Immobilized plasma Z-type composite film photocatalyst as well as preparation method and application thereof

Abstract

The invention relates to an immobilized plasma Z-type NiCuBi2O4 / Bi / NiO composite film photocatalyst as well as a preparation method and application thereof. The NiCuBi2O4 film photocatalyst is prepared by taking nickel foil as a substrate and adopting a coprecipitation method, a spin-coating method and a high-temperature calcination method. The NiCuBi2O4 / Bi thin film photocatalyst is prepared through an in-situ reduction method. And finally, preparing the plasma Z-type NiCuBi2O4 / Bi / NiO composite film photocatalyst through a sol-gel method, a spin-coating method and a high-temperature calcination method. The immobilized plasma Z-type NiCuBi2O4 / Bi / NiO composite film photocatalyst with the Ni foil as the substrate is constructed aiming at the problems of agglomeration and recovery in powder photocatalyst reaction, non-noble metal Bi nano particles are introduced to serve as conductive channels, the low-cost plasma resonance effect is achieved, the enhanced catalytic degradation activity is obtained under sunlight, and the photocatalytic degradation effect is improved. Meanwhile, the practical problem that precious metal depends on and powder catalysts are difficult to separate and recover is solved.

Description

Technical Field

[0001] This invention belongs to the field of photocatalyst preparation and application, specifically involving the construction of an immobilized plasma Z-type Ni|CuBi2O4 / Bi / NiO composite film photocatalyst with SPR effect using Ni foil as a substrate, employing sol-gel method, co-precipitation method, reduction method, high-temperature calcination method and spin coating method, and introducing non-noble metal Bi nanoparticles as conductive channels, and its application in the catalytic degradation of antibiotic wastewater under sunlight. Background Technology

[0002] Tetracycline (TC), due to its broad-spectrum antibacterial properties and low cost, is widely used in the medical and aquaculture industries, but this has also led to increasingly severe water pollution, making systematic remediation urgent. Photocatalytic oxidation technology, as an environmentally friendly advanced oxidation process, has become an effective means of degrading such persistent organic pollutants due to its advantages of high efficiency in oxidation-reduction, low cost, and complete mineralization of pollutants. However, most photocatalysts are currently in powder form, and their practical application in aqueous phases is still limited by a series of inherent problems. Powdered photocatalysts are prone to aggregation and sedimentation in aqueous systems, which not only blocks incident light, limiting their effective excitation and light energy utilization, but also reduces the accessibility of active sites. Furthermore, the catalyst recovery process relies on energy-intensive centrifugation and filtration operations, resulting in low recovery efficiency and unavoidable solid loss.

[0003] Based on this, this invention proposes an "immobilization" preparation strategy, constructing an immobilized Ni|CuBi2O4 / Bi / NiO composite film photocatalytic system using metallic Ni foil as a substrate. NiO and CuBi2O4 monomers, as photocatalysts, are inherently limited by narrow light response ranges and high recombination rates of photogenerated electron-hole pairs. However, they possess mutually compatible band structure characteristics. NiO has a relatively positive valence band potential, which is beneficial for photo-oxidation reactions, while CuBi2O4's narrow bandgap not only enhances visible light capture but also, due to its relatively negative conduction band position, is more conducive to photo-reduction reactions. Therefore, this characteristic can be fully utilized to construct a composite system. Furthermore, the localized surface plasmon resonance (SPR) effect induced by noble metal deposition can promote the enhancement of the system's photocatalytic activity. However, considering cost, this invention introduces non-noble metal Bi nanoparticles to replace noble metals as conductive channels to achieve a low-cost SPR effect, constructing an immobilized plasmonic Z-type Ni|CuBi2O4 / Bi / NiO composite film photocatalyst. This enhances the system's photocatalytic performance while solving the problems of noble metal dependence and the separation and recovery of powdered catalysts. Therefore, this invention constructs an immobilized plasma Z-type Ni|CuBi2O4 / Bi / NiO composite film photocatalyst to further enhance its photocatalytic activity and explore its catalytic degradation effect on total chloride (TC) in water. This technology provides a photocatalytic material system with greater practical application value for the efficient and sustainable treatment of this type of pollution. Summary of the Invention

[0004] The purpose of this invention is to solve the problem of separating and recovering powdered catalysts in noble metal-dependent and aqueous applications. By controlling the number of thin film deposition layers and introducing Bi nanoparticles, a novel immobilized plasma Z-type Ni|CuBi2O4 / Bi / NiO composite film photocatalyst with high catalytic activity is constructed. This composite system fully utilizes the bandgap structure and physicochemical properties of each component, enhancing catalytic degradation performance through multiple mechanisms including the SPR effect, Z-type electron transport pathway, and the high conductivity of the immobilized Ni foil. It also achieves simple separation and recovery operations, providing a photocatalytic material system with greater practical application value for the efficient degradation of antibiotics in water.

