Effect of size and shape of nanocrystalline TiO2 on photogenerated charges.: An EPR study

被引：106

作者：

Dimitrijevic, Nada M. ^{[1
]}

Saponjic, Zoran V. ^{[1
]}

Rabatic, Bryan M. ^{[1
]}

Poluektov, Oleg G. ^{[1
]}

Rajh, Tijana ^{[1
]}

机构：

[1] Argonne Natl Lab, Ctr Nanoscale Mat, Chem Div, Argonne, IL 60439 USA

来源：

JOURNAL OF PHYSICAL CHEMISTRY C | 2007年 / 111卷 / 40期

关键词：

D O I：

10.1021/jp0756395

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 continuous wave and pulsed electron paramagnetic resonance study of the photogenerated charges in differently shaped anatase nano-objects dispersed in aqueous solution is presented. Excitation of TiO2 nano-objects (spherical, faceted, rods, and bricks) at temperatures <80 K results in the formation of paramagnetic species that correspond to electrons trapped at lattice titanium within the bulk, (Ti3+)(latt), and holes trapped at oxygen atoms at the surface of nano-objects, as confirmed by the electron spin echo envelope modulation technique. The distortion of the Ti-O bond, which is a result of reconstruction of the surface of nano-objects, causes variations in g-tensor values and spin relaxation processes of lattice-trapped electrons. On the other hand, size and shape do not affect spin-spin relaxation times of surface-trapped holes as it was found that relaxation is determined by dipolar coupling with H-1 nuclei from surrounding water.

引用

页码：14597 / 14601

页数：5

共 32 条

[21] PHOTOLUMINESCENCE AND ELECTRO-LUMINESCENCE SPECTRA FROM AN N-TIO2 SEMICONDUCTOR ELECTRODE AS RELATED TO THE INTERMEDIATES OF THE PHOTO-OXIDATION REACTION OF WATER [J].

NAKATO, Y ;

TSUMURA, A ;

TSUBOMURA, H .

JOURNAL OF PHYSICAL CHEMISTRY, 1983, 87 (13) :2402-2405

[22] Calculation of activation energies for transport and recombination in mesoporous TiO2/dye/electrolyte films -: Taking into account surface charge shifts with temperature [J].

O'Regan, BC ;

Durrant, JR .

JOURNAL OF PHYSICAL CHEMISTRY B, 2006, 110 (17) :8544-8547

[23] Spatially confined corner defects induce chemical functionality of TiO2 nanorods [J].

Rabatic, BM ;

Dimitrijevic, NM ;

Cook, RE ;

Saponjic, ZV ;

Rajh, T .

ADVANCED MATERIALS, 2006, 18 (08) :1033-+

[24] Surface modification of small particle TiO2 colloids with cysteine for enhanced photochemical reduction: An EPR study [J].

Rajh, T ;

Ostafin, AE ;

Micic, OI ;

Tiede, DM ;

Thurnauer, MC .

JOURNAL OF PHYSICAL CHEMISTRY, 1996, 100 (11) :4538-4545

[25] Surface restructuring of nanoparticles: An efficient route for ligand-metal oxide crosstalk [J].

Rajh, T ;

Chen, LX ;

Lukas, K ;

Liu, T ;

Thurnauer, MC ;

Tiede, DM .

JOURNAL OF PHYSICAL CHEMISTRY B, 2002, 106 (41) :10543-10552

[26] Improving optical and charge separation properties of nanocrystalline TiO2 by surface modification with vitamin C [J].

Rajh, T ;

Nedeljkovic, JM ;

Chen, LX ;

Poluektov, O ;

Thurnauer, MC .

JOURNAL OF PHYSICAL CHEMISTRY B, 1999, 103 (18) :3515-3519

[27] Charge transfer across the nanocrystalline-DNA interface: Probing DNA recognition [J].

Rajh, T ;

Saponjic, Z ;

Liu, JQ ;

Dimitrijevic, NM ;

Scherer, NF ;

Vega-Arroyo, M ;

Zapol, P ;

Curtiss, LA ;

Thurnauer, MC .

NANO LETTERS, 2004, 4 (06) :1017-1023

[28] Shaping nanometer-scale architecture through surface chemistry [J].

Saponjic, ZV ;

Dimitrijevic, NM ;

Tiede, DM ;

Goshe, AJ ;

Zuo, XB ;

Chen, LX ;

Barnard, AS ;

Zapol, P ;

Curtiss, L ;

Rajh, T .

ADVANCED MATERIALS, 2005, 17 (08) :965-+

[29]

Standley K. J., 1969, ELECT SPIN RELAXATIO

[30]

STONEHAM AM, 1965, SOLID STATE COMMUN, V138, pA1500

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