Copper phosphide modified microspherical zinc selenide photocatalytic material, preparation method and application thereof

Abstract

The application provides a kind of copper phosphide modified microspheres type zinc selenide photocatalytic material and its preparation method and application, zinc selenide is microspherical structure, copper phosphide nanoparticles are loaded on the surface of zinc selenide microspheres, and the molar ratio of copper phosphide and zinc selenide is 1:99-5:95.The method comprises preparing ZnSe microsphere precursor and Cu3P nanoparticles;Cu3P nanoparticles and ZnSe microsphere precursor are dispersed in ethanol, after stirring for a certain time, ultrasonic treatment is carried out, and a mixed solution I is obtained;After centrifugation, washing and separation treatment, vacuum drying is carried out for 10-14h, and Cu3P / ZnSe composite photocatalytic material is obtained.Cu3P nanoparticle promoter prepared by phosphatization is used to modify microspherical zinc selenide, to realize low-cost Cu3P as promoter to form high-performance photocatalyst, as efficient photocatalytic or photoelectrocatalytic water splitting hydrogen production catalyst, with very high practical value and application prospect.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of semiconductor photocatalytic water splitting for hydrogen production, and particularly relates to a copper phosphide modified microspherical zinc selenide photocatalytic material and a preparation method and application thereof. BACKGROUND

[0002] Due to overuse of fossil energy, a series of environmental problems such as greenhouse effect and acid rain are caused, and hydrogen energy is considered as the most ideal new energy in the future because of its cyclic nature, zero pollution, high efficiency and safety. Photocatalytic water splitting for hydrogen production using abundant solar energy and water resources is a reasonable and clean way, and since Fujishima and Honda proposed that water is photoinduced to hydrogen and oxygen on a semiconductor titanium dioxide electrode, photocatalytic water splitting for hydrogen production has been widely concerned by researchers.

[0003] At present, common photocatalysts include metal oxides, metal sulfides, g-C3N4 and the like. However, the common semiconductors have some problems such as low solar utilization rate, high recombination rate of photo-generated carriers and poor stability of photocatalysts. Using a supported cocatalyst is an effective modification method, and currently, noble metal nanoparticles such as Pt or Pd are usually used as cocatalysts to be loaded on the surface of semiconductors to construct composite catalysts. However, the scarcity and high cost of platinum / palladium noble metals hinder their large-scale application. The application of transition metal phosphides in photocatalysis has also become a hot research object, and Cu3P as a member of transition metal phosphides has good visible light response and low cost, and is concerned by more researchers in the field of photocatalysis.

[0004] Metal selenides are considered as one of the good candidate materials due to their unique photoelectric and catalytic properties. Among them, zinc selenide (ZnSe) is a typical chalcogenide compound, and has excellent photoelectrochemical stability and photocatalytic performance, and thus is favored by many researchers. However, ZnSe has some problems such as low solar utilization rate, high recombination rate of photo-generated carriers and poor stability of photocatalysts, which seriously limits the photocatalytic activity of pure ZnSe. Therefore, taking appropriate modification strategies is the key to improving the photocatalytic hydrogen production ability of ZnSe. SUMMARY

[0005] In order to solve the problems mentioned in the technical background, the application provides a copper phosphide modified microspherical zinc selenide photocatalytic material and a preparation method and application thereof.

[0006] In a first aspect, the application provides a copper phosphide modified microspherical zinc selenide photocatalytic material, wherein the zinc selenide is in a microspherical structure, copper phosphide nanoparticles are loaded on the surface of the microspheres of the zinc selenide, and the molar ratio of the copper phosphide to the zinc selenide is 1:99-5:95.

[0007] In some specific embodiments, the molar ratio of copper phosphide to zinc selenide is one or more of 1:99, 2:98, 3:97, and 5:95.

[0008] In some specific embodiments, the diameter of the zinc selenide microspheres is 2-3 pm.

