CN112844413A

CN112844413A - Preparation method and application of photocatalyst with sphalerite/wurtzite junction

Info

Publication number: CN112844413A
Application number: CN202110235259.4A
Authority: CN
Inventors: 黄彩进; 郭晓盛
Original assignee: Fuzhou University
Current assignee: Fuzhou University
Priority date: 2021-03-03
Filing date: 2021-03-03
Publication date: 2021-05-28

Abstract

The invention discloses a cocatalyst-free Cd with sphalerite/wurtzite phase junction_1‑xZn_xA preparation method and application of an S nanometer popcorn photocatalyst belong to the technical field of photocatalytic materials. Zn (NO) in ethanediamine as solvent₃)₂•4H₂O and Cd (NO)₃)₂•4H₂O is taken as a precursor, thioacetamide is added, and Cd is prepared through a simple one-step solvothermal reaction process_1‑xZn_xAnd (S) a photocatalyst. The one-step solvothermal preparation method is simple in steps, does not need additional auxiliary conditions, is high in controllability and mild in conditions, and is beneficial to large-scale popularization and mass production. Cocatalyst-free Cd prepared by the invention_1‑ _xZn_xThe S nano popcorn obtained an excellent 282.14 mu mol h⁻¹mg⁻¹The photocatalytic hydrogen production activity and the apparent quantum yield of 64.4 percent at 420nm are higher than those of most Cd added with a promoter_1‑xZn_xAn S-based catalyst.

Description

Preparation method and application of photocatalyst with sphalerite/wurtzite junction

Technical Field

The present invention belongs toIn the technical field of photocatalytic materials, in particular to a cocatalyst-free Cd with sphalerite/wurtzite phase junction_1-xZn_xA preparation method and application of an S nanometer popcorn photocatalyst.

Background

In recent years, with the important development of hydrogen production technology and hydrogen storage materials, hydrogen has gradually become one of important ideal substitutes for non-renewable energy sources (such as fossil energy and the like). The semiconductor photocatalysis technology is utilized to convert renewable solar energy into hydrogen energy, which is a very environment-friendly way, thereby receiving wide attention. In recent decades, researchers have conducted extensive research and research on the application of semiconductor-based photocatalysts, particularly those having suitable band gaps and visible light responses, to photocatalytic hydrogen production. Cadmium zinc sulfide (Cd) as a low-toxicity and low-cost ternary solid solution_1- _xZn_xS) is widely researched due to the advantages of flexibility and adjustability of band gap and energy band edge position, simple preparation process, strong visible light response capability, light corrosion resistance and the like. But the further application of the solar cell is limited by the defects of high recombination speed of photo-induced electron-hole pairs, low solar energy utilization rate, susceptibility to photo-corrosion and the like. The construction of a combination (or a homojunction) is an important and effective method for promoting the photocatalytic hydrogen production performance, such as alpha/beta Ga₂O₃In combination, anatase/rutile TiO₂The successful construction combined with the hexagonal/cubic CdS greatly promotes the hydrogen production activity. The construction of the phase combination can not only promote the separation/transfer of the photon-generated carriers and prolong the service life of the carriers, but also provide enough driving force for the separation/transfer of the photon-generated carriers through an internal electric field formed by the phase combination. However, sphalerite/wurtzite junction Cd_1-xZn_xAdditional conditions, such as ultrasonic irradiation, high temperature, L-cysteine assistance, and cumbersome processes, are often required in the synthetic preparation of S.