[0005] Another objective of this invention is to utilize immobilized plasma Z-type Ni|CuBi2O4 / Bi / NiO composite membrane photocatalyst for the catalytic degradation of antibiotics in wastewater.

[0006] The technical solution adopted in this invention is: an immobilized plasma Z-type Ni|CuBi2O4 / Bi / NiO composite film photocatalyst, wherein the immobilized plasma Z-type Ni|CuBi2O4 / Bi / NiO composite film photocatalyst is composed of CuBi2O4 thin film, Bi nanoparticles, and NiO thin film sequentially disposed on Ni foil, wherein the number of NiO thin film layers is 1-3 layers.

[0007] The preparation method of the above-mentioned immobilized plasma Z-type Ni|CuBi2O4 / Bi / NiO composite film photocatalyst includes the following steps: Step 1: Polish the Ni foil with sandpaper, clean it, soak it in hydrochloric acid solution, clean it, and dry it; take a mixed solution of Ni(NO3)2·6H2O dissolved in deionized water and ethanol, stir it thoroughly, add citric acid monohydrate, stir under heating conditions, slowly add ammonia water, stir, and let it stand at room temperature until the solution becomes a fluid, high-viscosity, green NiO gel; prepare blue Cu(OH)2 precipitate; prepare white Bi(OH)3 precipitate; disperse the prepared Cu(OH)2 and Bi(OH)3 precipitates together in an appropriate amount of deionized water, stir continuously, filter and collect the mixed precipitate, and dry it to obtain a viscous coprecipitate; Step 2: The co-precipitated material is spin-coated onto Ni foil, dried after spin-coating, and calcined to obtain Ni|CuBi2O4 thin film photocatalyst; Step 3: Add NaBH4 solution dropwise onto the Ni|CuBi2O4 thin film photocatalyst, wash and dry after reaction to obtain Ni|CuBi2O4 / Bi thin film photocatalyst; Step 4: Spin-coat the Ni|CuBi2O4 / Bi thin film photocatalyst with NiO gel droplets, dry, and calcine to obtain the Ni|CuBi2O4 / Bi / NiO composite film photocatalyst.

[0008] In the above-mentioned method for preparing the immobilized plasma Z-type Ni|CuBi2O4 / Bi / NiO composite film photocatalyst, in step 1, the stirring under heating conditions is carried out continuously at 75 °C, and stirring is performed for 1 hour after adding ammonia water.

[0009] The preparation method of the above-mentioned immobilized plasma Z-type Ni|CuBi2O4 / Bi / NiO composite film photocatalyst, in step 1, the preparation method of blue Cu(OH)2 precipitate includes the following steps: dissolving Cu(NO3)2·3H2O in deionized water, adding a certain amount of NaOH solution to the solution after complete dissolution, stirring thoroughly and letting stand to obtain blue Cu(OH)2 precipitate; the preparation method of white Bi(OH)3 precipitate includes the following steps: dissolving Bi(NO3)3·5H2O in ethylene glycol, stirring continuously until completely dissolved, adding NaOH solution dropwise to the solution, stirring thoroughly and letting stand to obtain white Bi(OH)3 precipitate.

[0010] In the above-mentioned method for preparing the immobilized plasma Z-type Ni|CuBi2O4 / Bi / NiO composite film photocatalyst, step 2, the spin coating is performed on a Ni foil at a rotation speed of 1000 r / min for 20 s, and the calcination is performed at 700 °C for 2.0 h.

[0011] In the above-mentioned method for preparing the immobilized plasma Z-type Ni|CuBi2O4 / Bi / NiO composite film photocatalyst, step 4 involves spin coating at a rotation speed of 2500 r / min for 30 s, calcination at 500 °C for 1.0 ~ 3.0 h, and spin coating being performed twice.

