One-pot inorganic route to highly stable water-dispersible Ag2S quantum dots / Kozhevnikova Natalia S.,Vorokh Andrei S.,Shalaeva Elizaveta V.,Baklanova Inna V.,Tyutyunnik Alexander P.,Zubkov Vladimir G.,Yushkov Anton A.,Kolosov Vladimir Yu. // JOURNAL OF ALLOYS AND COMPOUNDS. - 2017. - V. 712, l. . - P. 418-424.

ISSN/EISSN:

0925-8388 / 1873-4669

Type:

Article

Abstract:

Direct aqueous synthesis of Ag2S QDs is a challenge because hydrophobic Ag2S QDs tend to aggregate to form large polycrystals. In this article, the low temperature one-pot route for obtaining highly stable aqueous colloid solutions of Ag2S QDs, using NH3 molecules as monodentate ligands, is reported. Ionic forms of all the species in solution including free ligand, free and complex silver ions, and free sulfide ions at any given experimental pH were calculated. The obtained speciation diagrams were necessary to determine synthetic parameters such as concentration ratios {[}Ag+]/{[}HS-] and INH3]/{[}Ag+], and pH. The comprehensive investigation of Ag2S QDs' colloid solutions was carried out by high-resolution transmission electron microscopy (HR-TEM) and scanning transmission electron microscopy (STEM), UV-vis-NIR spectroscopy, dynamic light scattering. The Ag2S QDs possessed monoclinic (acanthite) crystalline structure with an average size about 33 nm. Estimations of hydrodynamic diameter and degree of double layer charge in colloid solutions, i.e. the zeta-potential measurements, proved high stability of colloidal system of Ag2S QDs on the order of several months under ambient conditions. Combination of both electrostatic and steric stabilization mechanisms kept Ag2S QDs uniformly dispersed in aqueous medium, with NH3 molecules playing a crucial role in avoiding aggregation of as-prepared Ag2S QDs. Colloid Ag2S QDs exhibited NIR emission at 1280 nm under 808 nm excitation. (C) 2017 Elsevier B.V. All rights reserved.

Author keywords:

Water-dispersible Ag2S; Colloid solutions; Inorganic synthesis NEAR-INFRARED REGION; WINDOW; NANOCRYSTALS; LUMINESCENCE; FLUORESCENCE; BRIGHT; RANGE; CELLS

DOI:

10.1016/j.jallcom.2017.04.112

Web of Science ID:

ISI:000401881000053

Соавторы в МНС:

Другие поля

Поле	Значение
Month	JUL 25
Publisher	ELSEVIER SCIENCE SA
Address	PO BOX 564, 1001 LAUSANNE, SWITZERLAND
Language	English
EISSN	1873-4669
Keywords-Plus	NEAR-INFRARED REGION; WINDOW; NANOCRYSTALS; LUMINESCENCE; FLUORESCENCE; BRIGHT; RANGE; CELLS
Research-Areas	Chemistry; Materials Science; Metallurgy \& Metallurgical Engineering
Web-of-Science-Categories	Chemistry, Physical; Materials Science, Multidisciplinary; Metallurgy \& Metallurgical Engineering
Author-Email	kozhevnikova@ihim.uran.ru
Number-of-Cited-References	29
Usage-Count-Last-180-days	36
Usage-Count-Since-2013	36
Journal-ISO	J. Alloy. Compd.
Doc-Delivery-Number	EV6LN