纳米TiO2/聚氯乙烯共轭衍生物复合材料的制备及可见光催化性能

《复合材料学报》优先在线发表论文。

摘  要：聚氯乙烯(PVC)在270℃真空环境中经热处理脱除HCl得到具有共轭结构的衍生物(CDPVC)。纳米TiO2与CDPVC(质量比为2:1)经高能球磨复合得到纳米TiO2/CDPVC复合材料。采用TEM、XRD、XPS、FTIR、SEM和Raman等对纳米TiO2/CDPVC复合材料进行了分析表征，并采用RhB的光催化降解反应和K2Cr2O7的光催化还原反应评价其可见光催化活性及稳定性。结果表明，TiO2与CDPVC经高能球磨复合后形成了Ti—O—C结构，该结构有利于提高纳米TiO2/CDPVC复合材料的可见光吸收能力和光生电子/空穴分离效率。与纳米TiO2和普通研磨的TiO2-CDPVC相比，纳米TiO2/CDPVC复合材料具有较高的可见光催化活性和良好的可见光催化稳定性。其可见光催化机制是CDPVC吸收光子产生光生电子-空穴对，并容易将光生电子注入到TiO2的导带中，CDPVC内光生电子和TiO2导带上的光生电子(e-CB)被吸附在材料表面上的氧捕获产生·O2-自由基，·O2-自由基可以直接降解RhB分子，直至最后降解生成H2O和CO2。

关键词：TiO2；聚氯乙烯；共轭聚合物；球磨复合；光催化剂；可见光催化

Abstract: Polyvinyl chloride (PVC) was heat-treated in a vacuum at 270℃ to prepare a partly conjugated derivative (CDPVC) through a reaction of remove HCl. The nano TiO2/CDPVC composite was prepared by compounding commercial TiO2 and CDPVC with the mass ratio of 2:1 in a high-energy ball-miller, and was characterized by TEM, XRD, XPS, FTIR, SEM and Raman，et al. The photocatalytic degradation of RhB and the photocatalytic reduction of K2Cr2O7 were used to evaluate the visible photocatalytic activity and stability of the nano TiO2/CDPVC composite. The results show that the structure of Ti—O—C formed by compounding TiO2 and CDPVC in a high-energy ball-miller, which is advantageous to the improvement in both visible-light absorption capacity of the nano TiO2/CDPVC composite and separation efficiency of photogenerated electron/hole pairs. Compared to nano TiO2 and TiO2-CDPVC (an ordinary product after grinding TiO2 and CDPVC), nano TiO2/CDPVC composite exhibits the higher visible-light photocatalytic activity and excellent stability. The visible-light photocatalytic mechanism can be proposed that CDPVC adsorbs photos to produce photogenerated electron-hole pairs, and the photogenerated electrons can be easily injected into the conduction band of TiO2. The photogenerated electrons (e-CB) in CDPVC and conduction band of TiO2 can be captured by oxygen on the surface of the TiO2/CDPVC composite to form·O2-  radicals, and ·O2- radicals can directly degrade rhodamine B molecules even to produce H2O and CO2.

Keywords: TiO2; polyvinyl chloride; conjugated polymer; ball-milling composite; photocatalyst; visible-light photocatalysis

作者：米静艳等，河北科技大学 化学与制药工程学院，石家庄

通讯作者：王德松，河北科技大学 理学院，石家庄

全文详见中国知网学术期刊优先数字出版。