Double cobalt nickel composite material based on nickel foam and preparation method and application thereof

Abstract

The present invention discloses a double cobalt nickel composite material with nickel foam as the substrate, and a preparation method and application thereof. The present invention pre-treats nickel foam NF to remove oxides and impurities of nickel foam, mixes cobalt salt and thiourea in deionized water to obtain a precursor solution, adds the pre-treated nickel foam to the precursor solution, reacts at 175-185°C for 7-9h, cools to room temperature, washes, and dries to obtain a double cobalt nickel composite material Co with nickel foam as the substrate. 9 S 8 / CoS / Ni 3 S 2 @NF. The composite material of the present invention can achieve efficient removal of LOM within 60 minutes by activating PMS to generate highly active free radicals. After 4 cycles of reaction, it still has a good removal effect on LOM and effectively inhibits the dissolution of metal ions. It solves the problems of recycling and ion dissolution of powder catalysts. The preparation method of the material is simple and easy, suitable for large-scale production, and has broad application prospects and value.

Description

Technical Field

[0001] The invention belongs to the technical field of wastewater treatment, and in particular relates to a double cobalt nickel composite material (Co 9 S 8 / CoS / Ni 3 S 2 @NF composite material) and its preparation method and application. Background Art

[0002] Emerging pollutants do not refer to new chemicals, but a class of pollutants that have existed in the environment for a long time, but their existence and importance have not been discovered until now. The discussion on the environmental hazards of emerging pollutants (EPs) was first proposed by Rachel Carson in 1962. In recent years, as more and more emerging pollutants enter the environment and cause known or unknown ecotoxicity and harm to human health, EPs have received more and more attention. Among them, pharmaceutical pollutants (PPs), as the most common EPs, are widely used in the treatment of diseases, but only a small amount of PPs are absorbed by living organisms, and the rest of the PPs are eventually excreted from the body in the form of residues and metabolites in the form of feces and urine. The current treatment technology for excreted PPs is through sewage treatment plants, but due to its stable structure and difficulty in decomposition, some PPs will eventually appear in the environment. At present, the presence of antibiotics has been detected in water bodies at home and abroad. Although the concentration is very low, it still causes great harm to the human body due to its physiological toxicity. Fluoroquinolone antibiotics are widely used as a broad-spectrum antibacterial antibiotic. Lomefloxacin (LOM), one of the most common fluoroquinolone antibiotics, has been detected in rivers and river basins in China, posing a great threat to human health.

[0003] The main technologies for removing LOM from water bodies include physical methods, chemical methods, and biodegradation methods. However, some traditional treatment technologies are subject to certain restrictions due to their complex processes, high operating costs, unstable effects, and the possibility of causing secondary pollution.

[0004] Compared with other treatment technologies, the persulfate advanced oxidation technology based on sulfate radicals has the characteristics of strong oxidation ability, long half-life, and wider pH range, and can degrade antibiotics into low-toxic or non-toxic substances. Permonosulfate (PMS) is easier to activate than peroxydisulfate (PDS) and is widely used in the removal of LOM. Among the catalysts for activating PMS to remove LOM, transition metal oxides have attracted widespread attention due to their low cost and simple operation. The single electron transfer of transition metals such as silver, copper, iron, zinc, cobalt and manganese can be used to activate persulfate and produce sulfate radicals. Among these transition metals, cobalt and nickel have high catalytic activity in the activation of persulfate and are considered to be the best metal catalysts for activating persulfate. At the same time, sulfiding cobalt and nickel can accelerate the transfer between electrons and improve the activity of PMS. However, the development of transition metals in the activation of persulfate is limited because metal ion nanoparticles are easy to agglomerate, leach metals, and have poor recyclability, which ultimately causes secondary pollution.

[0005] Nickel foam (NF) has outstanding advantages, such as three-dimensional (3D) network structure, low price, high specific surface area and volume, and abundant available electroactive sites. It has attracted wide attention in applications such as lithium-ion batteries, energy storage and catalysis. However, nickel foam (NF) is rarely used in activating PMS to remove antibiotics. Therefore, in view of the low activation effect of existing catalysts, easy agglomeration, high ion dissolution and poor recovery performance, if nickel foam can be combined with transition metals, can a more efficient, safe and environmentally friendly catalyst be obtained to activate PMS to degrade and remove antibiotics in water. Summary of the invention

[0006] The primary purpose of the present invention is to provide a double cobalt nickel composite material (Co 9 S 8 / CoS / Ni 3 S 2 @NF composite material).

