学术论文

      CaFe2O4/TiO2光催化制氢性能

      Photocatalytic hydrogen evolution over CaFe2O4/TiO2

      摘要:
      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。
      Abstract:
      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.
      作者: 柯旭 [1] 王晟 [1] 皇甫彦 [1] 刘福生 [2] 胡海龙 [1] 黄集森 [1]
      Author: KE Xu [1] WANG Sheng [1] HUANGFU Yan [1] LIU Fusheng [2] HU Hailong [1] HUANG Jisen [1]
      作者单位: 南京工业大学 化工学院,江苏 南京,210009 南京林业大学 理学院,江苏 南京,210037
      年,卷(期): 2016, 38(6)
      分类号: O643
      在线出版日期: 2016年12月23日
      基金项目: 国家自然科学基金(50876047);江苏省普通高校研究生科研创新计划(SJLX 0342);江苏高校品牌专业建设工程