Volume 13, No. 2, April 2013, Pages 639-648 PDF(1.66 MB)
Preparation of Cu-Doped TiO2 Photocatalyst with Thermal Plasma Torch for Low-Concentration Mercury Removal
Cheng-Yen Tsai1, Hsing-Cheng Hsi2, Tien-Ho Kuo3, Yu-Min Chang2, Jian-Hong Liou4
1 Graduate Institute of Engineering Science and Technology, National Kaohsiung First University of Science and Technology, No. 2, Jhuoyue Rd., Nanzih, Kaohsiung 811, Taiwan
2 Institute of Environmental Engineering and Management, National Taipei University of Technology, No. 1, Sec. 3, Chung-Hsiao E. Rd., Taipei 106, Taiwan
3 Department of Environmental, Safety and Health Engineering, Tungnan University, 152, Sec. 3, Peishen Rd., Shenkeng District, New Taipei City 222, Taiwan
4 Department of Safety, Health and Environmental Engineering, National Kaohsiung First University of Science and Technology, No. 2, Jhuoyue Rd., Nanzih, Kaohsiung 811, Taiwan
A high-quality, Cu-doped TiO2 photocatalyst was prepared via a single-step process using an atmospheric-pressure plasma torch system. Degussa P-25 was thermally doped with Cu at Cu/(Cu + TiO2) ratios of 0–5 wt.%. The raw and resulting nanoparticles were characterized using TEM, XRD, UV-Vis, and XPS. TEM showed that the particle size of plasma-treated TiO2 was generally < 50 nm. 67–75% of the resulting particles, by number were between 10 and 20 nm. The remaining particles were < 10 nm (~10%) and between 20 and 30 nm (~10%). The XRD results showed that Cu doping decreased the anatase/rutile crystalline ratio compared to untreated P-25. Nevertheless, the greater the amount of Cu added, the greater the anatase/rutile ratio was for the Cu-doped TiO2. The UV-Vis results showed that the absorption wavelength for plasma-treated TiO2 extended to the visible light range, especially for TiO2 doped with 5 wt.% Cu. The XPS results revealed that the form of Ti was Ti3+ and Ti4+, O was O2–, and Cu was Cu+ and Cu2+. The Hg0 breakthrough tests indicated that the Cu-doped TiO2 underwent appreciable Hg0 removal under visible-light irradiation. Doped Cu effectively suppressed Hg reemission from the TiO2 surface.
Visible-light photocatalyst; Metal doping; Plasma torch; Hg.