Palladium-loaded donor-receptor type carbon nitride photocatalyst and preparation method thereof

Abstract

The invention discloses a palladium-loaded donor-acceptor type carbon nitride photocatalyst and a preparation method thereof, and the preparation method comprises the following steps: adding 2-aminobenzothiazole and palladium salt into a solvent for reaction to obtain a palladium complex crystal; and mixing the palladium complex crystal with a carbon nitride precursor, and calcining to obtain the carbon nitride photocatalyst. According to the palladium-loaded donor-acceptor type carbon nitride photocatalyst and the preparation method thereof provided by the invention, the carbon nitride photocatalytic material has a higher specific surface area, narrower band gap energy and a larger photoresponse range, also has oxygen adsorption capacity, and can adsorb oxygen from water to participate in a photocatalytic H2O2 production reaction.

Description

Technical Field

[0001] The invention belongs to the technical field of photocatalytic production of hydrogen peroxide, and in particular relates to a palladium-loaded donor-acceptor type carbon nitride photocatalyst and a preparation method thereof. Background Art

[0002] Photocatalytic technology is an efficient, safe and environmentally friendly purification technology. It is generally based on the redox ability of photocatalysts under light conditions to achieve the purpose of purifying pollutants, synthesizing and converting substances. For example, hydrogen peroxide, also known as hydrogen peroxide (chemical formula H2O2), is an important inorganic chemical product. Due to its green and clean characteristics, it is widely used in pulp bleaching, organic synthesis, environmental remediation, disinfection, fuel cells and military fields, and there is a huge demand of about 4 million tons every year. Usually, hydrogen peroxide is mainly prepared by anthraquinone process, which not only consumes a lot of energy, but also produces a lot of chemical waste. Therefore, using photocatalysts to generate H2O2 through the photocatalytic reaction of water and O2 under sunlight is a clean and safe preparation method, which has great potential compared with other H2O2 preparation methods.

[0003] Carbon nitride materials have become a research hotspot for photocatalytic materials in recent years due to their visible light response and easy functionalization. As an analog of graphite and metal-free polymer n-type semiconductors, carbon nitride materials have a two-dimensional (2D) structure of triazine stacking connected by tertiary amines. Due to their unique electrical, optical, structural and physicochemical properties, carbon nitride materials have been recognized as a new type of multifunctional electronic, catalytic and energy materials.

[0004] However, currently, graphite-phase carbon nitride materials are usually synthesized by directly calcining precursors such as melamine at high temperature. The carbon nitride materials obtained by this method have a low specific surface area, a wide band gap energy (2.7 eV), and can only respond to light with λ≤460nm, resulting in low photocatalytic efficiency. Summary of the invention

[0005] Based on the above technical problems, the present invention provides a palladium-loaded donor-acceptor type carbon nitride photocatalyst and a preparation method thereof. The carbon nitride photocatalytic material has a higher specific surface area, a narrower band gap energy and a larger light response range, and also has oxygen adsorption capacity, and can adsorb oxygen from water to participate in the photocatalytic H2O2 production reaction.

[0006] The present invention provides a method for preparing a palladium-supported donor-acceptor carbon nitride photocatalyst, comprising the following steps:

[0007] S1, adding 2-aminobenzothiazole and palladium salt into a solvent for reaction to obtain palladium complex crystals;

[0008] S2. Mixing the palladium complex crystal and the carbon nitride precursor, and calcining them to obtain the carbon nitride photocatalyst.

[0009] In the present invention, in view of the defects of the carbon nitride material in the prior art, such as low specific surface area, wide band gap energy (2.7 eV), and only being able to respond to light of λ≤460 nm, the palladium metal ions are fixed by forming a metal-organic complex by coordination complexation of palladium metal ions and 2-aminobenzothiazole, and then mixed with a carbon nitrogen precursor. The complex is dispersed and fixed by a precursor formed by self-assembly of the carbon nitrogen precursor and 2-aminobenzothiazole through hydrogen bonds, thereby inhibiting the agglomeration of palladium metal atoms. The carbon nitride photocatalytic material after calcination has a higher specific surface area, a narrower band gap energy, a larger light response range, and oxygen adsorption capacity, and can adsorb oxygen from water to participate in the photocatalytic H2O2 production reaction.