[0009] In a second aspect, the present application provides a preparation method of copper phosphide modified microsphere type zinc selenide photocatalytic material, comprising:

[0010] S1, preparing ZnSe microsphere precursor and Cu3P nanoparticles.

[0011] S2, dispersing the Cu3P nanoparticles and the ZnSe microsphere precursor in ethanol, stirring for a fixed time, and then ultrasonic treatment to obtain a mixed solution I, the molar ratio of the Cu3P nanoparticles to the ZnSe microsphere precursor being 1:99-5:95.

[0012] S3, after the mixed solution I is subjected to centrifugal, washing, and separation treatment, vacuum drying for 10-14 h to obtain a Cu3P / ZnSe composite photocatalytic material.

[0013] In some specific embodiments, the preparation step of the ZnSe microsphere precursor comprises:

[0014] S11, dissolving zinc acetate and sodium selenite with a molar ratio of 1:1 in deionized water, adding 5 mol / L sodium hydroxide solution after magnetic stirring for 30 min, and then obtaining a clear mixed solution II.

[0015] S12, mixing and stirring the mixed solution II with 10 mL of hydrazine hydrate for 30 min, then transferring to a stainless steel hydrothermal kettle, heating at 180°C for 24 h, cooling to room temperature, and obtaining a mixed product I.

[0016] S13, after washing the mixed product I, placing it in a vacuum drying box at 70°C, and drying for 8 h to obtain a ZnSe microsphere precursor.

[0017] Further, the amount of substance of sodium hydroxide in the sodium hydroxide solution added in the step S11 is 0.12 mol.

[0018] In some specific embodiments, the preparation step of the Cu3P nanoparticles comprises:

[0019] S11', dissolving copper sulfate pentahydrate in deionized water, slowly adding sodium hydroxide solution after stirring for 30 min, mixing and stirring for 60 min, washing and drying to obtain a Cu(OH)2 product, and the molar ratio of copper sulfate pentahydrate to sodium hydroxide being 0.3-0.5.

[0020] S12', after grinding the Cu(OH)2 product and sodium hypophosphite in a grinding body, calcining the mixture at 300 DEG C in a nitrogen environment for 60 min to obtain a mixed product two.

[0021] S13', washing and drying the mixed product two to obtain Cu3P nanoparticles.

[0022] Further, in the step S12', the molar ratio of the Cu(OH)2 product to sodium hypophosphite is 0.1-0.3.

[0023] In a third aspect, the application provides an application of the CuP modified microspherical ZnSe photocatalytic material, the CuP modified microspherical ZnSe photocatalytic material described in the first aspect or prepared by the method described in the second aspect is used as a photocatalyst in photocatalytic and photoelectrocatalytic water splitting.

[0024] In some specific embodiments, Na2S and Na2SO2 solution are used as a sacrificial agent in the application of photocatalytic water splitting.

[0025] Compared with the prior art, the application has the advantages of:

[0026] (1) The Cu3P nanoparticle cocatalyst prepared by phosphatization is used to modify the microspherical ZnSe by mechanical mixing to form a high-performance photocatalyst, and a small amount of Cu3P loaded on the photocatalyst shows high photocatalytic activity under visible light, and Cu3P has the function of promoting charge separation, which can improve the problems of low solar energy utilization rate, high photo-generated carrier recombination rate and poor stability of the photocatalyst.

[0027] (2) The application optimizes the molar ratio of Cu3P nanoparticles and ZnSe microspheres in the Cu3P / ZnSe composite catalyst to obtain a 3Cu3P / ZnSe composite photocatalytic material with high catalytic performance, and the photocatalytic performance is 5 times higher than that of pure microspherical ZnSe.

