PPy/TiO_(2)/CS@PTFE光催化分离复合膜的制备与性能

Preparation and Properties of Photocatalytic Separation Composite Membrane of PPy/TiO_(2)/CS@PTFE

为提高对印染废水的光催化分离处理效果,采用膜表面原位聚合制备聚吡咯(PPy)/二氧化钛(TiO_(2))/壳聚糖(CS)@聚四氟乙烯(PTFE)光催化分离复合膜,利用FTIR、XRD、SEM、N吸附-脱附、水接触角、UV-Vis光谱法和荧光发射光谱等手段对复合膜的结构和光催化性质进行表征,并测试其在全光谱氙灯激发下对亚甲基蓝(MB)和六价铬离子[Cr(Ⅵ)]的处理性能.结果表明,PPy/TiO_(2)/CS在PTFE膜表面固载且比表面积较TiO提高4.27倍,复合膜水接触角下降近50%.复合膜的光吸收强度增加,电子-空穴复合率降低,对MB和Cr(Ⅵ)的处理效率分别为93%和86%,对MB的5次循环使用性能降低14%.机理分析表明,复合膜对污染物有吸附和截留作用,并使其在h^(+)、·OH和·O_(2)^(-)等活性物质作用下发生光催化反应而除去.

For improving the photocatalytic and separation effect for the printing and dyeing wastewater treatment,the photocatalytic separation composite membrane of PPy/TiO_(2)/CS@PTFE was prepared by in-situ polymerization on membrane.The structure and photocatalytic property of PPy/TiO_(2)/CS@PTFE were characterized by FTIR,XRD,SEM,N_(2) adsorption-desorption,water contact angle,UV-Vis spectrum and fluorescence emission spectrum,and the wastewater treatment performance for methylene blue(MB)and hexavalent chromium [Cr(Ⅵ)] under full-spectrum xenon lamp light irradiation were investigated.The results showed that PPy/TiO_(2)/CS was stable loaded on PTFE,with specific surface area increased by 4.27 times compared with TiO_(2)and water contact angle of membrane decreased by 50%.The light absorption intensity of PPy/TiO_(2)/CS@PTFE were enhanced,and the electron-hole recombination rate was reduced.The treatment efficiencies for MB and Cr(Ⅵ)were 93%and 86%,respectively.The five-cycle performance of composite membrane for MB was reduced by 15%.The mechanism analysis demonstrated that pollutants can be absorbed and intercepted by the composite membrane,and removed by photocatalytic reaction under the action of active substances such as h^(+),·OH and·O_(2)^(-).