Heterojunctions on Titanium Oxide Nano Particles

Nanocrystalline anatase phase titanium oxide
converted from ammonium oxofluorotitanate by thermal
treatment was developed and a large bandgap
reduction due to the co-doping of high
concentrations of fluorine and nitrogen. It is 1.3
times the photocatalytic activities of P-25 due to
the visible region usage of Hg lamp light source.
The 11.2 times the visible photocatalytic activities
of P-25 using blue light-emitting diode as the light
source is obtained. The heterostructure of zinc
selenide/titanium oxide and zinc sulfide/titanium
oxide were prepared by metal-organic chemical vapor
deposition. The energy bandgap of zinc sulfide is
much larger than that of titanium oxide and can act
as a window for titanium oxide. It would not hinder
titanium oxide absorption and preserve the role of
fluorine and nitrogen co-doping. The energy bandgap
of zinc selenide is near the maximum intensity of
solar spectrum and acts as a sensitizer of titanium
oxide. Their photocatalytic activities are further
improved to 2.0 and 1.5 times higher than that of
commercial P-25, respectively.