Holothurian-like coo-cubio4 composite material and preparation and application thereof

Abstract

The application discloses a kind of sea cucumber-like CoO-CuBi2O4 composite materials, and the sea cucumber-like CoO-CuBi2O4 composite materials prepared are supported by one-dimensional rod structure CuBi2O4, zero-dimensional CoO nanoparticles are loaded on the surface of rod-shaped CuBi2O4, and form sea cucumber-like composite structure.The sea cucumber-like CoO-CuBi2O4 composite material shows good photocatalytic performance and degradation effect in the degradation of organic pollutants system by activating persulfate.The sea cucumber-like CoO-CuBi2O4 composite material has the advantages of stable structure, high safety, simple process, low cost, good removal effect, high efficiency, no secondary pollution, etc., and can meet the laboratory and industrial needs.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of photocatalysis, in particular to a kind of sea cucumber-like CoO-CuBi2O4 Composite material, preparation method and application. BACKGROUND

[0002] Since Fujishima and Honda found that n-type semiconductor TiO2 single crystal photoelectrode decomposes water in 1972, photocatalysis technology has attracted the attention of researchers.

[0003] Photocatalysis technology refers to the catalytic reaction and photochemical reaction of photocatalyst under the irradiation of sunlight (ultraviolet light, visible light or even infrared light). It has the advantages of green environmental protection, efficient and complete pollutant degradation, simple operation, no secondary pollution and low cost, and has ideal application prospect in the fields of environmental remediation and energy conversion.

[0004] The advanced oxidation technology (SR-AOPs) based on sulfate radical (SO4 ·- ) is a kind of advanced oxidation technology that generates SO4 ·- as the main active oxygen species with super strong oxidation ability, which is a new technology for the oxidation treatment of refractory organic matter developed rapidly in recent years. Compared with the hydroxyl radical (·OH) generated by traditional advanced oxidation technology, SO4 ·- has higher oxidation-reduction potential (E=2.5-3.1V vs E=1.8-2.7V), longer half-life (30-40μs vs 20ns) and stronger selectivity. Generally, SO4 ·- can be generated by activating persulfate including peroxymonosulfate (PMS) and peroxymonopersulfate (PDS). The conventional activation methods mainly include energy-based methods such as heat, ultraviolet light and ultrasound, chemical reagents such as alkali, carbonate and benzoquinone, transition metal ions such as Co 2+ and Cu 2+ , and heterogeneous catalysts mainly composed of transition metal oxides and carbon materials. At present, a variety of metal oxides that can efficiently activate persulfate mainly include Co, Fe, Mn and Cu-based single / dual metal oxides and composites of metal oxides.

[0005] Cobalt-based catalyst is an excellent material that can activate persulfate, and the loose 2d orbitals of cobalt promote its dispersed active sites. The catalytic ability of cobalt active center of nanoscale CoO is good, and the specific surface area is high. As an activator with strong SR-AOPs performance, it is increasingly concerned in the treatment of water pollution.

[0006] As a kind of narrow band gap (Eg=1.5-1.8eV) photocatalyst, P-type metal oxide copper bismuth oxide (CuBi2O4) has the edge of conduction band and valence band about-0.5V NHE and 1.1V NHE With the advantages of easy preparation, low cost and strong visible light response. However, like other semiconductor photocatalysts, the rapid recombination of photo-generated carriers makes the single CuBi2O4 photocatalytic activity poor. In order to improve the separation efficiency of photo-induced electron-hole pairs and enhance the photocatalytic performance, people often use morphology control or semiconductor composite method to improve its performance. Wang et al. prepared CuBi2O4 nanorod array by hydrothermal method, and the degradation rate of methylene blue was up to 91%. Liu et al. prepared CuBi2O4 / Bi2MoO6 composite photocatalyst by hydrothermal and solvothermal method, and the CuBi2O4 / Bi2MoO6 composite catalyst can degrade 97.4% of ciprofloxacin in 90min in photoelectric Fenton system. SUMMARY

[0007] The purpose of the present application is to provide a kind of sea cucumber-like CoO-CuBi2O4 Composite Material and its preparation method and application, the obtained sea cucumber-like CoO-CuBi2O4 Composite Material can increase the active site of reactant as photocatalyst, solve the problems such as fast recombination of photo-generated carriers and low visible light utilization rate of CuBi2O4, sea cucumber-like CoO-CuBi2O4 Composite Material can make its photocatalytic activity improve by activating persulfate, and the application prospect is more extensive.

