纳米TiO_2分散稳定性及降解甲醛的研究  

Study on dispersion and stability of nano-TiO_2 powders and photo-catalytic degradation of formaldehyde

作　　者：李协吉[1] 姚亚东[1] 尹光福[1] 游潘丽[1] 

机构地区：[1]四川大学材料科学与工程学院,四川成都610064

出　　处：《化学研究与应用》2006年第3期276-279,283,共5页Chemical Research and Application

基　　金：教育部优秀青年教师基金资助项目(2002123)

摘　　要：用自制纳米TiO2粉体(粒径<10nm),研究了超声分散,pH值对纳米TiO2-水体系的分散和稳定过程的影响,以TiO2分散体系对甲醛降解能力来表征其分散效果。实验结果表明,对纳米TiO2-水体系进行长时间超声强烈振荡(8h以上),对粒子在水中的分散起决定性作用,超声分散经历三个重要阶段:初级分散(超声2h左右),逆分散(3-5h),完全分散(8h以上);研究结果证实,pH值对纳米TiO2-水分散体系的稳定性起主要作用,分散体系的稳定性随pH值的增大而显著提高,在pH=8.5左右,分散液可达7天以上无沉降,其降解甲醛能力最佳。用1%浓度的分散液对甲醛进行光催化降解,其降解率达97%以上,该催化剂重复使用多次后,对甲醛的降解率由开始的97.4%到最终维持93%,表明该催化剂具有良好的重复使用性能。The effect of ultrasonic and pH value on the dispersion and stabilization process of TiO2/H2O suspension system were discussed. The degradation ratio of HCHO was used as the token of dispersion of the system. The results showed that lasting ultrasonic vibration was the decisive effect to the dispersion of system and the dispersion would experience three phases of primary-dispersion,counter - dispersion and fully - dispersion. The results also proved that pH value would greatly affect the stability of the TiO2/H2O suspension system. Its stability was improved with the increasing of pH value. The dispersed liquid could keep stably for 7 days without sedimentation and possessed the optical photo - catalytic activity at pH = 8. 5. It was found that the degradation ratio of HCHO was upward of 97% with the dispersed liquid of 1% TiO2 ,which could be relatively steady in activity after reused for sevend times.

关 键 词：纳米TIO2 超声振荡 PH值 降解甲醛 

分 类 号：O614.411[理学—无机化学]