[0028] (3) The photocatalyst of the application can be used for photocatalytic water splitting to produce hydrogen or photoelectrocatalytic water splitting to produce hydrogen, and realizes the use of low-cost Cu3P as a cocatalyst to modify ZnSe microspheres as a high-efficiency photocatalyst for water splitting to produce hydrogen, which has high practical value and application prospect. BRIEF DESCRIPTION OF DRAWINGS

[0029] The accompanying drawings are included to provide a further understanding of embodiments and are incorporated in and constitute a part of this specification. The drawings illustrate embodiments and, together with the description, serve to explain principles of the application. Other embodiments and many of the intended advantages of the present application will be readily appreciated as the same becomes better understood by reference to the following detailed description. The elements of the drawings are not necessarily to scale. Like reference numerals designate corresponding similar parts.

[0030] Figure 1 is a flow chart of a method for preparing a copper phosphide modified microspheres type zinc selenide photocatalytic material according to an embodiment of the present application;

[0031] Figure 2 is an X-ray diffraction (XRD) pattern of Cu3P, ZnSe, different ratios of Cu3P / ZnSe prepared by a method for preparing a copper phosphide modified microspheres type zinc selenide photocatalytic material according to an embodiment of the present application;

[0032] Figure 3 is an ultraviolet-visible diffuse reflectance (DRS) pattern of Cu3P, ZnSe, different ratios of Cu3P / ZnSe prepared by a method for preparing a copper phosphide modified microspheres type zinc selenide photocatalytic material according to an embodiment of the present application;

[0033] Figure 4 is a plot of the photocatalytic hydrogen evolution performance under visible light of Cu3P, ZnSe, different ratios of Cu3P / ZnSe prepared by a method for preparing a copper phosphide modified microspheres type zinc selenide photocatalytic material according to an embodiment of the present application;

[0034] Figure 5 is a field emission scanning electron microscope (FESEM) image of Cu3P prepared by a method for preparing a copper phosphide modified microspheres type zinc selenide photocatalytic material according to an embodiment of the present application;

[0035] Figure 6 is a field emission scanning electron microscope (FESEM) image of ZnSe prepared by a method for preparing a copper phosphide modified microspheres type zinc selenide photocatalytic material according to an embodiment of the present application;

[0036] Figure 7 is a field emission scanning electron microscope (FESEM) image of Cu3P / ZnSe prepared by a method for preparing a copper phosphide modified microspheres type zinc selenide photocatalytic material according to an embodiment of the present application. DETAILED DESCRIPTION

[0037] The technical solutions in the embodiments will be described clearly and completely below with reference to the drawings in the present application, and similar components are denoted by similar reference numerals in the drawings. Apparently, the embodiments described below are only a part but not all of the embodiments of the present application. Based on the embodiments in the present application, all of the other embodiments obtained by a person of ordinary skill in the art without creative work fall within the protection scope of the present application.

[0038] It should be understood that the terms "comprising" and "including" as used in the specification and the appended claims indicate the presence of the described features, integers, steps, operations, elements, and / or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof.

[0039] It should also be understood that the terms used in the present application specification are only for the purpose of describing specific embodiments and are not intended to limit the present application. As used in the present application specification and the appended claims, the singular forms "a", "an" and "the" are intended to include the plural forms unless the context clearly indicates otherwise.

[0040] The present application provides a preparation method of a copper phosphide modified microsphere type zinc selenide photocatalytic material, a preparation method of a copper phosphide modified microsphere type zinc selenide photocatalytic material, and a preparation method of a copper phosphide modified microsphere type zinc selenide photocatalytic material. Figure 1 As shown in the figure, the method comprises the following steps:

[0041] S101, preparing a ZnSe microsphere precursor and Cu3P nanoparticles.

[0042] In some specific embodiments, the preparation step of the ZnSe microsphere precursor comprises:

[0043] S1011, zinc acetate and sodium selenite with a molar ratio of 1:1 are dissolved in deionized water, 5 mol / L sodium hydroxide solution is added after magnetic stirring for 30 min, and a clear mixed solution two is obtained, wherein the amount of substance of sodium hydroxide in the added sodium hydroxide solution is 0.12 mol.

