CN111484070A

CN111484070A - Synthetic preparation method of semi-metal phase tin disulfide

Info

Publication number: CN111484070A
Application number: CN202010315530.0A
Authority: CN
Inventors: 许杰; 李超
Original assignee: Tianjin University of Technology
Current assignee: Tianjin University of Technology
Priority date: 2020-04-21
Filing date: 2020-04-21
Publication date: 2020-08-04

Abstract

The invention provides a synthesis preparation method of semi-metal phase tin disulfide, which comprises the following steps of synthesizing SnS of a semiconductor phase by a hydrothermal method₂As a precursor, under the assistance of hydrogen, the SnS of the semi-metal phase is directly obtained by low-temperature calcination₂Hydrogen in the semiconductor phase SnS₂SnS transformed into a semi-metallic phase by heating₂Plays a key role in the process. The invention successfully synthesizes the SnS of the semi-metallic phase for the first time₂The preparation method is simple, safe and easy to operate, good in economy and considerable in yield, and the obtained novel SnS₂The method can be used for scientific research and various practical applications, provides a new member for the family of two-dimensional transition metal sulfide materials, and has high practical application value.

Description

Synthetic preparation method of semi-metal phase tin disulfide

Technical Field

The invention relates to a nano material, in particular to a synthetic preparation method of a two-dimensional transition metal sulfide.

Background

It is well known that two-dimensional materials have attracted much attention from many scientists due to their unique atomic configuration and band structure. In which two-dimensional transition metal sulfides can be divided into a semiconducting phase (stable phase), a semi-metallic phase (metastable phase) and a metallic phase (metastable phase) depending on the atomic configuration, e.g. MoS₂，WS₂. The metastable phases of these two-dimensional materials are generally obtained by phase transformation of the stable phase by various methods. Interestingly, the metastable nature of these materials has better electron transport capabilities than their stable phase, as well as better physical or chemical properties.SnS, a typical two-dimensional transition metal sulfide₂The stable phase, i.e. the semiconducting phase, has been successfully applied in various fields, and particularly has good catalytic effect in the catalytic field. Theoretically, SnS₂There is also its metastable phase (the semi-metallic phase) and it has been predicted in theory that its metastable phase has a better electron transport capability than the stable phase. However, it has been difficult to synthesize metastable phases, particularly SnS₂Easily converted into SnS or Sn when heated₂S₃To synthesize SnS₂The metastable phase of (a) again increases the difficulty. So far, SnS₂The metastable phase of (a) has not been synthesized. We have no way to further study the SnS of the semi-metallic phase₂The practical application value, the physical and chemical properties and the like. SnS for semi-metallic phase₂The research of (2) also stays in the theoretical research stage.

SnS due to research on semimetallic phase₂Has very important significance in a plurality of fields, but no method can synthesize SnS of the semi-metallic phase so far₂So that an SnS capable of successfully synthesizing a semi-metallic phase was developed₂The method of (2) is particularly important.

Disclosure of Invention

The invention aims to solve the problem that no method can synthesize the semi-metallic phase SnS₂Successfully develops a SnS for synthesizing a semi-metallic phase₂The method also obtains the semi-metallic phase SnS with high purity for the first time₂。

The invention is realized by the following technical scheme.

Semi-metallic phase SnS₂The synthesis preparation method comprises the following steps:

(1) mixing tin chloride pentahydrate, thiourea and deionized water according to the mass ratio of 2.1: 3.0: 70, and magnetically stirring for 20-60 minutes to form a uniform solution; then heating the solution at 180 ℃ for 10-15 hours, washing the product with ethanol or water for 3-5 times, and then drying the product in vacuum at 40-70 ℃ for 2-10 hours to obtain the SnS of the semiconductor phase₂；

(2) SnS of the semiconductor phase obtained in the step (1)₂Placing the mixture in a tubular quartz furnace, introducing hydrogen and argon mixed gas containing 5-20% of hydrogen at the flow rate of 20-50 sccm into the quartz tubular furnace, keeping the flow rate of the gas constant, heating to 200-300 ℃ at the temperature rise rate of 3-8 ℃/min, preserving the heat for 5-8 hours, and naturally cooling to room temperature to obtain semi-metal phase SnS₂。

The heating time in the step (1) is 10 hours, the vacuum drying temperature is 50 ℃, and the vacuum drying time is 8 hours.

