【摘要】 TiO₂作为光催化剂在工业废水、环境污染物处理等多个领域具有广阔的应用前景,但TiO₂粉末易团聚,主要以悬浮态存在于水溶液中,回收性差,而回收不完全易导致二次污染,这极大限制了其在实际工业化中的应用。本研究通过紫外光照射纳米TiO₂直接催化N-乙烯基咔唑原位聚合反应合成聚（N-乙烯基咔唑）/TiO₂纳米复合材料（PVK/TiO₂）,利用NMR、TEM、XRD、FTIR、紫外可见吸收光谱仪、荧光分光光度法等对复合材料进行了性能测试和结构表征。结果表明:纳米TiO₂对N-乙烯基咔唑单体具有很高的光催化活性,在紫外光照射下无需外加光引发剂即可引发单体的聚合反应;经洗涤预处理的纳米TiO₂粒子在复合材料中呈颗粒状且分散均匀;随着TiO₂含量的增加,复合材料荧光淬灭效应明显增强。本工作首次发现PVK在紫外光照条件下对甲基橙具有显著的光催化降解活性,且相比于单独的纳米TiO₂或PVK,PVK/TiO₂复合材料在同等条件下降解甲基橙的性能更优,说明PVK显著提高了TiO₂的光催化降解性能。借助PVK优良的耐热、耐腐蚀、成膜性能以及高力学强度的优势,PVK/TiO₂复合材料可被制成粉状、膜状、纤维状、管状等多种光催化降解器件,具有良好的工业化应用前景。更多还原

【Abstract】 As a photocatalyst,TiO₂ has broad application prospects in many fields such as industrial wastewater and environmental pollutant treatment.However,TiO₂ powders are prone to aggregation and they primarily exist in aqueous solution with suspended state,and difficult to be completely recovered,thus leading to secondary pollution,which greatly limits its application in practical industrialization. In this work,poly（N-vinyl carbazole）/TiO₂ nanocomposites（PVK/TiO₂） were synthesized via a in-situ polymerization of N-vinylcarbazole catalyzed by TiO₂ nanoparticles under ultraviolet irradiations. A series of techniques including NMR,TEM,XRD,FTIR,UV-vis adsorption spectroscopy,and fluorescence spectroscopy were adopted to characterize the nanocomposites. The results indicate that the TiO₂ nanoparticles possess high photocatalytic activities for N-vinylcarbazole monomer and the polymerization can be initiated without the addition of external photoinitiators under ultraviolet irradiations.The TiO₂ nanoparticles are uniformly dispersed in the nanocomposites after a washing pretreatment. With the increase of TiO₂ content,the fluorescence quenching effect of the nanocomposite is obviously enhanced. It is found for the first time that PVK polymer itself has a significant photodegradation activity for methyl orange under ultraviolet light. The PVK/TiO₂ nanocomposites demonstrate superior photocatalytic performance than PVK or TiO₂ nanoparticles alone to degrade methyl orange under the same experimental conditions,indicating that the photodegradation property of TiO₂ is significantly enhanced by PVK. By taking advantages of excellent heat resistance,corrosion resistance,film forming properties and high mechanical strength of PVK,the PVK/TiO₂ nanocomposites can produce a large variety of photodegradation devices in the form of powders,films,fibers and tubes,and therefore have a bright prospect in industrial applications.更多还原