阅读说明：本技术 一种In掺杂CdS复合MoS2的异质结析氢材料及其制法 (In-doped CdS composite MoS2The heterojunction hydrogen evolution material and the preparation method thereof ) 是由 王顺方 于 2021-01-05 设计创作，主要内容包括：本发明涉及光催化析氢技术领域,且公开了一种In掺杂CdS复合MoS-2的异质结析氢材料,In掺杂CdS纳米花具有超高的比表面积,以其为基底,得到In掺杂CdS纳米花负载MoS-2纳米空心球,MoS-2纳米空心球具有超高的比表面积,有利于暴露出更多的光催化析氢活性位点,In掺杂减小CdS带隙,促进光生电子-空穴分离,同时使CdS带边红移,拓宽光吸收范围,CdS与MoS-2形成异质结,降低带隙宽度,进一步拓宽了光吸收范围,CdS导带上的光生电子转移到MoS-2的导带上,CdS价带上的部分空穴转移并累计在MoS-2价带上,抑制了光生电子-空穴的复合,提高了析氢材料的光学稳定性,使得In掺杂CdS复合MoS-2的异质结析氢材料具有优异的光催化析氢性能。(The invention relates to the technical field of photocatalytic hydrogen evolution, and discloses In-doped CdS composite MoS 2 The In-doped CdS nanoflower has an ultrahigh specific surface area, and the In-doped CdS nanoflower loaded MoS is obtained by taking the In-doped CdS nanoflower as a substrate 2 Hollow nanospheres, MoS 2 The hollow nanosphere has ultra-high specific surface areaMore photocatalytic hydrogen evolution active sites can be exposed, the In doping reduces the CdS band gap, the photoproduction electron-hole separation is promoted, the CdS band edge is red shifted, the light absorption range is widened, and the CdS and MoS are 2 Heterojunction is formed, band gap width is reduced, light absorption range is further widened, and photo-generated electrons on CdS conduction band are transferred to MoS 2 Partial holes on the CdS valence band are transferred and accumulated in MoS 2 On the valence band, the recombination of photo-generated electrons and holes is inhibited, the optical stability of the hydrogen evolution material is improved, and In doped CdS composite MoS is enabled 2 The heterojunction hydrogen evolution material has excellent photocatalytic hydrogen evolution performance.)

1. In-doped CdS composite MoS₂The heterojunction hydrogen evolution material of (2), characterized in that: what is needed isIn-doped CdS composite MoS₂The preparation method of the heterojunction hydrogen evolution material comprises the following steps:

(1) adding thiourea and cadmium chloride into deionized water, uniformly dispersing, adding indium chloride, and uniformly dispersing to obtain a dispersion liquid;

(2) transferring the dispersion liquid into a reaction kettle and placing the reaction kettle in a hydrothermal device for hydrothermal reaction, cooling, centrifuging, washing and drying to obtain indium-doped cadmium sulfide nanoflowers;

(3) adding sodium thiosulfate and sodium molybdate into deionized water, uniformly dispersing, adding hydrazine hydrate and indium-doped cadmium sulfide nanoflowers, and uniformly dispersing to obtain a mixed solution;

(4) transferring the mixed solution into a reaction kettle, carrying out hydrothermal process, cooling, filtering under reduced pressure, washing and drying to obtain In-doped CdS composite MoS₂The heterojunction hydrogen evolution material of (1).

2. An In doped CdS composite MoS according to claim 1₂The heterojunction hydrogen evolution material of (2), characterized in that: in the step (1), the mass ratio of thiourea to cadmium chloride to indium chloride is 50-80:100: 6-10.

3. An In doped CdS composite MoS according to claim 1₂The heterojunction hydrogen evolution material of (2), characterized in that: the medium-temperature heating device in the step (2) comprises a shell, a heat insulation layer is movably connected inside the heat insulation layer, a heating device is movably connected to the top of the heat insulation layer, a furnace chamber is movably connected inside the heat insulation layer, fixed shafts are movably connected to two sides of the heat insulation layer, gears are movably connected to the middles of the fixed shafts, and movable object carrying tables are movably connected to the tops of the gears.

