Semiconductor composite material, method for preparing the same and use thereof

Abstract

The application discloses a semiconductor composite material and a preparation method and application thereof, and relates to the technical field of photocatalysis, and specifically discloses a semiconductor composite material which comprises an MOFs material and bismuth oxychloride; the bismuth oxychloride is loaded on the surface of the MOFs material; and the MOFs material is NU-1000. The semiconductor composite material has a heterojunction formed between the NU-1000 and the bismuth oxychloride, effective charge carrier transfer exists on the heterojunction interface, the separation of photo-generated holes and electrons is better promoted, and the semiconductor composite material has enhanced adsorption performance, excellent photocatalytic activity and stability to tetracycline under visible light irradiation.

Description

Technical Field

[0001] This invention relates to the field of photocatalysis technology, and in particular to a semiconductor composite material, its preparation method, and its application. Background Technology

[0002] Antibiotic pollution of various water bodies is a serious environmental problem, necessitating the development of novel water treatment solutions that require less time and effort. Various drugs and pharmaceutical products are considered increasing pollutants in water bodies, threatening human health and environmental biodiversity. Tetracycline (TC) is a widely used antibiotic for treating infections in aquatic and terrestrial animals, as well as humans. However, TC is persistent and stable in aquatic environments, posing a serious threat to microorganisms, animals, plants, and humans. Currently, conventional treatment technologies such as adsorption, ozone oxidation, membrane filtration, and Fenton oxidation are insufficient for effectively and harmlessly removing TC from wastewater. Photocatalytic degradation technology, however, has attracted widespread attention due to its eco-friendly, low-cost, and high-efficiency advantages. In addition to TiO2-based oxides, numerous photocatalysts, such as sulfides (CdS), polymers (g-C3N4), and bismuth-based photocatalysts, have been developed to seek high photocatalytic activity. Bismuth oxychloride (BiOCl) exhibits a typical tetragonal martensitic structure and has attracted much attention due to its unique layered structure [Cl-O-Bi-O-Cl]. This structure generates an internal electrostatic field perpendicular to each layer and enhances the separation of photoexcitation charges. However, the wide bandgap structure of BiOCl leads to absorption of ultraviolet light and a low photoresponse under visible light conditions, thus BiOCl has only slight solar photocatalytic performance.

[0003] However, related technologies suffer from drawbacks such as poor photocatalytic degradation performance and instability. Therefore, it is necessary to develop a new semiconductor composite material that possesses both high photocatalytic degradation performance and high stability. Summary of the Invention

[0004] The present invention aims to at least solve one of the technical problems existing in the prior art. To this end, the first aspect of the present invention proposes a semiconductor composite material that can effectively improve photocatalytic degradation performance and stability.

[0005] A second aspect of the present invention also provides a method for preparing a semiconductor composite material.

[0006] A third aspect of the present invention also provides an application of a semiconductor composite material.

[0007] The semiconductor composite material provided according to a first aspect of the present invention includes MOFs material and bismuth oxychloride; the bismuth oxychloride is loaded on the surface of the MOFs material; the MOFs material is NU-1000.

[0008] The semiconductor composite material according to embodiments of the present invention has at least the following beneficial effects:

[0009] The semiconductor composite material of the present invention forms a heterojunction between NU-1000 and bismuth oxychloride, and there is effective charge carrier transfer at the heterojunction interface, which better promotes the separation of photogenerated holes and electrons. Under visible light irradiation, it has enhanced adsorption performance of tetracycline, excellent photocatalytic activity and stability.

[0010] According to some embodiments of the present invention, the NU-1000 accounts for 30% to 60% of the total mass of the semiconductor composite material. Therefore, within the above range, the photocatalytic degradation of tetracycline by the semiconductor composite material is more effective.

[0011] The method for preparing a semiconductor composite material according to a second aspect embodiment of the present invention includes the following steps:

[0012] S1. Mix NU-1000, a chlorine-containing compound, and solvent I to obtain solution A; mix bismuth salt and solvent II to obtain solution B;

[0013] S2. Mix solution A and solution B and carry out a hydrothermal reaction to obtain a semiconductor composite material.