[0044] S1012, the mixed solution two is mixed with 10 mL of hydrazine hydrate, stirred for 30 min, then transferred to a stainless steel hydrothermal kettle, heated at 180℃ for 24 h, cooled to room temperature, and a mixed product one is obtained.

[0045] Specifically, 10 mL of hydrazine hydrate is added to the clear mixed solution two, stirred for 30 min, then transferred to a 100 mL stainless steel hydrothermal kettle, heated at 180℃ for 24 h, and then cooled to room temperature to obtain a yellow mixed product one. The stainless steel hydrothermal kettle is a high-pressure kettle with a polytetrafluoroethylene lining.

[0046] S1013, after the mixed product is washed, the mixed product is placed in a vacuum drying box at 70 DEG C and dried for 8h to obtain a ZnSe microsphere precursor.

[0047] In some specific embodiments, the preparation step of the Cu3P nanoparticles comprises:

[0048] S1011', copper sulfate pentahydrate is dissolved in deionized water, after stirring for 30min, sodium hydroxide solution is slowly added, and the mixture is stirred for 60min, and then washed and dried to obtain a Cu(OH)2 product, wherein the molar ratio of copper sulfate pentahydrate to sodium hydroxide is 0.3-0.5.

[0049] S1012', after the Cu(OH)2 product and sodium hypophosphite are ground in a grinding body, the mixture is calcined at 300 DEG C in a nitrogen environment for 60min to obtain a mixed product two, wherein the molar ratio of the Cu(OH)2 product to sodium hypophosphite is 0.1-0.3.

[0050] S1013', the mixed product two is washed and dried to obtain Cu3P nanoparticles.

[0051] S102, the Cu3P nanoparticles and the ZnSe microsphere precursor are dispersed in ethanol, after stirring for a fixed time, ultrasonic treatment is performed to obtain a mixed solution one, and the molar ratio of the Cu3P nanoparticles to the ZnSe microsphere precursor is 1:99-5:95.

[0052] Specifically, the Cu3P nanoparticles and the ZnSe microsphere precursor prepared in step 101 are dispersed in an ethanol solution, stirred at room temperature for 30min, and then ultrasonically treated for 1h to obtain a mixed solution one.

[0053] S103, after the mixed solution one is subjected to centrifugation, washing, and separation treatment, vacuum drying is performed for 10-14h to obtain a Cu3P / ZnSe composite photocatalytic material.

[0054] Specifically, after the mixed solution one prepared in step 102 is subjected to centrifugation, washing, and separation, vacuum drying is performed for 10-14h to obtain a Cu3P / ZnSe composite photocatalytic material as a photocatalyst.

[0055] In another aspect, the embodiment of the present application provides a microsphere type zinc selenide photocatalytic material modified by copper phosphide, the zinc selenide is in a microsphere structure, the diameter of the microsphere of the microsphere structure is 2-3pm, the copper phosphide nanoparticles are loaded on the surface of the microsphere of the zinc selenide, and the molar ratio of the copper phosphide to the zinc selenide is 1:99-5:95.

