The replacement of {1 0 1} by {0 1 0} facets inhibits the photocatalytic activity of anatase TiO2

Anatase TiO2 crystals with {1 0 1}–{0 0 1} and {0 1 0}–{0 0 1} two facets coexistence were synthesized by (NH4)2TiF6 acting as titanium and fluorine sources and the photocatalytic activity of the samples were investigated. The replacement of {1 0 1} by {0 1 0} facets inhibits the photocatalytic activity of anatase TiO2. The mechanism was examined by photoluminescence spectrum, time-resolved photoluminescence spectra, field emission scanning electron microscope (FESEM) images of selected deposition of Ag, surface atoms structures and electronic band structures of anatase TiO2 facets. The results demonstrated that photoinduced charge transfer properties between {1 0 1} facets and {0 0 1} facets resulted in the efficient charge separation. Replacing {1 0 1} by {0 1 0}, the charge transfer mechanism was altered and the photoinduced electron–hole pairs cannot be separated well. The photocatalytic activity of it has thus been inhibited.

When {1 0 1} was replaced by {0 1 0} facets, the most photoinduced electron and hole transfer to {0 0 1} facets and cannot be separated well under UV light irradiation. The photocatalytic oxidation and reduction all happened on {0 0 1} or {1 0 1} facets synchronously. So, the replacement of {1 0 1} by {0 1 0} facets inhibits the photocatalytic activity of anatase TiO2.Figure optionsDownload as PowerPoint slideHighlights
► Synthesis of TiO2 crystals with {1 0 1}–{001} or {0 10}–{001} two facets coexistence.
► The replacement of {1 0 1} by {0 1 0} facet inhibits the photocatalytic activity of TiO2.
► Possible charge transfer mechanism photocatalytic mechanism was suggested.