Department of Environmental Engineering, Kyungpook National University, 80 Daehakro, Daegu 702-701, Korea.
J Air Waste Manag Assoc. 2013 Aug;63(8):963-70. doi: 10.1080/10962247.2013.801931.
This study synthesized multiwall carbon nanotube (MWNT)-titania (TiO2) composites and examined their characteristics and photocatalytic performance for the cleaning of gas-phase benzene, toluene, ethyl benzene, and o-xylene (BTEX) under simulated indoor conditions. Optical and spectral surveys of the as-synthesized composite confirmed that the TiO2 nanoparticles were bound intimately to the MWNT networks. The photocatalytic performance was evaluated using an annular-type reactor inner-coated with MWNT-TiO2 or Degussa P25 TiO2. The composite revealed gas removal ability superior to that of stand-alone TiO2. This composite was also less affected by humidity during toluene decomposition compared to the previous result obtained from a stand-alone TiO2. Unlike another previous result obtained from the TiO2, the performance of the composite was not affected by changes in input concentration (IC) within a simulated indoor air quality range (0.1-1.0 ppm) but it decreased significantly when the IC was increased to 5 and 10 ppm. As the flow rate was decreased from 4.0 to 1.0 L min(-1), the average efficiency for the target compounds increased to 95% or -100%. The MWNT-TiO2 composite could be applied effectively to the decomposition for BTEX under certain simulated indoor conditions.
Unlike water applications, there are few reports of gas-phase applications of multiwall carbon nanotubes (MWCNT)-TiO2 composites. This study found that MWCNT-TiO2 composites showed performance in the removal of toxic gaseous aromatic superior to that of stand-alone TiO2. In addition, the pollutant degradation efficiency of the composite was less affected by humidity than for a stand-alone TiO2 unit within a simulated indoor relative humidity range. Moreover, unlike the TiO2 unit, the composite's performance was not affected by variations in the input concentrations within the simulated indoor air quality (IAQ) range. In addition, the decomposition efficiencies increased to 100% with decreasing flow rate.
本研究合成了多壁碳纳米管（MWNT）-二氧化钛（TiO2）复合材料，并考察了其在模拟室内条件下对气相苯、甲苯、乙苯和邻二甲苯（BTEX）的清洁特性和光催化性能。对合成的复合材料进行的光学和光谱调查证实，TiO2 纳米粒子紧密结合在 MWNT 网络上。使用内涂有 MWNT-TiO2 或 Degussa P25 TiO2 的环形反应器评估光催化性能。与独立的 TiO2 相比，该复合材料具有优越的气体去除能力。与以前从独立 TiO2 获得的结果相比，该复合材料在甲苯分解过程中受湿度的影响也较小。与以前从 TiO2 获得的结果不同，在模拟室内空气质量范围内（0.1-1.0 ppm），输入浓度（IC）变化不会影响复合材料的性能，但当 IC 增加到 5 和 10 ppm 时，其性能会显著下降。当流速从 4.0 降至 1.0 L min(-1)时，目标化合物的平均效率增加到 95%或-100%。MWNT-TiO2 复合材料可在一定的模拟室内条件下有效地应用于 BTEX 的分解。
与水应用不同，很少有关于多壁碳纳米管（MWCNT）-TiO2 复合材料在气相中的应用报道。本研究发现，MWNT-TiO2 复合材料在去除有毒气态芳香族化合物方面的性能优于独立的 TiO2。此外，在模拟室内相对湿度范围内，与独立的 TiO2 相比，复合光催化剂的污染物降解效率受湿度的影响较小。此外，与 TiO2 单元不同，在模拟室内空气质量（IAQ）范围内，复合单元的性能不受输入浓度变化的影响。此外，随着流速的降低，分解效率增加到 100%。
