ChemInform Abstract: Ultra‐Large Scale Synthesis of High Electrochemical Performance SnO₂ Quantum Dots within 5 min at Room Temperature Following a Growth Self‐Termination Mechanism.

Abstract

SnO 2 quantum dots of 1.2 nm particle size are prepared at an ultra-large scale (at least 50 g) by grinding a solid mixture of SnCl2·2H2O, (NH4)2S2O8, and morpholine in a mortar at 25 C. The formation of SnO 2 is initiated by the reaction between Sn ions and OH groups generated by hydrolysis of morpholine with H 2O released from SnCl 2·2H2O. Due to the rapid consumption of the latter during the hydrolysis reaction, the growth process of particles is self-terminated immediately after nucleation. The material presents high electrochemical performance due to the effective faradaic reaction and the alternative trapping of electrons and holes at SnO2 surface defects. -(CUI*, H.; XUE, J.; REN, W.; WANG, M.; J. Alloys Compd. 645 (2015) 11-16, http://dx.doi.org/10.1016/j.jallcom.2015.05.015 ; Coll. Chem. Chem. Eng., Yantai Univ., Yantai 264005, Peop. Rep. China; Eng.) -J. Schramke 33-020

Highlights on advances in SnO2 quantum dots: insights into synthesis strategies, modifications and applications

“…In addition to those above mentioned commonly used methods to prepare SnO 2 QDs, there are some other ones, such as sonication [65], solution combustion [66], interfacial reaction [67], liquid phase refluxing [68], grinding [69]. Lee et al [67] have fabricated a serials of SnO 2 QDs with average diameters from 2 to 2.7 nm, energy band gaps between 5.70 and 4.39 eV through the interfacial reaction of Sn 4+ and OH − in interface between water and chloroform.…”

“…Kida et al [68] have prepared monodispersed SnO 2 QDs with size of 3.5 nm by refluxing tin (IV) acetylacetonate in dibenzyl ether at 280°C under the aid of oleylamine and oleic acid. Cui et al [69] have produced SnO 2 QDs with particle size of about 1.2 nm at an ultra large scale by grinding the solid mixture of SnCl 2 •H 2 O, ammonium persulphate and morpholine in a mortar at room temperature. Although these methods have the uniquely attractive advantages of facility, such as large scale, room temperature, and surfactant-free, the explorations of these approaches have just begun and thus will be a subject of future studies.…”

“…Another strategy is to combine ultrasmall SnO 2 with other nanomaterials, which can buffer the volume expansion or enhance the electronic conductivity of the electrodes. The currently used nanomaterials in this aspect include various carbonaceous materials, such as graphene nanosheets [66,[69][70][71][72][73]128], carbon nanotubes [75][76][77], amorphous carbon [107,109,129]; several kind of metal oxide, such as TiO 2 [114,115], and Li 4 Ti 5 O 12 [86]; conducting high polymer [122] and amorphous silica [120]. Song et al [86] have loaded the SnO 2 QDs with particle size below 5 nm onto graphene oxide (GO) to form a SnO 2 QDs/GO hybrid as shown in Figure 12(a,b).…”