[0056] In some specific embodiments, the molar ratio of the copper phosphide to the zinc selenide is an integer ratio in 1:99-5:95, for example, the molar ratio of the copper phosphide to the zinc selenide is one or more of 1:99, 2:98, 3:97, and 5:95.Figure 2 , Figure 2 The diagram shows X-ray diffraction (XRD) patterns of Cu3P, ZnSe, and Cu3P / ZnSe at different ratios prepared by a method for preparing copper phosphide-modified microsphere zinc selenide photocatalysts according to an embodiment of the present invention. Figure 2 As shown, the crystalline phases of the prepared ZnSe, Cu3P, and Cu3P / ZnSe catalysts with different ratios (such as 1Cu3P / ZnSe, 2Cu3P / ZnSe, 3Cu3P / ZnSe, and 5Cu3P / ZnSe) were detected by X-ray diffraction (XRD). All diffraction peaks of the prepared ZnSe and Cu3P corresponded to the cubic phase ZnSe (JCPDS#37-1463) and the hexagonal phase (JCPDS#71-2261), respectively. Among them, the diffraction peaks of ZnSe at 27.2°, 45.2°, 53.6°, 65.9°, 72.6°, and 83.5° corresponded to (1 1 1), (2 2 0), (3 1 1), (40 0), (3 3 1), (4 0), and (5 0), respectively. 22) Crystal planes: The diffraction peaks of Cu3P at 36.0°, 39.1°, 41.6°, 45.1°, 46.2°, 47.3°, 53.6°, and 58.9° correspond to the (112), (202), (211), (300), (113), (212), (104), (222), and (124) crystal planes, respectively. No impurity-related diffraction peaks were observed in either of them. The results indicate that both are pure phases. Using the method for preparing copper phosphide-modified microspherical zinc selenide photocatalysts of this application, Cu3P and ZnSe were used to prepare Cu3P / ZnSe composite photocatalysts with different ratios, namely 1Cu3P / ZnSe, 2Cu3P / ZnSe, 3Cu3P / ZnSe, and 5Cu3P / ZnSe, which are also pure phases.

[0057] Continue to refer to Figure 3 , Figure 3 The diagram shows the UV-Vis diffuse reflectance (DRS) spectra of Cu3P, ZnSe, and Cu3P / ZnSe in different ratios prepared according to an embodiment of the present invention, using a method for preparing copper phosphide-modified microspherical zinc selenide photocatalysts. The figures show that pure Cu3P exhibits near-full-spectrum absorption, while pure ZnSe shows strong absorption in the UV range, but its absorption rapidly decreases after 460 nm. Notably, loading Cu3P onto the ZnSe surface significantly improves the visible light absorption capacity of the Cu3P / ZnSe composite material beyond 460 nm. Furthermore, the light absorption performance of the composite material gradually increases with increasing Cu3P content. This indicates that the Cu3P-loaded composite catalyst broadens the catalyst's light absorption range, increases the utilization rate of sunlight, and achieves high-efficiency photocatalytic performance.

[0058] The third aspect of the embodiment of the present application provides application of the copper phosphide modified microspherical zinc selenide photocatalytic material in photocatalysis and photoelectrocatalytic water splitting.

[0059] In some specific embodiments, the prepared Cu3P, ZnSe, Cu3P / ZnSe system series of samples are tested for photocatalytic water splitting hydrogen production performance under visible light:

[0060] A photocatalytic system (Labsolar-6A, Perfect Light, Beijing) is used as a photocatalytic reaction activity test system. Sodium sulfide (0.35M) and sodium sulfite (0.25M) are used as sacrificial agents of the photocatalytic system, 10mg of the sample and 100mL of the sacrificial agent are added to a 250mL quartz bottle, and then transferred to the photocatalytic system. The water splitting hydrogen production is carried out under visible light irradiation. The photocatalytic system is subjected to vacuum degassing treatment before photocatalytic hydrogen evolution. A 300W Xe lamp is used as a visible light source, and a UV cutoff filter (λ>400nm) is used. A gas chromatograph equipped with a thermal conductivity detector is used for measurement, and Ar2 is used as a carrier gas. The total amount of hydrogen production recorded for 3 hours is the hydrogen production rate. The experimental results are shown in Table 1. Figure 4 , Table 1: Photocatalytic water splitting hydrogen production performance of Cu3P, ZnSe, and different ratios of Cu3P / ZnSe under visible light Figure 4 Figure 1 shows a photocatalytic water splitting hydrogen production performance diagram of Cu3P, ZnSe, and different ratios of Cu3P / ZnSe prepared by the preparation method of the copper phosphide modified microspherical zinc selenide photocatalytic material according to one embodiment of the present application. Cu3P / ZnSe adopts four different ratios of 1Cu3P / ZnSe, 2Cu3P / ZnSe, 3Cu3P / ZnSe and 5Cu3P / ZnSe photocatalysts, and the molar ratios are 1:99, 2:98, 3:97 and 5:95, respectively. Cu3P, ZnSe, Cu3P / ZnSe show good solar response under visible light irradiation. As can be seen from the figure, the photocatalytic performance of 5Cu3P / ZnSe is the best during 0-0.5 hours, and the photocatalytic performance of 3Cu3P / ZnSe is the best after the reaction proceeds to 0.55 hours, that is, the photocatalytic performance is the best when the molar ratio of Cu3P and ZnSe in the Cu3P / ZnSe composite material is 3:97, and the best yield of Cu3P / ZnSe is 12.53mmol·g -1 h -1 , which is 5 times that of pure ZnSe (2.49mmol g -1 h -1 ).

