TiO_2/SrTiO_3核壳结构光阳极制备及其光电化学性能

Preparation and Photoelectrochemical Properties of TiO_2/SrTiO_3 Core-shell Photoanodes

采用水热法在纳米多孔TiO2光阳极表面包覆一薄层SrTiO3,制得TiO2/SrTiO3核壳结构光阳极,并用X射线衍射、扫描电镜、能谱仪、透射电镜及紫外可见吸收光谱对其进行表征。探讨了水热反应时间对TiO2/SrTiO3光阳极组装的染料敏化太阳能电池(DSSCs)的光电化学性能的影响。结果表明:钙钛矿结构的SrTiO3包覆在纳米多孔TiO2光阳极的表面,形成TiO2为核SrTiO3为壳的光阳极;SrTiO3包覆的样品吸收边有红移;与TiO2光阳极相比,水热反应制备的TiO2/SrTiO3核壳结构光阳极组装的DSSC短路电流密度明显增加,5h时光电性能最优,短路电流密度为13.98mA/cm2,开路电压为0.74V,填充因子为0.45,全光转换效率为4.68%,提高了35.65%。

Nanoporous TiO2 photoanodes were coated with thin layers of SrTiO3 by the hydrothermal method.The as-prepared TiO2/SrTiO3core-shell photoanodes were characterized by X-ray diffraction,scanning electron microscope,energy dispersive spectrometer,transmission electron microscope and ultraviolet-visible absorption spectra.The effect of reacting time on photoelectrochemical properties of DSSCs based on TiO2/SrTiO3 photoanodes was studied.The results show that the surface of nanoporous TiO2 photoanodes is coated with perovskite SrTiO3 layer to form the photoanodes with TiO2 as the core,and SrTiO3 as the shell.The red-shifts of absorption edge were observed for the SrTiO3-coated samples.Compared to those of uncoated TiO2 photoanodes,DSSCs short circuit current density of TiO2/SrTiO3 electrodes prepared by hydrothermal method increases significantly.Solar cells based on TiO2/SrTiO3 electrodes modified with hydrothermal time of 5hshow the optimal performance with short-circuit current density（Jsc）of 13.98mA/cm^2,open-circuit voltage（Voc）of 0.74 V,fill factor（FF）of 0.45 and photoelectric conversion efficiency（η）of 4.68% with the enhancement of35.65%.