4. An In doped CdS composite MoS according to claim 1₂The heterojunction hydrogen evolution material of (2), characterized in that: the hydrothermal reaction condition in the step (2) is 150-180 ℃ for 2-5 h.

5. An In doped CdS composite MoS according to claim 1₂The heterojunction hydrogen evolution material of (2), characterized in that: the mass ratio of the sodium thiosulfate, the sodium molybdate, the hydrazine hydrate and the indium-doped cadmium sulfide nanoflower in the step (3) is 50-70:30-45:3-4.5: 100.

6. An In doped CdS composite MoS according to claim 1₂The heterojunction hydrogen evolution material of (2), characterized in that: the hydrothermal process in the step (4) is carried out at 170-200 ℃ for 18-36 h.

Technical Field

The invention relates to the technical field of photocatalytic hydrogen evolution, In particular to an In-doped CdS composite MoS₂The heterojunction hydrogen evolution material and the preparation method thereof.

Background

In the present society, environmental pollution and energy shortage are two worldwide problems to be solved, so that researchers need to develop a new high-efficiency green pollution-free clean energy, and among clean energy such as solar energy, wind energy, hydrogen energy and the like, hydrogen energy with higher combustion heat value is obtained in a stand-by mode.

TiO₂、WO₃The transition metal oxides such as the CdS and the transition metal sulfides such as the CuS and the CdS have excellent photocatalytic performance, wherein the nano CdS material has the advantages of a proper energy band structure, a large light absorption range and the like, and has a wide application prospect in the fields of photocatalytic hydrogen evolution, degradation and the like, but has a wide band gap, is easy to recombine photo-generated electrons and holes, is easy to corrode, and severely limits the application of the nano CdS material.

Technical problem to be solved

Aiming at the defects of the prior art, the invention provides an In-doped CdS composite MoS₂The heterojunction hydrogen evolution material and the preparation method thereof solve the problem of low hydrogen evolution efficiency of CdS photocatalysis.

(II) technical scheme

In order to achieve the purpose, the invention provides the following technical scheme: in-doped CdS composite MoS₂The In-doped CdS composite MoS₂The preparation method of the heterojunction hydrogen evolution material comprises the following steps:

(1) adding deionized water, thiourea and cadmium chloride into a reaction bottle, uniformly dispersing, adding indium chloride, and uniformly dispersing to obtain a dispersion liquid;

(2) transferring the dispersion liquid into a reaction kettle, placing the reaction kettle in a hydrothermal device, carrying out hydrothermal reaction, cooling to room temperature, centrifuging, washing with deionized water and absolute ethyl alcohol, and drying to obtain indium-doped cadmium sulfide nanoflowers;

(3) adding deionized water, sodium thiosulfate and sodium molybdate into a reaction bottle, uniformly dispersing, adding hydrazine hydrate and indium-doped cadmium sulfide nanoflowers, and uniformly dispersing to obtain a mixed solution;

(4) transferring the mixed solution into a reaction kettle, carrying out hydrothermal process, cooling to room temperature, filtering under reduced pressure, washing with deionized water and absolute ethyl alcohol, and drying to obtain In-doped CdS composite MoS₂The heterojunction hydrogen evolution material of (1).

Preferably, the mass ratio of the thiourea to the cadmium chloride to the indium chloride in the step (1) is 50-80:100: 6-10.

Preferably, the hydrothermal device in step (2) comprises a shell, the inside of the shell is movably connected with a heat insulation layer, the inside of the heat insulation layer is movably connected with a heat insulation layer, the top of the heat insulation layer is movably connected with a heating device, the inside of the heat insulation layer is movably connected with a furnace chamber, the two sides of the heat insulation layer are movably connected with fixed shafts, the middle of the fixed shafts is movably connected with gears, and the top of the gears is movably connected with a movable objective table.