And (3) placing the product in the step (2) in a magnetic boat or a product support, and then placing the product in a tubular quartz furnace.

And (3) in the step (2), the hydrogen-argon mixed gas of 10% hydrogen has the hydrogen content of 10% and the purity of the gas is more than 99%. The flow rate of the gas was 30 sccm.

The heating temperature in the step (2) is 200 ℃. The temperature rise rate is 5 ℃/min, and the temperature is kept for 6 hours.

The invention provides a method for preparing semi-metallic phase SnS₂The method is simple. First using a synthetic semiconducting phase SnS₂Or commercial SnS₂As a precursor, introducing hydrogen-argon mixed gas, and calcining at low temperature to obtain the semi-metal phase SnS₂. Before that, SnS due to the semi-metallic phase₂Has not been synthesized all the time, but is a two-dimensional transition metal sulfide which is very important, so that the synthesis of SnS of a semi-metallic phase is urgently needed₂The catalyst is used in various fields, especially in the fields of photoelectric materials and catalysis. During the synthesis, we found that hydrogen plays a very critical role, and without hydrogen, the SnS of the semiconductor phase₂SnS unsuccessfully transformed into a semi-metallic phase upon heating₂. The method can rapidly produce the SnS of the semi-metallic phase₂Meanwhile, the method is economical, simple, convenient, easy to operate and high in safety, and can provide novel raw materials for industrial production and scientific research.

Drawings

FIG. 1 shows a semiconductor phase SnS in example 1₂An XRD pattern of (a);

FIG. 2 shows a semiconductor phase SnS in example 1₂Fluorescence spectrum of

FIG. 3 shows a semiconductor phase SnS in example 1₂Low power topography;

FIG. 4 shows a semiconductor phase SnS in example 1₂EDS mapping of (1);

FIG. 5 shows a semiconductor phase SnS in example 1₂Schematic of the atomic structure of (a);

FIG. 6 shows a semiconductor phase SnS in example 1₂HAADF image of atomic-level resolution of;

FIG. 7 shows the semi-metallic phase SnS in example 1₂An XRD pattern of (a);

FIG. 8 shows the semi-metallic phase SnS in example 1₂The fluorescence spectrum of (a);

FIG. 9 shows the semi-metallic phase SnS in example 1₂Low power topography;

FIG. 10 shows the semi-metallic phase SnS in example 1₂EDS mapping of (1);

FIG. 11 shows the semi-metallic phase SnS in example 1₂Schematic of the atomic structure of (a);

FIG. 12 shows the semi-metallic phase SnS in example 1₂HAADF image of atomic-level resolution of;

FIG. 13 shows the mixed phase SnS of semiconductor and semi-metal in example 2₂HAADF image of (a);

FIG. 14 shows a semiconductor phase SnS obtained in comparative example 1₂HAADF image of (a);

FIG. 15 shows a semiconductor phase SnS obtained in comparative example 2₂HAADF image of (1).

Detailed Description

The invention is further illustrated by the following specific examples. The embodiments are merely illustrative and not restrictive.

