负载Pt对锐钛矿-板钛矿双相TiO_2光催化性能的影响

采用水热法合成了板钛矿-锐钛矿双相TiO_2,通过浸渍和氢还原法将贵金属Pt负载在双相TiO_2表面制成Pt/双相TiO_2催化剂。TEM表征结果显示:Pt/双相TiO_2催化剂中Pt的晶粒尺寸很小,晶粒尺寸分布较窄;低负载量(质量分数0.2%和2.0%)时,Pt晶粒在TiO_2表面分布非常均匀,Pt负载量达到4.0%时,Pt晶粒在TiO_2表面的分散性变差。光催化活性实验结果表明:负载Pt能显著提高双相TiO_2催化剂的甲基橙降解率;2.0%Pt/双相TiO_2催化剂的光降解性能最佳。光催化活性提高的主要原因是由于Pt颗粒的电子贮存能力促进了光生电子-空穴对的分离。

Effect of loaded Pt on photo-degradation performance of anatase-brookite biphasic TiO2

The biphasic TiO₂ consisting of anatase and brookite was synthesized by hydrothermal method,and the Pt/biphasic TiO₂ catalyst was prepared by impregnation and H₂ reduction method. The TEM characterization results showed that：The size of Pt grain in the Pt/biphasic TiO₂ catalyst was very small with a rather narrow distribution;with low Pt loading （0.2% and 2.0% of mass fraction）,Pt dispersed well on the surface of TiO₂,but with 4.0% of Pt loading,the dispersion worsened. The results of photocatalytic activity experiment showed that：The loaded Pt could markedly improve the degradation rate of methyl orange on biphasic TiO₂ catalyst;The Pt/biphasic TiO₂ with 2.0% of Pt mass fraction exhibited the highest performance. The main reason for the improvement of photocatalytic activity is that the electron storage ability of Pt particles promotes the separation of photo-generated electron-hole pairs.