Preferably, the hydrothermal reaction in the step (2) is carried out under the conditions of 150 ℃ and 180 ℃ for 2-5 h.

Preferably, the mass ratio of the sodium thiosulfate, the sodium molybdate, the hydrazine hydrate and the indium-doped cadmium sulfide nanoflower in the step (3) is 50-70:30-45:3-4.5: 100.

Preferably, the hydrothermal process in the step (4) is carried out at 170-200 ℃ for 18-36 h.

(III) advantageous technical effects

Compared with the prior art, the invention has the following beneficial technical effects:

the In-doped CdS composite MoS₂The heterojunction hydrogen evolution material takes thiourea as a sulfur source, cadmium chloride as a cadmium source and indium chloride as a doping source, and through hydrothermal treatment, the thiourea can be used as a surfactant to prevent CdS nanorods from agglomerating and self-assemble to obtain In-doped CdS nanoflowers with unique flower-shaped nanometer morphology and ultrahigh specific surface area, so that more photocatalysis hydrogen evolution materials can be exposedHydrogen active site is used as a substrate, hydrazine hydrate with strong reducibility reacts with sodium molybdate to generate MoO₂Precipitate and form spherical aggregates, further rapidly react with Na₂S₂O₃Reaction at MoO₂MoS generation on the surface of a sphere₂Nanosheets, MoO inside the sphere₂By loose MoS₂The shell is transported out of the shell and further reacts with Na₂S₂O₃Reaction, MoO inside the sphere₂Completely consumed, forms a nano hollow spherical shape, has an ultra-high specific surface area, further exposes more photocatalytic hydrogen evolution active sites, and obtains In-doped CdS nanoflower loaded MoS₂The hollow nanospheres.

The In-doped CdS composite MoS₂The heterojunction hydrogen evolution material of (1), In is In³⁺The CdS crystal lattice doped with the CdS quantum dots reduces the band gap of the CdS, promotes the separation of photo-generated electrons and holes, enables the absorption band edge of the CdS to be red-shifted, widens the light absorption range, and improves the sunlight utilization rate.

The In-doped CdS composite MoS₂The heterojunction hydrogen evolution material of (3) has reduced electron cloud density of CdS and electron-to-MoS₂Transferring to form I-type heterojunction structure, reducing band gap width of hydrogen evolution material, further widening light absorption range, improving sunlight utilization rate, and improving conduction band potential ratio of CdS MoS₂The potential of the conduction band is more negative, and when the CdS is excited by light, the photo-generated electrons generated by the transition from the valence band to the conduction band are transferred to MoS₂While part of the holes in the CdS valence band are transferred and accumulated in MoS₂On the valence band, the oxidation product is further reacted with a sacrificial agent triethanolamine to generate an oxidation product, the transfer of photo-generated electrons and the accumulation and consumption of holes effectively inhibit the recombination of the photo-generated electrons and the holes, the optical stability of the hydrogen evolution material is improved, the photo corrosion phenomenon of CdS is inhibited, the service life of the hydrogen evolution material is prolonged, and the In-doped CdS composite MoS is enabled to be formed₂The heterojunction hydrogen evolution material has excellent photocatalytic hydrogen evolution performance.

Drawings

FIG. 1 is a schematic structural view of a hydrothermal device in front view;

FIG. 2 is a schematic side view of a hydrothermal apparatus;

fig. 3 is a schematic view of a gear structure.

1. A housing; 2. a thermal insulation layer; 3. a heat-insulating layer; 4. a heating device; 5. a furnace chamber; 6. a fixed shaft; 7. a gear; 8. a movable object stage.