Example 1

Preparation of semi-metallic phase SnS₂The method comprises the following specific steps:

(1) we first added 2.1g of tin chloride pentahydrate and 3.0g of thiourea to 70 ml of deionized water and magnetically stirred for 20 minutes to form a homogeneous solution. Then the solution is transferred toThe mixture was transferred to a 100 ml stainless steel shell autoclave and heated at 180 ℃ for 10 hours. Finally, the product was washed with ethanol 3 times and dried under vacuum at 50 ℃ for 8 hours to obtain a semiconductor phase SnS₂(i.e., SnS)₂Stable phase of (a). As shown in FIG. 1, the XRD pattern is good and the SnS is crystalline₂In match, the crystallinity of the product synthesized by the method is proved to be good. Meanwhile, FIG. 2 shows SnS of a semiconductor phase₂Can also explain the SnS of the semiconductor phase₂Successfully synthesized, FIG. 3 shows the SnS of the resulting semiconducting phase₂The macroscopic morphology of the product is uniform in size. FIG. 4 is a semiconductor phase SnS₂The topography and the EDS mapping chart (energy spectrometer map) obtained from it can further illustrate that both Sn and S elements are actually present in the product, and it can be seen that both Sn and S elements are uniformly distributed in the material. FIG. 5 is a semiconductor phase SnS₂Schematic of the atomic structure of (a). FIG. 6 is a semiconductor phase SnS₂An atom-resolved HAADF (high-angle annular dark field) image, i.e., an atom-resolved structural image, of a microscopic region is obtained by scanning a transmission electron microscope (model FEI titanium cube G2300).

(2) SnS of the semiconductor phase obtained in the step (1)₂100mg of the powder was taken out and placed in a magnetic boat, and the magnetic boat with the product was placed in a tubular quartz furnace, and a hydrogen-argon mixture gas (flow rate 30sccm, purity > 99%) containing 10% hydrogen was introduced into the quartz tubular furnace while keeping the gas flow rate constant. Followed by heating to 200 ℃ at a rate of 5 ℃/min and holding at 200 ℃ for 6 hours. Then naturally cooling to obtain the SnS of the semi-metallic phase₂. XRD pattern shown in FIG. 7 and SnS of semiconductor phase shown in FIG. 1₂Almost the same, this is because of the SnS of the semi-metallic and semiconducting phases₂The crystal symmetry of (a) is the same and is indistinguishable by XRD. Meanwhile, FIG. 8 shows SnS of a semi-metallic phase₂Compared to SnS of the semiconductor phase of FIG. 2₂The fluorescence spectrum of (2) shows that the signal of the main fluorescence peak at 594.7nm disappears. FIG. 9 shows SnS of the resulting semimetallic phase₂Low power topography ofTo see that the product we synthesized is very uniform in size. FIG. 10 shows a semi-metallic phase SnS₂The morphology of the material and the EDS mapping chart obtained from the material can further illustrate that two elements of Sn and S are actually present in the product, and the distribution of the two elements of Sn and S in the material is also very uniform. FIG. 11 is a semi-metallic phase SnS₂Schematic of the atomic structure of (a). FIG. 12 is a semi-metallic phase SnS₂An atom-resolved HAADF image, i.e., an atom-resolved dark field image, of one microscopic region was obtained by scanning a transmission electron microscope (type FEI Titan cube G2300). Because of SnS of semiconductor phase and semimetal phase₂Are different and are the most direct and efficient way to distinguish them by comparison of their atomic configurations.

Example 2

(1) The procedure was exactly the same as in (1) in example 1.

(2) SnS of the semiconductor phase obtained in the step (1)₂100mg of the powder is taken out and put into a magnetic boat, the magnetic boat with the product is put into a tubular quartz furnace, and hydrogen and argon mixed gas (the flow rate is 30sccm, the purity is more than 99 percent) containing 20 percent of hydrogen is firstly introduced into the quartz tubular furnace, and the gas flow rate is kept constant. Subsequently, the mixture was heated to 300 ℃ at a rate of 5 ℃/min and held at 300 ℃ for 6 hours. Then naturally cooling to obtain the SnS of the semi-metallic phase₂. FIG. 13 is a semi-metallic phase SnS₂An atom-resolved HAADF image, namely an atom-resolved dark field image, of a micro-region is obtained by a scanning transmission electron microscope (model number is FEI Titan cube Themis G2300).

Comparative example 1

(1) The procedure was exactly the same as in (1) in example 1.

