Prepared Of Heterojunction Photocatalyst And Evalution Of Photocatalysis Property

: a new heterojunction photocatalyst ZrTi₂O₆/TiO₂ was synthesized by sol-gel method using ZrOCl₂·8H₂O and tetrabutyl titanate [Ti(OC4H9)4] as the raw materials. The structure and optical properties of the ZrTi₂O₆/TiO₂ was characterized by XRD, HR-TEM, and UV–Vis diffuse reflection spectrum (DRS). The photocatalytic activity of the photocatalyst was evaluated by photocatalytic reduction of Cr₂O₇^2- and photocatalytic oxidation of methyl orange (MO). The production of hydroxyl radicals (·OH) on the surface of UV-illuminated ZrTi₂O₆/TiO₂ were detected by a photoluminescence (PL) technique with use of terephthalic acid as a probe molecule. The results showed that photocatalytic activity of the ZrTi₂O₆/TiO₂ photocatalyst (mole ratio of Zr/Ti is 1:1, heat treatment at 600°C for 2h) was higher than that of other samples and pure-TiO₂. The heterojunction between ZrTi₂O₆ and TiO₂ was confirmed by HR-TEM. And the mechanism of the increased photocatalytic activity was also discussed. Then nitro-aromatic compounds could be photocatalytically reduced into the corresponding amine-aromatic compounds using TiO₂ as a photocatalyst in the UV/TiO₂/holes scavenger and Vis/TiO₂/dye-sensitized systems. In UV/TiO₂/holes scavenger system, reaction substrate alcohols such as methanol, ethanol could be used as the holes scavengers; and in Vis/TiO₂/dye-sensitized system, substrate alcohols could be selective oxidized to the corresponding aldehydes with high selectivity. At the same time, the reaction mechanisms were also investigated. According to the mechanism, photocatalyst Ce₂S₃ was synthesized by co-precipitation method using cerium nitrate and thioacetamide as raw material. The photocatalytic activity of the photocatalyst Ce₂S₃ was evaluated by photocatalytic reduction of nitrobenzen and photocatalytic oxidation of alcohol. The result showed that Ce₂S₃ (300℃) was a better reduced form photocatalysis. photocatalytic mechanism was also discussed.