聚3-甲基噻吩修饰量子点硫化镉连接纳米结构TiO_2复合膜电极光电化学研究

A photoelectrochemical study of poly(3-methylthiophene) modified Q-CdS anchored nanostructured TiO_2 film

采用原位化学法在纳米结构TiO2电极上制备了量子点CdS(Q-CdS),并用电化学方法在TiO2/Q-CdS表面聚合3-甲基噻吩poly(3-Methylthio-phene)(PMeT)。通过对PMeT修饰Q-CdS连接TiO2纳米结构膜的研究表明,PMeT和Q-CdS单独修饰纳米结构TiO2电极和PMeT修饰Q-CdS连接纳米结构TiO2电极的光电流产生的起始波长都向长波方向移动;一定条件下在可见光区光电转换效率均较纳米结构TiO2的光电转换效率有明显的提高;聚3-甲基噻吩(PMeT)与Q-CdS连接的纳米结构TiO2之间存在p-n异质结。在一定条件下p-n异质结的存在有利于光生电子/空穴的分离,提高了光电转换效率。

The CdS quantum dots were formed in situ in the nanocrystalline TiO2 electrode using chemical bath deposition techniques and the PMeT were prepared with electrochemical method on TiO2/Q-CdS film. The photoelectrochemical properties of poly （3-Methylthiophene） （PMeT） modified Q-CdS anchored nanostructured TiO2 film were studied. The results indicated PMeT and Q-CdS respectively modified TiO2 film and PMeT modified Q-CdS anchored nanostructured TiO2 film produced photocurrent in the longer wavelength region. In infrared light region, the conversion efficiency of light to electricity for the composite semiconductor nanoporous films was greatly improved when it was compared with nanostructured TiO2. The experiment result showed that the p-n heterojuction existed in the nanostructure TiO2/Q-CdS/PMeT film electrode, which favored the separation of electron/hole pairs generated by photoexcitation.