[0007] Another object of the present invention is to provide the above-mentioned Co 9 S 8 / CoS / Ni 3 S 2 @ Preparation method of NF composite material.

[0008] Another object of the present invention is to provide the above-mentioned Co 9 S 8 / CoS / Ni 3 S 2 The application of @NF composite materials in the treatment of wastewater containing antibiotics is intended to solve the various deficiencies existing in the prior art in the above-mentioned background technology.

[0009] The present invention is achieved by a method for preparing a double cobalt-nickel composite material with nickel foam as a substrate, the method comprising the following steps:

[0010] (1) pre-treating the nickel foam NF to remove oxides and impurities in the nickel foam;

[0011] (2) mixing cobalt salt and thiourea in deionized water to obtain a precursor solution, wherein the molar volume ratio of the cobalt salt, thiourea and deionized water is 0.0015 mol: 0.0040-0.050 mol: 30-40 mL;

[0012] (3) adding the pretreated nickel foam to the precursor solution, reacting at 175-185° C. for 7-9 hours, cooling to room temperature, washing, and drying to obtain a double cobalt nickel composite material Co based on the nickel foam. 9 S 8 / CoS / Ni 3 S 2 @NF.

[0013] Preferably, in step (1), the pretreatment is specifically to perform ultrasonic treatment with acetone, 12 mol / L hydrochloric acid and ethanol solution in sequence, each for 10 minutes, and then perform ultrasonic treatment with deionized water three times, each for 5 minutes, and then dry the nickel foam in a vacuum oven at 80°C for 12 hours to obtain the pretreated nickel foam.

[0014] Preferably, in step (2), the cobalt salt is cobalt nitrate hexahydrate.

[0015] Preferably, in step (3), pretreated nickel foam is added to 30-40 mL of the precursor solution, wherein the nickel foam has a thickness of 1 mm and a surface area of ​​2*2 cm on both sides. 2 .

[0016] Preferably, in step (3), the washing and drying are: washing repeatedly with deionized water and then drying at 60° C. for 12 h.

[0017] Preferably, the Co 9 S 8 / CoS / Ni 3 S 2 @NF,Co 9 S 8 / CoS / Ni 3 S 2 The loading mass on NF is 21 mg / cm 2 .

[0018] The present invention further discloses a double cobalt nickel composite material Co with nickel foam as the substrate obtained by the above preparation method. 9 S8 / CoS / Ni 3 S 2 @NF.

[0019] The present invention further discloses the above-mentioned double cobalt nickel composite material Co based on nickel foam. 9 S 8 / CoS / Ni 3 S 2 @Application of NF activated persulfate to degrade antibiotics in water.

[0020] Preferably, the antibiotic comprises a fluoroquinolone antibiotic.

[0021] The present invention overcomes the shortcomings of the prior art and provides a double cobalt nickel composite material (Co 9 S 8 / CoS / Ni 3 S 2 @NF composite material) and its preparation method and application. Nickel foam (NF) has outstanding advantages such as three-dimensional (3D) network structure, low price, high specific surface area and volume, and abundant available electroactive sites. It has attracted wide interest in applications such as lithium-ion batteries, energy storage and catalysis; however, it has been rarely used in activating PMS to remove antibiotics. On this basis, the present invention successfully prepared Co by a simple hydrothermal synthesis reaction. 9 S 8 / CoS / Ni 3 S 2 @NF, which is in situ grown from nickel foam, can be used to activate PMS to efficiently degrade LOM.

[0022] In the preparation method of the present invention, nickel foam is used as a substrate, which promotes the transfer efficiency of electrons and holes, solves the problem that the composite material is difficult to recycle, effectively inhibits the dissolution of metal ions, and improves the cycle stability of the composite material. In addition, nickel foam not only serves as a metal carrier to solve the problem of catalyst recovery, but also provides a nickel source and participates in the catalytic reaction.

