CN110385146B

CN110385146B - Ni0.85Se/PDA/g-C3N4Composite photocatalyst and application thereof

Info

Publication number: CN110385146B
Application number: CN201910731656.3A
Authority: CN
Inventors: 陈文倩; 唐量; 陈锦怡; 柯书强; 吴明红
Original assignee: University of Shanghai for Science and Technology
Current assignee: University of Shanghai for Science and Technology
Priority date: 2019-08-08
Filing date: 2019-08-08
Publication date: 2022-06-24
Anticipated expiration: 2039-08-08
Also published as: CN110385146A

Abstract

The invention discloses Ni_0.85Se/PDA/g‑C₃N₄The composite photocatalyst takes carbon nitride nanosheets as carriers, and Polydopamine (PDA) and Ni are loaded on the carbon nitride nanosheets_0.85Se nanoparticles. The composite catalyst has the advantages of environmental friendliness, high separation efficiency of photon-generated carriers, large visible light absorption area and the like; meanwhile, the raw materials are easy to obtain, the preparation process is simple, the operation is easy, and the method has good repeatability and high photocatalytic activity. By optimizing Ni_0.85The loading capacity and hydrogen generation capacity of the Se cocatalyst are 3.17 times higher than those of pure carbon nitride nanosheets and are higher than those of PDA/g-C₃N₄The composite catalyst is 2.4 times higher. Therefore, the method has good application prospect in the field of photolysis of water to produce hydrogen.

Description

Ni0.85Se/PDA/g-C3N4Composite photocatalyst and application thereof

Technical Field

The invention belongs to the technical field of multi-element semiconductor composite materials, and particularly relates to Ni_0.85Se/PDA/g-C₃N₄The composite photocatalyst and the application thereof in the direction of hydrogen production by photolysis.

Background

Hydrogen energy is a clean energy source. Sustainable solar energy is converted into hydrogen energy by utilizing a semiconductor catalyst, and the problems of fossil fuel exhaustion and environmental pollution can be reduced at the same time. Graphite phase carbon nitride (g-C)₃N₄) The first semiconductor polymer without metal attracts great attention in the field of photocatalytic energy conversion due to the advantages of visible light absorption, no toxicity, low cost, excellent chemical and thermal stability, environmental friendliness and the like. However, the carbon nitride has a small specific surface area, photogenerated carriers are easy to recombine, and the edge absorption (absorption wavelength) in a visible light region is realized<455) And the poor conductivity limits the practical application of carbon nitride in the field of hydrogen production by water photolysis.

Recent studies have shown thatThe carbon material or the catalyst promoter is loaded on the surface of the carbon nitride, which is one of the simplest and most effective methods for improving the low efficiency of separation of photo-generated electrons and holes and improving the absorption of visible light so as to realize the effective photolysis of the activity of water to generate hydrogen. The noble metal platinum has proved to be an excellent promoter, but it has the disadvantages of scarce resources and high price. In recent years, transition metal chalcogenides, such as MoS₂，NiS，CoS，MoSe₂Etc., have been widely used as gC instead of platinum₃N₄The cocatalyst of (1).

Dopamine is a small biological molecule that spontaneously polymerizes under slightly alkaline conditions on any surface to form a tight Polydopamine (PDA) coating. PDA, as a carbon material, does not have the capability of photolyzing water to produce hydrogen. But since PDA has excellent light trapping ability, good photoconductivity and abundant catechol group, it can effectively transfer and separate photogenerated carriers. Recent studies have shown that the photocatalytic activity of carbon nitride can be improved by using PDA as a polymer nano-coating to modify carbon nitride.

Disclosure of Invention

In order to overcome the defects in the prior art, the invention provides Ni_0.85Se/PDA/g-C₃N₄The ternary composite photocatalyst is used for hydrogen production by photolysis of water and degradation of organic dye, so as to achieve the purposes of reducing the catalytic cost and improving the catalytic efficiency.

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

the first aspect of the present invention is to provide Ni_0.85Se/PDA/g-C₃N₄The composite photocatalyst material takes a carbon nitride nanosheet as a carrier, and polydopamine PDA and Ni are loaded on the carbon nitride nanosheet_0.85Se nanoparticles.

