碳纳米管负载TiO2对1,2,4-三氯苯的光降解研究

碳纳米管负载TiO2复合光催化剂与纳米TiO2光催化剂对1,2,4-三氯苯的光催化降解效果,及降解动力学的研究结果表明,复合光催化剂比纳米TiO2有更好的光催化降解效果,经254 nm紫外光辐照60 min后,使用复合光催化剂的1,2,4-三氯苯降解了70%,而使用纳米TiO2为催化剂的1,2,4-三氯苯仅降解了51%...

Photocatalytic Degradation of 1,2,4-Trichlorobenzene with TiO2 Coated on Carbon Nanotubes

Effects and kinetics of photocatalytic degradation of 1,2,4-trichlorobenzene with composite photocatalysts of TiO2 coated on carbon nanotubes and nano-TiO2 photocatalysts were studied, respectively. It was found that the composite photocatalysts was better than the nano-TiO2 for photocatalytic degradation of 1,2,4-trichlorobenzene. After 60 min UV irradiation at 254 nm, there was 70% of the initial 1,2,4-trichlorobenzene degraded with the composite photocatalyst while only 51% of the initial 1,2,4-trichlorobenzene degraded with the nano-TiO2. Results of photocatalytic degradation kinetics also proved that the 1,2,4-trichlorobenzene degradation rate constant with the composite photocatalyst was 0.019 6 h(-1), which was increased by 63.3% compared to that with nano-TiO2. According to molecular structure theory, analysis of dissociation energy of C--Cl bond of chlorobenzenes predicated that main pathway of photocatalytic degradation of 1,2,4-trichlorobenzene followed that its ortho-Cl could be took off first to form 1, 4-dichlorobenzene, and it might be further dechlorized and finally be mineralized. The first step of photodechlorination for 1,2,4-trichlorobenzene was also experimentally confirmed through identified 1,4-dichlorobenzene as its product.