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Acta Chimica Sinica ›› 2006, Vol. 64 ›› Issue (17): 1761-1764. Next Articles
Original Articles
付姚; 曹望和*; 田莹
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FU Yao; CAO Wang-He*; TIAN Ying
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The anatase-type nanocrystalline TiO2 film electrode with characteristics of uniformity and transparency was prepared by sol-gel method. The transport properties of photo-generated carriers in the prepared electrode contacted with aqueous electrolyte were studied by transient photocurrent spectra. The results show that there exist two kinds of surface states on the TiO2/electrolyte interface. One (shallow surface state), created by chemisorbed oxygen molecule, locates in the range of 0.5 eV which is just below the conduction band, and its electron-capturing onset potential is about -0.4 V. The other (deep surface state), formed by lattice oxygen ion, locates near the middle of the band gap, and plays a role as a center for electron-hole surface recombination. The electron-capturing efficiencies of these two surface states are related to the pH value of the electrolyte and the electrode potential (U). A potential higher than 0.4 V can remarkably increase the transfer rate of photo-generated carriers and make a downward shift of the TiO2 film’s Fermi level (EFn), which could effectively suppress the surface-capturing process of photo-generated electrons, and improve the intensity and stability of the anode photocurrent.
Key words: inorganic nonmetallic material, transport property of photogenerated carrier, photoelectric property, nanocrystalline TiO2 film electrode
FU Yao; CAO Wang-He*; TIAN Ying. Study on Transport Properties of Photo-generated Carriers in Nanocrystalline TiO2 Film Electrode[J]. Acta Chimica Sinica, 2006, 64(17): 1761-1764.
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