[0010] Preferably, in step S1, the palladium salt is at least one of palladium acetate, palladium chloride or palladium nitrate; the solvent is an alcohol solvent, and the alcohol solvent is preferably methanol or ethanol.

[0011] Preferably, in step S1, the molar ratio of the 2-aminobenzothiazole to the palladium salt is 1-3:1, preferably 2:1; the mass volume ratio of the 2-aminobenzothiazole to the palladium salt in the solvent is 0.01-0.03 g:1 mL.

[0012] Preferably, in step S1, the reaction temperature is 20-30°C and the reaction time is 3-5h.

[0013] Preferably, in step S2, the carbon nitride precursor is at least one of melamine, dicyandiamide or urea.

[0014] Preferably, in step S2, the mass ratio of the palladium complex crystal to the carbon nitride precursor is 0.002-0.02:1, preferably 0.01:1;

[0015] Preferably, before mixing, the palladium complex crystals further include grinding the palladium complex crystals into powder.

[0016] Preferably, in step S2, the calcination includes a first calcination and a second calcination, the calcination temperature is 500-550°C, and the calcination time is 4-6h.

[0017] Preferably, the first calcination temperature is 500-550°C, preferably 550°C, the calcination time is 2-3h, the heating rate is 1-10°C / min, and the second calcination temperature is 500-550°C, preferably 500°C, the calcination time is 2-3h, and the heating rate is 1-10°C / min.

[0018] The present invention also provides a palladium-loaded donor-acceptor type carbon nitride photocatalyst, which is prepared by the above preparation method.

[0019] The present invention also proposes an application of the palladium-loaded donor-acceptor carbon nitride photocatalyst in photocatalytic production of hydrogen peroxide.

[0020] The beneficial effects of the present invention are as follows:

[0021] (1) In the preparation method of the palladium-loaded donor-acceptor type carbon nitride photocatalyst provided by the present invention, 2-aminobenzothiazole and palladium chloride are used to prepare a metal-loaded acceptor unit, which is then calcined with melamine to obtain a palladium-loaded donor-acceptor type carbon nitride photocatalyst. The preparation method is simple and easy to operate, and the obtained carbon nitride material has n-π * Transition can increase the light absorption range and has the ability to adsorb oxygen, and can adsorb oxygen from water to participate in the photocatalytic H2O2 production reaction.

[0022] (2) The preparation method of the present invention not only obtains * The photocatalytic H2O2 production activity of the Pd-loaded donor-acceptor carbon nitride photocatalyst was increased by about 6.8 times compared with that of the one without Pd loading. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 These are high-resolution scanning electron microscopy images and transmission electron microscopy images of the palladium-supported donor-acceptor carbon nitride photocatalyst described in Example 1 of the present invention; wherein, Figure (a) is a high-resolution scanning electron microscopy image, and Figure (b) is a high-resolution transmission electron microscopy image;

[0024] Figure 2 The X-ray diffraction patterns (XRD) of the palladium-loaded donor-acceptor carbon nitride photocatalyst described in Example 1 of the present invention, the unloaded palladium donor-acceptor carbon nitride photocatalyst described in Comparative Example 1, and the ordinary carbon nitride photocatalyst described in Comparative Example 2;

[0025] Figure 3 It is a Fourier transform infrared spectra (FT-IR) of the palladium-loaded donor-acceptor type carbon nitride photocatalyst described in Example 1 of the present invention, the unloaded palladium donor-acceptor type carbon nitride photocatalyst described in Comparative Example 1, and the ordinary carbon nitride photocatalyst described in Comparative Example 2;

[0026] Figure 4 is the Pd3d spectrum of the X-ray photoelectron spectrum of the palladium-supported donor-acceptor carbon nitride photocatalyst described in Example 1 of the present invention;

