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.