[0061] In some specific embodiments, the prepared Cu3P / ZnSe system series of samples can be applied to the photoelectrocatalytic decomposition of water to produce hydrogen. The specific steps include preparing an electrolyte solution: the electrolyte solution can be 0.5M NaSO or other inert electrolyte, and the pH value of the electrolyte solution is moderate, neutral or weakly alkaline. Install the electrolytic cell: fix the photoelectrocatalyst sample of the Cu3P / ZnSe system series on the working electrode, and put it into the electrolytic cell together with the reference electrode and the counter electrode. Connect the gas trapping device to ensure that the gas produced by the reaction can be effectively collected, and airtight system or gas bag can be used to trap hydrogen. Light source irradiation: aim the light source at the reactor and start the light source to simulate sunlight irradiation. The light intensity and spectrum should be close to sunlight, and a xenon lamp simulating sunlight is usually used. Electrochemical control: control the reaction voltage through the electrochemical workstation, and the commonly used voltage range is between 0.2V and 1.2V, depending on the characteristics of the photoelectrocatalyst. The photoelectrocatalytic decomposition of water to produce hydrogen can further enhance the photocatalytic performance of the Cu3P / ZnSe system series and increase the yield of hydrogen.

[0062] Example 1

[0063] Step A, Cu3P nanoparticles, 2.5mmol copper sulfate pentahydrate was dissolved in 70mL deionized water, stirred for 30min, then 30mL 0.25M sodium hydroxide solution was slowly added to the above solution, fully mixed and stirred for 60min, washed and dried to obtain blue Cu(OH)2 for standby. Then 0.05g of the above blue Cu(OH)2 and 0.25g of sodium hypophosphite were placed in a grinding body and ground, and the ground mixture was calcined at 300°C in a nitrogen atmosphere for 60min. Finally, the obtained sample was washed with water and ethanol three times and dried to obtain the final product Cu3P, wherein the molar ratio of copper sulfate pentahydrate and sodium hydroxide is 1:3, and the molar ratio of Cu(OH)2 and sodium hypophosphite is 1:5.

[0064] Specifically, referring to Figure 5 , Figure 5 The field emission scanning electron microscope (FESEM) image of Cu3P prepared according to the preparation method of the copper phosphide modified microspherical zinc selenide photocatalytic material according to one embodiment of the present application is shown as follows: Figure 5 It can be seen that Cu3P is a cluster of aggregated nanoparticles, and the particle structure can provide abundant catalytic active sites.

[0065] Step B, preparation of ZnSe microspheres, 2 mmol of zinc acetate and 2 mmol of sodium selenite were dissolved in 40 mL of deionized water and magnetically stirred for 30 min, then 25 mL of 5M sodium hydroxide solution was added to the solution until the solution became clear, then 10 mL of hydrazine hydrate was added to the solution and stirred for 30 min, finally the stirred mixed solution was transferred to a 100 mL stainless steel hydrothermal kettle, heated at 180℃ for 24 hours, then cooled to room temperature, the obtained yellow product was centrifuged, washed with water and ethanol several times, and dried in a vacuum drying oven at 70℃ for 8h to obtain ZnSe microspheres, wherein the molar ratio of zinc acetate and sodium selenite is 1:1, and the amount of substance of sodium hydroxide is 0.12 mol.

