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PVC衍生物(CDPVC)。纳米TiO_2与CDPVC(质量比为2∶1)经高能球磨复合得到纳米TiO_2/CDPVC复合材料。采用TEM、XRD、XPS、FTIR、SEM和Raman等对纳米TiO_2/CDPVC复合材料进行了分析表征,并采用罗丹明B(RhB)的光催化降解反应和K_2Cr_2O_7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,TiO_2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TiO_2/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TiO_2和普通研磨的TiO_2-CDPVC相比,纳米TiO_2/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TiO_2的导带中,CDPVC内光生电子和TiO_2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·O_2^-自由基,·O_2^-自由基可以直接降解RhB分子,直至最后降解生成H_2O和CO_2。
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 rhodamine B(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(eCB-)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.
作者
米静艳
殷蓉
罗青枝
王尚霞
安静
王德松
MI Jingyan;YIN Rong;LUO Qingzhi;WANG Shangxia;AN Jing;WANG Desong(School of Chemical and Pharmaceutical Engineering, Hebei University of Science and Technology, Shijiazhuang 050018, China;College of Sciences, Hebei University of Science and Technology, Shijiazhuang 050018, China)
出处
《复合材料学报》
EI
CAS
CSCD
北大核心
2019年第5期1263-1274,共12页
Acta Materiae Compositae Sinica
基金
国家自然科学基金(21271061)
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
TiO2
polyvinyl chloride
conjugated polymer
ball-milling composite
photocatalyst
visible-light pho tocatalysis
