Preparation method of small-layer-number MoSe2 nanosheet/nitrogen and phosphorus co-doped graphene composite nanomaterial

Abstract

The invention discloses a preparation method of a small-layer-number MoSe2 nanosheet / nitrogen and phosphorus co-doped graphene composite nanomaterial. The method includes the steps that S1, graphene oxide is dispersed into water, quaternary phosphonium salt is added and evenly mixed, and then molybdate, selenium powder and hydrazine are sequentially added and evenly mixed; S2, a mixed dispersion system obtained in the S1 is subjected to hydrothermal reaction and cooled, a solid product is collected through centrifugation, washed, dried and subjected to heat treatment under nitrogen or argon atmosphere, and then the small-layer-number MoSe2 nanosheet / nitrogen and phosphorus co-doped graphene composite nanomaterial can be obtained through preparation. With graphene oxide, molybdate, selenium powder and hydrazine as raw materials, the small-layer-number MoSe2 nanosheet / nitrogen and phosphorus co-doped graphene composite nanomaterial is successfully prepared through the hydrothermal method assisted by quaternary phosphonium salt and the subsequent heat treatment method. The method has the advantages of being simple and convenient to implement, and the industrialized application range of the method can be easily widened.

Description

technical field [0001] The invention belongs to the technical field of preparation of inorganic micro-nano materials, in particular, relates to a kind of MoSe with few layers 2 A preparation method of nanosheet / nitrogen and phosphorus co-doped graphene composite nanomaterial. Background technique [0002] Two-dimensional nanomaterials have many excellent properties due to their unique morphology, and their research has aroused great interest. Graphene is the most typical two-dimensional nanomaterial. Its unique two-dimensional nanosheet structure makes it have many unique physical, chemical and mechanical properties and has important scientific research significance and broad technical application prospects. Graphene has extremely high specific surface area, high electrical and thermal conductivity, high charge mobility and excellent mechanical properties. These excellent characteristics make graphene have great potential in micro-nano electronic devices, energy storage mat...

AI Technical Summary

Problems solved by technology

[0003] Currently preparing MoSe 2 The technology of nanosheets and their composite materials with graphene is generally prepared by using sodium molybdate and selenium powder or selenium dioxide, hydrazine and graphene oxide or graphene as reactants through hydrothermal reaction or vapor deposition technology. However, there are the following deficiencies: First, in the preparation process, how to effectively regulate the MoSe 2 The number of layers of nanosheets and the number of active edges can be effectively increased; the second is to use quaternary phosphonium salts as both a phosphorus source and to regulate MoSe 2 The number of layers, using hydrothermal and heat treatment technology to prepare MoSe with few layers 2 The method of nanosheet / nitrogen and phosphorus co-doped graphene composite nanomaterials and its application as an electrocatalyst in the electrocatalytic hydrogen evolution reaction have not been reported yet.

For the liquid-phase synthesis method, the water solubility of inorganic phosphate is very good, but because the phosphate or hydrogen phosphate itself is negatively charged, it is difficult to adsorb on the graphene oxide with the same load; and the phosphorus in the phosphate - The bond energy of the oxygen bond is relatively large, and it needs to be broken at high temperature, so the doping degree of phosphorus in the phosphorus-doped graphene prepared by using phosphate or hydrogen phosphate as the phosphorus source is not high

Although organic phosphine such as butyl phosphate and triphenylphosphine are not strong in phosphorus-carbon bonds and are easy to break, because organic phosphorus has poor solubility in water and does not have a positive charge, it cannot be combined with negatively charged ones in aqueous solution. Graphene oxide and molybdate or thiomolybdate produce strong electrostatic interaction, resulting in poor composite material or uneven doping

If the reaction is carried out in an organic solvent, and the solubility of molybdate or thiomolybdate in organic solvent is relatively poor, it will not only be difficult to react, but also produce more organic waste and pollute the environment

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