[0027] Figure 5It is the ultraviolet-visible spectra (UV-Vis) of the palladium-loaded donor-acceptor type carbon nitride photocatalyst described in Example 1 of the present invention, the unloaded palladium donor-acceptor type carbon nitride photocatalyst described in Comparative Example 1, and the ordinary carbon nitride photocatalyst described in Comparative Example 2;

[0028] Figure 6 It is a specific surface area diagram (BET) of the palladium-loaded donor-acceptor carbon nitride photocatalyst described in Example 1 of the present invention, the unloaded palladium donor-acceptor carbon nitride photocatalyst described in Comparative Example 1, and the ordinary carbon nitride photocatalyst described in Comparative Example 2;

[0029] Figure 7 The impedance spectra (EIS) of the palladium-loaded donor-acceptor carbon nitride photocatalyst described in Example 1 of the present invention, the unloaded palladium donor-acceptor carbon nitride photocatalyst described in Comparative Example 1, and the ordinary carbon nitride photocatalyst described in Comparative Example 2;

[0030] Figure 8 It is the steady-state fluorescence spectra (PL) of the palladium-loaded donor-acceptor carbon nitride photocatalyst described in Example 1 of the present invention, the unloaded palladium donor-acceptor carbon nitride photocatalyst described in Comparative Example 1, and the ordinary carbon nitride photocatalyst described in Comparative Example 2;

[0031] Fig. 9 It is a graph of the production of H2O2 under visible light of the palladium-loaded donor-acceptor carbon nitride photocatalyst described in Example 1 of the present invention, the unloaded palladium donor-acceptor carbon nitride photocatalyst described in Comparative Example 1, and the ordinary carbon nitride photocatalyst described in Comparative Example 2;

[0032] Fig.10 This is a graph showing the production of H2O2 under visible light for a long time using the palladium-supported donor-acceptor carbon nitride photocatalyst described in Example 1 of the present invention. DETAILED DESCRIPTION

[0033] Hereinafter, the present invention will describe the technical solution in detail through specific embodiments, but it should be clearly stated that these embodiments are for illustration only and are not to be construed as limiting the scope of the present invention.

[0034] Example 1

[0035] This embodiment provides a palladium-supported donor-acceptor carbon nitride photocatalyst, the preparation method of which comprises the following steps:

[0036] (1) Weigh 0.6 g of 2-aminobenzothiazole and 0.355 g of palladium chloride, put them in a glass beaker, add 40 mL of ethanol, place on an electromagnetic stirrer at room temperature and stir for 4 h. After the reaction is completed, place the resulting mixed solution in a suction filtration device and filter and wash it with ethanol several times. After the lower layer is naturally air-dried, yellow-brown crystals are obtained, which are palladium complex crystals;

[0037] (2) After grinding the palladium complex crystals obtained in step (1) into powder, weighing 0.05 g of the crystalline powder and 5 g of melamine, mixing them, and then placing them in a muffle furnace for calcination treatment, the calcination treatment includes a first calcination and a second calcination, the first calcination temperature is 550° C., the calcination time is 3 h, and the heating rate is 5° C. / min, the second calcination temperature is 500° C., the calcination time is 2 h, and the heating rate is 5° C. / min. After the end, it is cooled to room temperature to obtain a light brown solid, which is the palladium-supported donor-acceptor type carbon nitride photocatalyst, recorded as Pd-ABT-CN.

[0038] This embodiment also proposes an application of the above palladium-supported donor-acceptor carbon nitride photocatalyst in photocatalytic production of hydrogen peroxide, which specifically includes the following steps:

[0039] (1) Weigh 0.005 g of the above palladium-supported donor-acceptor carbon nitride photocatalyst (Pd-ABT-CN) and place it in a glass beaker, and add a mixed solution of 3 mL of isopropanol and 27 mL of distilled water;

[0040] (2) Place the glass beaker obtained in step (1) on a stirring table, illuminate it under a 300 W xenon lamp for 1 h, take 1 mL of the reaction solution, and filter it;

[0041] (3) Add 1 mL of the filtrate obtained in step (2) to 1 mL of a 0.4 mol / L potassium iodide solution, add 1 mL of a 0.1 mol / L potassium cyanide phthalate solution, shake well to develop color, measure the liquid absorbance using a UV-visible spectrophotometer, and calculate the H2O2 concentration based on the absorbance.