Detailed Description

To achieve the above object, the present invention provides the following embodiments and examples: in-doped CdS composite MoS₂The In-doped CdS composite MoS₂The preparation method of the heterojunction hydrogen evolution material comprises the following steps:

(1) adding deionized water, thiourea and cadmium chloride into a reaction bottle, uniformly dispersing, and adding indium chloride, wherein the mass ratio of thiourea to cadmium chloride to indium chloride is 50-80:100:6-10, and uniformly dispersing to obtain a dispersion liquid;

(2) transferring the dispersion liquid into a reaction kettle to be arranged in a hydrothermal device, wherein the hydrothermal device comprises a shell, the interior of the shell is movably connected with a heat insulation layer, the interior of the heat insulation layer is movably connected with a heat insulation layer, the top of the heat insulation layer is movably connected with a heating device, the interior of the heat insulation layer is movably connected with a furnace chamber, two sides of the heat insulation layer are movably connected with fixed shafts, the middle of each fixed shaft is movably connected with a gear, the top of each gear is movably connected with a movable objective table, carrying out hydrothermal reaction, and the hydrothermal reaction is carried out under the conditions of 150 plus materials and 180 ℃ for 2-5h, cooling to room temperature, centrifuging, washing with deionized water and absolute ethyl;

(3) adding deionized water, sodium thiosulfate and sodium molybdate into a reaction bottle, uniformly dispersing, adding hydrazine hydrate and indium-doped cadmium sulfide nanoflowers, wherein the mass ratio of the sodium thiosulfate to the sodium molybdate to the hydrazine hydrate to the indium-doped cadmium sulfide nanoflowers is 50-70:30-45:3-4.5:100, and uniformly dispersing to obtain a mixed solution;

(4) transferring the mixed solution into a reaction kettle to carry out a hydrothermal process, wherein the hydrothermal process is to react for 18-36h at the temperature of 170-200 ℃, cooling to room temperature, filtering under reduced pressure, washing with deionized water and absolute ethyl alcohol, and drying to obtain In-doped CdS composite MoS₂The heterojunction hydrogen evolution material of (1).

Example 1

(1) Adding deionized water, thiourea and cadmium chloride into a reaction bottle, uniformly dispersing, and adding indium chloride, wherein the mass ratio of thiourea to cadmium chloride to indium chloride is 50:100:6, and uniformly dispersing to obtain a dispersion liquid;

(2) transferring the dispersion liquid into a reaction kettle to be placed in a hydrothermal device, wherein the hydrothermal device comprises a shell, the interior of the shell is movably connected with a heat insulation layer, the interior of the heat insulation layer is movably connected with a heat insulation layer, the top of the heat insulation layer is movably connected with a heating device, the interior of the heat insulation layer is movably connected with a furnace chamber, two sides of the heat insulation layer are movably connected with fixed shafts, the middle of each fixed shaft is movably connected with a gear, the top of each gear is movably connected with a movable objective table, carrying out hydrothermal reaction, reacting for 2 hours at 150 ℃, cooling to room temperature, centrifuging, washing with deionized water and absolute ethyl alcohol, and drying to obtain indium-doped cadmium sulfide;

(3) adding deionized water, sodium thiosulfate and sodium molybdate into a reaction bottle, uniformly dispersing, adding hydrazine hydrate and indium-doped cadmium sulfide nanoflowers, wherein the mass ratio of the sodium thiosulfate to the sodium molybdate to the hydrazine hydrate to the indium-doped cadmium sulfide nanoflowers is 50:30:3:100, and uniformly dispersing to obtain a mixed solution;

(4) transferring the mixed solution into a reaction kettle, carrying out a hydrothermal process, wherein the hydrothermal process comprises the steps of reacting for 18 hours at 170 ℃, cooling to room temperature, filtering under reduced pressure, washing with deionized water and absolute ethyl alcohol, and drying to obtain In-doped CdS composite MoS₂The heterojunction hydrogen evolution material of (1).

