Effect of transition metal doping under reducing calcination atmosphere on photocatalytic property of TiO sub(2) immobilized on SiO sub(2) beads

• Published in: Journal of environmental sciences (China) 2013-07, Vol.25 (7), p.1419-1423
• Main Authors: Chand, R, Obuchi, E, Katoh, K, Luitel, H N, Nakano, K
• Format: Article
• Language: English
• Subjects: Atmospheres; Beads; Calcination; Photocatalysis; Silicon dioxide; Titanium dioxide; Transition metals; X-rays
• ISSN: 1001-0742
• DOI: 10.1016/S1001-0742(12)60211-3

TiO sub(2) immobilized on SiO sub(2) (TiO sub(2)/SiO sub(2)) have been prepared by sol-gel method and various ions of transition metals (Cr super(3+), Co super(2+), Ni super(2+), Cu super(2+), and Zn super(2+)) were doped on the photocatalyst using wet impregnation method under reducing calcination atmosphere. The photocatalytic activity of metal doped TiO sub(2)/SiO sub(2) towards phenol degradation under black light irradiation were investigated and compared with undoped TiO sub(2)/SiO sub(2). The results showed that the photoresponse of Cu super(2+) and Zn super(2+) doped TiO sub(2)/SiO sub(2) were larger than undoped TiO sub(2)/SiO sub(2), indicating that the photogenerated carriers were separated more efficiently in Cu super(2+) and Zn super(2+) doped TiO sub(2)/SiO sub(2). The reactivity was in the order of Cu super(2+) > Zn super(2+) > Ni super(2+) > Cr super(3+) > Co super(2+). The different photoreactivity was ascribed to combine effect of the different ionic radii and photocorrison tendency of the dopants. The sample was also characterized by surface analytical methods such as X-ray diffraction, scanning electron micrograph/electron dispersive X-ray analyzer and UV-Vis absorption spectrum.