Method for preparing two-dimensional black phosphorus crystals from white phosphorus as raw material

Abstract

The invention discloses a method for preparing two-dimensional black phosphorus crystals from white phosphorus as a raw material. The method comprises the steps that firstly, in an inert gas atmosphere, the white phosphorus, metallic elemental tin and a mineralizer tin tetraiodide are weighed and placed on the bottom of a single-head sealed quartz tube, and the raw materials for reaction are sealed into the vacuum quartz tube by using a vacuum tube sealing system; the quartz tube is heated by optimized programmed heating and freezing, and after a reaction is finished, the large-sized high-purity high-quality two-dimensional black phosphorus crystals are prepared finally. In the method, the white phosphorus is used as the raw material, the metallic elemental tin and the mineralizer tin tetraiodide are added, and the two-dimensional black phosphorus crystals are prepared by heating under the vacuum condition. Compared with a traditional preparation method that red phosphorus serves as araw material, the method can significantly reduce reaction temperature and shorten reaction time in the synthesizing process, and the energy consumption is reduced. For synthesizing the high-quality lblack phosphorus crystals, compared with the raw material high-purity red phosphorus, the cost of the raw material white phosphorus is lower, the synthesized black phosphorus crystals are higher in size and higher in purity, and industrial scaled preparation of the black phosphorus crystals is more easily achieved.

Description

technical field [0001] The invention belongs to the technical field of two-dimensional materials, and in particular relates to a method for preparing two-dimensional black phosphorus crystals using white phosphorus as a raw material. Background technique [0002] As a new member of the family of two-dimensional materials, black phosphorus is the most stable allotrope of phosphorus. It has a natural wrinkled structure similar to but different from the graphene sheet structure. This unique wrinkled structure endows black phosphorus with many unique physical and chemical properties. For example, black phosphorus has a semiconductor gap that graphene does not have and it is a direct band gap, that is, the bottom of the electronic conductive energy band (conduction band) and the top of the non-conductive energy band (valence band) are at the same position, realizing from non-conductive to conductive, electrons only Energy needs to be absorbed, no momentum needs to be changed. T...

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Problems solved by technology

Patents CN105133009A, CN105603517A and CN106087050A also announced improvements to this method, but they still have problems such as high requirements for reaction devices (the first two require dual temperature zone temperature control) and high reaction temperatures (the minimum temperature is above 500 °C) and other problems

[0005] In short, the current methods for preparing black phosphorus crystals are basically limited to the above-mentioned categories, and all of them have problems such as harsh reaction conditions, high reaction temperature, long reaction time, complicated reaction equipment, high cost of raw materials, crystal A series of problems such as small growth size and low crystal purity

However, there are few reports on the preparation of black phosphorus crystals by chemical vapor transport method using white phosphorus as raw material.

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