Further, Ni in the composite photocatalyst_0.85The load capacity of the Se nano-particles is 3 wt% -20 wt%. More preferably, Ni_0.85The load capacity of the Se nano-particles is 8-12 wt%; most preferably, Ni_0.85The loading of the Se nanoparticles was 10 wt%.

Further, the preparation method of the composite photocatalyst comprises the following steps:

step 1) ultrasonically mixing carbon nitride nanosheets and weakly alkaline Tris-HCl buffer solution, adding dopamine hydrochloride, and strongly stirring for 15-25 hours;

step 2) adding a certain amount of Ni_0.85Ultrasonically mixing Se nanoparticles with a weakly alkaline Tris-HCl buffer solution to obtain Ni_0.85Se homogenizing liquid; adding the Ni_0.85Dropwise adding the Se homogeneous solution into the solution obtained in the step 1), and stirring for 6-10 hours; the product is filtered, dried and ground to obtain Ni_0.85Se/PDA/g-C₃N₄A ternary composite photocatalyst.

Further, the preparation step of the carbon nitride nanosheet comprises: the carbon nitride nanosheet is prepared from urea serving as a raw material through calcination and thermal stripping.

Further, the Ni_0.85The preparation steps of the Se nano-particles comprise: preparing Ni from selenium powder, sodium borohydride and nickel chloride through solvothermal reaction_0.85Se nanoparticles.

Further, the dosage of the dopamine hydrochloride in the step 1) is 8-15% of the mass of the carbon nitride nanosheet; more preferably, the dosage of the dopamine hydrochloride is 10% of the mass of the carbon nitride nanosheet, and the polymerization time is 20 hours.

Further, the pH value of the weak alkaline Tris-HCl buffer solution is 8-9; more preferably, the pH is 8.5.

Further, in the step 2), the stirring time is 8 hours.

Further, the preparation method of the composite photocatalyst specifically comprises the following steps:

step 1: weighing a predetermined amount of urea, calcining at 520-580 ℃ for 2-6 h at a heating rate of 4-6 ℃/min, cooling to room temperature, and grinding into fine powder; calcining the fine powder at 470-530 ℃ for 1-3 h at the heating rate of 4-6 ℃/min, and cooling to room temperature to obtain carbon nitride nanosheets;

and 2, step: weighing a predetermined amount of selenium powder and sodium borohydride, putting the selenium powder and the sodium borohydride into a certain amount of DMF, and stirring for 0.5-2 hours; then adding reservationContinuously stirring the nickel chloride hexahydrate for 20-40 min, and reacting for 18-30 h at 140-180 ℃; repeatedly washing the obtained black product with ethanol and deionized water, drying at 50-70 ℃ for 8-16 hours, and grinding into powder to obtain Ni_0.85Se nanoparticles.

And step 3: weighing a predetermined amount of the carbon nitride nanosheets prepared in the step 1, putting the carbon nitride nanosheets into a weak alkaline Tris-HCl buffer solution, and performing ultrasonic homogenization; adding a predetermined amount of dopamine hydrochloride, and violently stirring for 15-25 h;

and 4, step 4: weighing a predetermined amount of Ni prepared in step 2_0.85Placing Se nanoparticles into a weak alkaline Tris-HCl buffer solution, and carrying out intermittent ultrasonic treatment for 0.5-2 min to obtain a homogeneous solution; dropwise adding the homogenized solution into the solution obtained in the step (3), and violently stirring for 6-10 hours;

and 5: performing suction filtration, drying and grinding on the product obtained in the step 4 for multiple times to obtain polydopamine PDA and Ni_0.85Se-loaded ternary composite catalyst Ni_0.85Se/PDA/g-C₃N₄。

step 1: weighing a predetermined amount of urea, calcining at 550 ℃ for 4h at a heating rate of 5 ℃/min, cooling to room temperature, and grinding into fine powder; calcining the fine powder at the temperature rise rate of 5 ℃/min for 2h at 500 ℃, and cooling to room temperature to obtain carbon nitride nanosheets;

step 2: weighing a predetermined amount of selenium powder and sodium borohydride, putting the selenium powder and the sodium borohydride into a certain amount of DMF, and stirring for 1 h; adding a predetermined amount of nickel chloride hexahydrate, continuously stirring for 30min, and reacting for 24h at 160 ℃; washing the obtained black product with ethanol and deionized water repeatedly, drying at 60 deg.C for 12 hr, grinding into powder to obtain Ni_0.85Se nanoparticles.

