采用溶胶-凝胶法制备了多壁碳纳米管(MWCNTs)负载的ITO/MWCNTs-TiO2/ITO复合器件,利用SEM、XPS、UV-Vis光谱等技术对复合样品进行形貌和结构表征,以液相罗丹明B(RhB)的可见光光催化降解为探针反应,评价MWCNTs-TiO2复合薄膜的催化活性.XPS结果表明MWCNTs与TiO2之间没有形成Ti-C键.I-V特性表明负载了MWCNTs的ITO/MWCNTs-TiO2/ITO复合器件的光电流增强.与空白TiO2薄膜相比,MWCNTs-TiO2复合薄膜的可见光光催化降解RhB的速率提高了3.2倍.MWCNTs并没有掺杂到TiO2晶格中,而是起到了类似光敏剂的作用,可在可见光激发下将导带电子转移到TiO导带上,经一系列反应降解RhB有机物.
Multi-walled carbon nanotubes(MWCNTs) and TiO2 composite catalysts device-ITO/MWCNTs-TiO2/ITO,was prepared by a sol-gel method coated on indium tin oxide(ITO) substrate.The surface morphology and properties of devices were characterized by SEM,XPS and UV-Vis spectrophotometer.We employed photocatalytic degradation of rhodamine B(RhB) under visible light irradiation as the probe reaction to evaluate its photocatalytic activity.The XPS spectra indicated that Ti-C structures did not form between MWCNTs and TiO2.The linear scan voltammograms(I-V curves) showed that the ITO/MWCNTs-TiO2/ITO exhibited better photoresponse of visible light than the blank device ITO/TiO2/ITO.For photocatalytic degradation of RhB under visible light irradiation,ITO/MWCNTs-TiO2/ITO exhibited better activity,presented 4.2 times of the ITO/TiO2/ITO.The MWCNTs did not substitute O ions in the TiO2 lattice,but served as a photosensitizer.The photoelectrons generated in the CB of MWCNTs could transfer to the CB of TiO2,and the resulting reactive oxygen species could further attack RhB to make it degrade.