YFeO3粉体的制备与可见光光催化性能

采用溶胶凝胶法制备了不同晶型的YFeO₃粉末，通过DTA-TG，XRD，BET，UV-Vis DRS等技术手段对样品进行表征分析，并且根据亚甲基蓝溶液在可见光下的分解情况研究了样品的可见光光催化性能.结果表明:在温度从973K上升到1073K的过程中，YFeO₃的晶型发生了变化，从开始的六方相向正交相转变.与正交相YFeO₃相比，六方相YFeO₃具有更大的比表面积、更大的吸收边、更窄的禁带宽度，其价带位置更负，导带位置更正，在可见光下对于亚甲基蓝溶液的降解效果也更好.

Preparation and Photocatalytic Properties of Visible Light for YFeO3 Powders

The YFeO₃ powder of different crystallographic structures was prepared by using the sol-gel method. The products were characterized by X-ray diffraction (XRD)， differential thermal analysis-thermogravimetric (DTA-TG) analysis， special surface area analysis (the BET method)， and ultraviolet-visible diffuse reflectance spectroscopy (UV-Vis DRS). The photocatalytic activities of the samples were evaluated by using the photocatalytic degradation of methylene blue (MB) under visible light. The results show when the temperature increases from 973K to 1073K， the crystallographic structure of the YFeO₃ power changes from hexagonal to orthorhombic phase. Compared with orthorhombic phase of the YFeO₃， the hexagonal phase presents a relatively larger specific surface area， a wider absorption edge， a narrower bandgap width， a more negative valence position， and a more positive conduction band position. Meanwhile， the performance of photocatalytic degradation of the MB is better.