[0008] In order to achieve the above task, the technical solutions adopted by the present application are as follows:

[0009] A kind of sea cucumber-like CoO-CuBi2O4 Composite Material, characterized in that the prepared sea cucumber-like CoO-CuBi2O4 Composite Material is supported by CuBi2O4 with one-dimensional rod structure, and zero-dimensional CoO nanoparticles are loaded on the surface thereof.

[0010] According to the present application, the length of the rod-shaped CuBi2O4 is about 2-4 μm, and the particle size of CoO is 250-450 nm.

[0011] The preparation method of the above-mentioned sea cucumber-like CoO-CuBi2O4 Composite Material, characterized in that it comprises the following steps:

[0012] (1) brownish powder CuBi2O4 with one-dimensional rod structure is prepared by a hydrothermal method;

[0013] (2) n-octanol and ethanol are mixed to obtain solution A, and cobalt acetate is added to solution A to obtain solution B;

[0014] (3) adding brownish-powder CuBi2O4 with one-dimensional rod-like structure into solution B, stirring and ultrasonicating to obtain precursor C;

[0015] (4) treating precursor C by hydrothermal method, and cooling, washing and drying to obtain powder CoO-CuBi2O4 composite material with sea cucumber-like structure.

[0016] Specifically, the specific process of preparing brownish-powder CuBi2O4 with one-dimensional rod-like structure in step (1) is as follows:

[0017] 2.42 g Bi(NO3)3·5H2O, 0.6 g Cu(NO3)3·3H2O and 0.87 g NaOH are added into 80 mL deionized water, and stirred for 3 hours until the solute is completely dissolved. Then the dissolved solution is poured into a reaction kettle lined with an inner liner, and reacted at 180℃ for 24 hours. After cooling to room temperature, the product is repeatedly washed with ethanol and deionized water, and then placed in a drying box at 70℃ for drying. Finally, the one-dimensional rod-like brownish-powder CuBi2O4 is obtained by grinding.

[0018] Specifically, in step (2), the volume ratio of n-octanol to ethanol is 4:1.

[0019] In step (2), solution B is obtained by adding 0.92 g of cobalt acetate into 40 mL of solution A and stirring for 2 hours.

[0020] Further, in step (3), the rod-like CuBi2O4 powder is 0.02-2.1 g; the stirring time is 10 minutes, and the ultrasonicating time is 10 minutes.

[0021] Preferably, in step (4), the precursor is added into a 50 mL high-pressure reaction kettle; the reaction is carried out in an oven at 220℃ for 4 hours, and after cooling to room temperature, the product is washed and dried.

[0022] The applicant's experiments show that the sea cucumber-like CoO-CuBi2O4 composite material can be used as a photocatalyst for removing organic pollutants in water.

[0023] The specific application process is as follows:

[0024] The sea cucumber-like CoO-CuBi2O4 composite material is mixed with water containing organic pollutants, and a photocatalytic reaction is carried out under light conditions to remove the organic pollutants in the water; or the sea cucumber-like CoO-CuBi2O4 composite photocatalyst is mixed with peroxysulfate and then mixed with water containing organic pollutants, and a photocatalytic reaction is carried out under light conditions to remove the organic pollutants in the water.

[0025] The ratio of the CoO-CuBi2O4 composite material to the water body containing organic pollutants is 0.6 g: 1 L; the organic pollutants in the water body containing organic pollutants are tetracycline antibiotics, the initial concentration of which is 40 mg / L, the photocatalytic reaction temperature is 25 DEG C, the photocatalytic reaction time is 90 min, the light source used in the photocatalytic reaction is a xenon lamp, and the light power of the xenon lamp is 45-50 W.

[0026] The CoO-CuBi2O4 composite material has the advantages of stable structure, high safety, simple process, low cost, good removal effect, high efficiency and no secondary pollution, and can meet the needs of laboratories and industries.

[0027] (1) The CoO-CuBi2O4 composite material has excellent physical and chemical properties such as chemical and thermal stability, and the one-dimensional rod-shaped CuBi2O4 is used as a base material; further, the cobalt monoxide (CoO) is loaded on the surface of the one-dimensional rod-shaped CuBi2O4 to form a composite material, which can inhibit the rapid recombination of photo-generated carriers of CuBi2O4 monomers and CoO monomers, improve the utilization rate of visible light, avoid the agglomeration of CoO nanoparticles, and thus ensure the stability of CoO, which is conducive to improving the photocatalytic performance. Subsequently, the CoO-CuBi2O4 composite material is further activated by persulfate to generate more active free radicals, thereby realizing efficient degradation of organic pollutants.

