负载型光催化剂还原Cr6+的研究

采用一种新型负载型TiO2光催化剂进行光催化还原Cr^6 的研究。实验结果表明光催化还原过程中生成了氧气，通过测定光催化反应过程溶液中溶乳量的变化验征了TiO2光催化还原Cr^6 的机理。溶液pH值对反应有较大的影响，还原反应速率随pH增大而减小。有机物的存在对光催化还原反应有不同的影响，甲醇、乙酸对Cr^6 的光催化还原具有促进作用，而三氯甲烷、戊烷、甲苯表现出抑制作用。由于还原产物三价铬离子以Cr(OH)3的形式沉积于催化剂表面致使催化剂活性下降，可以通过用稀硫酸浸泡的方法使催化剂再生。

Reduction of Cr6+ Ions on Immobilized Photo-catalyst

The photo catalytic reduction of Cr 6+ ions on a novel immobilized photo catalyst(TiO 2)is studied. Oxygen produced by the photo catalytic reduction was measured. The mechanism of photo catalytic reduction of Cr 6+ ions was verified by detecting the change of dissolved oxygen of the solution. The effects of pH values on the rate of the reaction were investigated: the higher pH results in lower reduction rate. The experimental results show that some organic compounds also have influence on the reduction reaction: methanol and acetic acid accelerate the process, while chloroform, pentane and toluene restrain it. The deposition of Cr(OH) 3 on the surface of photo catalyst will result in the deactivation of the photo catalyst. The deactivated photo catalyst can be partially regenerated by immersing it in diluted acidic solution.