[0042] Example 2

[0043] This example provides a palladium-supported donor-acceptor carbon nitride photocatalyst, the preparation method of which is the same as that of Example 1, except that in step (2), 0.01 g of crystalline powder and 5 g of dicyandiamide are weighed and mixed.

[0044] Example 3

[0045] This embodiment provides a palladium-supported donor-acceptor carbon nitride photocatalyst, and its preparation method is the same as that of Example 1, except that in step (2), 0.1 g of crystalline powder and 5 g of urea are weighed and mixed.

[0046] Example 4

[0047] This embodiment proposes a palladium-loaded donor-acceptor type carbon nitride photocatalyst, and its preparation method is the same as that of Example 1, except that in step (2), the first calcination temperature is 500°C, the calcination time is 3 hours, and the heating rate is 1°C / min, and the second calcination temperature is 550°C, the calcination time is 3 hours, and the heating rate is 10°C / min.

[0048] Example 5

[0049] This embodiment proposes a palladium-loaded donor-acceptor type carbon nitride photocatalyst, and its preparation method is the same as that of Example 1, except that in step (2), the first calcination temperature is 550°C, the calcination time is 2h, and the heating rate is 10°C / min, and the second calcination temperature is 500°C, the calcination time is 3h, and the heating rate is 1°C / min.

[0050] Comparative Example 1

[0051] This comparative example proposes a non-palladium-supported donor-acceptor carbon nitride photocatalyst, the preparation method of which comprises the following steps:

[0052] Weigh 0.05 g of 2-aminobenzothiazole and 5 g of melamine, mix them, and then place them in a muffle furnace for calcination. The calcination treatment includes a first calcination and a second calcination. The first calcination temperature is 550°C, the calcination time is 3 h, and the heating rate is 5°C / min. The second calcination temperature is 500°C, the calcination time is 2 h, and the heating rate is 5°C / min. After the end, cool to room temperature to obtain a light brown solid, which is the unloaded palladium donor-acceptor type carbon nitride photocatalyst, recorded as ABT-CN.

[0053] This comparative example also proposes an application of the above-mentioned unloaded palladium donor-acceptor type carbon nitride photocatalyst in photocatalytic production of hydrogen peroxide. The preparation method is the same as that of Example 1, except that Pd-ABT-CN is replaced by ABT-CN.

[0054] Comparative Example 2

[0055] This comparative example proposes a common carbon nitride photocatalyst, and its preparation method comprises the following steps:

[0056] Weigh 5 g of melamine and mix it evenly, then place it in a muffle furnace for calcination. The calcination treatment includes a first calcination and a second calcination. The first calcination temperature is 550°C, the calcination time is 3 hours, and the heating rate is 5°C / min. The second calcination temperature is 500°C, the calcination time is 2 hours, and the heating rate is 5°C / min. After the end, it is cooled to room temperature to obtain a light brown solid, which is the ordinary carbon nitride photocatalyst, recorded as g-CN.

[0057] This comparative example also proposes an application of the above-mentioned common carbon nitride photocatalyst in photocatalytic production of hydrogen peroxide. The preparation method is the same as that of Example 1, except that Pd-ABT-CN is replaced by g-CN.

[0058] Comparative Example 3

[0059] This comparative example proposes a palladium-supported carbon nitride photocatalyst, the preparation method of which comprises the following steps:

[0060] Weigh 0.05 g of palladium chloride and 5 g of melamine, mix them, and then place them in a muffle furnace for calcination. The calcination treatment includes a first calcination and a second calcination. The first calcination temperature is 550°C, the calcination time is 3 h, and the heating rate is 5°C / min. The second calcination temperature is 500°C, the calcination time is 2 h, and the heating rate is 5°C / min. After the end, cool to room temperature to obtain a light brown solid, which is the palladium-supported carbon nitride photocatalyst, recorded as Pd-CN.