[0012] The above-mentioned immobilized plasma Z-type Ni|CuBi2O4 / Bi / NiO composite film photocatalyst is used in the degradation of antibiotics in wastewater under light irradiation.

[0013] In the above application, the immobilized plasma Z-type Ni|CuBi2O4 / Bi / NiO composite membrane photocatalyst is added to wastewater containing antibiotics to degrade antibiotics under light irradiation.

[0014] In the above application, the antibiotic is tetracycline, and the concentration of the tetracycline is 10 mg / L.

[0015] The beneficial effects of this invention are as follows: This invention employs an "immobilization" preparation strategy, using metallic Ni foil as a substrate, and utilizes sol-gel, co-precipitation, reduction, high-temperature calcination, and spin-coating methods. It introduces non-precious metal Bi nanoparticles as conductive channels to construct an immobilized plasma Z-type Ni|CuBi2O4 / Bi / NiO composite film photocatalytic system, achieving enhanced catalytic activity and solving the problems of precious metal dependence and the separation and recovery of powdered catalysts in aqueous phases. This design constructs a Z-type electron transfer mechanism, fully utilizing the structural advantages of NiO and CuBi2O4. The composite system not only improves the separation efficiency of photogenerated carriers but also retains the system's strong redox capabilities. Furthermore, considering cost, this invention introduces non-precious metal Bi nanoparticles to replace precious metals, achieving a low-cost SPR effect. The Bi nanoparticles, acting as conductive channels, promote the electron transfer efficiency between CuBi2O4 and NiO. The immobilization design enables simple separation and recovery operations. This technology provides a more practically valuable photocatalytic material morphology for the efficient degradation of total chemical substances (TC) in water. Attached Figure Description

[0016] Figure 1 This is the X-ray diffraction pattern of Ni|NiO nanoparticles and its standard card.

[0017] Figure 2 This is the X-ray diffraction pattern of Ni|CuBi2O4 nanoparticles and its standard card.

[0018] Figure 3 This is the X-ray diffraction pattern of the Ni|CuBi2O4 / NiO composite photocatalyst.

[0019] Figure 4 This is the X-ray diffraction pattern of the Ni|CuBi2O4 / Bi / NiO composite photocatalyst. Detailed Implementation

[0020] First, the Ni foil used in this invention is 50 mm long, 20 mm wide, and 0.2 mm thick. The Ni foil is repeatedly polished with sandpaper and then ultrasonically cleaned. Subsequently, the Ni foil is immersed in 1.5 mol / L hydrochloric acid for 30 min, and after immersion, it is repeatedly rinsed with deionized water. The purified Ni foil is then transferred to a 60 °C drying oven for 2.0 h for later use. Ni(NO3)2·6H2O is dissolved in a mixed solution of 50 mL of deionized water and ethanol. After thorough stirring, citric acid monohydrate is added and the mixture is heated and stirred. During this process, ammonia is slowly added dropwise to the solution. After thorough stirring, heating is stopped, and the sol is allowed to stand at room temperature until the solution becomes a fluid, high-viscosity, green NiO gel. Next, Cu(OH)2 and Bi(OH)3 are prepared by liquid-phase precipitation and dispersed together in an appropriate amount of deionized water, with continuous stirring to ensure thorough mixing. The mixed precipitate is then collected by filtration and dried in a 60 °C drying oven to form a co-precipitate with a certain viscosity. Subsequently, the co-precipitate was spin-coated onto a Ni foil, dried, and calcined at 700 °C for 2.0 h to obtain a Ni|CuBi2O4 photocatalyst film. NaBH4 solution was dropped onto the Ni|CuBi2O4 photocatalyst film, and after reaction, the surface was rinsed with deionized water and dried to obtain a Ni|CuBi2O4 / Bi photocatalyst film. Finally, the obtained Ni|CuBi2O4 / Bi was vacuum adsorbed and fixed on a spin coater, and the prepared NiO gel was dropped onto the film and spin-coated at 2500 r / min for 30 s, followed by drying. The dried film was calcined in a muffle furnace at 500 °C for 1.0–3.0 h, with the optimal number of NiO deposition layers being 2, yielding Ni|CuBi2O4 / Bi / NiO composite film photocatalysts under different conditions.