[0028] (2) The CoO-CuBi2O4 composite material has the advantages of high photo-generated electron-hole separation efficiency, high catalytic activity, good structural stability, no secondary pollution, and the like, and through the further activation of persulfate by Co and Cu, the organic pollutants in the water body can be removed faster, and as a new type of photocatalytic material, the catalytic material can improve the actual application efficiency in the field of degrading organic pollutants in the environment.

[0029] (3) The CoO-CuBi2O4 composite material further improves the photocatalytic activity of the photocatalyst by optimizing the mass percentage of CoO, because the composite ratio has an important influence on the performance of the photocatalyst. When the amount of CoO added is appropriate, the separation efficiency of photo-generated carriers cannot reach the best; when the amount of CoO added is too much, the excess CoO will accumulate on the surface of the composite material, which will block part of the light beam after agglomeration, thereby reducing the utilization rate of light. The formation of the sea cucumber-like structure and the appropriate composite ratio enable the CoO-CuBi2O4 composite material to have more excellent photocatalytic performance.

[0030] (4) The application also provides application of the sea cucumber-like CoO-CuBi2O4 composite material in removal of organic pollutants in water bodies by activating persulfate.

[0031] When the sea cucumber-like CoO-CuBi2O4 composite material is used as a photocatalyst for photocatalytic degradation of organic pollutants, e - moves to the conduction band of CuBi2O4, so that e - accumulates on the conduction band of CuBi2O4, h + is enriched on the valence band of CoO, and the e - stored in the sea cucumber-like CuBi2O4 reacts with O2 to generate ·O2 - , and then ·O2 - degrades the organic pollutants. On the other hand, when the sea cucumber-like CoO-CuBi2O4 composite photocatalyst is used to remove organic pollutants in water bodies by activating persulfate, the activation of persulfate by Co and Cu can produce more SO4 ·- , ·O2 - , ·OH and other active substances to rapidly degrade the organic pollutants, on the one hand, and can promote the transfer of e - on the conduction band of CoO to the conduction band of CuBi2O4, inhibit the recombination of electron-hole pairs, enhance the photocatalytic activity of the composite material, and realize efficient degradation of the organic pollutants. The sea cucumber-like CoO-CuBi2O4 composite material can rapidly and efficiently degrade various types of organic pollutants in water bodies, especially can efficiently remove antibiotics in water bodies, and has extremely high practical application value. BRIEF DESCRIPTION OF DRAWINGS

[0032] Figure 1 is a preparation schematic diagram of the sea cucumber-like CoO-CuBi2O4 composite material of the application;

[0033] Figure 2 is an XRD diagram of the sea cucumber-like CoO-CuBi2O4 composite material prepared in Examples 1, 2, 3, 4 and 5;

[0034] Figure 3 is a scanning electron microscope diagram (3a) and transmission electron microscope diagrams (3b and 3c) of the sea cucumber-like CoO-CuBi2O4 composite material prepared in Example 2;

[0035] Figure 4The photocatalytic degradation graph (4a) of the TC degraded by the sea cucumber-like CoO-CuBi2O4 composite material prepared in Examples 1, 2, 3, 4, 5, the corresponding pseudo-first-order kinetic graph, the corresponding rate constant graph (4b), the photocatalytic degradation graph (4c) of the TC degraded by the sea cucumber-like CoO-CuBi2O4 composite material prepared in Examples 1, 2, 3, 4, 5 in combination with persulfate, the corresponding pseudo-first-order kinetic graph, the corresponding rate constant graph (4d), the 5-cycle degradation graph (4e) of the TC degraded by the sea cucumber-like CoO-CuBi2O4 composite material in combination with persulfate, and the X-ray diffraction graph (4f) of the CoO-CuBi2O4 composite material before and after the reaction of the TC degraded by the sea cucumber-like CoO-CuBi2O4 composite material in combination with persulfate.

[0036] The application will be described in further detail below with reference to the drawings and examples. DETAILED DESCRIPTION

[0037] In order to make the objectives, characteristics and advantages of the application more clear and easy to understand, the application will be described in further detail below with reference to specific examples. It should be noted that the following illustrative examples are preferred examples, and the application is not limited to the following examples.

[0038] This example provides a sea cucumber-like CoO-CuBi2O4 composite material, which is supported by one-dimensional rod-like structure CuBi2O4 and uniformly loaded with zero-dimensional CoO nanoparticles on the surface of the one-dimensional rod-like structure CuBi2O4.

[0039] In this example, the length of the one-dimensional rod-like structure CuBi2O4 is 2 μm-4 μm, and the particle size of the CoO nanoparticles is 250 nm-450 nm.