And 3, step 3: weighing a predetermined amount of the carbon nitride nanosheet prepared in the step 1, putting the carbon nitride nanosheet into Tris-HCl buffer solution with the pH value of 8.5, and performing ultrasonic homogenization on the carbon nitride nanosheet; adding a predetermined amount of dopamine hydrochloride, and stirring vigorously for 20 hours;

and 4, step 4: weighing a predetermined amount of Ni prepared in step 2_0.85Nanoparticles of SeAdding into Tris-HCl buffer solution with pH of 8.5, and intermittently performing ultrasonic treatment for 1min to obtain homogeneous solution; dropwise adding the homogenized solution into the solution obtained in the step (3), and violently stirring for 8 hours;

A second aspect of the present invention is to provide any one of the above Ni_0.85Se/PDA/g-C₃N₄The application of the photocatalyst in the photolysis of water to produce hydrogen or the degradation of organic dye.

Further, the method for producing hydrogen by photolyzing water comprises the following steps: weighing a preset amount of composite photocatalyst, mixing the composite photocatalyst with a preset amount of triethanolamine aqueous solution, and performing ultrasonic treatment; and (3) sealing and vacuumizing the mixed solution, and simulating sunlight by using a xenon lamp for illumination to prepare the hydrogen.

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

(1) the invention has the advantages of easily obtained raw materials, simple preparation process, easy operation, no toxicity and good repeatability, and is beneficial to the popularization and application of the technology.

(2) In the invention, the composition of Polydopamine (PDA) not only obviously improves the absorption range of the carbon nitride nanosheet in a visible light region and the separation efficiency of a photon-generated carrier, but also can be used as a binder to tightly fix the nickel selenide nanoparticle in the polymerization process.

(3) Ni in the invention_0.85Se/PDA/g-C₃N₄The ternary composite photocatalyst has excellent hydrogen production photolysis activity. By optimizing Ni_0.85Se loading amount of Ni of 10% by mass_0.85Three-way catalyst of Se nanoparticles has the best catalytic activity, H₂The yield is 3.17 times higher than that of pure carbon nitride nano-sheets and is higher than that of PDA/g-C₃N₄The composite catalyst is 2.4 times higher.

Drawings

FIG. 1 shows Ni in an embodiment of the present invention_0.85Se/PDA/g-C₃N₄Ternary complexA schematic flow diagram of the preparation of the synthetic catalyst;

FIG. 2 shows 10Ni prepared according to example 3 of the present invention_0.85Se/PDA/g-C₃N₄TEM images of the catalyst;

FIG. 3 shows CN, PDA/CN and different Ni prepared according to examples of the present invention and comparative examples_0.85XRD pattern of Se-loaded three-way catalyst;

FIG. 4 shows Ni prepared in an embodiment of the present invention_0.85XRD pattern of Se;

FIG. 5 shows CN, PDA/CN and 10Ni prepared according to example 3 of the present invention and comparative example_0.85Solid fluorescence spectrum of Se-PDA/CN catalyst;

FIG. 6 shows CN, PDA/CN and 10Ni prepared according to example 3 of the present invention and comparative example_0.85Solid ultraviolet spectrogram of Se-PDA/CN catalyst;

FIG. 7 shows CN, PDA/CN and different Ni prepared according to examples and comparative examples of the present invention_0.85And performing hydrogen production diagram of photolyzing water by using the three-way catalyst with Se loading.

Detailed Description

The invention relates to Ni_0.85Se/PDA/g-C₃N₄The composite photocatalyst takes a carbon nitride nanosheet as a carrier, and polydopamine PDA and Ni0.85Se nanoparticles are loaded on the carbon nitride nanosheet; wherein, Ni is contained in the composite photocatalyst_0.85The load capacity of the Se nano-particles is 3 wt% -20 wt%. Ni in the following examples_0.85Se/PDA/g-C₃N₄The preparation process of the three-way composite catalyst is shown in figure 1.

The following description of the embodiments of the present invention will be made with reference to the accompanying drawings. The following examples are only for illustrating the technical solutions of the present invention more clearly, and the protection scope of the present invention is not limited thereby.

The experimental methods in the following examples are all conventional methods unless otherwise specified; the raw materials, reagents and the like used in the following examples are all available from public commercial sources unless otherwise specified.