[0014] The method for preparing semiconductor composite materials according to embodiments of the present invention has at least the following beneficial effects:

[0015] The method of this invention can prepare composite materials with uniform morphology because NU-1000 has a positively charged Zeta potential, while chloride ions are negatively charged. By separating the solution into solutions A and B, the purpose is to allow chloride ions to fully contact NU-1000 and adsorb onto the surface of NU-1000, thereby achieving in-situ growth of BiOCl on the surface of NU-1000. However, if the solutions are directly mixed, chloride ions and bismuth ions cannot generate BiOCl in-situ on the surface of NU-1000, and a uniform composite material cannot be formed.

[0016] According to some embodiments of the present invention, the chlorine-containing compound includes at least one selected from hexadecylmethylimidazolium chloride, BiCl3, potassium chloride, and NH4Cl. Furthermore, when the chlorine-containing compound is selected from hexadecylmethylimidazolium chloride and BiCl3, nanoscale BiOCl can be obtained, resulting in a more uniform morphology of the composite material.

[0017] According to some embodiments of the present invention, the temperature of the hydrothermal reaction is 100–180°C.

[0018] According to some embodiments of the present invention, the hydrothermal reaction time is 12h to 36h.

[0019] According to some embodiments of the present invention, solvent I and solvent II are independently selected from at least one of mannitol, ethylene glycol, and glycerol.

[0020] According to some embodiments of the present invention, the bismuth salt is selected from at least one of bismuth nitrate and BiCl3.

[0021] According to some embodiments of the present invention, the CAS number of the NU-1000 is 1446138-63-1.

[0022] According to some embodiments of the present invention, the NU-1000 can be purchased commercially.

[0023] A third aspect of the present invention provides the application of the aforementioned semiconductor composite material in the photocatalytic degradation of antibiotics.

[0024] According to some embodiments of the present invention, the antibiotic includes at least one of tetracycline, ciprofloxacin, or sulfamethoxazole.

[0025] Other features and advantages of the invention will be set forth in the description which follows, and will be apparent in part from the description, or may be learned by practicing the invention. Attached Figure Description

[0026] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which:

[0027] Figure 1 This is a schematic diagram of the structure of the semiconductor composite material prepared in Example 1 of the present invention;

[0028] Figure 2 These are electrochemical performance test images of the semiconductor composite material prepared in Example 1 of this invention;

[0029] Figure 3 These are the photocatalytic degradation effect diagram and stability experiment diagram of the semiconductor composite material prepared in the embodiments of the present invention for tetracycline degradation. Detailed Implementation

[0030] The following are specific embodiments of the present invention, and the technical solutions of the present invention will be further described in conjunction with the embodiments, but the present invention is not limited to these embodiments.

[0031] Unless otherwise specified, the reagents, methods and equipment used in this invention are all conventional reagents, methods and equipment in this technical field.

[0032] Example 1

[0033] Example 1 provides a semiconductor composite material, comprising MOF materials and bismuth oxychloride; bismuth oxychloride is supported on the surface of the MOF material; the MOF material is NU-1000. Its preparation method is as follows:

[0034] Preparation of NU-1000:

[0035] Synthesis of H4TBAPY:

[0036]

[0037] Step 1: A mixture of 5 g of 1,3,6,8-tetrabromopyrene (9.5 mmol), 8.5 g of 4-(methoxycarbonyl)-phenylboronic acid (54.4 mmol), 0.75 g of tetra(triphenylphosphine)palladium (0.7 mmol), 16.5 g of potassium carbonate (121 mmol), and 300 mL of dioxane was reacted at 100 °C for 3 days. The mixture was washed with water and acetone and extracted with chloroform (500 mL). Methanol (300 mL) was added, resulting in a yellow precipitate. After filtration, 1,3,6,8-tetra(4-methoxycarbonylphenyl)pyrene (M1) was collected and dried under vacuum, yielding 71%.

