聚硅硫酸钛制备复合光催化剂及降解甲基橙的研究

Preparation of TiO_2/SiO_2 composite photocatalyst and the study of the degeneration on methyl orange

以无机钛盐、硅酸盐为原料,制备了聚硅硫酸钛絮凝剂,然后利用其水溶液水解产物制备复合光催化剂,考察了钛与硅摩尔比、水解pH值、调节pH值所用碱的种类、煅烧温度和煅烧时间对该复合光催化剂降解甲基橙时活性的影响,并利用扫描电镜(SEM)和X射线衍射(XRD)对其进行了物性测试分析。结果表明:n(Ti):n(Si)=12:1的聚硅酸硫酸钛,以NH3.H2O调节pH值,在pH值为6时水解,产物在650℃煅烧1.5h后制得的复合光催化剂活性最高,当其投加量为0.5g.L-1时,光催化反应30min后,甲基橙的脱色率可达100%。物性分析表明,聚硅钛制备的复合光催化剂是一种以锐钛矿为主、分散均匀的纳米级球形颗粒。

The TiO2/SiO2 composite photocatalyst were prepared by controlling the hydrolysis of inorganic titanium salts and silicates.The effects of the ratio of titanium and silicon,pH value and calcine temperature and time on the photocatalytic activity of the photocatalysts were studied during photodegradation of methyl orange in aqueous solution.It was characterized by scanning electron microscope and X-ray diffraction spectra techniques.The experimental results show that the ratio of titanium and silicon is 12∶1,with ammonia water regulation flocculation under pH=6 in 650℃ calcining 1.5h get the composite light catalyst has the highest activity.When the dosing quantity is 0.5g·L-1,processing 25mg·L-1 methyl orange,with the solution of photocatalytic reactions 30min,the processing efficiency can reach 100%.Properties of matter analysis showed that TiO2/SiO2 composite photocatalysts were a kind of nanometre spheric particles,which disperse evenly,have large surface area and form anatase TiO2 mostly.