[0021] The application of immobilized plasma Z-type Ni|CuBi2O4 / Bi / NiO composite membrane photocatalyst in the degradation of antibiotics in wastewater under light irradiation is described below. The method involves adding the aforementioned immobilized plasma Z-type Ni|CuBi2O4 / Bi / NiO composite membrane photocatalyst to antibiotic-containing wastewater, and then degrading the antibiotic under light irradiation. The antibiotic is tetracycline, and the concentration of tetracycline is 10 mg / L.

[0022] Example 1 Preparation process

[0023] (I) Immobilized plasma Z-type Ni|CuBi2O4 / Bi / NiO composite film photocatalyst, the preparation method is as follows: First, the Ni foil used in this invention is 50 mm long, 20 mm wide, and 0.2 mm thick. The Ni foil is repeatedly polished with sandpaper and then ultrasonically cleaned. Subsequently, the Ni foil is immersed in 1.5 mol / L hydrochloric acid for 30 min, followed by repeated rinsing with deionized water. The purified Ni foil is then transferred to a 60 °C drying oven for 2.0 h for later use. 2.910 g of Ni(NO3)2·6H2O is weighed and dissolved in a 50 mL mixture of deionized water and ethanol. After thorough stirring, 2.10 g of citric acid monohydrate is added to improve sol stability. The solution is then continuously stirred at 75 °C, during which ammonia is slowly added dropwise to adjust the pH to a slightly alkaline state. After stirring for 1.0 h, heating is stopped, and the sol is allowed to stand at room temperature until the solution becomes a fluid, high-viscosity, green NiO gel.

[0024] Next, 0.6050 g of Cu(NO3)2·3H2O was dissolved in deionized water. After dissolution, 5 mL of 1.0 mol / L NaOH solution was added to the solution, stirred thoroughly, and allowed to stand to obtain a blue Cu(OH)2 precipitate. 2.425 g of Bi(NO3)3·5H2O was dissolved in ethylene glycol. After continuous stirring until completely dissolved, 15 mL of 1.0 mol / L NaOH solution was added dropwise to the solution. After thorough stirring and standing, a white Bi(OH)3 precipitate was obtained. The prepared Cu(OH)2 and Bi(OH)3 precipitates were then dispersed together in an appropriate amount of deionized water. After continuous stirring to ensure thorough mixing, the mixture was filtered and collected. The precipitate was then dried in a 60 °C drying oven to form a relatively dry, viscous coprecipitate.

[0025] Subsequently, the co-precipitated material was spin-coated onto a Ni foil at a speed of 1000 r / min for 20 s, and the sample was dried after spin-coating. The sample was then transferred to a muffle furnace and calcined at 700 °C for 2.0 h to obtain a Ni|CuBi2O4 photocatalyst film. A certain amount of NaBH4 solution was added dropwise to the Ni|CuBi2O4 photocatalyst film, and after the reaction, the surface was rinsed three times with deionized water. The sample was then transferred to a drying oven at 70 °C and dried for 2.0 h to obtain a Ni|CuBi2O4 / Bi photocatalyst film.

[0026] Finally, the obtained Ni|CuBi2O4 / Bi was vacuum adsorbed and fixed on a spin coater. 1.0 mL of the prepared NiO gel was dropped onto the film and spin-coated at 2500 r / min for 30 s. After spin-coating, the film was dried. The above steps were repeated 1-3 times. The dried films were then calcined in a muffle furnace at 500 °C for 1.0, 2.0, and 3.0 h, respectively, to obtain Ni|CuBi2O4 / Bi / NiO composite film photocatalysts under different calcination time conditions.

[0027] (ii) Comparative Example 1

[0028] Preparation of Ni|NiO thin-film photocatalyst: 2.910 g of Ni(NO3)2·6H2O was weighed and dissolved in a mixed solution of 50 mL of deionized water and ethanol. After thorough stirring, 2.10 g of citric acid monohydrate was added. The solution was then continuously stirred at 75 °C, during which ammonia was slowly added dropwise to adjust the pH to weakly alkaline. After stirring for 1.0 h, heating was stopped, and the sol was allowed to stand at room temperature until the solution became a fluid, high-viscosity, green NiO gel. 1.0 mL of NiO gel was uniformly dropped onto a pretreated Ni foil and coated using a spin coater at 2500 r / min for 30 s. After spin coating, the sample was dried and calcined at 500 °C for 2.0 h to obtain the Ni|NiO thin-film photocatalyst.

