Towards visible light applications of TiO2 nanostructures

Authors

  • Wang-Chi Vincent Yeh Department of Physics, National Dong Hwa University

Abstract

In recent years titanium dioxide nanostructures have been studied intensively in many fields of applications, including environmental issues such as self-cleaning, bacteria killing, or energy related areas like solar cells, water splitting, etc. Owing to its availability titanium dioxide is one of the major candidates for applications in greener energies. However, the drawback of using titanium dioxide for energy application is the large band gap: about 3.2 eV. This gap corresponds to absorption of photons with a wavelength around 390 nm, which is in the ultraviolet region that occupies only less than 5% of the solar radiation. This wide band gap makes it inappropriate for immediate use in solar cells, in spite of the fact that it has been identified as the most effective photocatalyst. Nonetheless, there are still many researchers trying to effectively reduce its band gap by doping different elements such as nitrogen, carbon, and many others. Among all the possible ways nitrogen and carbon have been shown to effectively extend the absorption spectra of into the visible light region, greatly increased the possibilities of applications in energy problems. Particularly, research groups in our university had shown that combination of anatase and rutile nanostructures, plus the help of carbon, can absorb light wave all the way from ultra violet to infrared, making it more promising in converting solar energy to produce electricity or split hydrogen and oxygen from water. Even though the absorption spectrum has been pushed towards visible light and even infrared, the absorption is still poor compared to the ultra violet region. It is then important to study in detail the effects and properties of carbon containing mixed phase titanium dioxide, in order to find ways to increase the absorption efficiency in the visible region, hence to provide low cost and sustainable solutions to energy and environmental problems.

About the Speaker

Wang-Chi Vincent Yeh, Department of Physics, National Dong Hwa University

Wang-Chi Vincent Yeh is currently an Associate Professor at the Department of Physics of the National Dong Hwa University (NDHU) in Taiwan. He is currently in charge of an X-ray Photoelectron Spectrometer (XPS, ThermoFisher K-alpha) at the Nanotechnology Research Center of NDHU, which offers services to domestic and international researchers for precise elemental analysis, including point measurements, surface mapping, depth profiling, and others. Professor Yeh got his Ph.D. degree in 2003 from Iowa State University, specializing in experimental surface sciences, and kept working on surface sciences for a while. Recently his research interests had shifted to oxide nanotechnologies and their potential applications. He is currently working on the manufacturing and modification of TiO2 nanostructures, particularly in 1D nanowires, in the hope of increasing its visible light activities to serve as, for example, a low cost solution to energy and/or pollution problems. 

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Article ID

SPP-2016-3C-01

Section

Invited Presentations

Published

2016-08-18

How to Cite

[1]
W-CV Yeh, Towards visible light applications of TiO2 nanostructures, Proceedings of the Samahang Pisika ng Pilipinas 34, SPP-2016-3C-01 (2016). URL: https://proceedings.spp-online.org/article/view/SPP-2016-3C-01.