学术探索
学术期刊
新闻热点
数据分析
智能评审

Charge trapping and photoadsorption of O2 on dehydroxylated TiO2 nanocrystals -: An electron paramagnetic resonance study

被引：119
作者：
Berger, T
Sterrer, M
Diwald, O
Knözinger, E
机构：
[1] Vienna Univ Technol, Inst Mat Chem, A-1210 Vienna, Austria
[2] Max Planck Soc, Fritz Haber Inst, Dept Phys Chem, D-14195 Berlin, Germany
来源：
CHEMPHYSCHEM | 2005年 / 6卷 / 10期
关键词：
charge transfer; EPR spectroscopy; oxygen; TiO2; nanocrystals; UV-induced charge separation;
D O I：
10.1002/cphc.200500161
中图分类号：
O64 [物理化学（理论化学）、化学物理学];
学科分类号：
070304 ; 081704 ;
摘要：
The interaction of photogenerated charges with molecular oxygen was investigated on TiO2 nonocrystals by means of paramagnetic resonance (EPR) spectroscopy. Compared to photoactivation experiments in Vacuum at p < 10(-6) mbar and T = 740 K, the presence of O-2 enhances the concentration of persistently trapped electron and hole centres-by a factor of ten-due to the formation of adsorbed O-2(-) species. The photoadsorption of oxygen was also tracked quantitatively by pressure measurements, and the number of trapped charges, hole centres and 0,was found to correspond to ten electron-hole pairs per TiO2 nanocrystal. Conversely, in experiments at p < 10(-6) mbar with one trapped electron-hole pair per particle, charge separation is not persistent and completely reversible with respect to temperature. Heating to 298 K causes the total annihilation of photogenerated and trapped charges.
引用
收藏
页码：2104 / 2112
页数：9
相关论文
共 69 条
  • [1] Kinetics of O2 reduction at illuminated TiO2 films
    Ahmed, S
    Fonseca, SM
    Kemp, TJ
    Unwin, PR
    [J]. JOURNAL OF PHYSICAL CHEMISTRY B, 2003, 107 (24) : 5892 - 5900
  • [2] Role of synthesis method and particle size of nanostructured TiO2 on its photoactivity
    Almquist, CB
    Biswas, P
    [J]. JOURNAL OF CATALYSIS, 2002, 212 (02) : 145 - 156
  • [3] Generation of superoxide ions at oxide surfaces
    Anpo, M
    Che, M
    Fubini, B
    Garrone, E
    Giamello, E
    Paganini, MC
    [J]. TOPICS IN CATALYSIS, 1999, 8 (3-4) : 189 - 198
  • [4] An EPR study of thermally and photochemically generated oxygen radicals on hydrated and dehydrated titania surfaces
    Attwood, AL
    Murphy, DM
    Edwards, JL
    Egerton, TA
    Harrison, RW
    [J]. RESEARCH ON CHEMICAL INTERMEDIATES, 2003, 29 (05) : 449 - 465
  • [5] Identification of a surface alkylperoxy radical in the photocatalytic oxidation of acetone/O2 over TiO2
    Attwood, AL
    Edwards, JL
    Rowlands, CC
    Murphy, DM
    [J]. JOURNAL OF PHYSICAL CHEMISTRY A, 2003, 107 (11) : 1779 - 1782
  • [6] Photocatalytic water treatment: solar energy applications
    Bahnemann, D
    [J]. SOLAR ENERGY, 2004, 77 (05) : 445 - 459
  • [7] FLASH-PHOTOLYSIS OBSERVATION OF THE ABSORPTION-SPECTRA OF TRAPPED POSITIVE HOLES AND ELECTRONS IN COLLOIDAL TIO2
    BAHNEMANN, D
    HENGLEIN, A
    LILIE, J
    SPANHEL, L
    [J]. JOURNAL OF PHYSICAL CHEMISTRY, 1984, 88 (04) : 709 - 711
  • [8] Structure, morphology and surface properties of nanostructured ZrO2 particles
    Benfer, S
    Knözinger, E
    [J]. JOURNAL OF MATERIALS CHEMISTRY, 1999, 9 (05) : 1203 - 1209
  • [9] Light-induced charge separation in anatase TiO2 particles
    Berger, T
    Sterrer, M
    Diwald, O
    Knözinger, E
    Panayotov, D
    Thompson, TL
    Yates, JT
    [J]. JOURNAL OF PHYSICAL CHEMISTRY B, 2005, 109 (13) : 6061 - 6068
  • [10] PHOTOADSORPTION AND PHOTOCATALYSIS AT RUTILE SURFACES .1. PHOTOADSORPTION OF OXYGEN
    BICKLEY, RI
    STONE, FS
    [J]. JOURNAL OF CATALYSIS, 1973, 31 (03) : 389 - 397
1234567