Example 1

This example is Ni_0.85Se loading of 3 wt% Ni_0.85Se/PDA/g-C₃N₄A better preparation method of the ternary composite photocatalyst comprises the following steps:

step 1: about 30 g of urea was weighed into a 50ml crucible with a cover, calcined at 550 ℃ for 4h at a heating rate of 5 ℃/min, cooled to room temperature, and ground into fine powder with a mortar. And then placing the fine powder into a crucible without a cover, calcining for 2 hours at 500 ℃ at the heating rate of 5 ℃/min, and cooling to room temperature to obtain the carbon nitride nanosheet.

And 2, step: 0.316g of selenium powder and 0.190g of sodium borohydride are weighed and put into 65mL of DMF, and the mixture is magnetically stirred for 1 hour. 0.808g of nickel chloride (hexahydrate) was added and stirring was continued for 30 min. It was transferred to a 100mL autoclave and reacted at 160 ℃ for 24 hours. The obtained black product was repeatedly washed with ethanol and deionized water, dried at 60 ℃ for 12 hours, and ground into powder with a mortar to obtain Ni_0.85Se nanoparticles.

And step 3: 0.1g of carbon nitride was accurately weighed, put into 40mL of Tris-HCl buffer (pH 8.5), and sonicated in an ultrasonic cleaner at 100Hz for 0.5 h. Then 10mg dopamine hydrochloride is added and stirred vigorously for 20 h.

And 4, step 4: accurately weigh 3mg of Ni obtained in step 2_0.85Se nanoparticles were put into 20mL of Tris-HCl buffer (pH 8.5), and subjected to intermittent ultrasound with an ultrasonic bar at a power of 300W for 1min to obtain a homogeneous solution. The homogeneous solution was added dropwise to the solution of step 3 and stirred vigorously for 8 h.

And 5: the product is filtered, dried and ground for a plurality of times to obtain 3 wt% Ni_0.85Se-supported three-way composite catalyst named 3Ni_0.85Se-PDA/CN。

Example 2

This example is Ni_0.85Se loading of 5 wt% Ni_0.85Se/PDA/g-C₃N₄A better preparation method of the ternary composite photocatalyst comprises the following steps:

steps 1 to 3 are the same as in example 1.

And 4, step 4: accurately weigh 5mg of Ni obtained in step 2_0.85Se nanoparticles were put into 20mL of Tris-HCl buffer (pH 8.5), and subjected to intermittent ultrasound with an ultrasonic bar at a power of 300W for 1min to obtain a homogeneous solution. The homogeneous solution was added dropwise to the solution of step 3 and stirred vigorously for 8 h.

And 5: the product is filtered, dried and ground for a plurality of times to obtain 5 wt% Ni_0.85Se-supported three-way composite catalyst named as 5Ni_0.85Se-PDA/CN。

Example 3

This example is Ni_0.85Se loading of 10 wt% Ni_0.85Se/PDA/g-C₃N₄A better preparation method of the ternary composite photocatalyst comprises the following steps:

steps 1 to 3 are the same as in example 1.

And 4, step 4: accurately weigh 10mg of Ni obtained in step 2_0.85Se nanoparticles were put into 20mL of Tris-HCl buffer (pH 8.5), and subjected to intermittent ultrasound with an ultrasonic bar at a power of 300W for 1min to obtain a homogeneous solution. The homogeneous solution was added dropwise to the solution of step 3 and stirred vigorously for 8 h.

And 5: the product is filtered, dried and ground for a plurality of times to obtain 10 wt% Ni_0.85Se-supported three-way composite catalyst named as 10Ni_0.85Se-PDA/CN。

Example 4

This example is Ni_0.85Se loading of 20 wt% Ni_0.85Se/PDA/g-C₃N₄A better preparation method of the ternary composite photocatalyst comprises the following steps:

steps 1 to 3 are the same as in example 1.

And 4, step 4: accurately weigh 20mg of Ni obtained in step 2_0.85Se nanoparticles were put into 20mL of Tris-HCl buffer (pH 8.5), and subjected to intermittent ultrasound with an ultrasonic bar at a power of 300W for 1min to obtain a homogeneous solution. The homogeneous solution was added dropwise to the solution of step 3 and stirred vigorously for 8 h.

