing at 500 degrees Celsius and 800 degrees Celsius. The crystal structures of the samples were probed by X-ray diffraction and then reconfirmed by Raman spectroscopy. Extended x-ray absorption fine structure analysis shows that the dopant atoms substitute for titanium sites in TiO2. Visible-light absorption properties and band gaps for all samples were determined by using an ultraviolet-visible spectrometer. We observed enhanced visible-light absorption in 500 degrees Celsius-annealed (Co,Zr) co-doped TiO2 due to defects and impurities.

並列關鍵字

XAFS ； Titanium dioxide ； Sol-Gel

參考文獻

[1] Mingi Choi and Kijung Yong. A facile strategy to fabricate high-quality single crystalline brookite TiO2 nanoarrays and their photoelectrochemical properties. Nanoscale, 6(22):13900.13909, 2014.

[2] David O. Scanlon, Charles W. Dunnill, John Buckeridge, Stephen A. Shevlin, Andrew J. Logsdail, Scott M. Woodley, C. Richard A. Catlow, Michael. J. Powell, Robert G. Palgrave, Ivan P. Parkin, Graeme W. Watson, Thomas W. Keal, Paul Sherwood, Aron Walsh, and Alexey A. Sokol. Band alignment of

[3] Akira Fujishima. Electrochemical photolysis of water at a semiconductor electrode. nature, 238:37–38, 1972.

[4] Ryoji Asahi, Takeshi Morikawa, Ohwaki. T, K Aoki, and Y Taga. Visiblelight photocatalysis in nitrogen-doped titanium oxides. science, 293(5528): 269–271, 2001.

[5] Huarong Zhang, Keqi Tan, Haiwu Zheng, Yuzong Gu, and W.F. Zhang. Preparation, characterization and photocatalytic activity of TiO2 codoped with yttrium and nitrogen. Materials Chemistry and Physics, 125(1):156–160, 2011.