[0040] Referring to Figure 1 , the preparation method of the sea cucumber-like CoO-CuBi2O4 composite photocatalyst comprises:

[0041] (1) preparing brownish powder-like CuBi2O4 with one-dimensional rod-like structure by a hydrothermal method;

[0042] (2) mixing n-octanol and ethanol to obtain solution A, and adding cobalt acetate into solution A to obtain solution B;

[0043] (3) adding the CuBi2O4 powder with rod-like structure into solution B, stirring and ultrasonicating to obtain precursor C;

[0044] (4) treating precursor C by a hydrothermal method, cooling, washing, drying to obtain powder-like sea cucumber-like CoO-CuBi2O4 composite material.

[0045] In the preparation method, the specific process of hydrothermal method for preparing CuBi2O4 in step (1) is as follows:

[0046] 2.42 g of Bi (NO3) 3·5H2O, 0.6 g of Cu (NO3) 3·3H2O and 0.87 g of NaOH were added into 80 mL of deionized water, and stirred for 3 hours until the solution was completely dissolved. Then the solution was poured into a reaction kettle lined with a liner, and reacted at 180℃ for 24 hours. After cooling to room temperature, the solution was repeatedly washed with ethanol and deionized water, and then placed in a drying box at 70℃ for drying. Finally, the brownish-brown CuBi2O4 powder was obtained by grinding.

[0047] In the preparation method, the volume ratio of n-octanol to ethanol in step (2) is 4:1, and solution A is obtained.

[0048] In step (2), 0.92 g of cobalt acetate was added to 40 ml of solution A and stirred for 2 hours to obtain solution B.

[0049] In step (3), the CuBi2O4 powder with rod-like structure is 0.02-2.1 g; the stirring time is 10 min, and the ultrasonic time is 10 min, to obtain the precursor C.

[0050] In the preparation method, the precursor is added to a 50 mL high-pressure reaction kettle in step (4); the heating temperature of the oven is 220℃, and the reaction time is 4 hours. After cooling to room temperature, washing and drying are performed to obtain the product.

[0051] In the preparation method, the product is dried in a vacuum drying box at 80℃ for 12 hours to obtain the sea cucumber-like CoO-CuBi2O4 composite photocatalyst.

[0052] The applicant's experiments show that the sea cucumber-like CoO-CuBi2O4 composite material can be used to remove organic pollutants in water body in cooperation with persulfate.

[0053] In the application, the sea cucumber-like CoO-CuBi2O4 composite material is mixed with water body containing organic pollutants, and a photocatalytic reaction is carried out under light conditions to remove the organic pollutants in the water body. The sea cucumber-like CoO-CuBi2O4 composite photocatalyst is mixed with persulfate and water body containing organic pollutants, and a photocatalytic reaction is carried out under light conditions to remove the organic pollutants in the water body.

[0054] The application has the proportion of 0.6 g: 1 L between the sea cucumber-like CoO-CuBi2O4 composite material and the water body containing organic pollutants, the organic pollutants in the water body containing organic pollutants are tetracycline antibiotics, the initial concentration of the tetracycline antibiotics is 40 mg / L, the photocatalytic reaction temperature is 25 DEG C, the photocatalytic reaction time is 90 min, the light source used in the photocatalytic reaction is a xenon lamp, and the light power of the xenon lamp is 45-50 W.

[0055] The following is a specific embodiment given by the inventor, and the five embodiments are different in that the mass ratio of CoO to CuBi2O4 is different, which is 1:9, 3:7, 5:5, 7:3 and 9:1 respectively.

[0056] Example 1:

[0057] The preparation method of the sea cucumber-like CoO-CuBi2O4 composite photocatalyst of the embodiment comprises the following steps:

[0058] (1) 2.42 g of Bi (NO3) 3·5H2O, 0.6 g of Cu (NO3) 3·3H2O and 0.87 g of NaOH were added to 80 mL of deionized water, stirred for 3 hours until the solution was completely dissolved. Then the solution was poured into the inner lining of the reaction kettle, reacted at 180 DEG C for 24 hours, cooled to room temperature, washed repeatedly with ethanol and deionized water, then placed in a drying box at 70 DEG C for drying, and finally ground to obtain a brownish powder of CuBi2O4 with one-dimensional rod-like structure.

[0059] (2) 0.92 g of cobalt acetate was weighed and dissolved in a mixed solution of 32 mL of n-octanol and 8 mL of ethanol, and stirred on a constant temperature magnetic stirrer for 2 h to form solution A.

