Bi_2MoO_6纳米薄膜的制备及其光电性能

Preparation and Photoelectrochemical Properties of Bi_2MoO_6 Films

采用非晶态配合物法在ITO导电玻璃上制备了Bi_2MoO_6薄膜.采用扫描电子显微镜(SEM)、X射线衍射(XRD)、激光拉曼光谱(LRS)、紫外-可见漫反射谱(DRS)、光电流响应谱、光电转换量子效率(IPCE)等技术研究了Bi_2MoO_6薄膜的制备工艺、形貌、结构与薄膜光电性能的关系.结果表明,500℃、1h焙烧后的Bi_2MoO_6薄膜为γ- Bi_2MoO_6晶相,沿(131)晶面方向生长,薄膜厚度约为69 nm.随着焙烧温度的升高和焙烧时间的延长,Bi_2MoO_6薄膜的平均颗粒度增大,并且在525℃焙烧出现β-Bi_2MoO_6和γ'-Bi_2MoO_6晶相.Bi_2MoO_6薄膜具有可见光响应活性,在可见光照射下可以产生光电流,优化条件下的Bi_2MoO_6薄膜在400 nm的光电转换量子效率可以达到2.14%.薄膜的光电响应和光电转换量子效率受薄膜形貌及结晶状态影响,可以通过控制薄膜的制备条件来提高薄膜的光电转换量子效率.

Bi2MoO6 films on ITO glass substrates were prepared from amorphous complex precursor by dip-coating technique. The relationships between conditions of preparation, structures, morphologies and photoelectrochemical properties of Bi2MoO6 films were investigated by using scanning electron microscope （SEM）, X-ray diffraction （XRD）, laser Raman spectroscopy （LRS）, diffuse reflectance spectroscopy （DRS）, photocurrent action curves, and incident photon- to-current conversion efficiency （IPCE）. Bi2MoO6 films prepared at 500 ℃ for I h were γ-Bi2MoO6 phase, and Bi2MoO6 nanoparticles grew along （131） plane. The thickness of the films obtained was about 69 nm. The size of the Bi2MoO6 nanoparticles was increased with rising calcination temperature and extention of calcination time, in addition γ- Bi2MoO6 changed into β-Bi2MoO6 and γ＇-Bi2MoO6 at 525 ℃. Bi2MoO6 films had visible-light response, and detectable photocurrent was generated under the visible-light （A〉400 nm） irradiation. The IPCE of the optimized Bi2MoO6 films was 2.14% at 400 nm. The photocurrent density and IPCE could be controlled by modifying the surface structure of Bi2MoO6 films, which could be achieved by changing the preparation conditions.