[0029] (iii) Comparative Example 2

[0030] Preparation of Ni|CuBi2O4 thin-film photocatalyst: Cu(NO3)2·3H2O was dissolved in deionized water. After dissolution, a certain amount of NaOH solution was added to the solution, stirred thoroughly, and allowed to stand to obtain a blue Cu(OH)2 precipitate. Bi(NO3)3·5H2O was dissolved in ethylene glycol. After continuous stirring until completely dissolved, NaOH solution was added dropwise to this solution. After thorough stirring and standing, a white Bi(OH)3 precipitate was obtained. The prepared Cu(OH)2 and Bi(OH)3 precipitates were co-dispersed in an appropriate amount of deionized water. After continuous stirring to ensure thorough mixing, the mixed precipitate was collected by filtration and dried in a 60 °C drying oven to form a relatively dry and viscous coprecipitate. Subsequently, the coprecipitate was spin-coated onto a Ni foil at a speed of 1000 r / min for 20 s. After spin-coating, the sample was dried. The sample was then transferred to a muffle furnace and calcined at 700 °C for 2.0 h to obtain the Ni|CuBi2O4 photocatalyst thin film.

[0031] (iv) Comparative Example 3

[0032] Preparation of Ni|CuBi2O4 / NiO thin film photocatalyst: 2.910 g of Ni(NO3)2·6H2O was weighed and dissolved in a mixed solution of 50 mL of deionized water and ethanol. After thorough stirring, 2.10 g of citric acid monohydrate was added. The solution was then continuously stirred at 75 °C while ammonia was slowly added dropwise to adjust the pH to weakly alkaline. After 1.0 h of heating and stirring, the sol was allowed to stand at room temperature until the solution became a fluid, high-viscosity, green NiO gel. Next, Cu(NO3)2·3H2O and Bi(NO3)3·5H2O were dissolved in deionized water and ethylene glycol, respectively. After dissolution, a certain amount of NaOH solution was added to the solution, and after thorough stirring and standing, a blue Cu(OH)2 precipitate and a white Bi(OH)3 precipitate were obtained. The prepared Cu(OH)₂ and Bi(OH)₃ precipitates were co-dispersed in an appropriate amount of deionized water. After continuous stirring to ensure thorough mixing, the mixed precipitate was collected by filtration and dried in a 60 °C drying oven to form a relatively dry, viscous coprecipitate. Subsequently, the coprecipitate was spin-coated onto a Ni foil at 1000 r / min for 20 s and then dried. The sample was then transferred to a muffle furnace and calcined at 700 °C for 2.0 h to obtain a Ni|CuBi₂O₄ photocatalyst film. The obtained Ni|CuBi₂O₄ was vacuum adsorbed and fixed on a spin coater. 1.0 mL of the prepared NiO gel was dropped onto the film and spin-coated at 2500 r / min for 30 s. After spin-coating, the film was dried and calcined at 500 °C for 2.0 h to obtain a Ni|CuBi₂O₄ / NiO thin film photocatalyst.

[0033] (III) Characterization of Catalysts

[0034] Figure 1 The XRD pattern and standard card of the Ni|NiO thin film photocatalyst prepared in Comparative Example 1 are shown. Figure 1 As shown, the characteristic peaks of Ni|NiO are obvious and sharp, and they correspond one-to-one with the diffraction peaks of the standard card of NiO (JCPDS 47-1049) and the standard card of Ni (JCPDS04-0850). This indicates that the Ni|NiO thin film photocatalyst was successfully prepared and has a good crystal structure.

[0035] Figure 2 The XRD pattern and standard card of the Ni|CuBi2O4 thin film photocatalyst prepared in Comparative Example 2 are shown. Figure 2 As shown, the characteristic peaks of Ni|CuBi2O4 are obvious and sharp, and highly consistent with the diffraction peaks of the standard card for CuBi2O4 (JCPDS 71-1774) and the standard card for Ni (JCPDS 04-0850). This result indicates that the present invention successfully prepared a Ni|CuBi2O4 thin-film photocatalyst with good crystal structure.

