Synthesis and photoluminescence properties of aqueous CdWO4 quantum dots with WO66− luminescence center

Autor: Wei Zhou, Yongxian Wang, Zheng Li, Haiying Zhang, Hua Shen, Sefei Yang, Guoxin Zhang, Lan Zhang
Rok vydání: 2010
Předmět:
Zdroj: Applied Surface Science. 257:302-305
ISSN: 0169-4332
DOI: 10.1016/j.apsusc.2010.07.001
Popis: Aqueous CdWO 4 QDs were synthesized by the reaction of CdCl 2 and Na 2 WO 4 in the presence of mercaptoacetic acid (TGA) as capping reagent. The crystal morphology, particle size and its distribution of as-prepared products were characterized by transmission electron microscopy (TEM, SAED) atomic force microscopy (AFM), high-resolution transmission electron microscopy (HRTEM), and photon correlation spectroscopy (PCS), respectively. Qualitative assays for functional groups on the QDs’ surface were measured by fourier transform infrared spectroscopy (FTIR). Photoluminescence properties of QDs were studied by photoluminescence spectroscopy (PL). The results showed that the single QD with diameter of about 8 ± 2 nm was single-crystal. The particle size distribution of QDs was normal. Infrared absorption bands of carboxylic group on the surface of CdWO 4 QDs were observed around 1610–1550 cm −1 (nonsymmetrical vibration of –COO − ) and 1400 cm −1 (symmetric vibration of C–O). With reaction-time going, PL peak position shifted from 498 to 549 nm and intensity of PL increased first and then decreased. PL peak position of QDs was blue-shift compared with 570 nm WO 6 6− luminescence center of bulk CdWO 4 .
Databáze: OpenAIRE
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