纳米TiO2薄膜光催化降解橡椀栲胶的研究
PHOTOCATALYTIC DEGRADATION OF VOLANEA TANNIN EXTRACT ON NANOPARTICLE TITANIA THIN FILM
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摘要: 以Ti(OC4H9)4为原料,溶胶-凝胶法制备纳米TiO2薄膜,用原子力显微镜(AFM)观察了纳米TiO2薄膜的形貌,X-射线衍射(XRD)考察相同条件下粉体的相结构.研究水中橡椀栲胶的光催化降解行为.结果表明,橡椀栲胶的降解可用Langmuir-Hinshelwood方程来描述,即浓度较高时,栲胶降解液的光催化降解符合零级动力学方程;浓度较低时,栲胶降解液的光催化降解符合一级动力学方程.外加H2O2对橡椀栲胶的光催化降解有极大的促进作用,但这种促进作用会因为光生电子效率的影响而有一个极限值.在远离橡椀栲胶溶液等电点的起始pH值条件下光催化降解效果较好,且在碱性条件下的降解速率高于酸性条件下的降解速率.Abstract: Nanoparticle TiO2 film photocatalysts was prepared by sol-gel method using Ti(OC4H9)4 as the precursor Surface morphologies of the photocatalyst were characterized by AFM, XRD patterns were obtained using a powder diffractometer, and the photocatalytic degradation of volanea tannin extract in water was studied in the reactor with UV lamp as light source The results showed that the kinetic of photocatalytic degradation rate of volanea tannin extract can be described by Langmuir-Hinshelwood equation, which is photocatalytic degradation of volanea tannin extract degradation solution conforms to zero order dynamics equation at high concentration; and conforms to first order dynamics equation at low concentration External addition of H2O2 shows a high acceleration for the photocatalytic degradation of volanea tannin extract, but it is limited as a result of the amount of light-induced electron Effects of nano-TiO2 thin film photocatalytic oxidatic degrade volanea tannin extract are better at initial pH far from isoelectric point of volanea tannin extract; and degradation speed is more rapid under alkaline condition than acidity condition.
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Key words:
- nanoparticle titania /
- photocatalytic degradation /
- volanea tannin extract /
- kinetics
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