CN110975886B discloses mixing zinc salt, ethylenediamine aqueous solution and sulfur source, and performing a first solvothermal reaction to obtain a zinc sulfide-ethylenediamine precursor; the zinc sulfide-ethylenediamine precursor, cadmium salt and organic solvent are addedMixing the solvents, and carrying out a second solvothermal reaction to obtain a zinc cadmium sulfide-ethylenediamine precursor; the zinc cadmium sulfide-ethylenediamine precursor is mixed with water to carry out hydrothermal reaction to obtain porous two-dimensional zinc cadmium sulfide nanosheets, but the one-step hydrothermal method adopts a NaOH coprecipitation method to prepare severely agglomerated nanoparticles, and Cd at present_1-xZn_xThere are many reports of S crystal structure, such as twin Cd with a combined (or homojunction) structure_0.5Zn_0.5S is always a leading topic in the field of photocatalytic hydrogen production, but in recent years, pure twin crystal Cd_0.5Zn_0.5There was little breakthrough development on S. The invention first innovatively reports Cd with sphalerite/wurtzite phase junction_0.7Zn_0.3S nanometer popcorn structure (non-twin), but Cd prepared by CN110975886B_0.5Zn_0.5S is a pure wurtzite crystal form, and no phase is generated. The catalyst prepared by the invention has the hydrogen production activity of 282.14 mu mol h in the presence of a sacrificial agent⁻¹mg⁻¹About 16 times that of CN 110975886B. And patent CN110975886B is at a wavelength of 350 ‒ 780 nm, i.e. at uv-visible wavelengths. All the applied illumination conditions of the invention are visible light (lambda is more than or equal to 420 nm).

Disclosure of Invention

The aim of the invention is to design a more efficient Cd_1-xZn_xS-based photocatalyst, and provided cocatalyst-free Cd with sphalerite/wurtzite junction_1-xZn_xA preparation method and application of an S nanometer popcorn photocatalyst. The invention constructs a ZB/WZ phase Cd_1-xZn_xThe S nano popcorn particles show excellent activity and stability in hydrogen production by photolysis of water.

In order to achieve the purpose, the invention adopts the following technical scheme:

zn (NO) is added in the presence of ethylenediamine as solvent₃)₂•4H₂O and Cd (NO)₃)₂•4H₂O is used as a precursor, and excessive thioacetamide is added to carry out simple one-step solvothermal reactionProcess for preparing the sphalerite/wurtzite junction Cd_1-xZn_xS nanometer popcorn photocatalyst.

The invention relates to a cocatalyst-free Cd_1-xZn_xThe preparation method of the S-based photocatalyst comprises the following specific steps:

(1) 10x (x = 0, 0.1, 0.3, 0.5, 0.7, 0.9, 1) mmol of Zn (NO)₃)₂•4H₂O (x refers to the molar ratio of Zn to Zn plus Cd in Zn and Cd precursors) is dispersed in 60 mL of ethylenediamine (en) and stirred for 30 min. Subsequently, 10(1-x) mmol of Cd (NO) was added₃)₂•4H₂And O, stirring for 30 min.

(2) Then, an equal (10 mmol) or an excess (16 mmol) of Thioacetamide (TAA) was added as a sulfur source and the reaction mixture was stirred for 1h until a homogeneous viscous suspension was formed. The resulting suspension was sealed in a polytetrafluoroethylene-lined autoclave having a capacity of 100 mL, reacted at 180 ℃ for 24 hours, and after the reaction was completed, the obtained precipitate was washed.

(3) Finally, the product was dried overnight in a vacuum oven at 60 ℃ and collected for further characterization. Marking the obtained samples as Cd according to the addition amount of Thioacetamide (TAA)_1-xZn_xS-10 and Cd_1-xZn_xS-16。

Wherein x is any one of the value ranges of 0, 0.1, 0.3, 0.5, 0.7, 0.9 and 1, and the value of thioacetamide is between 10 mmol and 22 mmol.

Further, when x = 0.5 and the dose of Thioacetamide (TAA) was 16 mmol, a sphalerite/wurtzite junction Cd containing Cd was obtained_1-xZn_xS nanometer popcorn and ZnS (en)_0.5Photocatalyst mixed by nanosheets and marked as Cd_0.5Zn_0.5S-16。

Wherein, the invention also relates to Cd_0.5Zn_0.5The amount of S-Thioacetamide (TAA) added was adjusted (10 mmol-22 mmol), and the samples obtained were labeled Cd_0.5Zn_0.5S-10、Cd_0.5Zn_0.5S-13、Cd_0.5Zn_0.5S-16、Cd_0.5Zn_0.5S-19 and Cd_0.5Zn_0.5S-22。

Wherein for Cd_1-xZn_xS-16 (x = 0-1) photocatalyst, and a series of Cd-like compounds can be obtained by changing the value of x_1-xZn_xAn S-based photocatalyst. Wherein the CdS-16 is nanorod-shaped, has a diameter of about 50 nm and a length of about 500 nm-1 μm.