[0060] (3) 2.07 g of brownish powder of CuBi2O4 with one-dimensional rod-like structure was added to solution A, stirred for 10 min, and ultrasonically treated for 10 min to form solution B.

[0061] (4) Solution B was poured into a 50 mL high-pressure reaction kettle, heated to 220 DEG C in an oven, and reacted for 4 h. The obtained product was washed with deionized water and ethanol for several times, and dried in a vacuum drying box at 80 DEG C for 12 h. Finally, the powder of the sea cucumber-like CoO-CuBi2O4 composite photocatalyst was obtained by grinding. According to the different addition amount of CuBi2O4, the sample with an addition amount of 2.07 g was marked as 10% CoO-CuBi2O4.

[0062] Example 2:

[0063] The preparation method of the sea cucumber-like CoO-CuBi2O4 composite photocatalyst of the embodiment comprises the following steps:

[0064] (1) 2.42 g Bi(NO3)3·5H2O, 0.6 g Cu(NO3)3·3H2O and 0.87 g NaOH were added into 80 mL deionized water, stirred for 3 hours until the solution was completely dissolved. Then the solution was poured into the inner lining of the reactor, reacted at 180°C for 24 hours, washed repeatedly with ethanol and deionized water after cooling to room temperature, and then placed in a drying oven at 70°C for drying. Finally, a brownish powder of CuBi2O4 with one-dimensional rod-like structure was obtained by grinding.

[0065] (2) 0.92 g of cobalt acetate was weighed and dissolved in a mixed solution of 32 mL of n-octanol and 8 mL of ethanol. The solution was stirred on a constant temperature magnetic stirrer for 2 hours to form solution A.

[0066] (3) 0.537 g of brownish powder of CuBi2O4 with one-dimensional rod-like structure was added to solution A, stirred for 10 min, and ultrasonically treated for 10 min to form solution B.

[0067] (4) Solution B was poured into a 50 mL high-pressure reactor and heated to 220°C in an oven for 4 hours. The obtained product was washed with deionized water and ethanol several times and dried in a vacuum drying oven at 80°C for 12 hours. Finally, a powder of CoO-CuBi2O4 composite photocatalyst with sea cucumber-like structure was obtained by grinding. According to the different amounts of CuBi2O4 added, the sample with an addition amount of 0.537 g was marked as 30% CoO-CuBi2O4.

[0068] Figure 3 The scanning electron microscope and transmission electron microscope images of the CoO-CuBi2O4 composite photocatalyst with sea cucumber-like structure prepared in Example 2 are shown in Figure 3 (a) and Figure 3 (b), respectively. The rod-like CuBi2O4 surface is uniformly distributed with CoO nanoparticles, showing a sea cucumber-like structure. Figure 3 (c) is the transmission electron microscope image of the CoO-CuBi2O4 composite photocatalyst with sea cucumber-like structure. It can be clearly observed that one-dimensional CoO nanoparticles are loaded on the surface of the rod-like CuBi2O4, proving that the sea cucumber-like CoO-CuBi2O4 composite photocatalyst is successfully prepared.

[0069] Example 3:

[0070] The preparation method of the sea cucumber-like CoO-CuBi2O4 composite photocatalyst of the present embodiment comprises the following steps:

[0071] (1) 2.42 g Bi(NO3)3·5H2O, 0.6 g Cu(NO3)3·3H2O and 0.87 g NaOH were added into 80 mL deionized water, stirred for 3 hours until the solution was completely dissolved. Then the solution was poured into the inner lining of the reactor, reacted at 180°C for 24 hours, washed repeatedly with ethanol and deionized water after cooling to room temperature, and then placed in a drying oven at 70°C for drying. Finally, a brownish powder of CuBi2O4 with one-dimensional rod-like structure was obtained by grinding.

[0072] (2) 0.92 g of cobalt acetate was weighed and dissolved in a mixed solution of 32 mL of n-octanol and 8 mL of ethanol, and stirred on a constant temperature magnetic stirrer for 2 h to form solution A.

[0073] (3) 0.23 g of brownish powder of CuBi2O4 with one-dimensional rod-like structure was added to solution A, stirred for 10 min, and ultrasonically treated for 10 min to form solution B.

[0074] (4) Solution B was poured into a 50 mL high-pressure reactor, heated to 220°C in an oven, and reacted for 4 h. The obtained product was washed with deionized water and ethanol several times, and dried in a vacuum drying oven at 80°C for 12 h. Finally, a powder of CoO-CuBi2O4 composite photocatalyst with sea cucumber-like structure was obtained by grinding. According to the different amounts of CuBi2O4 added, the sample with an addition amount of 0.23 g was marked as 50% CoO-CuBi2O4.