[0066] Specifically, referring to Figure 6 , Figure 6 A field emission scanning electron microscope (FESEM) image of ZnSe prepared according to the preparation method of the copper phosphide modified microspherical zinc selenide photocatalytic material according to one embodiment of the present application is shown in FIG. 1. Figure 6 As shown in FIG. 1, the ZnSe exhibits a uniform and dispersed microspherical morphology with a diameter of 2-3 microns.

[0067] Step C, preparation of Cu3P / ZnSe composite catalyst, the Cu3P nanoparticles and ZnSe microspheres prepared in steps A and B were dispersed in an ethanol solution, stirred at room temperature for 30 min, then ultrasonically treated for 1 h, then the mixture was centrifuged, washed, separated, and vacuum dried for 10-14 hours to obtain a Cu3P / ZnSe composite catalyst as a photocatalyst, wherein the molar ratio of Cu3P nanoparticles to ZnSe microsphere precursors is 1:99, specifically, 0.01 mol of Cu3P nanoparticles and 0.99 mol of ZnSe microspheres can be dispersed in an ethanol solution.

[0068] Specifically, referring to Figure 7 , Figure 7 A field emission scanning electron microscope (FESEM) image of Cu3P / ZnSe prepared according to the preparation method of the copper phosphide modified microspherical zinc selenide photocatalytic material according to one embodiment of the present application is shown in FIG. 2. Figure 7 As shown in FIG. 2, Cu3P nanoparticles can be observed to be loaded on the ZnSe microspheres on the surface of Cu3P / ZnSe, and the Cu3P loading has no effect on the morphology of ZnSe.

[0069] Example 2

[0070] The difference from example 1 is that in step C, the Cu3P / ZnSe composite catalyst is prepared. The Cu3P nanoparticles and ZnSe microspheres prepared in steps A and B are dispersed in an ethanol solution, stirred at room temperature for 30 min, then ultrasonic for 1 h, then the mixture is centrifuged, washed, separated, and vacuum dried for 10-14 hours to obtain a 2Cu3P / ZnSe composite catalyst as a photocatalyst, wherein the molar ratio of Cu3P nanoparticles to ZnSe microsphere precursors is 2:98, specifically 0.02 mol of Cu3P nanoparticles and 0.98 mol of ZnSe microspheres can be dispersed in an ethanol solution.

[0071] Example 3

[0072] The difference from example 1 is that in step C, the Cu3P / ZnSe composite catalyst is prepared. The Cu3P nanoparticles and ZnSe microspheres prepared in steps A and B are dispersed in an ethanol solution, stirred at room temperature for 30 min, then ultrasonic for 1 h, then the mixture is centrifuged, washed, separated, and vacuum dried for 10-14 hours to obtain a 3Cu3P / ZnSe composite catalyst as a photocatalyst, wherein the molar ratio of Cu3P nanoparticles to ZnSe microsphere precursors is 3:97, specifically 0.03 mol of Cu3P nanoparticles and 0.97 mol of ZnSe microspheres can be dispersed in an ethanol solution.

[0073] Example 4

[0074] The difference from example 1 is that in step C, the Cu3P / ZnSe composite catalyst is prepared. The Cu3P nanoparticles and ZnSe microspheres prepared in steps A and B are dispersed in an ethanol solution, stirred at room temperature for 30 min, then ultrasonic for 1 h, then the mixture is centrifuged, washed, separated, and vacuum dried for 10-14 hours to obtain a 5Cu3P / ZnSe composite catalyst as a photocatalyst, wherein the molar ratio of Cu3P nanoparticles to ZnSe microsphere precursors is 5:95, specifically 0.05 mol of Cu3P nanoparticles and 0.95 mol of ZnSe microspheres can be dispersed in an ethanol solution.