Cd_0.9Zn_0.1S-16 is the shape of a nanorod with a diameter of about 30-50 nm and a length of about 500 nm. Cd [ Cd ]_0.5Zn_0.5S-16 presents a mixture of popcorn nanoparticles (called nano-popcorn) and platelet-shaped nanoparticles (called nanosheets). Cd [ Cd ]_0.3Zn_0.7S-16 and Cd_0.1Zn_0.9Most of the S-16 produced were nanosheets, while all of ZnS-16 were ZnS (en)_0.5Nanosheets. Cd [ Cd ]_0.5Zn_0.5S-16 is represented by Cd_1-xZn_xS nanometer popcorn and ZnS (en)_0.5And (4) nano sheets. Cd of about 500 nm to 1 μm in diameter_1-xZn_xS nanometer popcorn is composed of many highly crystalline small nanoparticles, ZnS (en)_0.5The nano-sheet presents a polycrystalline crystal form, and the size is about 500 nm-2 μm. Lattice fringes with lattice spacing of 0.32 nm and 0.36 nm respectively correspond to Cd_1−xZn_xThe ZB lattice (111) plane of the S solid solution and the WZ lattice (100) plane form a phase.

The Cd with sphalerite/wurtzite junction_1-xZn_xThe S nano popcorn photocatalyst can be applied to photocatalytic hydrogen production under visible light.

The invention has the following remarkable advantages:

(1) the present invention provides for the first time a method for preparing Cd with sphalerite/wurtzite junctions by using an excess of thioacetamide_1-xZn_xS nano popcorn photocatalyst preparation strategy. The one-step solvothermal preparation method is simple in steps, does not need additional auxiliary conditions, is high in controllability and mild in conditions, and is beneficial to large-scale popularization and mass production.

(2) Cocatalyst-free Cd prepared by the invention_1-xZn_xS nanometer popcorn obtainsExcellent 282.14. mu. mol h⁻¹mg⁻¹The photocatalytic hydrogen production activity and the apparent quantum yield of 64.4 percent at 420nm are higher than those of most Cd added with a promoter_1-xZn_xAn S-based catalyst.

(3) Low-toxicity and low-price Cd prepared by using method_1-xZn_xThe S photocatalyst is applied to hydrogen production by photolysis of water by visible light in the presence of a sacrificial agent, and the prepared photocatalyst has high stability, can be recycled, and has high practical application value and prospect.

Drawings

FIG. 1 shows Cd in the present invention_1-xZn_xS-16 and Cd_1-xZn_xAn X-ray diffraction pattern (XRD) of S-10;

FIG. 2 shows Cd in the present invention_1-xZn_xScanning Electron Microscopy (SEM) of S-16 material;

FIG. 3 shows Cd in the present invention_0.5Zn_0.5Transmission Electron Microscopy (TEM) and selected area elemental mapping (EDX-mapping) of S-16;

FIG. 4 shows Cd in the present invention_1-xZn_xS-16 and Cd_1-xZn_xS-10 photocatalyst photolysis of water to produce hydrogen activity diagram and Cd_0.5Zn_0.5And (3) a hydrogen production apparent quantum yield and stability test chart of the S-16 sample.

Detailed Description

In order to make the present invention more comprehensible, the technical solutions of the present invention are further described below with reference to specific embodiments, but the present invention is not limited thereto.