And 5: the product is filtered, dried and ground for a plurality of times to obtain 20 wt% Ni_0.85Ternary recombination of Se loadCatalyst, named 20Ni_0.85Se-PDA/CN。

Comparative example 1

The comparative example is a method of preparing unsupported carbon nitride nanoplates, comprising the steps of:

about 30 g of urea was weighed into a 50ml crucible with a cover, calcined at 550 ℃ for 4h at a heating rate of 5 ℃/min, cooled to room temperature, and ground into fine powder with a mortar. And then putting the fine powder into a crucible without a cover, calcining for 2 hours at 500 ℃ at the heating rate of 5 ℃/min, and cooling to room temperature to obtain the carbon nitride nanosheet, which is named as CN.

Comparative example 2

The comparative example is a preparation method of a carbon nitride nanosheet only loaded with PDA, and the preparation method comprises the following steps:

And 2, step: 0.1g of carbon nitride was accurately weighed, and put into 40mL of Tris-HCl buffer (pH 8.5) and sonicated in a sonicator at a frequency of 100Hz for 0.5 h. Then 10mg dopamine hydrochloride is added, and the mixture is stirred for 20 hours by intense magnetic force. 20mL of Tris-HCl buffer (pH 8.5) was added and stirring was continued for 8 h. And carrying out suction filtration, drying and grinding on the product to obtain the polydopamine/carbon nitride composite catalyst named PDA/CN.

Performance characterization examples

The characterization of the catalysts prepared in the embodiments 1-4 and the comparative examples 1-2 of the invention specifically comprises the following steps:

_0.85(1) transmission electron microscopy characterization of 10NiSe-PDA/CN

Specifically, FIG. 2 shows 10Ni prepared according to example 3_0.85The transmission electron microscope picture of the Se-PDA/CN ternary composite photocatalyst shows that the layered g-C is uniformly coated with the PDA coating₃N₄Upper, much black Ni_0.85Nanoparticles of Se are deposited on the surface thereof.

_0.85(2) X-ray diffraction characterization of CN, PDA/CN and three-way catalyst of different NiSe loading

Specifically, FIG. 3 clearly shows CN, PDA/CN and different Ni prepared in examples 1 to 4 and comparative examples 1 to 2_0.85XRD pattern of powder characterized by X-ray diffraction of Se-loaded three-way catalyst; it can be seen that all XRD patterns exhibit similar patterns with the most typical characteristic peaks of graphite phase carbon nitride. In the XRD patterns of all three-way composite catalyst samples in figure 3, no PDA or Ni can be detected_0.85Se, which may be due to Ni loading_0.85Low Se nanoparticle content and low PDA crystallinity.

_0.85(3) X-ray diffraction characterization of NiSe

Specifically, fig. 4 clearly shows Ni prepared according to example 1_0.85XRD pattern of powder of Se; therefore, the actually measured XRD pattern is perfectly matched with the standard card, thereby showing that the prepared Ni is_0.85The purity of Se is high.

_0.85(4) Solid state fluorescence characterization of CN, PDA/CN and 10NiSe-PDA/CN

Specifically, fig. 5 shows 10Ni prepared according to example 3_0.85Se-PDA/CN ternary composite photocatalyst and CN prepared in comparative examples 1-2 and solid fluorescence spectrograms of PDA/CN can be seen in 10Ni_0.85The Se-PDA/CN catalyst has the lowest fluorescence emission intensity, which shows that the separation efficiency of the photo-generated carriers of the catalyst is the fastest.

_0.85(5) UV characterization of solids for CN, PDA/CN and 10NiSe-PDA/CN

Specifically, in the solid UV spectrogram of CN and PDA/CN prepared in FIG. 6, the loading of visible PDA is significantly improved in the visible light region (λ)>420nm) with 10 wt% Ni_0.85The Se loading further improves the visible light absorption of PDA/CN.

Application examples

In the application example, the photocatalyst according to examples 1 to 4 and comparative examples 1 to 2 is used for photolyzing water to prepare hydrogen, and the method specifically comprises the following steps:

step 1, weighing 50mg of photocatalyst and adding the photocatalyst into a glass reaction bottle;

step 2, adding 50mL of 10% triethanolamine aqueous solution into the glass reaction bottle, and carrying out ultrasonic treatment for a period of time;

and 3, connecting the glass reaction bottle to a multi-channel reactor communicated with a gas chromatograph, sealing and vacuumizing, and simulating sunlight by using a 300W xenon lamp for illumination to prepare hydrogen.

