Bandara J, Udawatta C P K, Rajapakse C S K
Institute of Fundamental Studies, Hantana Road, Kandy, Sri Lanka.
Photochem Photobiol Sci. 2005 Nov;4(11):857-61. doi: 10.1039/b507816d. Epub 2005 Sep 8.
A CuO incorporated TiO(2) catalyst was found to be an active photo-catalyst for the reduction of H(2)O under sacrificial conditions. The catalytic activity originates from the photogeneration of excited electrons in the conduction bands of both TiO(2) and CuO resulting in a build-up of excess electrons in the conduction band of CuO. Consequently, the accumulation of excess electrons in CuO causes a negative shift in the Fermi level of CuO. The efficient inter-particle charge transfer leads to a higher catalytic activity and the formation of highly reduced states of TiO(2)/CuO, which are stable even under oxygen saturated condition. Negative shift in the Fermi level of CuO of the catalyst TiO(2)/CuO gains the required over-voltage necessary for efficient water reduction reaction. The function of CuO is to help the charge separation and to act as a water reduction site. The amount of CuO and crystalline structure were found to be crucial for the catalytic activity and the optimum CuO loading was ca. approximately 5-10%(w/w).
发现一种掺入CuO的TiO₂催化剂是在牺牲条件下用于还原H₂O的活性光催化剂。催化活性源于TiO₂和CuO导带中激发电子的光生,导致CuO导带中多余电子的积累。因此,CuO中多余电子的积累导致CuO费米能级的负移。有效的粒子间电荷转移导致更高的催化活性以及TiO₂/CuO高还原态的形成,即使在氧饱和条件下这些高还原态也是稳定的。催化剂TiO₂/CuO的CuO费米能级的负移获得了高效水还原反应所需的过电压。CuO的作用是帮助电荷分离并作为水还原位点。发现CuO的量和晶体结构对催化活性至关重要,最佳CuO负载量约为5 - 10%(w/w)。