The preparation steps of the invention are as follows:

10x (x = 0, 0.1, 0.3, 0.5, 0.7, 0.9, 1) mmol of Zn (NO)₃)₂•4H₂O (x refers to the molar ratio of Zn to Zn plus Cd in Zn and Cd precursors) is dispersed in 60 mL of ethylenediamine (en) and stirred for 30 min. Subsequently, 10(1-x) mmol of Cd (NO) was added₃)₂•4H₂And O, stirring for 30 min. Then, an equivalent (10 mmol) or excess (16 mmol) dose ofThioacetamide (TAA) as a sulfur source. The reaction mixture was stirred continuously for 1h until a homogeneous viscous suspension was formed. The suspension was then transferred to a 100 mL autoclave and reacted for 24 h at 180 ℃ at constant temperature. After the reaction is finished, the obtained precipitate is centrifugally washed by deionized water and absolute ethyl alcohol. Finally, the product was dried overnight in a vacuum oven at 60 ℃.

Example 1

To 60 mL of ethylenediamine was added 10 mmol of Cd (NO)₃)₂•4H₂And O, stirring for 30 min. Then, 16 mmol of thioacetamide TAA was added. The reaction mixture was stirred continuously for 1h until a homogeneous viscous suspension was formed. The suspension was then transferred to a 100 mL autoclave and reacted for 24 h at 180 ℃ at constant temperature. After the reaction is finished, the obtained precipitate is centrifugally washed by deionized water and absolute ethyl alcohol. And finally, drying the product in a vacuum oven at 60 ℃ overnight to obtain the cadmium sulfide photocatalyst CdS-16.

Example 2

Adding 1 mmol of Zn (NO)₃)₂•4H₂O was dispersed in 60 mL of ethylenediamine and stirred for 30 min. Subsequently, 9 mmol of Cd (NO) were added₃)₂•4H₂And O, stirring for 30 min. Then, 16 mmol of TAA was added. The reaction mixture was stirred continuously for 1h until a homogeneous viscous suspension was formed. The suspension was then transferred to a 100 mL autoclave and reacted for 24 h at 180 ℃ at constant temperature. After the reaction is finished, the obtained precipitate is centrifugally washed by deionized water and absolute ethyl alcohol. Finally, drying the product in a vacuum oven at 60 ℃ overnight to obtain the cadmium zinc sulfide photocatalyst Cd_0.9Zn_0.1S-16。

Example 3

3 mmol of Zn (NO)₃)₂•4H₂O was dispersed in 60 mL of ethylenediamine and stirred for 30 min. Subsequently, 7 mmol of Cd (NO) were added₃)₂•4H₂And O, stirring for 30 min. Then, 16 mmol of TAA was added. The reaction mixture was stirred continuously for 1h until a homogeneous viscous suspension was formed. The suspension was then transferred to a 100 mL autoclave and reacted for 24 h at 180 ℃ at constant temperature. After the reaction is finished, deionized water and absolute ethyl alcohol are usedThe resulting precipitate was washed by centrifugation. Finally, drying the product in a vacuum oven at 60 ℃ overnight to obtain the cadmium zinc sulfide photocatalyst Cd_0.7Zn_0.3S-16。

Example 4

Adding 5 mmol of Zn (NO)₃)₂•4H₂O was dispersed in 60 mL of ethylenediamine and stirred for 30 min. Subsequently, 5 mmol of Cd (NO) was added₃)₂•4H₂And O, stirring for 30 min. Then, 16 mmol of TAA was added. The reaction mixture was stirred continuously for 1h until a homogeneous viscous suspension was formed. The suspension was then transferred to a 100 mL autoclave and reacted for 24 h at 180 ℃ at constant temperature. After the reaction is finished, the obtained precipitate is centrifugally washed by deionized water and absolute ethyl alcohol. Finally, drying the product in a vacuum oven at 60 ℃ overnight to obtain the cadmium zinc sulfide photocatalyst Cd_0.5Zn_0.5S-16。

Example 5

Adding 7 mmol of Zn (NO)₃)₂•4H₂O was dispersed in 60 mL of ethylenediamine and stirred for 30 min. Subsequently, 3 mmol of Cd (NO) were added₃)₂•4H₂And O, stirring for 30 min. Then, 16 mmol of TAA was added. The reaction mixture was stirred continuously for 1h until a homogeneous viscous suspension was formed. The suspension was then transferred to a 100 mL autoclave and reacted for 24 h at 180 ℃ at constant temperature. After the reaction is finished, the obtained precipitate is centrifugally washed by deionized water and absolute ethyl alcohol. Finally, drying the product in a vacuum oven at 60 ℃ overnight to obtain the cadmium zinc sulfide photocatalyst Cd_0.3Zn_0.7S-16。

