量子点与TiO2电极参数对光阳极电子寿命及性能影响

通过对P25Ti O2光阳极薄膜厚度、敏化的量子点种类及量子点敏化方法研究,探讨了使用连续离子层吸附反应法的敏化方法(SILAR)时,P25Ti O2薄膜厚度与光阳极电子寿命的关系,以及量子点种类、共敏化工艺对光阳极光电性能的影响.采用电化学阻抗(EIS)、开路电压衰减(OCVD)及紫外-可见吸收方法,对影响光阳极光电性能的Ti O2薄膜厚度、量子点种类及共敏化工艺因素进行测试分析.实验结果表明:当光阳极薄膜厚度为12μm时,电子复合几率最小,光阳极的电子寿命相对最长;采用连续离子层吸附反应法(SILAR)对多种量子点共敏化的光阳极(Ti O2/Cd S/Cd Se/Zn S)与单一量子点敏化的光阳极(Ti O2/Cd S)相比,短路电流提高了34%,光转换效率提高了42%;合适的共敏化工艺也有助于提高光阳极的电子寿命、光谱吸收范围和吸收强度.

Influence of quantum dots and TiO2 photoanode parameters on electron lifetimes and performance of photonode

Effects of film thickness of P25TiO₂ photoanode, different types of quantum dots sensitized and method of quantum dots co-sensitization, which are the factors of interest, on P25TiO₂ photoanode were analyzed. The relationship between P25TiO₂ film thickness and electron lifetimes were investigated by the method of successive ionic layer absorption and reaction (SILAR). Besides, the influence of quantum dots type and method of quantum dots co-sensitization on photoelectrochemical performance of photoanode was studied. Electrochemical impedance spectra (EIS), open circuit voltage decay (OCVD) and UV-Vis absorption spectra were used to measure and analyze the factors which influence the photoelectrochemical performance and electron lifetimes of P25TiO₂ photoanode. The results indicate that P25TiO₂ with the film thickness of 12μm exhibits the minimum recombination losses and longer electron lifetimes. Furthermore, the short circuit current and power conversion efficiency of co-sensitized photoanode (TiO₂/CdS/CdSe/ZnS) increase 34% and 42% respectively compared to those of single sensitized photoanode (TiO₂/CdS). Besides, appropriate film thickness of P25TiO₂ photoanode and method of co-sensitization are important factors to increase the electron lifetimes of photoanode, the absorption spectrum and intensity of photoanode.