[0036] Figure 3 The image shows the XRD pattern of the Ni|CuBi2O4 / NiO thin film photocatalyst prepared in Comparative Example 3. Figure 3 As shown, characteristic peaks belonging to NiO, CuBi2O4, and metallic Ni can all be observed, indicating that the present invention has successfully prepared Ni|CuBi2O4 / NiO thin film photocatalyst with good crystal structure.

[0037] Figure 4 This is the XRD pattern of the Ni|CuBi2O4 / Bi / NiO composite film photocatalyst prepared in Example 1. Figure 4 As shown, characteristic peaks belonging to NiO, CuBi2O4, metallic Ni, and Bi nanoparticles can all be observed. This result indicates that the present invention has successfully prepared a Ni|CuBi2O4 / Bi / NiO composite film photocatalyst with a good crystal structure.

[0038] Example 2: Application of immobilized plasma Z-type Ni|CuBi2O4 / Bi / NiO composite film photocatalyst in the degradation of antibiotics under sunlight.

[0039] (I) Effect of different NiO film deposition layers on the degradation of tetracycline

[0040] Experimental Methods: A 300 W xenon lamp was used as a simulated sunlight source. The Ni|CuBi2O4 / Bi / NiO composite film photocatalyst was placed in a quartz tube containing 40 mL of TC solution, with the Ni foil containing the catalyst facing the light source. After irradiation under simulated sunlight for 2.0 h, the supernatant was collected, filtered, and its absorbance was measured. The degradation rate of TC was calculated based on the absorbance. The results are shown in Table 1.

[0041] Degradation rate (%) = (1-C) t / C0) × 100% (where C0: concentration of TC in the original solution; C t (Concentration of TC in the sample)

[0042] Table 1 Effect of different NiO film deposition layers on tetracycline degradation rate

[0043] Table 1 shows that when the number of NiO film deposition layers is 2, the prepared Ni|CuBi2O4 / Bi / NiO composite film photocatalyst has the highest efficiency for TC degradation, and the TC degradation efficiency can reach 92.4% within 2.0 h of simulated sunlight.

[0044] (II) Effect of calcination time on tetracycline degradation rate

[0045] Experimental Methods: A 300 W xenon lamp was used as a simulated solar light source. When the NiO film deposition layer number was 2, the Ni|CuBi2O4 / Bi / NiO composite film photocatalyst with different calcination times (1.0, 2.0, 3.0 h) was placed in a quartz tube containing 40 mL of TC solution, with the Ni foil containing the catalyst facing the light source. After irradiation under simulated sunlight for 2.0 h, the supernatant was collected, filtered, and its absorbance was measured. The degradation rate of TC was calculated based on the absorbance. The results are shown in Table 2.

[0046] Table 2 Effect of calcination time on tetracycline degradation rate

[0047] As shown in Table 2, when the calcination time is 2.0 h, the Ni|CuBi2O4 / Bi / NiO composite film photocatalyst exhibits the greatest degree of TC degradation, with a TC degradation rate of up to 92.4% within 2.0 h of simulated sunlight.

[0048] (III) Effects of different catalysts on the degradation of tetracycline

[0049] Experimental Methods: A 300 W xenon lamp was used as a simulated solar light source. Immobilized plasma Z-type Ni|CuBi₂O₄ / Bi / NiO composite film photocatalysts, Ni|NiO, Ni|CuBi₂O₄, and Ni|CuBi₂O₄ / NiO thin film photocatalysts were added to 40 mL of TC solution with an initial concentration of 10 mg / L, respectively. After irradiation under simulated sunlight for 2.0 h, the supernatant was collected, filtered, and its absorbance was measured. The TC degradation rate was calculated based on the absorbance. The results are shown in Table 3.

[0050] Table 3 Effect of different catalysts on tetracycline degradation rate

[0051] As shown in Table 3, the immobilized plasma Z-type Ni|CuBi2O4 / Bi / NiO composite film photocatalyst exhibited the highest degradation rate for TC, achieving a degradation rate of 92.4% within 2.0 h, significantly higher than that of Ni|NiO, Ni|CuBi2O4, and Ni|CuBi2O4 / NiO thin film photocatalysts. This result can be attributed to the Z-type electron transfer path, SPR effect, and the high conductivity of the immobilized Ni foil in the immobilized composite film system prepared in this invention, which significantly improve the degradation ability of antibiotics.