Example 6

Adding 9 mmol of Zn (NO)₃)₂•4H₂O was dispersed in 60 mL of ethylenediamine and stirred for 30 min. Subsequently, 1 mmol of Cd (NO) was added₃)₂•4H₂And O, stirring for 30 min. Then, 16 mmol of TAA was added. The reaction mixture was stirred continuously for 1h until a homogeneous viscous suspension was formed. The suspension was then transferred to a 100 mL autoclave and reacted for 24 h at 180 ℃ at constant temperature. After the reaction is finished, the obtained precipitate is centrifugally washed by deionized water and absolute ethyl alcohol. Finally, will produceDrying the material in a vacuum oven at 60 ℃ overnight to obtain the cadmium zinc sulfide photocatalyst Cd_0.1Zn_0.9S-16。

Example 7

Adding 10 mmol of Zn (NO)₃)₂•4H₂O was dispersed in 60 mL of ethylenediamine and stirred for 30 min. Then, 16 mmol of TAA was added. The reaction mixture was stirred continuously for 1h until a homogeneous viscous suspension was formed. The suspension was then transferred to a 100 mL autoclave and reacted for 24 h at 180 ℃ at constant temperature. After the reaction is finished, the obtained precipitate is centrifugally washed by deionized water and absolute ethyl alcohol. And finally, drying the product in a vacuum oven at 60 ℃ overnight to obtain a zinc sulfide ethylenediamine sample ZnS-16.

Comparative example 1

To 60 mL of ethylenediamine was added 10 mmol of Cd (NO)₃)₂•4H₂And O, stirring for 30 min. Then, 10 mmol of TAA was added. The reaction mixture was stirred continuously for 1h until a homogeneous viscous suspension was formed. The suspension was then transferred to a 100 mL autoclave and reacted for 24 h at 180 ℃ at constant temperature. After the reaction is finished, the obtained precipitate is centrifugally washed by deionized water and absolute ethyl alcohol. And finally, drying the product in a vacuum oven at 60 ℃ overnight to obtain the cadmium sulfide photocatalyst CdS-10.

Comparative example 2

Adding 1 mmol of Zn (NO)₃)₂•4H₂O was dispersed in 60 mL of ethylenediamine and stirred for 30 min. Subsequently, 9 mmol of Cd (NO) were added₃)₂•4H₂And O, stirring for 30 min. Then, 10 mmol of TAA was added. The reaction mixture was stirred continuously for 1h until a homogeneous viscous suspension was formed. The suspension was then transferred to a 100 mL autoclave and reacted for 24 h at 180 ℃ at constant temperature. After the reaction is finished, the obtained precipitate is centrifugally washed by deionized water and absolute ethyl alcohol. Finally, drying the product in a vacuum oven at 60 ℃ overnight to obtain the cadmium zinc sulfide photocatalyst Cd_0.9Zn_0.1S-10。

Comparative example 3

3 mmol of Zn (NO)₃)₂•4H₂O was dispersed in 60 mL of ethylenediamine and stirred for 30 min. Then, addAdding 7 mmol Cd (NO)₃)₂•4H₂And O, stirring for 30 min. Then, 10 mmol of TAA was added. The reaction mixture was stirred continuously for 1h until a homogeneous viscous suspension was formed. The suspension was then transferred to a 100 mL autoclave and reacted for 24 h at 180 ℃ at constant temperature. After the reaction is finished, the obtained precipitate is centrifugally washed by deionized water and absolute ethyl alcohol. Finally, drying the product in a vacuum oven at 60 ℃ overnight to obtain the cadmium zinc sulfide photocatalyst Cd_0.7Zn_0.3S-10。

