Resumen de The investigation of optical and photocatalytic properties in Dy_(2)M_(2)O_(7) (M= Hf, Zr and Ce ) (7 pages)
H. Zaari, K. Ouassoul, F. Mezzat, F. Elyahyaoui, A. El Kenz, A. Benyoussef
This paper aims to present a group of compounds Dy_(2)M_(2)O_(7) (with M = Hf, Ce and Zr) which could be an alternative having the same function as TiO_(2). Based on our studies and those reported in the literature, we will discuss in detail the roles and the functional mechanism of the catalysts. The results show that Zr_(2)Dy_(2)O_(7) is the best candidate to be a photo-catalyst: it has a band gap close to 2.2 eV, and a Good absorption in visible range compared to the other compounds having absorption in UV. The quantum efficiency of Zr_(2)Dy_(2)O_(7) reaches up to 3%, and the conduction and valence band limits are localized in a potential redox zone. Doping with Cerium gives another energy level, which allows having other optical transitions and improving the absorption and reaching the quantum efficiency to 4% in a visible range.