[0052] In the above embodiments, tetracycline was used as the antibiotic, but this does not limit the antibiotic degraded by the present invention to tetracycline. The method of the present invention is applicable to the degradation of antibiotics and dye wastewater, etc.

Claims

1. An immobilized plasma Z-type Ni|CuBi2O4 / Bi / NiO composite film photocatalyst, characterized in that, The immobilized plasma Z-type Ni|CuBi2O4 / Bi / NiO composite film photocatalyst consists of a Ni foil with a CuBi2O4 film, Bi nanoparticles, and a NiO film arranged sequentially, wherein the number of NiO film layers is 1-3.

2. The method for preparing the immobilized plasma Z-type Ni|CuBi2O4 / Bi / NiO composite film photocatalyst according to claim 1, characterized in that, Includes the following steps: Step 1: Polish the Ni foil with sandpaper, clean it, soak it in hydrochloric acid solution, clean it, and dry it; take a mixed solution of Ni(NO3)2·6H2O dissolved in deionized water and ethanol, stir it thoroughly, add citric acid monohydrate, stir under heating conditions, slowly add ammonia water, stir, and let it stand at room temperature until the solution becomes a fluid, high-viscosity, green NiO gel; prepare blue Cu(OH)2 precipitate; prepare white Bi(OH)3 precipitate; disperse the prepared Cu(OH)2 and Bi(OH)3 precipitates together in an appropriate amount of deionized water, stir continuously, filter and collect the mixed precipitate, and dry it to obtain a viscous coprecipitate; Step 2: The co-precipitated material is spin-coated onto Ni foil, dried after spin-coating, and calcined to obtain Ni|CuBi2O4 thin film photocatalyst; Step 3: Add NaBH4 solution dropwise onto the Ni|CuBi2O4 thin film photocatalyst, wash and dry after reaction to obtain Ni|CuBi2O4 / Bi thin film photocatalyst; Step 4: Spin-coat the Ni|CuBi2O4 / Bi thin film photocatalyst with NiO gel droplets, dry, and calcine to obtain the Ni|CuBi2O4 / Bi / NiO composite film photocatalyst.

3. The method for preparing the immobilized plasma Z-type Ni|CuBi2O4 / Bi / NiO composite film photocatalyst according to claim 2, characterized in that, In step 1, the stirring under heating conditions is carried out continuously at 75 °C, and ammonia water is added dropwise and then stirred for 1 hour.

4. The method for preparing the immobilized plasma Z-type Ni|CuBi2O4 / Bi / NiO composite film photocatalyst according to claim 2, characterized in that, In step 1, the preparation method of blue Cu(OH)2 precipitate includes the following steps: dissolving Cu(NO3)2·3H2O in deionized water, adding a certain amount of NaOH solution to the solution after complete dissolution, stirring thoroughly, and allowing it to stand to obtain blue Cu(OH)2 precipitate; the preparation method of white Bi(OH)3 precipitate includes the following steps: dissolving Bi(NO3)3·5H2O in ethylene glycol, stirring continuously until completely dissolved, adding NaOH solution dropwise to the solution, stirring thoroughly, and allowing it to stand to obtain white Bi(OH)3 precipitate.

5. The method for preparing the immobilized plasma Z-type Ni|CuBi2O4 / Bi / NiO composite film photocatalyst according to claim 2, characterized in that, In step 2, the spin coating is performed on the Ni foil at a rotation speed of 1000 r / min for 20 s, and the calcination is performed at 700 °C for 2.0 h.

6. The method for preparing the immobilized plasma Z-type Ni|CuBi2O4 / Bi / NiO composite film photocatalyst according to claim 2, characterized in that, In step 4, the spin coating is performed at a rotation speed of 2500 r / min for 30 s, the calcination is performed at 500 °C for 1.0 ~ 3.0 h, and the spin coating is performed twice.

7. The application of the immobilized plasma Z-type Ni|CuBi2O4 / Bi / NiO composite membrane photocatalyst as described in claim 1 in the degradation of antibiotics in wastewater under light irradiation.

8. The application according to claim 7, characterized in that, In wastewater containing antibiotics, the immobilized plasma Z-type Ni|CuBi2O4 / Bi / NiO composite membrane photocatalyst described in claim 1 is added to degrade the antibiotics under light irradiation.

9. The application according to claim 7, characterized in that, The antibiotic is tetracycline, and the concentration of the tetracycline is 10 mg / L.

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