Comparative example 4

Adding 5 mmol of Zn (NO)₃)₂•4H₂O was dispersed in 60 mL of ethylenediamine and stirred for 30 min. Subsequently, 5 mmol of Cd (NO) was added₃)₂•4H₂And O, stirring for 30 min. Then, 10 mmol of TAA was added. The reaction mixture was stirred continuously for 1h until a homogeneous viscous suspension was formed. The suspension was then transferred to a 100 mL autoclave and reacted for 24 h at 180 ℃ at constant temperature. After the reaction is finished, the obtained precipitate is centrifugally washed by deionized water and absolute ethyl alcohol. Finally, drying the product in a vacuum oven at 60 ℃ overnight to obtain the cadmium zinc sulfide photocatalyst Cd_0.5Zn_0.5S-10。

Comparative example 5

Adding 7 mmol of Zn (NO)₃)₂•4H₂O was dispersed in 60 mL of ethylenediamine and stirred for 30 min. Subsequently, 3 mmol of Cd (NO) were added₃)₂•4H₂And O, stirring for 30 min. Then, 10 mmol of TAA was added. The reaction mixture was stirred continuously for 1h until a homogeneous viscous suspension was formed. The suspension was then transferred to a 100 mL autoclave and reacted for 24 h at 180 ℃ at constant temperature. After the reaction is finished, the obtained precipitate is centrifugally washed by deionized water and absolute ethyl alcohol. Finally, drying the product in a vacuum oven at 60 ℃ overnight to obtain the cadmium zinc sulfide photocatalyst Cd_0.3Zn_0.7S-10。

Comparative example 6

Adding 9 mmol of Zn (NO)₃)₂•4H₂O was dispersed in 60 mL of ethylenediamine and stirred for 30 min. Subsequently, 1 mmol of Cd (NO) was added₃)₂•4H₂And O, stirring for 30 min. Then, 10 mmol of TAA was added. The reaction mixture was stirred continuously for 1h until a homogeneous viscous suspension was formed. The suspension was then transferred to a 100 mL autoclave and reacted for 24 h at 180 ℃ at constant temperature. After the reaction is finished, the obtained precipitate is centrifugally washed by deionized water and absolute ethyl alcohol. Finally, drying the product in a vacuum oven at 60 ℃ overnight to obtain the cadmium zinc sulfide photocatalyst Cd_0.1Zn_0.9S-10。

Comparative example 7

Adding 10 mmol of Zn (NO)₃)₂•4H₂O was dispersed in 60 mL of ethylenediamine and stirred for 30 min. Then, 10 mmol of TAA was added. The reaction mixture was stirred continuously for 1h until a homogeneous viscous suspension was formed. The suspension was then transferred to a 100 mL autoclave and reacted for 24 h at 180 ℃ at constant temperature. After the reaction is finished, the obtained precipitate is centrifugally washed by deionized water and absolute ethyl alcohol. And finally, drying the product in a vacuum oven at 60 ℃ overnight to obtain a zinc sulfide ethylenediamine sample ZnS-10.

Application example 1

The obtained CdS-16 and Cd_0.1Zn_0.9S-16、Cd_0.3Zn_0.7S-16、Cd_0.5Zn_0.5S-16、Cd_0.7Zn_0.3S-16、Cd_0.9Zn_0.1S-16、ZnS-16、CdS-10、Cd_0.1Zn_0.9S-10、Cd_0.3Zn_0.7S-10、Cd_0.5Zn_0.5S-10、Cd_0.7Zn_0.3S-10、Cd_0.9Zn_0.1The S-10 and ZnS-10 catalysts are sequentially used for hydrogen production by water decomposition under visible light, and the specific steps are as follows: 1 mg of the sample was weighed out and added to 100 mL of a solution containing 1.225M Na₂S /0.875 M Na₂SO₃A solution of a sacrificial reagent. The solution is placed in a photocatalytic hydrogen production system, the system is vacuumized for 30 minutes, and then a xenon lamp light source is started to carry out photocatalytic hydrogen production. A photolytic water splitting hydrogen production chromatographic instrument with a TCD detector and a carbon molecular sieve column (TDX-01) is adopted, argon is used as carrier gas, and the generated hydrogen is measured by gas chromatography every 1 h.

