苯酚水溶液光催化降解的盐效应

实验研究了不同浓度的NaCl, KCl, KBr, CaCl₂和Na₂SO₄等电解质对323K下苯酚水溶液光催化降解速度的影响,采用分光光度法测定了光催化降解的动力学曲线.结果表明,各种电解质对苯酚的光催化降解均有抑制作用,且随电解质浓度的增加而增强;盐效应强弱主要取决于阴离子而不是阳离子;对于所研究的体系,阴离子的盐效应作用顺序为Br->SO₄^2->Cl^-.光催化过程的盐效应可能与阴离子对光催化剂表面光生空穴的俘获和稳定作用以及阳离子的电导作用引起催化剂表面光生电子和空穴之间的短路有关.

Salt effect of photocatalytic degradation of benzyl phenol aqueous solution

The influence of different concentrations of NaCl, KCl, KBr, CaCl2 and Na2SO4 electrolytes on the photocatalytic degradation rate of benzyl phenol aqueous solution at 323K was studied experimentally; and the kinetic curves of photocatalysis were determined with spectrophotometer. All kinds of electrolytes have prohibitive action on the photocatalytic degradation of benzyl phenol with the action strengthened as the electrolyte concentration increases; and the strength of salt effect depends mainly on anion while not on cation. The order of salt effect of anion on the studied system is Br-> SO42-> Cl-. The salt effect of photocatalysis process might be related with the capture and stabilization of photo-induced holes of photocatalyst surface by anion and the short circuit between photo-induced electron-hole pairs on the surface of photocatalyst induced by the electrical conductive action of cation.