Referring to FIG. 7, it can be seen that a species of Ni_0.85The Se-PDA/CN ternary composite material is used as a photocatalyst, and the photocatalytic activity is improved under the condition that triethanolamine is used as a hole sacrificial agent. By optimizing the loading of the nickel selenide promoter, 10Ni_0.85Se-PDA/CN has the best catalytic activity, and the hydrogen generation amount is 3.17 times higher than that of pure carbon nitride nanosheets and 2.4 times higher than that of the PDA/CN composite catalyst. It can be seen that the Ni prepared in the examples of the present invention_0.85Se/PDA/g-C₃N₄The three-way catalyst has high photocatalytic activity and can decompose water into hydrogen without any photosensitizer or platinum promoter.

The embodiments of the present invention have been described in detail, but the embodiments are merely examples, and the present invention is not limited to the embodiments described above. Any equivalent modifications and substitutions to those skilled in the art are also within the scope of the present invention. Accordingly, equivalent changes and modifications made without departing from the spirit and scope of the present invention should be covered by the present invention.

Claims

1. Ni_0.85Se/PDA/g-C₃N₄The composite photocatalyst is characterized in that the composite photocatalyst material takes a carbon nitride nanosheet as a carrier, and polydopamine PDA and Ni are loaded on the carbon nitride nanosheet_0.85Nanoparticles of Se; ni in the composite photocatalyst_0.85The load capacity of the Se nano-particles is 3 wt% -20 wt%.

2. Ni according to claim 1_0.85Se/PDA/g-C₃N₄The composite photocatalyst is characterized by comprising the following preparation steps:

3. Ni according to claim 2_0.85Se/PDA/g-C₃N₄The composite photocatalyst is characterized in that the preparation steps of the carbon nitride nanosheet comprise: the method takes urea as a raw material, and prepares the carbon nitride nanosheet through calcination and thermal stripping.

4. Ni according to claim 2_0.85Se/PDA/g-C₃N₄The composite photocatalyst is characterized in that Ni is_0.85The preparation steps of the Se nano-particles comprise: preparing Ni by taking selenium powder, sodium borohydride and nickel chloride as raw materials through solvothermal reaction_0.85Nanoparticles of Se.

5. Ni according to claim 2_0.85Se/PDA/g-C₃N₄The composite photocatalyst is characterized in that in the step 1), the dosage of dopamine hydrochloride is 8-15% of the mass of the carbon nitride nanosheets, the polymerization pH is 8-9, and the polymerization time is 15-25 h.

6. Ni according to claim 2_0.85Se/PDA/g-C₃N₄The composite photocatalyst is characterized by comprising the following preparation steps:

and 2, step: weighing a predetermined amount of selenium powder and sodium borohydride, putting the selenium powder and the sodium borohydride into a certain amount of DMF, and stirring for 0.5-2 hours; adding a predetermined amount of nickel chloride hexahydrate, continuously stirring for 20-40 min, and reacting for 18-30 h at 140-180 ℃; repeatedly washing the obtained black product with ethanol and deionized water, drying at 50-70 ℃ for 8-16 hours, and grinding into powder to obtain Ni_0.85Se nanoparticles;

and step 3: weighing a predetermined amount of the carbon nitride nanosheets prepared in the step 1, putting the carbon nitride nanosheets into a weakly alkaline Tris-HCl buffer solution, and carrying out ultrasonic homogenization on the carbon nitride nanosheets; adding a predetermined amount of dopamine hydrochloride, and violently stirring for 15-25 h;

and 5: filtering, drying and grinding the product obtained in the step 4 for multiple times to obtain polydopamine PDA and Ni_0.85Se-loaded ternary composite catalyst Ni_0.85Se/PDA/g-C₃N₄。

7. Ni according to any one of claims 1 to 6_0.85Se/PDA/g-C₃N₄The composite photocatalyst is applied to the photolysis of water to produce hydrogen or the degradation of organic dyes.

8. The use according to claim 7, wherein the method for photolyzing water to produce hydrogen comprises the following steps: weighing a predetermined amount of composite photocatalyst, mixing with a predetermined amount of triethanolamine aqueous solution, and performing ultrasonic treatment; and (3) sealing and vacuumizing the mixed solution, and simulating sunlight by using a xenon lamp for illumination to prepare the hydrogen.