[0075] Example 4:

[0076] The preparation method of the sea cucumber-like CoO-CuBi2O4 composite photocatalyst of the present embodiment comprises the following steps:

[0077] (1) 2.42 g Bi(NO3)3·5H2O, 0.6 g Cu(NO3)3·3H2O and 0.87 g NaOH were added into 80 mL deionized water, stirred for 3 hours until the solution was completely dissolved. Then the solution was poured into the inner lining of the reactor, reacted at 180°C for 24 hours, washed repeatedly with ethanol and deionized water after cooling to room temperature, and then placed in a drying oven at 70°C for drying. Finally, a brownish powder of CuBi2O4 with one-dimensional rod-like structure was obtained by grinding.

[0078] (2) 0.92 g of cobalt acetate was weighed and dissolved in a mixed solution of 32 mL of n-octanol and 8 mL of ethanol, and stirred on a constant temperature magnetic stirrer for 2 h to form solution A.

[0079] (3) 0.0986 g of brownish powder of CuBi2O4 with one-dimensional rod-like structure was added to solution A, stirred for 10 min, and ultrasonically treated for 10 min to form solution B.

[0080] (4) Pour solution B into a 50 mL autoclave, heat to 220°C in an oven, and react for 4 h. The resulting product is washed with deionized water and ethanol multiple times and dried in a vacuum drying oven at 80°C for 12 h. Finally, the powder-like CoO-CuBi2O4 composite photocatalyst with a sea cucumber-like structure is obtained by grinding. According to the different amounts of CuBi2O4 added, the sample with an added amount of 0.0256 g is marked as 90% CoO-CuBi2O4.

[0081] Example 5:

[0082] The preparation method of the sea cucumber-like CoO-CuBi2O4 composite photocatalyst of the present example comprises the following steps:

[0083] (1) 2.42 g of Bi(NO3)3·5H2O, 0.6 g of Cu(NO3)3·3H2O, and 0.87 g of NaOH are added to 80 mL of deionized water, stirred for 3 hours until the solution is completely dissolved. Then pour the solution into the inner lining of the reactor, react at 180°C for 24 hours, cool to room temperature, wash repeatedly with ethanol and deionized water, and then put into a drying oven at 70°C for drying. Finally, the one-dimensional rod-like structure brownish powder CuBi2O4 is obtained by grinding.

[0084] (2) Weigh 0.92 g of cobalt acetate and dissolve it in a mixed solution of 32 mL of n-octanol and 8 mL of ethanol. Stir it on a constant temperature magnetic stirrer for 2 h to form solution A.

[0085] (3) Add 0.0256 g of one-dimensional rod-like structure brownish powder CuBi2O4 to solution A, stir for 10 min, and ultrasonic for 10 min to form solution B.

[0086] (4) Pour solution B into a 50 mL autoclave, heat to 220°C in an oven, and react for 4 h. The resulting product is washed with deionized water and ethanol multiple times and dried in a vacuum drying oven at 80°C for 12 h. Finally, the powder-like CoO-CuBi2O4 composite photocatalyst with a sea cucumber-like structure is obtained by grinding. According to the different amounts of CuBi2O4 added, the sample with an added amount of 0.0256 g is marked as 90% CoO-CuBi2O4.

[0087] The above photocatalyst photocatalytic performance and application test process is as follows:

[0088] Combined Figure 2The crystal structure of the sea cucumber-like CoO-CuBi2O4 composite photocatalyst was tested by XRD. The CoO crystal form was consistent with the standard card JCPDS 71-1178, and the CuBi2O4 crystal form corresponded to the standard card JCPDS 72-0493. The sea cucumber-like CoO-CuBi2O4 composite photocatalyst contained two diffraction peaks of CoO and CuBi2O4, wherein the XRD pattern of the rod-shaped CuBi2O4 had characteristic diffraction peaks at 28°, 29.67°, 30.73°, 33.27°, and 46.66° corresponding to the (211), (220), (002), (310), and (411) crystal planes of CuBi2O4. Pure CoO had obvious diffraction peaks at 2θ = 36.49°, 42.38°, 61.49°, 73.66°, and 77.52° corresponding to the (111), (200), (220), (311), and (222) crystal planes. In addition, TEM and HRTEM further confirmed the successful preparation of the sea cucumber-like CoO-CuBi2O4 composite photocatalyst.

