本文制备了p n复合半导体光催化剂CaFe2 O4／TiO2，采用X线衍射仪（ XRD）、扫描电子显微镜（ SEM）、紫外可见漫反射光谱仪（ UV Vis DRS）及电化学工作站对光催化剂的结构和性能进行表征。以模拟太阳光催化产氢速率评价p n复合半导体光催化剂CaFe2 O4／TiO2的光催化活性。探讨光催化剂中CaFe2 O4添加量、甲醛浓度、反应体系pH对光催化产氢性能的影响，并对光催化活性的提高进行了机制分析。结果表明：CaFe2 O4的导带比TiO2的导带更负，同时在CaFe2 O4／TiO2内存在内建电场，两者均促进了电子从CaFe2 O4向TiO2的迁移，增强了光催化活性，0?4％CaFe2O4／TiO2具有最高的光催化活性，2 h 内的产氢速率达到0?989 mmol／（g·h）。此外， CaFe2 O4／TiO2的稳定性较好，可多次循环使用。
A series of p?n coupled CaFe2 O4/TiO2 photocatalysts were prepared. The structure and properties of CaFe2O4/TiO2 catalysts were characterized by X?ray diffraction (XRD), scanning electron microscope (SEM), ultraviolet?visible diffuse reflectance spectrum (UV?Vis DRS) and electrochemical tests. The photocatalytic activities of CaFe2 O4/TiO2 catalysts were evaluated by photocatalytic hydrogen production under solar light. The effects of the amount of CaFe2 O4 , the concentration of HCHO and pH on hydrogen production were investigated. The mechanism of photocatalytic activity was discussed. Results showed that CaFe2 O4/TiO2 exhibited higher photocatalytic activity attributed to electrons transferring from CaFe2 O4 to TiO2 , resulted from the more negative conduction band potential of CaFe2 O4 than TiO2 and the inner electric field. 0?4%CaFe2 O4/TiO2 had the best performance among the various CaFe2 O4/TiO2 composite powders tested, with a hydrogen evolution rate of up to 0?989 mmol/( g · h ) in 2 h, and CaFe2 O4/TiO2 also exhibited the good stability with several recycling times.