[0075] The copper phosphide modified microspherical zinc selenide photocatalytic material, its preparation method and application in the present application, the Cu3P nanoparticles prepared by phosphatization as a cocatalyst, the microspherical ZnSe is modified by a simple mechanical mixing method, a small amount of Cu3P is loaded, and high photocatalytic activity is shown under visible light, the function of promoting charge separation is used to improve the problems of low solar energy utilization rate, high photo-generated carrier recombination rate, and poor photocatalyst stability of ZnSe, and the cost of Cu3P is low and convenient for large-scale popularization and application.

[0076] It is clear that a person skilled in the art can make various modifications and alterations to the embodiments of the application without departing from the spirit and scope of the application. In this manner, the application is also intended to cover these modifications and alterations if they come within the scope of the claims of the application and their equivalents. The word "comprising" does not exclude the presence of elements or steps not listed in a claim. The mere fact that different claims enumerate mutually different measures does not indicate that a combination of these measures cannot be used to advantage. Any reference signs in the claims should not be construed as limiting the scope.

Claims

1. Application of copper phosphide modified microspherical zinc selenide photocatalytic material in photocatalytic and photoelectrocatalytic decomposition of water, characterized in that, The zinc selenide is a microsphere structure, and copper phosphide nanoparticles are loaded on the outer surface of the microsphere structure, and the molar ratio of the copper phosphide to the zinc selenide is 1:99 - 5:

95.

2. Use according to claim 1, characterized in that, The molar ratio of the copper phosphide to the zinc selenide is 1:99, 2:98, 3:97 or 5:

95.

3. Use according to claim 1, characterized in that, The microsphere diameter of the microsphere structure is 2-3 μm.

4. Use according to claim 1, characterized in that, The preparation method of the copper phosphide modified microsphere type zinc selenide photocatalytic material comprises: S1, preparing a ZnSe microsphere precursor and Cu3P nanoparticles; S2, dispersing the Cu3P nanoparticles and the ZnSe microsphere precursor in ethanol, stirring for a fixed time, and then ultrasonic treatment to obtain a mixed solution one, and the molar ratio of the Cu3P nanoparticles to the ZnSe microsphere precursor is 1:99 - 5:95; S3, after the mixed solution one is subjected to centrifugal, washing and separation treatment, vacuum drying for 10 - 14 h to obtain a Cu3P / ZnSe composite photocatalytic material.

5. Use according to claim 4, characterized in that, The preparation steps of the ZnSe microsphere precursor comprise: S11, dissolving zinc acetate and sodium selenite with a molar ratio of 1:1 in deionized water, and after magnetic stirring for 30 min, adding a 5 mol / L sodium hydroxide solution until a clear mixed solution two is obtained; S12, mixing and stirring the mixed solution two with 10 mL of hydrazine hydrate for 30 min, then moving to a stainless steel hydrothermal kettle, heating at 180 ℃ for 24 h, and cooling to room temperature to obtain a mixed product one; S13, washing the mixed product one and placing it in a vacuum drying box at 70 ℃ for drying for 8 h to obtain the ZnSe microsphere precursor.

6. Use according to claim 5, characterized in that, The amount of substance of sodium hydroxide in the sodium hydroxide solution added in the S11 step is 0.12 mol.

7. Use according to claim 4, characterized in that, The preparation steps of the Cu3P nanoparticles comprise: S11', dissolving copper sulfate pentahydrate in deionized water, stirring for 30 min, slowly adding a sodium hydroxide solution, mixing and stirring for 60 min, and then washing and drying to obtain a Cu(OH)2 product, and the molar ratio of the copper sulfate pentahydrate to the sodium hydroxide is 0.3 - 0.5; S12', after the Cu(OH)2 product and sodium hypophosphite are ground in a grinding body, they are placed in a nitrogen environment at 300 ℃ for calcination for 60 min to obtain a mixed product two; S13', washing and drying the mixed product two to obtain the Cu3P nanoparticles.

8. Use according to claim 7, characterized in that, In the S12' step, the molar ratio of the Cu(OH)2 product to the sodium hypophosphite is 0.1 - 0.3.

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