[0061] This comparative example also proposes an application of the above palladium-supported carbon nitride photocatalyst in photocatalytic production of hydrogen peroxide. The preparation method is the same as that of Example 1, except that Pd-ABT-CN is replaced by Pd-CN.

[0062] Comparative Example 4

[0063] This comparative example proposes a cobalt-supported donor-acceptor type carbon nitride photocatalyst, and its preparation method comprises the following steps:

[0064] (1) Weigh 0.6 g of 2-aminobenzothiazole and 0.499 g of cobalt acetate tetrahydrate, put them in a glass beaker, add 40 mL of ethanol, place them on an electromagnetic stirrer at room temperature and stir for 4 h. After the reaction is completed, place the resulting mixed solution in a suction filtration device and filter and wash it with ethanol several times. After the lower layer is naturally air-dried, dark purple crystals are obtained, which are cobalt complex crystals;

[0065] (2) After grinding the cobalt complex crystals obtained in step (1) into powder, weighing 0.05 g of the crystalline powder and 5 g of melamine, mixing them, and then placing them in a muffle furnace for calcination treatment, the calcination treatment includes a first calcination and a second calcination, the first calcination temperature is 550°C, the calcination time is 3 h, and the heating rate is 5°C / min, the second calcination temperature is 500°C, the calcination time is 2 h, and the heating rate is 5°C / min. After the end, it is cooled to room temperature to obtain a dark brown solid, which is the cobalt-loaded donor-acceptor type carbon nitride photocatalyst, recorded as Co-ABT-CN.

[0066] This comparative example also proposes an application of the above-mentioned cobalt-loaded donor-acceptor type carbon nitride photocatalyst in photocatalytic production of hydrogen peroxide. The preparation method is the same as that of Example 1, except that Pd-ABT-CN is replaced by Co-ABT-CN.

[0067] Comparative Example 5

[0068] This comparative example proposes a zinc-supported donor-acceptor type carbon nitride photocatalyst, and its preparation method comprises the following steps:

[0069] (1) Weigh 0.6 g of 2-aminobenzothiazole and 0.402 g of zinc acetate monohydrate, put them in a glass beaker, add 40 mL of ethanol, place them on an electromagnetic stirrer at room temperature and stir for 4 h. After the reaction is completed, place the resulting mixed solution in a suction filtration device and filter and wash it with ethanol several times. After the lower layer is naturally air-dried, light brown crystals are obtained, which are zinc complex crystals;

[0070] (2) After grinding the zinc complex crystals obtained in step (1) into powder, weighing 0.05 g of the crystalline powder and 5 g of melamine, mixing them, and then placing them in a muffle furnace for calcination treatment, the calcination treatment includes a first calcination and a second calcination, the first calcination temperature is 550° C., the calcination time is 3 h, and the heating rate is 5° C. / min, the second calcination temperature is 500° C., the calcination time is 2 h, and the heating rate is 5° C. / min. After the end, it is cooled to room temperature to obtain a light brown solid, which is the zinc-loaded donor-acceptor type carbon nitride photocatalyst, denoted as Zn-ABT-CN.

[0071] This comparative example also proposes an application of the zinc-loaded donor-acceptor carbon nitride photocatalyst in photocatalytic production of hydrogen peroxide. The preparation method is the same as that of Example 1, except that Pd-ABT-CN is replaced by Zn-ABT-CN.

[0072] The carbon nitride photocatalysts prepared in Comparative Examples 1, 2 and Example 1 were tested for performance. The specific test results are shown in Figure 1-10 , as shown in Table 1.

[0073] Figure 1 The high-resolution scanning electron microscopy and transmission electron microscopy images of the palladium-supported donor-acceptor carbon nitride photocatalyst described in Example 1 of the present invention are shown in FIG. Figure 1 It can be seen that the morphology of the palladium-supported donor-acceptor type carbon nitride photocatalyst of the present invention is a nanosheet structure.