Example 2

(1) Adding deionized water, thiourea and cadmium chloride into a reaction bottle, uniformly dispersing, and adding indium chloride, wherein the mass ratio of thiourea to cadmium chloride to indium chloride is 60:100:7.3, and uniformly dispersing to obtain a dispersion liquid;

(2) transferring the dispersion liquid into a reaction kettle to be placed in a hydrothermal device, wherein the hydrothermal device comprises a shell, the interior of the shell is movably connected with a heat insulation layer, the interior of the heat insulation layer is movably connected with a heat insulation layer, the top of the heat insulation layer is movably connected with a heating device, the interior of the heat insulation layer is movably connected with a furnace chamber, two sides of the heat insulation layer are movably connected with fixed shafts, the middle of each fixed shaft is movably connected with a gear, the top of each gear is movably connected with a movable objective table, carrying out hydrothermal reaction, reacting for 3 hours at 160 ℃, cooling to room temperature, centrifuging, washing with deionized water and absolute ethyl alcohol, and drying to obtain indium-doped cadmium sulfide;

(3) adding deionized water, sodium thiosulfate and sodium molybdate into a reaction bottle, uniformly dispersing, adding hydrazine hydrate and indium-doped cadmium sulfide nanoflowers, wherein the mass ratio of the sodium thiosulfate to the sodium molybdate to the hydrazine hydrate to the indium-doped cadmium sulfide nanoflowers is 56:35:3.5:100, and uniformly dispersing to obtain a mixed solution;

(4) transferring the mixed solution into a reaction kettle, carrying out a hydrothermal process, wherein the hydrothermal process comprises the steps of reacting at 180 ℃ for 24 hours, cooling to room temperature, filtering under reduced pressure, washing with deionized water and absolute ethyl alcohol, and drying to obtain In-doped CdS composite MoS₂The heterojunction hydrogen evolution material of (1).

Example 3

(1) Adding deionized water, thiourea and cadmium chloride into a reaction bottle, uniformly dispersing, and adding indium chloride, wherein the mass ratio of thiourea to cadmium chloride to indium chloride is 70:100:8.6, and uniformly dispersing to obtain a dispersion liquid;

(2) transferring the dispersion liquid into a reaction kettle to be placed in a hydrothermal device, wherein the hydrothermal device comprises a shell, the interior of the shell is movably connected with a heat insulation layer, the interior of the heat insulation layer is movably connected with a heat insulation layer, the top of the heat insulation layer is movably connected with a heating device, the interior of the heat insulation layer is movably connected with a furnace chamber, two sides of the heat insulation layer are movably connected with fixed shafts, the middle of each fixed shaft is movably connected with a gear, the top of each gear is movably connected with a movable objective table, carrying out hydrothermal reaction, and washing and drying the dispersion liquid by deionized water and absolute ethyl alcohol under the condition of 170 ℃ for 4 hours, cooling the dispersion liquid to room temperature;

(3) adding deionized water, sodium thiosulfate and sodium molybdate into a reaction bottle, uniformly dispersing, adding hydrazine hydrate and indium-doped cadmium sulfide nanoflowers, wherein the mass ratio of the sodium thiosulfate to the sodium molybdate to the hydrazine hydrate to the indium-doped cadmium sulfide nanoflowers is 63:40:4:100, and uniformly dispersing to obtain a mixed solution;

(4) transferring the mixed solution into a reaction kettle, carrying out a hydrothermal process, wherein the hydrothermal process comprises the steps of reacting for 30 hours at 190 ℃, cooling to room temperature, filtering under reduced pressure, washing with deionized water and absolute ethyl alcohol, and drying to obtain In-doped CdS composite MoS₂The heterojunction hydrogen evolution material of (1).

