Metallorganic Chemical Vapor Deposition of Oxides
We are Interested in thin films and nanoparticles of TiO2 for applications in the field of photocatalysis. We use metallorganic CVD to prepare the TiO2 nanoparticles and thin films. For nanoparticles, the control of size distribution is easily accomplished by simply controlling the temperature of the substrates and the flow rate of the precursors. Dopant can also be easily introduced into the reactor either through a solid source, separated from the Ti-precursor, or mixed in with the precursor. We carry out photodegradation experiments to measure the quantum efficiency of pure and doped TiO2. Our work also includes the characterization of the sample to understand the location of the dopants and the effect of different locations on the efficiency of the photocatalyst.
"Band gap tailoring of Nd3+ doped TiO2 nanoparticles" W. Li, Y. Wang, H. Lin, J. McCormick, S.I. Shah, C.P. Huang, D. J. Doren, J.G. Chen, and M.A. Barteau Appl. Phys. Lett. (in press 2003)
"Size dependency of thermal stability in TiO2 Nanoparticles" W. Li, C. Ni, H. Lin, C.-P. Huang, and S. I. Shah J. Appl. Phys. (to be submitted 2003)
"Structure and size distribution of TiO2 nanoparticles on stainless steel mesh" W. Li, S.I. Shah, M. Sung, and C.-P. Huang J. Vac. Sci. Technol. B 20, 2303 (2002).
"Metalorganic chemical vapor deposition and characterization of TiO2 nanoparticles" W. Li, S.I. Shah, C.-P. Huang, O. Jung, and C. Ni Mater. Sci. Eng. B 96, 247 (2002).
"Study of Nd3+, Pt4+, Pd2+, and Fe3+ dopant effect on the photoreactivity of TiO2 nanoparticles" S.I. Shah, W. Li, C.-P. Huang, O.Jung, and C. Ni PNAS USA 99, 6482 (2002).
"Sol-gel synthesis and characterization of neodymium-ion doped nanostructured titania thin films" A. Burns, W. Li, C. Baker, and S.I. Shah Proc. Mater. Res. Soc. Sym. 703, 193 (2002).
"Neodymium ion dopant effects on phase transformation in sol-gel derived titania nanostructures" A. Burns, G. Hayes, W. Li, J. Hirvonen, and S.I. Shah Mater. Sci. Eng. B (submitted 2003).
W. Li and S.I. Shah, in Encyclopedia of Nanoscience and Nanotechnology, (H. S. Nalwa, Ed.). American Scientific Publishers, Stevenson Ranch, CA, 2003.
S. I. Shah, A. Rumaiz, and W. Li, in Nanotechnology and the Environment, (B. Karn, et al. Eds.). ACS/Oxford University Press, 2003.