物理化学学报 >> 2012, Vol. 28 >> Issue (04): 865-870.doi: 10.3866/PKU.WHXB201202152

电化学和新能源 上一篇    下一篇

煅烧温度对阳极氧化WO3多孔薄膜的形貌及光电化学性能的影响

黄晔, 刘昱阳, 李文章, 陈启元   

  1. 中南大学化学化工学院, 有色金属资源化学教育部重点实验室, 长沙 410083
  • 收稿日期:2011-12-02 修回日期:2012-02-01 发布日期:2012-03-21
  • 通讯作者: 李文章, 陈启元 E-mail:lijieliu@csu.edu.cn; liwenzhang@csu.edu.cn
  • 基金资助:

    国家高技术研究发展计划项目(863) (2011AA050528)及国家自然科学基金(51072232, 21171175)资助

Effects of Calcination Temperature on Morphologies and Photoelectrochemical Properties of Anodized WO3 Nanoporous Films

HUANG Ye, LIU Yu-Yang, LI Wen-Zhang, CHEN Qi-Yuan   

  1. Key Laboratory of Resources Chemistry of Nonferrous Metals Ministry of Education, School of Chemistry and Chemical Engineering, Central South University, Changsha 410083, P. R. China
  • Received:2011-12-02 Revised:2012-02-01 Published:2012-03-21
  • Contact: CHEN Qi-Yuan E-mail:lijieliu@csu.edu.cn; liwenzhang@csu.edu.cn
  • Supported by:

    The project was supported by the National High Technology Research and Development Program of China (863) (2011AA050528) and National Natural Science Foundation of China (51072232, 21171175).

摘要: 采用一步式阶跃电压加压方法, 在NH4F/(NH4)2SO4电解质溶液中对W片进行阳极氧化处理制备了WO3多孔薄膜, 通过后续热处理温度的控制, 制备了性能规律性变化的WO3多孔纳米薄膜材料. 用场发射扫描电镜(FE-SEM)、X 射线衍射(XRD)分析等手段考察了热处理温度对氧化钨晶体结构和形貌影响的规律, 在450 °C以下的煅烧温度下, 薄膜保持50-100 nm孔径; 通过对光电化学性质、光催化降解甲基橙动力学行为的研究, 考察了不同热处理温度对WO3多孔薄膜光电转换性能影响的规律. 研究表明, 450 °C煅烧处理后的WO3薄膜在500 W氙灯光源照射及1.2 V偏压下, 光电流密度达到5.11 mA·cm-2; 340 及400 nm单色光辐射下光电转换效率(IPCE)值分别达到87.4%及22.1%. 电化学交流阻抗谱显示, 450 °C煅烧处理后的WO3薄膜表现出最佳的导电率及最小的界面电荷转移电阻. 实验结果证明, 高结晶度的多孔结构是WO3薄膜具有高光电转换效率的主要因素, 控制热处理温度是实现薄膜具有高孔隙率、完整结晶度、低电阻的重要手段.

关键词: 三氧化钨多孔薄膜, 光电化学性质, 光降解, 光电转换效率

Abstract: Visible-light-responsive WO3 porous films were synthesized via step-voltage anodization in NH4F/(NH4)2SO4 solution and calcined at various temperatures. The crystalline phase and surface morphology were characterized using X-ray diffraction (XRD) and field emission scanning electron microscopy (FE-SEM). The as-anodized nanoporous films converted to a monoclinic phase with preferential orientation in the (020) planes, and the pore diameters of the films calcined below 450 °C were estimated to be in the region of 50-100 nm. The photocatalytic activity was evaluated via photodegradation of methyl orange. The film calcined at 450 °C showed the highest photocatalytic activity. Photoelectrochemical measurements showed that the incident photon-to-current conversion efficiency (IPCE) values of the film calcined at 450 ° C were 87.4% at 340 nm and 22.1% at 400 nm. Under visible light (λ ≥400 nm), the photocurrent density in 0.5 mol·L-1 H2SO4 solution at 1.2 V (vs Ag/AgCl (KCl saturated)) was 5.11 mA·cm-2. Electrochemical impedance spectroscopy (EIS) measurements showed that the film calcined at 450 °C exhibited the smallest interface charge transfer resistance and optimal electroconductivity. Perfect crystallinity, high porosity and low resistance can therefore be obtained by controlling the calcination temperature. A large surface area and a porous structure are important factors in affecting photocatalytic activity.

Key words: Tungsten oxide porous film, Photoelectrochemical property, Photodegradation, Incident photon-to-current conversion efficiency

MSC2000: 

  • O646