[0038]

[0039] Step 2: Reflux 7.1 g of KOH (125.9 mmol), 4.5 g of M1 (6.1 mmol), and 1000 mL of a THF / H2O (1:1 ratio) mixture for one day. Remove the solvent under vacuum, then add water to form a clear yellow solution. Adjust the pH to 1 using concentrated hydrochloric acid (12 M), collect the resulting yellow solid by filtration, and wash several times with water. Collect the product 1,3,6,8-tetra(benzoic acid)pyrene (H4TBAPy, yellow solid), recrystallize from a mixture of DMF and dichloromethane, filter, wash with chloroform, and dry under vacuum. The yield is 90%.

[0040] Step 3:

[0041] Solution C: 970 mg (3.00 mmol) ZrOCl2·8H2O and 16.0 g (131 mmol) benzoic acid were dissolved in 80 mL DMF and placed in an oven at 100 °C.

[0042] Solution D: 200 mg (0.300 mmol) of 1,3,6,8-tetra(parabenzoic acid)pyrene (H4TBAPY) ligand was dissolved in 80 mL of LMF and placed in an oven at 100 °C.

[0043] 1 mL of solution C and 1 mL of solution D were added to 20 μL of trifluoroacetic acid to obtain a translucent yellow solution. Ten sample vials were prepared at once under the same conditions and placed in an oven at 100 °C for 1 h, during which time a yellow suspension formed. After cooling to room temperature, the ten vials were combined and the suspension was separated by centrifugation at 7800 rpm for 10 min. The sample was further washed twice with DMF and acetone, and then activated with HCl.

[0044] S1. Add the prepared NU-1000 (65 mg) and 0.17 g hexadecylmethyl imidazole chloride to 10 mL of 0.1 M mannitol solution, and label it solution A. Add 0.24 g Bi(NO3)3·5H2O to 10 mL of 0.1 M mannitol solution, and label it solution B.

[0045] S2. After mixing solutions A and B above, a yellowish-white emulsion suspension was obtained. The suspension was transferred to a 25 mL Teflon-lined autoclave and heated in an oven at 140°C for 24 hours. After the reaction was completed, the precipitate was washed several times with distilled water and alcohol. After drying at 60°C for 24 hours, the semiconductor composite material was obtained. This resulted in NU-1000 accounting for 50% of the total mass of the semiconductor composite material.

[0046] Example 2

[0047] Example 2 also provides a semiconductor composite material, prepared in the same way as in Example 1, except that the amount of NU-1000 added in step S1 is different, so that NU-1000 accounts for 30% of the total mass of the semiconductor composite material.

[0048] Example 3

[0049] Example 3 also provides a semiconductor composite material, which is prepared in the same way as in Example 1, except that the amount of NU-1000 added in step S1 is different, so that NU-1000 accounts for 40% of the total mass of the semiconductor composite material.

[0050] Example 4

[0051] Example 4 also provides a semiconductor composite material, which is prepared in the same way as in Example 1, except that the amount of NU-1000 added in step S1 is different, so that NU-1000 accounts for 60% of the total mass of the semiconductor composite material.

[0052] Comparative Example 1

[0053] Comparative Example 1 was prepared under the same conditions, using pure BiOCl.

[0054] Performance testing

[0055] Electrochemical impedance spectroscopy (EIS) and photocurrent response spectroscopy were selected to study the charge separation and transfer efficiency in the composite material of this invention. Figure 2 Figure a shows the EIS Nyquist plots of NU-1000, BiOCl, and NU-1000 / BiOCl(50%) in the frequency range of 10000 to 0.01 Hz. NU-1000 / BiOCl(50%) has a smaller Nyquist arc radius, indicating that NU-1000 / BiOCl(50%) has the lowest interface resistance and the highest charge mobility. The transient photocurrent density of NU-1000, BiOCl, and NU-1000 / BiOCl(50%) under visible light illumination varies with time as shown in Figure a. Figure 2 As shown in b, it can be seen that the photocurrent density increases rapidly when exposed to visible light and decreases rapidly when the visible light is turned off. Among them, NU-1000 / BiOCl (50%) shows the highest photocurrent density compared with other materials, indicating that it has the best photogenerated charge separation efficiency.

