2.3 Titania Photocatalyst
Titanium dioxide is widely used in the formulation of sunscreen and plastics, as
pigments, or as catalyst (Carp et al. 2004). For example, when used in catalysis, it
enhances the hydrodesulfurization (HDS) of transition metal sulfides (TMS) by
transferring electronic density toward the TMS (Castillo-Villalón and Ramírez
2009). More recently, thanks to their good biocompatibility titania-based materials
which have attracted much attention for enzyme immobilization. For example, Gao
et al. have reported the immobilization of horseradish peroxidase (HRP) in templated
titania through the biomimetic titanification process (Jiang et al. 2014). The authors
have shown that the encapsulated HRP exhibits improvement of pH and thermal
stability as well as tolerance against inactive agents. The encapsulated HRP also
presents better removal efficiency than the free enzyme for the removal of both
phenol and 2-chlorophenol. Titania is a semiconductor that has received
Fig. 2.1 Structure of the main synthetic dyes studied in degradation. Reprinted with permission
from Forgacs et al. 2004. Copyright 2004 Elsevier, Environment International
2 Dyes Depollution of Water Using Porous TiO 2 -Based Photocatalysts
39
Titanium dioxide is widely used in the formulation of sunscreen and plastics, as
pigments, or as catalyst (Carp et al. 2004). For example, when used in catalysis, it
enhances the hydrodesulfurization (HDS) of transition metal sulfides (TMS) by
transferring electronic density toward the TMS (Castillo-Villalón and Ramírez
2009). More recently, thanks to their good biocompatibility titania-based materials
which have attracted much attention for enzyme immobilization. For example, Gao
et al. have reported the immobilization of horseradish peroxidase (HRP) in templated
titania through the biomimetic titanification process (Jiang et al. 2014). The authors
have shown that the encapsulated HRP exhibits improvement of pH and thermal
stability as well as tolerance against inactive agents. The encapsulated HRP also
presents better removal efficiency than the free enzyme for the removal of both
phenol and 2-chlorophenol. Titania is a semiconductor that has received
Fig. 2.1 Structure of the main synthetic dyes studied in degradation. Reprinted with permission
from Forgacs et al. 2004. Copyright 2004 Elsevier, Environment International
2 Dyes Depollution of Water Using Porous TiO 2 -Based Photocatalysts
39