Acta Phys. -Chim. Sin. ›› 2014, Vol. 30 ›› Issue (6): 1099-1106.doi: 10.3866/PKU.WHXB201404282

• ELECTROCHEMISTRY AND NEW ENERGY • Previous Articles     Next Articles

Effect of HF Treatment on the Photoelectrochemical Properties of a Hematite Thin Film Photoanode for Water Splitting

HU Yu-Xiang, JIANG Chun-Xiang, FANG Liang, ZHENG Fen-Gang, DONG Wen, SU Xiao-Dong, SHEN Ming-Rong   

  1. Jiangsu Key Laboratory of Thin Films and College of Physics, Optoelectronics and Energy, Soochow University, Suzhou 215006, Jiangsu Province, P. R. China
  • Received:2014-03-21 Revised:2014-04-25 Published:2014-05-26
  • Contact: SHEN Ming-Rong
  • Supported by:

    The project was supported by the National Natural Science Foundation of China (91233109) and Project Funded by the Priority Academic Program Development of Jiangsu Higher Education Institutions, China.


The effects of HF treatment on the photoelectrochemical (PEC) properties of sol-gel prepared hematite (α-Fe2O3) thin films were investigated. Pores and interstices between the grains developed on the film surface as the HF etching time increased. The photocurrent density of the α-Fe2O3 photoanode decreased within the first 5 min of etching, and then increased quickly as the etching time increased. At longer time than 15 min the photocurrent density deteriorated. Re-annealing the etched samples significantly enhanced the photocurrent density. Based on electrochemical impedance spectroscopy, Raman and X-ray photoelectron spectroscopies, we propose that two factors contribute to photocurrent density reversely: the porosity and the lowered crystallinity of the α-Fe2O3 surface because of HF treatment.Aschematic model was compiled to explain the enhanced PEC activities of the etched plus re-annealed α-Fe2O3 photoanode. The PEC and water splitting measurements showed that the etched plus re-annealed photoanode is more stable than the as-prepared one.

Key words: α-Fe2O3 photoelectrode, Surface treatment, Photoelectrochemical property


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