Se-doped less-layer WS2 nano-sheet/nitrogen and phosphorus co-doped graphene composite nanometer material preparation method

Abstract

The present invention discloses a Se-doped less-layer WS2 nano-sheet / nitrogen and phosphorus co-doped graphene composite nanometer material preparation method, which comprises: S1, dispersing graphene oxide in water, adding a quaternary phosphonium salt, uniformly mixing, sequentially adding ammonium thiotungstate, selenium powder and hydrazine, and uniformly mixing; and S2, carrying out a hydrothermal reaction on the mixed dispersion system obtained in the step S1, cooling, collecting the solid product through centrifugation, washing, drying, and carrying out a heat treatment in a nitrogen or argon atmosphere so as to prepare the Se-doped less-layer WS2 nano-sheet / nitrogen and phosphorus co-doped graphene composite nanometer material. According to the present invention, graphene oxide, ammonium thiotungstate, selenium powder and hydrazine are adopted as the raw materials, and the quaternary phosphonium salt assisted hydrothermal method and the subsequent heat treatment method are used to successfully prepare the Se-doped less-layer WS2 nano-sheet / nitrogen and phosphorus co-doped graphene composite nanometer material; and the method has advantages of simpleness, convenience, and easy industrial application expanding.

Description

technical field [0001] The invention belongs to the technical field of inorganic micro-nano materials, and in particular relates to a Se-doped WS with few layers 2 A preparation method of nanosheet / nitrogen and phosphorus co-doped graphene composite nanomaterial. Background technique [0002] The combustion product of hydrogen is water, which will not cause any pollution to the environment, and it can be used as clean energy in all aspects of life. Therefore, in today's increasingly serious energy and environmental crisis, hydrogen energy has been highly valued by everyone. The most abundant source of hydrogen is water, and it is imminent to find efficient catalysts for splitting water to produce hydrogen. At present, the most efficient catalysts for electrocatalytic hydrogen production are platinum group metals, but they are severely limited by their natural scarcity and high cost. Therefore, it is urgent to develop new economical, stable, environmentally friendly and eff...

AI Technical Summary

Problems solved by technology

The prior art uses ammonium thiotungstate, hydrazine and graphene oxide or graphene as reactants, and prepares it through hydrothermal reaction or vapor deposition technology, but there are the following deficiencies: First, no consideration is given to how to effectively Regulation WS 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 WS 2 Number of layers, using hydrothermal and heat treatment techniques to prepare Se-doped WS 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 thiotungstate 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 thiotungstate in an 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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