[0074] Figure 2 The X-ray diffraction patterns (XRD) of the palladium-loaded donor-acceptor carbon nitride photocatalyst described in Example 1 of the present invention, the unloaded palladium donor-acceptor carbon nitride photocatalyst described in Comparative Example 1, and the ordinary carbon nitride photocatalyst described in Comparative Example 3; Figure 3 The Fourier transform infrared spectra (FT-IR) of the palladium-loaded donor-acceptor carbon nitride photocatalyst described in Example 1 of the present invention, the unloaded palladium donor-acceptor carbon nitride photocatalyst described in Comparative Example 1, and the ordinary carbon nitride photocatalyst described in Comparative Example 2 are shown in Table 1. Figure 2 , 3 It can be seen that the structure of the palladium-loaded donor-acceptor type carbon nitride photocatalyst of the present invention and the loading of Pd do not change its structure.

[0075] Figure 4is the Pd3d spectrum of the X-ray photoelectron spectrum of the palladium-supported donor-acceptor carbon nitride photocatalyst described in Example 1 of the present invention, referring to Figure 4 It can be seen that the Pd atoms in the palladium-supported donor-acceptor type carbon nitride photocatalyst of the present invention are successfully supported.

[0076] Figure 5 The UV-Vis spectra (UV-Vis) of the palladium-loaded donor-acceptor carbon nitride photocatalyst described in Example 1 of the present invention, the unloaded palladium donor-acceptor carbon nitride photocatalyst described in Comparative Example 1, and the ordinary carbon nitride photocatalyst described in Comparative Example 2 are shown in Table 1. Figure 5 It can be seen that the donor-acceptor structure in the palladium-supported donor-acceptor type carbon nitride photocatalyst of the present invention increases the light absorption range.

[0077] Figure 6 The specific surface area diagram (BET) of the palladium-loaded donor-acceptor carbon nitride photocatalyst described in Example 1 of the present invention, the unloaded palladium donor-acceptor carbon nitride photocatalyst described in Comparative Example 1, and the ordinary carbon nitride photocatalyst described in Comparative Example 2 is shown in FIG. Figure 6 It can be seen that in the palladium-loaded donor-acceptor type carbon nitride photocatalyst of the present invention, the specific surface area is greatly improved after loading Pd.

[0078] Figure 7 The impedance spectra (EIS) of the palladium-loaded donor-acceptor carbon nitride photocatalyst described in Example 1 of the present invention, the unloaded palladium donor-acceptor carbon nitride photocatalyst described in Comparative Example 1, and the ordinary carbon nitride photocatalyst described in Comparative Example 2, Figure 8 The steady-state fluorescence spectra (PL) of the palladium-loaded donor-acceptor carbon nitride photocatalyst described in Example 1 of the present invention, the unloaded palladium donor-acceptor carbon nitride photocatalyst described in Comparative Example 1, and the ordinary carbon nitride photocatalyst described in Comparative Example 2 are shown in Table 1. Figure 7 , 8 It can be seen that the palladium-supported donor-acceptor type carbon nitride photocatalyst of the present invention has a higher charge carrier separation efficiency.

[0079] Fig. 9 It is a graph showing the production of H2O2 under visible light by the palladium-loaded donor-acceptor carbon nitride photocatalyst described in Example 1 of the present invention, the unloaded palladium donor-acceptor carbon nitride photocatalyst described in Comparative Example 1, and the ordinary carbon nitride photocatalyst described in Comparative Example 2. Fig.10 is a graph showing the H2O2 production of the palladium-supported donor-acceptor carbon nitride photocatalyst under visible light for a long time as described in Example 1 of the present invention, referring to Fig. 9 , 10 It can be seen that the photocatalytic performance of the palladium-loaded donor-acceptor type carbon nitride photocatalyst of the present invention is greatly improved and has good stability.