Example 4

(1) Adding deionized water, thiourea and cadmium chloride into a reaction bottle, uniformly dispersing, and adding indium chloride, wherein the mass ratio of thiourea to cadmium chloride to indium chloride is 80:100:10, and uniformly dispersing to obtain a dispersion liquid;

(2) transferring the dispersion liquid into a reaction kettle to be placed in a hydrothermal device, wherein the hydrothermal device comprises a shell, the interior of the shell is movably connected with a heat insulation layer, the interior of the heat insulation layer is movably connected with a heat insulation layer, the top of the heat insulation layer is movably connected with a heating device, the interior of the heat insulation layer is movably connected with a furnace chamber, two sides of the heat insulation layer are movably connected with fixed shafts, the middle of each fixed shaft is movably connected with a gear, the top of each gear is movably connected with a movable objective table, carrying out hydrothermal reaction, and washing and drying the dispersion liquid by deionized water and absolute ethyl alcohol under the condition of 180 ℃ for 5 hours, cooling the dispersion liquid to room temperature;

(3) adding deionized water, sodium thiosulfate and sodium molybdate into a reaction bottle, uniformly dispersing, adding hydrazine hydrate and indium-doped cadmium sulfide nanoflowers, wherein the mass ratio of the sodium thiosulfate to the sodium molybdate to the hydrazine hydrate to the indium-doped cadmium sulfide nanoflowers is 70:45:4.5:100, and uniformly dispersing to obtain a mixed solution;

(4) transferring the mixed solution into a reaction kettle, carrying out a hydrothermal process, wherein the hydrothermal process comprises the steps of reacting for 36 hours at 200 ℃, cooling to room temperature, filtering under reduced pressure, washing with deionized water and absolute ethyl alcohol, and drying to obtain In-doped CdS composite MoS₂The heterojunction hydrogen evolution material of (1).

Comparative example 1

(1) Adding deionized water, thiourea and cadmium chloride into a reaction bottle, uniformly dispersing, and adding indium chloride, wherein the mass ratio of thiourea to cadmium chloride to indium chloride is 40:100:5, and uniformly dispersing to obtain a dispersion liquid;

(2) transferring the dispersion liquid into a reaction kettle to be placed in a hydrothermal device, wherein the hydrothermal device comprises a shell, the interior of the shell is movably connected with a heat insulation layer, the interior of the heat insulation layer is movably connected with a heat insulation layer, the top of the heat insulation layer is movably connected with a heating device, the interior of the heat insulation layer is movably connected with a furnace chamber, two sides of the heat insulation layer are movably connected with fixed shafts, the middle of each fixed shaft is movably connected with a gear, the top of each gear is movably connected with a movable objective table, carrying out hydrothermal reaction, and washing and drying the dispersion liquid by deionized water and absolute ethyl alcohol under the condition of 170 ℃ to obtain indium-doped cadmium sulfide nanoflowers;

(3) adding deionized water, sodium thiosulfate and sodium molybdate into a reaction bottle, uniformly dispersing, adding hydrazine hydrate and indium-doped cadmium sulfide nanoflowers, wherein the mass ratio of the sodium thiosulfate to the sodium molybdate to the hydrazine hydrate to the indium-doped cadmium sulfide nanoflowers is 40:20:2:100, and uniformly dispersing to obtain a mixed solution;

(4) transferring the mixed solution into a reaction kettle, carrying out a hydrothermal process, wherein the hydrothermal process comprises the steps of reacting at 180 ℃ for 24 hours, cooling to room temperature, filtering under reduced pressure, washing with deionized water and absolute ethyl alcohol, and drying to obtain In-doped CdS composite MoS₂The heterojunction hydrogen evolution material of (1).

200mL of triethanolamine aqueous solution with the volume fraction of 10 percent and 200mg of heterojunction hydrogen evolution material of In-doped CdS composite MoS2 obtained In the examples and the comparative examples are added into a reaction bottle, the materials are uniformly dispersed, a photocatalytic water decomposition hydrogen production test is carried out In a quartz reactor connected with a closed vacuum circulation system, the hydrogen evolution amount is measured by an AS-3901ASF type gas chromatograph under the illumination condition of a 300W xenon lamp, and the test standard is GB/T26915-plus 2011.