摘要
通过硬模板法制备中空CdS微球,并利用苯胺在微球表面聚合制备了形貌良好的中空CdS/PANI复合微球光催化剂.通过调控CdS和苯胺的配比,得到不同形貌的复合结构,利用透射电子显微镜(TEM)、X射线衍射(XRD)、傅里叶变换红外光谱仪(FTIR)、紫外-可见漫反射光谱(UV-VisDRS)、光致发光光谱(PL)、紫外光电子能谱(UPS)和电流-电压曲线(CV)等手段对催化剂进行了表征,并在可见光照射下进行光催化产氢,评估其光催化活性.结果显示,与中空CdS微球相比,中空CdS/PANI复合微球光催化剂表现出更好的光催化活性和循环稳定性,产氢速率最高可达328μmol·g^-1·h^-1,比单一的CdS光催化剂提升了2.1倍(157μmol·g^-1·h^-1).经过5次循环实验,中空CdS/PANI复合微球的光催化活性几乎没有下降.这可能是因为PANI的引入,使得光生空穴转移到了PANI上,而光生电子留在CdS表面催化产氢.这一方面抑制了CdS在光催化过程中的光腐蚀效应,另一方面也使光生电子-空穴对得到有效分离,进而提升了其光催化活性和循环稳定性.
Hollow CdS/PANI nanocomposite microspheres were successfully synthesized by the polymerization of aniline in the presence of hollow CdS microspheres,which were prepared via "hard core template" approach.The morphology and structures of nanocomposites could be controlled by adjusting the amount of aniline.The as-prepared photocatalysts were characterized by transmission electronic microscope (TEM),X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR),ultraviolet-visable diffraction reflection spectrum (UV-Vis DRS), photoluminescence spectroscopy (PL),ultraviolet photoelectron spectroscopy (UPS ),and current-voltage (CV) measurements.The results demonstrate that the hollow CdS/PANI nanocomposite microspheres exhibit superior photocatalytic activity under visible light illumination,and the highest photocatalytic hydrogen generation rate reaches 328 μmol·g ^-1 ·h^-1,2.1 times higher than the hollow CdS microspheres (157 μmol·g ^-1 ·h^-1 ).At the same time,the photocatalytic activity of the hollow CdS/PANI nanocomposite microspheres shows almost no decrease after five recycling tests,exhibiting high recycling stability.These may be attributed to the fact that the photogenerated holes transfer from the valence band (VB) of CdS to that of PANI,while the photogenerated electrons stay in the conduction band (CB) of CdS.On the one hand,it can restrain the photocorrosion effect of CdS through quenching the photogenerated holes by sacrificial agent on the PANI;on the other hand,it separates the photogenerated electrons and holes spatially,resulting in the improvement of photocatalytic activity and recycling stability.
作者
袁伟
崔晓玲
张震
邰晨
宋元瑞
刘华蓉
YUAN Wei;CUI Xiaoling;ZHANG Zhen;TAI Chen;SONG Yuanrui;LIU Huarong(Department of Polymer Science and Engineering,University of Science and Technology of China,Hefei 230026,China)
基金
国家自然科学基金(51373160)资助
关键词
中空CdS微球
聚苯胺
复合光催化剂
光催化活性
循环稳定性
hollow CdS microspheres
polyaniline (PANI)
nanocomposite photocatalyst
photocatalytic activity
recycling stability