[0089] The photocatalytic and application performance of the sea cucumber-like CoO-CuBi2O4 composite photocatalyst prepared above was measured in a photocatalytic reaction system (CEL-LAB500). A 300W xenon lamp was selected as the light source, and the system temperature was maintained at about 6°C by circulating cooling water. A 40mg / L tetracycline hydrochloride solution was used to simulate organic pollutant wastewater, and 30mg of the above photocatalyst was placed in a 50mL quartz test tube, and a 40mg / L TC solution was added. It was moved to the photocatalytic reactor and magnetically stirred in the dark for 30min to ensure that the above photocatalyst reached adsorption-desorption equilibrium. A 300W xenon lamp was turned on for light, and every 15min, 3mL of solution was taken out, separated by a centrifuge, and the supernatant was extracted. The absorbance of TC was measured at a wavelength of 357nm using a UV-visible spectrophotometer, and then the recorded absorbance was converted to TC concentration by a standard curve to determine the photocatalytic and application performance of the photocatalyst.

[0090] The photocatalytic and application performance of the prepared sea cucumber-like CoO-CuBi2O4 composite photocatalyst in the degradation of organic pollutants was measured in a photocatalytic reaction system (CEL-LAB500). A 300W xenon lamp was used as the light source, and the temperature of the system was maintained at about 6°C by circulating cooling water. A 40mg / L tetracycline hydrochloride solution was used to simulate organic pollutant wastewater, and 30mg of the above-mentioned photocatalyst was placed in a 50mL quartz test tube, and a 40mg / L TC solution was added. The test tube was moved to the photocatalytic reactor and magnetically stirred in the dark for 30min to ensure that the above-mentioned photocatalyst reached adsorption-desorption equilibrium. Then 3mL of 4mol / L persulfate was added, and the 300W xenon lamp was turned on for light irradiation. Every 15min, 3mL of solution was taken out, separated by a centrifuge, and the supernatant was extracted. The absorbance of TC was measured at a wavelength of 357nm using a UV-visible spectrophotometer, and then the recorded absorbance was converted to the TC concentration by a standard curve to determine the photocatalytic and application performance of the above-mentioned photocatalyst.

[0091] As shown in Figure 4 a, without adding any photocatalyst, TC itself is difficult to degrade, and the removal rate is not more than 4%. After 90min of light irradiation, the photocatalytic degradation rates of monomer CuBi2O4 and CoO on TC are 24.5% and 34%, respectively. The photocatalytic degradation rate of sea cucumber-like CoO-CuBi2O4 binary composite photocatalyst on TC can reach 58.4%, which is 33.9% and 24.4% higher than that of monomer CuBi2O4 and CoO. In addition, as shown in Figure 4 b, the photocatalytic degradation of CuBi2O4, CoO, 10% CoO-CuBi2O4, 30% CoO-CuBi2O4, 50% CoO-CuBi2O4, 70% CoO-CuBi2O4, and 90% CoO-CuBi2O4 photocatalysts on TC matches the pseudo-first-order reaction kinetics (Langmuir-HinShelwood model) successfully. The rate constant of 90% CoO-CuBi2O4 degrading TC (0.00642min -1 ) is the highest, which is 2.15 and 1.57 times that of pure CuBi2O4 (0.00298min -1 ) and CoO (0.00408min -1 ), respectively.

[0092] In the system of sea cucumber-like CoO-CuBi2O4 photocatalyst and persulfate degrading TC, as shown in Figure 4c, the degradation of TC by persulfate is not more than 10%. After 90 min of light reaction, the photocatalytic degradation rate of TC by activated persulfate is 76.5% and 34% for monomer CuBi2O4 and CoO, respectively. While the photocatalytic degradation rate of TC by activated persulfate is up to 89.5% for the sea cucumber-like CoO-CuBi2O4 binary composite photocatalyst, which is 13% and 55.5% higher than that of monomer CuBi2O4 and CoO. In addition, as shown in Figure 4 d, the photocatalytic degradation of TC by CuBi2O4, CoO, 10% CoO-CuBi2O4, 30% CoO-CuBi2O4, 50% CoO-CuBi2O4, 70% CoO-CuBi2O4, 90% CoO-CuBi2O4 photocatalyst in cooperation with persulfate is successfully matched with the pseudo-first-order reaction kinetics (Langmuir-HinShelwood model). The rate constant of 30% CoO-CuBi2O4 in cooperation with PMS for degrading TC (0.03164 min -1 ) is the highest, which is 1.39 and 8.03 times of that of pure CuBi2O4 (0.0227 min -1 ) and CoO (0.00394 min -1 ), respectively. It shows that the sea cucumber-like CoO-CuBi2O4 binary composite photocatalyst prepared in Example 2 has good photocatalytic performance in the system of degrading organic pollutants in cooperation with persulfate, and can effectively remove organic pollutants in water.