FIG. 1 shows Cd in the present invention_1-xZn_xS-16 and Cd_1-xZn_xAn X-ray diffraction pattern (XRD) of S-10; the Cd obtained is shown in a in FIG. 1_1-xZn_xThe XRD peak positions in S-16 are respectively positioned at (002), (110) and (112) faces of the hexagonal CdS in the positions of 26.5 degrees, 43.7 degrees and 51.8 degrees and gradually move to a high angle, which shows that Cd_1-xZn_xSuccessful preparation of S solid solution (dashed line a in fig. 1). B in FIG. 1 also illustrates a series of Cd-like_1-xZn_xSuccessful preparation of S-10 samples. From c in FIG. 1, Cd_0.5Zn_0.5The S-16 crystal form is dominated by sphalerite and comprises wurtzite crystal forms, and ZnS (en) can be observed_0.5Characteristic peak of (2). (quadrangle marking position)

FIG. 2 shows Cd in the present invention_1-xZn_xScanning Electron Microscope (SEM) for S-16. CdS-16 (i.e., pure CdS) has well-grown nanorod morphology, with a diameter of about 50 nm and a length of about 500 nm-1 μm (a in FIG. 2). For Cd_0.9Zn_0.1S-16, the morphology of nanorods about 30-50 nm in diameter and about 500 nm in length can be observed (b in FIG. 2). Cd [ Cd ]_0.5Zn_0.5S-16 presents the morphology of a mixture of popcorn nanoparticles (called nano-popcorn) and platelet-shaped nanoparticles (called nanosheets) (d in FIG. 2). When the material adding amount of the Zn precursor is further increased, Cd_0.3Zn_0.7S-16 and Cd_0.1Zn_0.9Most of the S-16 produced were nanosheets (e and f in FIG. 2), while all of the ZnS-16 produced were ZnS (en)_0.5Nanoplatelets (g in fig. 2).

FIG. 3 shows Cd in the present invention_0.5Zn_0.5Transmission Electron Microscopy (TEM) and selected area elemental mapping (EDX-mapping) of S-16; nano popcorn Cd_1-xZn_xS is composed of many small nanoparticles with high crystallinity (fig. 3a ‒ c). The lattice fringes with interplanar spacing of 0.32 nm and 0.36 nm respectively displayed by high-resolution transmission electron microscopy (HRTEM) images correspond to Cd_1−xZn_xThe ZB lattice (111) plane of S solid solution and the WZ lattice (100) plane. A phase formed between ZB and WZ crystal lattices, i.e. sphalerite/wurtzite phase junction Cd_1-xZn_xAnd S nanometer popcorn. For Cd_0.5Zn_0.5Nanosheets in S-16 (d in FIG. 3), on nanoplatesLattice fringes measuring about 0.32 nm interplanar spacing can be attributed to ZnS (en)_0.5Middle (020) diffraction plane. Selected Area Electron Diffraction (SAED) images (inset in fig. 3 e) and HRTEM images (f in fig. 3) indicate that the nanoplatelets are polycrystalline. High angle annular dark field transmission electron microscopy (HAADF-STEM) and energy dispersive X-ray spectroscopy (e-g in FIG. 2) illustrate ZnS (en)_0.5Nanosheet and Cd_1−xZn_xS successfully preparing the nano popcorn.

FIG. 4 shows Cd in the present invention_1-xZn_xS-16 and Cd_1-xZn_xS-10 photocatalyst photocatalytic water splitting hydrogen production activity diagram and Cd_0.5Zn_0.5And (3) a hydrogen production apparent quantum yield and stability test chart of the S sample. As can be seen from a ‒ b in FIG. 4, Cd_0.5Zn_0.5The hydrogen production rate of S-16 reaches 282.14 mu mol h⁻¹mg⁻¹Cd prepared with the same dose of thioacetamide_0.5Zn_0.5The hydrogen production rate of S is improved by about 12 times. The excellent photocatalytic hydrogen production performance exceeds most of reported Cd_1-xZn_xAn S-based material. Meanwhile, as can be seen from c ‒ d in fig. 4, the apparent quantum yield of the catalyst at 420nm reaches 64.4%, and the catalyst has excellent stability.

