光电催化降解苯胺的研究——单槽与双槽光反应器对比

Photoelectrocatalytic degradation of aniline-comparison of single compartment with double compartment photoreactor

以直接热氧化制备的TiO2 为催化剂 ,采用单双槽光反应器 ,研究了水中苯胺的光电催化降解行为 .结果表明 :氧的还原反应不是光电催化反应的速率控制步骤 ,但氧的还原和还原产物能加快苯胺的光电催化降解速率 ;单槽光电反应器中 ,当pH由 4 38升至 10 30 ,苯胺降解反应速率是逐渐增大 ,当pH大于 10 30后 ,反应速率迅速下降 ;使用双槽反应器 ,阳极室鼓氮气时 ,苯胺的反应速率始终随pH的升高而下降 ,而当阳极室鼓空气时 ,苯胺反应速率在pH 9 0左右时最大 ;在相同的气氛条件下 ,苯胺在单槽的光电催化反应速率大于双槽的速率 ;利用光电流的大小可判断反应速率的快慢 ,但光电流的利用效率与溶液pH。

The photoelectrocatalytic degradation of aniline on thermally formed TiO\-2/Ti photoanodes was investigated in single and double compartment photoreactor.The results showed that the reduction of oxygen was no longer rate\|limiting step during photoelectrocatalhytic reaction,but its reduction and products could accelerate the degradation rate of aniline.For single\|compartment photoreactor,whether purged with air or nitrogen,increasing pH from 4.38 to 10.30,the reaction rate increased slowly,but when pH was larger than 10.30,the reaction rate decreased sharply.For double\|compartment cell,the reaction rate almost decreased with increasing pH when purged with nitrogen in the anodic compartment.However,when purged air,the reaction rate increased with pH either higher or lower than 9.The oxidation rate of aniline conducted in single\|compartment was a slightly larger than that in double\|compartment with the same gas purging.The rate of aniline oxidation could be evaluated by the photocurrent,but the photocurrent efficiency of aniline degradation was dependent on pH,bias potential and etc.