[0056] The materials prepared in the above examples and comparative examples were used for photocatalytic degradation of tetracycline hydrochloride (TCH).

[0057] The photodegradation of TCH by the prepared samples was evaluated using a 300W xenon lamp with an ultraviolet cutoff filter (λ>400nm) as the visible light source. Specifically, 3.0 mg of the composite materials prepared in the examples and comparative examples were dispersed in 20 mL of TCH aqueous solution (20 mg L⁻¹) and continuously magnetically stirred to maintain uniform dispersion of reactants and catalyst. Before turning on the lamp, the suspension was magnetically stirred in the dark for 30 minutes to reach equilibrium between adsorption and desorption. Under light irradiation, 2.5 mL of solution was sampled from the suspension every 5 minutes. The photocatalyst was then recovered by centrifugation (8000 rpm, 10 minutes) for recycling. The TCH concentration was determined at a wavelength of 357 nm using a UV-Vis spectrophotometer.

[0058] The results are as follows Figure 3 As shown in 3a and 3b, in Figure 3 Figure a shows the photocatalytic activity of composite materials with NU-1000 contents of 30%, 40%, 50%, and 60% under visible light, as well as the catalytic activity of pure NU-1000, pure BiOCl, and the blank group. Figure 3Figure a shows that all photocatalysts exhibited degradation of tetracycline hydrochloride solution under visible light irradiation. The figure above shows that the NU-1000 / BiOCl photocatalyst has a significant photocatalytic degradation effect on TCH. After 25 minutes of illumination, the degradation rate was only 5% without the catalyst, while the degradation rate was 26% with the catalyst and without light irradiation. Among the various photocatalysts, NU-1000 / BiOCl (50%) achieved a photocatalytic degradation efficiency of 84% for TCH, exhibiting the best photocatalytic activity. In addition, other composite materials with different NU-1000 loadings also showed excellent degradation effects. Figure 3 As shown in b, under visible light irradiation, after four cycles of testing, the photocatalytic degradation rate was still 73.3%, verifying its stability and reusability.

[0059] The present invention has been described in detail above with reference to the embodiments of the present invention. However, the present invention is not limited to the above embodiments. Within the scope of knowledge possessed by those skilled in the art, various changes can be made without departing from the spirit of the present invention.

Claims

1. A semiconductor composite material, characterized in that, It includes MOF materials and bismuth oxychloride; the bismuth oxychloride is loaded on the surface of the MOF materials; the MOF materials are NU-1000; Based on the total mass of the semiconductor composite material, the NU-1000 accounts for 30% to 60% of the total mass; The semiconductor composite material is prepared by the following method: S1. Mix NU-1000, a chlorine-containing compound, and solvent I to obtain solution A; mix bismuth salt and solvent II to obtain solution B; S2. Mix solution A and solution B and carry out a hydrothermal reaction to obtain a semiconductor composite material; Solvent I and Solvent II are independently selected from at least one of mannitol, ethylene glycol, and glycerol.

2. The semiconductor composite material according to claim 1, characterized in that, The chlorine-containing compound includes at least one of hexadecylmethyl imidazolium chloride, BiCl3, potassium chloride, and NH4Cl.

3. The semiconductor composite material according to claim 1, characterized in that, The temperature of the hydrothermal reaction is 100~180℃.

4. The semiconductor composite material according to claim 1, characterized in that, The hydrothermal reaction time is 12h~36h.

5. The semiconductor composite material according to claim 1, characterized in that, The bismuth salt is selected from at least one of bismuth nitrate and BiCl3.

6. The application of the semiconductor composite material according to any one of claims 1 to 5 in the photocatalytic degradation of antibiotics.

7. The application according to claim 6, characterized in that, The antibiotics include at least one of tetracycline, ciprofloxacin, or sulfamethoxazole.

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