The preferred embodiments of the present invention described above are only for illustrating the present invention and are not to be construed as limiting the scope of the present invention. All equivalent changes and modifications made within the scope of the present application shall fall within the scope of the present invention without creative efforts.

Claims

1. CdZnTe Cd with sphalerite/wurtzite junction_1-xZn_xThe preparation method of the S-16 photocatalyst is characterized by comprising the following steps: using ethylenediamine as solvent and Zn (NO)₃)₂•4H₂O and Cd (NO)₃)₂•4H₂O as a precursor, or Zn (NO)₃)₂•4H₂O and Cd (NO)₃)₂•4H₂O, one of the reagents is used as a precursor, equivalent or excessive thioacetamide is added as a sulfur source, and the nano popcorn-shaped cadmium zinc sulfide Cd is prepared by one-step solvothermal reaction_1-xZn_xAn S-16 photocatalyst, wherein x = 0-1.

2. Cadmium zinc sulfide (Cd) as claimed in claim 1_1-xZn_xThe preparation method of the S-based photocatalyst is characterized by comprising the following steps: the method comprises the following specific steps:

(1) adding 10x mmol of Zn (NO)₃)₂•4H₂Dispersing O in 60 mL of ethylenediamine en, and stirring for 30 min; subsequently, 10(1-x) mmol of Cd (NO) was added₃)₂•4H₂O, continuously stirring for 30 min;

(2) then, adding thioacetamide TAA with the same amount or excessive dose as a sulfur source, continuously stirring the reaction mixture for 1h until uniform viscous suspension is formed, sealing the obtained suspension in a 100 mL-capacity autoclave with a polytetrafluoroethylene lining, carrying out solvothermal reaction, and washing the obtained precipitate after the reaction is finished;

(3) finally, the product is dried in a vacuum oven overnight to obtain Cd_1-xZn_xAn S-based photocatalyst.

3. Cadmium zinc sulfide (Cd) as claimed in claim 2_1-xZn_xThe preparation method of the S-based photocatalyst is characterized by comprising the following steps: wherein x refers to the molar ratio of Zn/(Zn + Cd) in the Zn and Cd precursors.

4. Cadmium zinc sulfide (Cd) as claimed in claim 3_1-xZn_xThe preparation method of the S-based photocatalyst is characterized by comprising the following steps: the value of x is any one of the ranges of 0, 0.1, 0.3, 0.5, 0.7, 0.9 and 1.

5. Cadmium zinc sulfide (Cd) as claimed in claim 2_1-xZn_xThe preparation method of the S-based photocatalyst is characterized by comprising the following steps: the thioacetamide is 10-22 mmol.

6. Cadmium zinc sulfide (Cd) as claimed in claim 2_1-xZn_xThe preparation method of the S-based photocatalyst is characterized by comprising the following steps: said equivalent weightThe thioacetamide value is 10 mmol, and the excessive value is 16 mmol.

7. Cadmium zinc sulfide (Cd) as claimed in claim 2_1-xZn_xThe preparation method of the S-based photocatalyst is characterized by comprising the following steps: the solvent thermal reaction in the step (2) is carried out for 24 hours at 180 ℃.

8. Cadmium zinc sulfide (Cd) as claimed in claim 1_1-xZn_xThe preparation method of the S-based photocatalyst is characterized by comprising the following steps: and (4) controlling the temperature of the vacuum oven in the step (3) to be 60 ℃.

9. Cadmium zinc sulfide (Cd) with sphalerite/wurtzite junction prepared by the method of any one of claims 1 to 8_1- _xZn_xS-16 photocatalyst.

10. Cadmium zinc sulfide (Cd) with sphalerite/wurtzite junction prepared by the method of any one of claims 1 to 8_1- _xZn_xThe S-16 photocatalyst is applied to the visible light photocatalytic decomposition of water to produce hydrogen.