[0080] Table 1 shows the amount of H2O2 produced by the carbon nitride photocatalysts described in Example 1 of the present invention and Comparative Examples 1-5 under visible light, specifically as follows:

[0081] Table 1 List of H2O2 produced by photocatalytic water decomposition of carbon nitride photocatalysts obtained in Examples and Comparative Examples

[0082] sample Hydrogen production rate (μmol / h·g) Pd-ABT-CN (Example 1) 2629.8 ABT-CN (Comparative Example 1) 388.6 g-CN (Comparative Example 2) 299.1 Pd-CN (Comparative Example 3) 1032.5 Co-ABT-CN (Comparative Example 4) 852.6 Zn-ABT-CN (Comparative Example 5) 1123.3

[0083] According to the above results, it can be seen that the palladium-loaded donor-acceptor carbon nitride obtained by the embodiments of the present invention using raw materials such as melamine, 2-aminobenzothiazole, palladium chloride, and simple operations such as stirring, calcination, and illumination can increase the specific surface area and improve the light response range, thereby improving the photocatalytic H2O2 production capacity. Moreover, the carbon nitride photocatalytic material prepared by this preparation method has oxygen adsorption capacity, and can adsorb oxygen from water to participate in the photocatalytic H2O2 production reaction without the need to introduce oxygen. The present invention not only obtains a carbon nitride photocatalyst with a high specific surface area, but also the palladium-loaded donor-acceptor carbon nitride photocatalyst has a photocatalytic H2O2 production activity that is 6.8 times higher than that of the unloaded Pd, and has broad market prospects.

[0084] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A method for preparing a palladium-supported donor-acceptor type carbon nitride photocatalyst, characterized in that: The steps include: S1, adding 2-aminobenzothiazole and palladium salt into a solvent for reaction to obtain palladium complex crystals; S2. Mixing the palladium complex crystal and the carbon nitride precursor, and calcining them to obtain the carbon nitride photocatalyst.

2. The method for preparing the palladium-supported donor-acceptor carbon nitride photocatalyst according to claim 1, characterized in that: In step S1, the palladium salt is at least one of palladium acetate, palladium chloride or palladium nitrate; the solvent is an alcohol solvent, and the alcohol solvent is preferably methanol or ethanol.

3. The method for preparing the palladium-supported donor-acceptor carbon nitride photocatalyst according to claim 1 or 2, characterized in that: In step S1, the molar ratio of the 2-aminobenzothiazole and the palladium salt is 1-3:1, preferably 2:1; the mass volume ratio of the 2-aminobenzothiazole and the palladium salt in the solvent is 0.01-0.03 g:1 mL, preferably 0.024 g:1 mL.

4. The method for preparing the palladium-supported donor-acceptor carbon nitride photocatalyst according to any one of claims 1 to 3, characterized in that: In step S1, the reaction temperature is 20-30°C and the reaction time is 3-5h.

5. The method for preparing the palladium-supported donor-acceptor carbon nitride photocatalyst according to any one of claims 1 to 4, characterized in that: In step S2, the carbon nitride precursor is at least one of melamine, dicyandiamide or urea.

6. The method for preparing the palladium-supported donor-acceptor carbon nitride photocatalyst according to any one of claims 1 to 5, characterized in that: In step S2, the mass ratio of the palladium complex crystal to the carbon nitride precursor is 0.002-0.02:1, preferably 0.01:1; Preferably, before mixing, the palladium complex crystals further include grinding the palladium complex crystals into powder.

7. The method for preparing the palladium-supported donor-acceptor carbon nitride photocatalyst according to any one of claims 1 to 6, characterized in that: In step S2, the calcination includes a first calcination and a second calcination, the calcination temperature is 500-550°C, and the calcination time is 4-6h.

8. The method for preparing the palladium-supported donor-acceptor carbon nitride photocatalyst according to claim 7, characterized in that: The first calcination temperature is 500-550°C, preferably 550°C, the calcination time is 2-3h, the heating rate is 1-10°C / min, the second calcination temperature is 500-550°C, preferably 500°C, the calcination time is 2-3h, and the heating rate is 1-10°C / min.

9. A palladium-supported donor-acceptor carbon nitride photocatalyst, characterized in that: The compound is prepared by the preparation method according to any one of claims 1 to 8.

10. Use of the palladium-supported donor-acceptor carbon nitride photocatalyst according to claim 9 in photocatalytic production of hydrogen peroxide.

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