Abstract

CATANO, F.A. et al. A comparative study between tiO₂ and ZnO photocatalysis: photocatalytic degradation of cibacron yellow FN-2R DYE. Lat. Am. appl. res. [online]. 2012, vol.42, n.1, pp.33-38. ISSN 0327-0793.

Cibacron Yellow FN-2R dye was degraded by heterogeneous photocatalysis with both titanium dioxide (TiO₂), Degussa P-25, and zinc oxide (ZnO). A 3² factorial design was used with photocatalyst amount and pH as factors and the pseudo-first-order constant as response variable. On the optimal conditions the pseudo-first order rate constant was higher when ZnO was used as catalyst. However, the evolution of total zinc (Zn) in solution indicated a significant loss of ZnO on those optimal conditions as consequence of its susceptibility to chemical dissolution and photodissolution. Due to the solubility curve of ZnO has a minimum at pH around 10 and its photodissolution does not occur at pH>10, the photodegradation experiments using ZnO were performed with a pH control near to 10. In this condition, the photocatalytic activity of ZnO was similar to that obtained with TiO₂ when it is used in its optimal conditions.

Keywords : Heterogeneous Photocatalysis; TiO₂; ZnO; Azo Dyes; Decolorization; Photocatalyst.

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