Acta Phys. -Chim. Sin. ›› 2012, Vol. 28 ›› Issue (10): 2276-2284.doi: 10.3866/PKU.WHXB201209101

• ELECTROCHEMISTRY AND NEW ENERGY • Previous Articles     Next Articles

Preparation and Photoelectrocatalytic Water Oxidation Properties of FeO(OH)-TiO2/CoPi Composite Photoanodes

JIN Tao, XU Di, DIAO Peng, XIANG Min   

  1. Key Laboratory of Aerospace Science and Engineering, Department of Materials Science and Engineering School, Beihang University, Beijing 100191, P. R. China
  • Received:2012-07-04 Revised:2012-09-10 Published:2012-09-26
  • Supported by:

    The project was supported by the National Natural Science Foundation of China (20973020, 21173016), Doctoral Fund of Ministry of Education of China (20101102110002), and Program for New Century Excellent Talents in University, China (NCET-08-0034).

Abstract:

TiO2 nanocrystals were synthesized using a sol-gel method, and then the impregnation technique was used to modify the surface of the TiO2 nanocrystals with FeO(OH). The optimal concentration of Fe3+ for the modification of the TiO2 nanocrystals was determined by UV-Vis spectroscopy. A cobalt-phosphate (CoPi) water oxidation catalyst was electrochemically deposited onto the FeO(OH)- TiO2 photoanodes. The resulting FeO(OH)-TiO2/CoPi composite photoanodes were systematically characterized by transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HRTEM), X-ray diffraction (XRD), and scanning electron microscopy (SEM), and the photoelectrochemical water oxidation properties of the FeO(OH)-TiO2/CoPi composite photoanodes were investigated in neutral conditions by electrochemical and photoelectrochemical methods. The results indicated that the TiO2 particles were pure anatase nanocrystals, and the FeO(OH) phase on the TiO2 surfaces was goethite. The optimal light absorption properties of the FeO(OH)-TiO2 photoanodes were achieved when the photoanodes were prepared in the precursor solution with a Fe3+:TiO2 mass ratio of 0.05%. The overpotential for oxygen evolution on the FeO(OH)-TiO2/CoPi composite photoanodes under illumination decreased significantly compared with that obtained on the CoPi catalyst. The high oxygen evolution activity of the composite photoanodes can be attributed to modification of FeO(OH) on TiO2 nanocrystal surfaces changing the light absorption band from the ultraviolet to the visible region and CoPi inhibited hole-electron recombination through facilitating the photon-induced hole transfer for water oxidation.

Key words: Hydrogen ferric oxide, TiO2 nanocrystal, Cobalt-phosphate catalyst, Photoelectrochemical oxygen evolution, Photon-induced holes

MSC2000: 

  • O644