The Mechanism Of Enhanced Visible Light Absorption And Photocatalytic Efficiency Of Black Titanium Dioxide

Undoubtedly, titania dioxide is the most popularly, the most relevant studies of many semiconductor photocatalytic material because it was low price, green, and other advantages. However, titania is wide band gap semiconductor, only under ultraviolet light until a catalytic effect, which greatly reduces the range of applications. In2011, black titanium dioxide solved this problem. The color change not only enhances absorbed within the visible, but also greatly enhanced its photocatalytic effect. Principle of titanium dioxide color change have not a uniform represent. Some people suggested the band-gap reduction caused surface lattice structure disorder is the most important factor. Some other people considered that the reaction vessel containing the Cr ions into the titanium oxide is such that the photocatalytic effect of greatly enhancing the mportant reason, provide help Cr ions into titania lattice,which is the role of the hydrogen in reaction. Mechanism of titanium dioxide discolor blur directly restricts its development and application in photosensitive devices, optoelectronic devices and other areas.We revealed the mechanism of the black titanate acid nanaotubes increased absorotion in the visible light by preparing the blue-black discoloration titanate nanotubes, through a series of testing and characterization of titanate nanotubes. The photocatalytic experiments show that unusual effective for the enhanced visiable-light absorption with the titanate nanotube of the blue-black discoloration prepared by hydrogenation plasma chemical vapor depositone method at350℃and500℃. Discoloration titanate acid nanotubes have above the ordinary absorption within the visible range of400-800nm. Greatly updated efficiency of photocatalytic decomposition of Rhodamine B decolorization reaction which photocatalyst was titanate acid nanotubes without hydrogenated. XRD results showed that the the titanate acid nanotubes crystal structure belonged the orthorhombic system. The most transition to the anatase phase when after hydrogenation treatment. Raman spectrum results indicated the new chemical bonds were production. Photographs of TEM tell us that apparently disordered on the titanate acid nanotubes surface lattice stucture after the a certain temperature hydrogenation treatment. EDX record can be concluded that the reaction in the the Cr metal sheet container does not make the Cr incorporated titanate acid nanotubes. PL data allow us to clear the defective electron ladder formationed by oxygen defects in the bulk crystal lattice of titanate acid nanotubes. ESR spectrogram of titanate acid nanotubes by hydrogenation plasma chemical vapor depositone method at a certain temperature and pressure give us a key factor signal at g=2.003, this signal located the oxygen defects bound single electron in the surface of titanate acid nanotubes lattice. The oxygen vacancy caused by the valence band have a tale to the direction of the bottom of the conduction band and the oxygen defects exist in the forbidden band as like "electronic ladder". Foremost impact come from the oxyen defects for hydrogenated treatment discoloration TAN have enhanced visible light absorption and enhanced photocatalytic efficiency. All of experiment information in this paper were excluded the influence from Cr ion.