纳米Ag_2S/TiO_2异质复合薄膜的制备和光电性能

Study of the Preparation and Photoelectric Property of Nanocrystalline Ag_2S/TiO_2 Heterostructure Films

以异丙醇钛(C12H28O4Ti)为主要原料合成氧化钛(TiO2)前驱体溶胶,并结合230℃水热处理得到TiO2溶胶,利用电流体动力学(EHD)技术在掺氟氧化锡导电(FTO)玻璃基片上镀膜,450℃高温煅烧制备具有多级结构锐钛矿TiO2纳米薄膜。以硝酸银(AgNO3)及硫化钠(Na2S)分别为银源和硫源,采用化学浴沉积技术在TiO2薄膜上沉积制备了纳米硫化银敏化的异质复合薄膜。采用X射线衍射(XRD)、电子扫描电镜(SEM)、电子透射电镜(TEM)、紫外-可见吸收光谱(UV-vis ab-sorbance spectra)对薄膜结构和性能进行表征,并对制备的复合薄膜组装光电化学电池进行了光电性能测试。结果表明,纳米TiO2薄膜具有亚微米球簇堆积结构,球簇之间形成尺寸连续分布的微纳通道。异质复合薄膜中硫化银以尺寸为3-5nm范围内纳米颗粒形式存在。UV-vis absorbancespectra证实量子点的量子限域效应。光电化学性能测试表明,该复合薄膜具有光电响应特性,但光电性能信号随时间发生衰减现象。

Nanocrystalline TiO2 solution was prepared by hydro-thermal treatment at 230℃ with Titanium（Ⅳ） isopropoxide（C12H28O4Ti） as precursor solution.Anatase TiO2 nanocrystalline films with hierarchical structure were prepared on FTO glass substrates by electrohydrodynamic（EHD） technique and sintered at 450℃.Nanocrystalline Ag2S/TiO2 heterostructure films were deposited by chemical bath method using the AgNO3 solution and Na2S solution as the reactants.The crystal structure,morphology and optical property of the film were investigated.The photoelectrochemical cells have been assembled with nanocrystalline Ag2S/TiO2 heterostructure films as the photoanode.The results indicate that nanocrystalline TiO2 films stack with the submicron spherical clusters,submicron and nanometer channels with wide dimension formed among the clusters which can facilitate the solution facilitation and ions adsorption.Ag2S nanocrystalline exist in the Ag2S/TiO2 heterostructure Films within the range of 3 to 5nm.UV-vis absorbance spectra verifies the quantum confinement effects of Ag2S nanocrystalline.The photoelectrochemical measurement shows the film possesses photoelectric response characteristic and its photoelectric property decays as illumination time prolonging.