electrons. In particular, the interaction of holes with the polymeric membrane, in
O 2 , results in the formation of peroxy radicals, which can be considered responsible
for the stabilization of both holes and electrons (trapped on Ti
3+ centers).
5.49 Discussion of the Case
In Fig. 5.36 is reported the catalyst morphology.
Figure 5.37 reports the mineralization curves of phenol under UV irradiation, in
the presence of O 2 and TPM catalyst.
It appears that the efficacy of the embedded catalyst is comparable with that of
the slurry catalyst, as if the matrix would not affect the interaction between substrate
and catalyst. For this reason, a more accurate investigation of the electronic
Fig. 5.37 Phenol
mineralization curves
obtained by the total organic
carbon (TOC) analysis. ● In
the absence of catalyst, □
after the first run of reaction,
□ (fill the squares) after 6
runs, ◊ P25 slurry catalyst
[25]
(a)
(b)
Fig. 5.36 Anatase crystals embedded in the membrane. a TEM and b HRTEM images [25]
132
5 The Symmetry Properties Describe the Electronic Structure …