[0093] As shown in Figure 4 e, the sea cucumber-like CoO-CuBi2O4 composite photocatalyst prepared in Example 2 still has good photocatalytic degradation performance after multiple cycles, and has excellent stability and recyclability. In addition, Figure 4 f is the XRD pattern of the sea cucumber-like CoO-CuBi2O4 composite photocatalyst prepared in Example 2 before and after use, which further shows that the composite material has good stability.

[0094] Although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art can still add and modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacement for part of the technical features. All of them should be included in the protection scope recorded in the claims of the present application.

Claims

1. The application of a sea cucumber-like CoO-CuBi2O4 composite material as a photocatalyst for removing organic pollutants from water bodies, characterized in that, The aforementioned sea cucumber-like CoO-CuBi2O4 composite material is based on CuBi2O4 with a one-dimensional rod-shaped structure as a support, with zero-dimensional CoO nanoparticles loaded on the surface of the one-dimensional rod-shaped CuBi2O4. The specific application process is as follows: the sea cucumber-like CoO-CuBi2O4 composite material is mixed with water containing organic pollutants, and a photocatalytic reaction is carried out under light conditions to remove organic pollutants from the water; or the sea cucumber-like CoO-CuBi2O4 composite photocatalyst is mixed with persulfate in synergy with water containing organic pollutants, and a photocatalytic reaction is carried out under light conditions to remove organic pollutants from the water. The ratio of the sea cucumber-like CoO-CuBi2O4 composite material to the water containing organic pollutants is 0.6g:1L; the organic pollutant in the water containing organic pollutants is tetracycline, an antibiotic, with an initial concentration of 40mg / L; the photocatalytic reaction temperature is 25℃; the photocatalytic reaction time is 90min; the light source used in the photocatalytic reaction is a xenon lamp with a light power of 45-50W.

2. The application as described in claim 1, characterized in that, The length of the one-dimensional rod-shaped CuBi2O4 is 2μm to 4μm, and the particle size of the CoO nanoparticles is 250nm to 450nm.

3. The application as described in claim 1 or 2, characterized in that, The preparation method of the sea cucumber-like CoO-CuBi2O4 composite material includes the following steps: (1) A brownish-red powder CuBi2O4 with a one-dimensional rod-like structure was prepared by hydrothermal method; (2) Mix n-octanol and ethanol to obtain solution A, and add cobalt acetate to solution A to obtain solution B; (3) Add brown CuBi2O4 powder with a one-dimensional rod-like structure to solution B, stir and sonicate to obtain precursor C; (4) The precursor C was treated by hydrothermal method, cooled, washed and dried to obtain a powdered CoO-CuBi2O4 composite material with a sea cucumber-like structure.

4. The application as described in claim 3, characterized in that, The specific process for preparing brownish-red powdered CuBi2O4 with a one-dimensional rod-like structure by hydrothermal method in step (1) is as follows: 2.42 g Bi(NO3)3•5H2O, 0.6 g Cu(NO3)3•3H2O and 0.87 g NaOH were added to 80 mL of deionized water and stirred for 3 hours until the solution was completely dissolved. The dissolved solution was then poured into a liner and placed in a reaction vessel. The reaction was carried out at 180 °C for 24 hours. After cooling to room temperature, the mixture was repeatedly washed with ethanol and deionized water and then dried in a drying oven at 70 °C. Finally, the mixture was ground to obtain a brownish-red powder of one-dimensional rod-shaped structure, CuBi2O4.

5. The application as described in claim 3, characterized in that, In step (2), the volume ratio of n-octanol to ethanol is 4:

1.

6. The application as described in claim 3, characterized in that, In step (2), solution B is obtained by adding 0.92g of cobalt acetate to 40ml of solution A and stirring for 2h.

7. The application as described in claim 3, characterized in that, In step (3), the CuBi2O4 powder with a one-dimensional rod-like structure is 0.02 to 2.1 g; the stirring time is 10 min and the ultrasonic time is 10 min.

8. The application as described in claim 3, characterized in that, The specific process of step (4) is as follows: add precursor C into a 50 mL high-pressure reactor; react in an oven at 220 °C for 4 h; after cooling to room temperature, wash and dry to obtain a brownish-brown powder CuBi2O4 with a one-dimensional rod-like structure.

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