(2) SnS of the semiconductor phase obtained in the step (1)₂100mg of the powder is taken out and put into a magnetic boat, then the magnetic boat with the product is put into a tubular quartz furnace, pure argon (the flow rate is 30sccm, the purity is more than 99 percent) is firstly introduced into the quartz tubular furnace, and the gas flow rate is kept constant. Followed by heating to 200 ℃ at a rate of 5 ℃/min and holding at 200 ℃ for 6 hours. Then naturally cooling to obtain SnS of semiconductor phase₂. FIG. 14 is a semiconductorPhase SnS₂An atom-resolved HAADF image, namely an atom-resolved dark field image, of a micro-region is obtained by a scanning transmission electron microscope (model number is FEI Titan cube Themis G2300). By comparison with FIG. 6, it can be seen that it remains as well as the semiconducting phase SnS₂The same atomic configuration indicates that the semiconductor phase SnS has no hydrogen atmosphere₂Is unable to be converted into a semi-metallic phase SnS₂。

Comparative example 2

(1) The procedure was exactly the same as in (1) in example 1.

(2) SnS of the semiconductor phase obtained in the step (1)₂100mg of the powder is taken out and put into a magnetic boat, then the magnetic boat with the product is put into a tubular quartz furnace, pure argon (the flow rate is 30sccm, the purity is more than 99 percent) is firstly introduced into the quartz tubular furnace, and the gas flow rate is kept constant. Subsequently, the mixture was heated to 300 ℃ at a rate of 5 ℃/min and held at 300 ℃ for 6 hours. Then naturally cooling to obtain SnS of semiconductor phase₂. FIG. 15 is a semiconductor phase SnS₂An atom-resolved HAADF image, namely an atom-resolved dark field image, of a micro-region is obtained by a scanning transmission electron microscope (model number is FEI Titan cube Themis G2300). By comparison with FIG. 6, it can be seen that it remains as well as the semiconducting phase SnS₂The same atomic configuration, which shows that the semiconductor phase SnS without hydrogen atmosphere, even if we increase the heating temperature₂Still cannot be converted into semi-metallic phase SnS₂。

Claims

1. A synthetic preparation method of semi-metal phase tin disulfide comprises the following steps:

(1) mixing tin chloride pentahydrate, thiourea and deionized water according to the mass ratio of 2.1: 3.0: 70, and magnetically stirring for 20-60 minutes to form a uniform solution; then heating the solution at 180 ℃ for 10-15 hours, washing the product with ethanol or water for 3-5 times, and then drying the product in vacuum at 40-70 ℃ for 2-10 hours to obtain the SnS of the semiconductor phase₂。

(2) SnS of the semiconductor phase obtained in the step (1)₂Placing the quartz tube in a tubular quartz furnace at a flow rate of 20-50 sccm and containing 5 toIntroducing hydrogen-argon mixed gas of 20% hydrogen into a quartz tube furnace, keeping the gas flow rate constant, heating to 200-300 ℃ at the heating rate of 3-8 ℃/min, preserving the heat for 5-8 hours, and naturally cooling to room temperature to obtain semi-metal phase SnS₂。

2. The synthetic preparation method of semi-metallic phase tin disulfide according to claim 1, wherein the heating time in step (1) is 10 hours, the vacuum drying temperature is 50 ℃, and the vacuum drying time is 8 hours.

3. The method for synthesizing and preparing semi-metallic phase tin disulfide according to claim 1, wherein the product of step (2) is placed in a magnetic boat or product holder and then in a tubular quartz furnace.

4. The method for preparing the semi-metallic phase tin disulfide synthetically according to claim 1, characterized in that, in the step (2), the hydrogen-argon mixture of 10% hydrogen has a hydrogen content of 10% and a gas purity of more than 99%. The flow rate of the gas was 30 sccm.

5. The synthetic preparation method of semi-metallic phase tin disulfide as claimed in claim 1, wherein the heating temperature in step (2) is 200 ℃. The temperature rise rate is 5 ℃/min, and the temperature is kept for 6 hours.