Method of preparing superfine monolayer transition metal compound quantum dot solution

Abstract

The invention discloses a method of preparing a superfine monolayer transition metal compound quantum dot solution. The method comprises the following steps: (a) mixing a n-butyllithium solution with a transition metal compound solution to react to obtain an intermediate product, wherein the transition metal compound has the formula of MX2, M is a transition metal element and X is S or Se or Te; (b) drying the intermediate product to obtain a dried product; (c) adding deionized water into the dried product for ultrasonic reaction to obtain an ultrasonic product; (d) centrifuging the ultrasonic product obtained by the step c to obtain the supernate which is the superfine monolayer transition metal compound quantum dot solution. The solution prepared by the invention is uniform in distribution of particle size, has a monolayer structure, and is simple in process equipment, short in reaction period, good in repeatability and easy for industrial production.

Description

technical field [0001] The invention relates to the field of preparation of quantum dots, in particular to a method for preparing an ultra-small single-layer transition metal compound quantum dot solution. Background technique [0002] Transition metal compounds refer to compounds formed by transition group metals and oxygen group nonmetal elements, such as MoS 2 、MoSe 2 、MoTe 2 、WS 2 、WSe 2 , WTe 2 , NbS, etc., which have the same layered structure as graphene, and the layers are combined with weak van der Waals forces. When changing from a bulk to a single-layer 2D structure, there will be a change from indirect band gap to The sudden change of the direct bandgap, the single-layer transition metal compound has a high on-off ratio up to 1X10 8 , electron mobility 200 cm2*V -1 *s -1 , is a very good solid lubricant and catalyst, and the monolayer structure greatly improves its fluorescence effect. The thickness band gap of the transition metal compound compou...

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Problems solved by technology

[0003] Currently, only a few methods have prepared smaller MoS 2 Quantum dots, such as Václav Stengl et al. using ultrasonic treatment, refluxing MoS at the boiling point of organic solvents 2 Obtained MoS 2 Quantum dots are around 40 nm, but the resulting MoS 2 The thickness and size distribution of is a broad Gaussian distribution; Hongtao Yu et al. used molybdenum hexacarbonyl and S powder to synthesize MoS with good dispersion less than 5nm in trioctylphosphine and octadecene solution. 2 Quantum dots, MoS 2 The size of quantum dots can be controlled by the reaction temperature, but the MoS prepared by this synthesis method 2 The crystallinity of quantum dots is not good, and trioctylphosphorus solvent is easy to decompose when heated, so the compound is doped with P element; Zhuangzhi Wu et al. used Wo 3 Mixed with S powder and ball milled to synthesize sheet-like WS after heat treatment in a high-temperature furnace 2 , whose size is around 100 nm, the WS prepared by this method 2 Mixed with more unreacted Wo 3 ; J. J. Hu et al. used laser bombardment of WS placed in aqueous solution 2 target to prepare WS 2 Quantum dots, this method can prepare spherical WS with an average particle size of 20 nm 2 Quantum dots, but the product prepared by this method is mixed with lamellar WS 2 Nanosheets

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