Photodeposition of CdS Quantum Dots on TiO2: Preparation, Characterization, and Reaction Mechanism

被引:82
作者
Fujii, Masashi [1 ]
Nagasuna, Kazuki [1 ]
Fujishima, Musashi [1 ]
Akita, Tomoki [2 ]
Tada, Hiroaki [1 ]
机构
[1] Kinki Univ, Sch Sci & Engn, Dept Appl Chem, Osaka 5778502, Japan
[2] Natl Inst Adv Ind Sci & Technol, Osaka 5638577, Japan
关键词
TITANIUM-DIOXIDE; REDUCTION; DEPOSITION; EFFICIENCY; PARTICLES;
D O I
10.1021/jp9056626
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
Ultraviolet light irradiation (lambda(ex) > 300 nm) to a mixed ethanol solution of cadmium perchlorate and elemental sulfur (S-8) under deaerated conditions has led to deposition of CdS quantum dots on the surfaces of TiO2 particles and films (CdS/TiO2). High-resolution transmission electron rnicroscopy (HRTEM) confirmed that the hexagonal CdS crystals are in good contact with TiO2. The loading amount and band gap of CdS can be controlled by irradiation time. Photoelectrochemical measurements using cyclic voltammetry and photochronopotentiometry indicated the photodeposition of CdS on TiO2 preferentially proceeds via an atomic route (Cd-0 + S -> CdS), whereas that on An nanoparticle-loaded TiO2 (Au/TiO2) follows an ionic route (Cd2+ + S2- -> CdS). This difference was revealed to result from the predominant adsorption of Cd2+ over S-8 on TiO2 (adsorbent-selective adsorption) in the former system and the selective adsorption Of S-8 and Cd2+ ions on Au and TiO2, respectively, (site-selective adsorption) in the latter system.
引用
收藏
页码:16711 / 16716
页数:6
相关论文
共 29 条
[2]   Photoinduced reactivity of titanium dioxide [J].
Carp, O ;
Huisman, CL ;
Reller, A .
PROGRESS IN SOLID STATE CHEMISTRY, 2004, 32 (1-2) :33-177
[3]   Underpotential photocatalytic deposition: A new preparative route to composite semiconductors [J].
Chenthamarakshan, CR ;
Ming, Y ;
Rajeshwar, K .
CHEMISTRY OF MATERIALS, 2000, 12 (12) :3538-+
[4]   Quantum Dot Solar Cells. Semiconductor Nanocrystals as Light Harvesters [J].
Kamat, Prashant V. .
JOURNAL OF PHYSICAL CHEMISTRY C, 2008, 112 (48) :18737-18753
[5]   DISCRETE EXCITONIC TRANSITIONS IN QUANTUM-SIZED CDS PARTICLES [J].
KATSIKAS, L ;
EYCHMULLER, A ;
GIERSIG, M ;
WELLER, H .
CHEMICAL PHYSICS LETTERS, 1990, 172 (3-4) :201-204
[6]   Ultrafast photosynthetic reduction of elemental sulfur by Au nanoparticle-loaded TiO2 [J].
Kiyonaga, Tomokazu ;
Mitsui, Tomohiro ;
Torikoshi, Motofumi ;
Takekawa, Manabu ;
Soejima, Tetsuro ;
Tada, Hiroaki .
JOURNAL OF PHYSICAL CHEMISTRY B, 2006, 110 (22) :10771-10778
[7]   HETEROGENEOUS PHOTOCATALYTIC PREPARATION OF SUPPORTED CATALYSTS - PHOTODEPOSITION OF PLATINUM ON TIO2 POWDER AND OTHER SUBSTRATES [J].
KRAEUTLER, B ;
BARD, AJ .
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY, 1978, 100 (13) :4317-4318
[8]   PULSE RADIOLYSIS AND POLAROGRAPHY - HALF-WAVE POTENTIALS FOR OXIDATION AND REDUCTION OF SHORT-LIVED ORGANIC RADICALS ON HG ELECTRODE [J].
LILIE, J ;
BECK, G ;
HENGLEIN, A .
BERICHTE DER BUNSEN-GESELLSCHAFT FUR PHYSIKALISCHE CHEMIE, 1971, 75 (05) :458-&
[9]   PHOTOCATALYTIC REDUCTION AND IMMOBILIZATION OF HEXAVALENT CHROMIUM AT TITANIUM-DIOXIDE IN AQUEOUS BASIC-MEDIA [J].
LIN, WY ;
WEI, C ;
RAJESHWAR, K .
JOURNAL OF THE ELECTROCHEMICAL SOCIETY, 1993, 140 (09) :2477-2482
[10]   CALCULATION OF THE BAND-GAP FOR SMALL CDS AND ZNS CRYSTALLITES [J].
LIPPENS, PE ;
LANNOO, M .
PHYSICAL REVIEW B, 1989, 39 (15) :10935-10942