[0023] Compared with the shortcomings and deficiencies of the prior art, the present invention has the following beneficial effects:

[0024] (1) The preparation process of the composite material of the present invention is simple, easy to operate, low in cost, pollution-free, and suitable for large-scale production;

[0025] (2) The present invention is the first to load Co on nickel foam 9 S 8 / CoS / Ni 3 S 2 @NF, through the activation of PMS, produces highly active free radicals (SO 4· - , ·OH, ·O 2 - , 1 O 2 ) can achieve efficient removal of LOM within 60 minutes, and it still has a good removal effect on LOM after 4 cycles of reaction, and the material has good cyclic stability. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 The present invention Co 9 S 8 / CoS / Ni 3 S 2 @XRD pattern of NF composite material 1;

[0027] Figure 2 This is a comparative degradation effect diagram under different systems in the application examples of the present invention;

[0028] Figure 3 Co in the application embodiment of the present invention 9 S 8 / CoS / Ni 3 S 2 @NF composite material 1 recycling effect diagram;

[0029] Figure 4 Co in the application embodiment of the present invention 9 S 8 / CoS / Ni 3 S 2 @Ion dissolution diagram of NF composite material 1. DETAILED DESCRIPTION

[0030] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0031] Example 1

[0032] (1) treating the nickel foam with acetone, 12 mol / L hydrochloric acid and ethanol solution in sequence (10 minutes each time), and then treating the nickel foam with deionized water for three times (5 minutes each time); thereafter, drying the nickel foam in a vacuum oven at 80° C. for 12 hours to obtain a pretreated nickel foam;

[0033] (2) 0.0015 mol of cobalt nitrate hexahydrate (Co(NO 3 ) 2 6H 20,0.43 g) and 0.0045 mol thiourea (0.34 g) were dissolved in 30 mL of deionized water and stirred for 20 minutes to mix the solution evenly to obtain a precursor solution;

[0034] (3) Transfer the precursor solution to a 50 mL autoclave and add 2*2 cm 2 The pretreated nickel foam (thickness 1 mm) was reacted at 180 ° C for 8 h, cooled naturally to room temperature, washed repeatedly with deionized water, and finally dried at 60 ° C for 12 h to obtain Co 9 S 8 / CoS / Ni 3 S 2 @NF Composites 1.

[0035] Co 9 S 8 / CoS / Ni 3 S 2 @NF composite material 1, Co 9 S 8 / CoS / Ni 3 S 2 The loading mass on NF is about 21 mg / cm 2 (The loading amount was determined by taking the average difference between the NF weighings before and after the hydrothermal reaction).

[0036] For this Co 9 S 8 / CoS / Ni 3 S 2 @NF composite material 1 was observed, and the results were as follows Figure 1 As shown, Co 9 S 8 / CoS / Ni 3 S 2 The diffraction peaks in the XRD pattern of @NF composite material 1 were analyzed by jade software. Compared with the standard card of the material, the obvious characteristic peaks of different materials can be seen, proving that Co 9 S 8 / CoS / Ni 3 S 2 @Successful preparation of NF composite material 1.

[0037] Example 2

[0038] (1) treating the nickel foam with acetone, 12 mol / L hydrochloric acid and ethanol solution in sequence (10 minutes each time), and then treating the nickel foam with deionized water for three times (5 minutes each time); thereafter, drying the nickel foam in a vacuum oven at 80° C. for 12 hours to obtain a pretreated nickel foam;

[0039] (2) dissolving 0.0015 mol of cobalt nitrate and 0.0040 mol of thiourea in 40 mL of deionized water and stirring for 20 minutes to mix the solution evenly to obtain a precursor solution;

[0040] (3) Transfer the precursor solution to a 50 mL autoclave and add 2*2 cm 2 The pretreated nickel foam (thickness 1 mm) was reacted at 175 ° C for 7 h, cooled naturally to room temperature, washed repeatedly with deionized water, and finally dried at 60 ° C for 12 h to obtain Co 9 S 8 / CoS / Ni 3 S 2 @NF Composites 2.

[0041] Example 3

[0042] (1) treating the nickel foam with acetone, 12 mol / L hydrochloric acid and ethanol solution in sequence (10 minutes each time), and then treating the nickel foam with deionized water for three times (5 minutes each time); thereafter, drying the nickel foam in a vacuum oven at 80° C. for 12 hours to obtain a pretreated nickel foam;

[0043] (2) dissolving 0.0015 mol of cobalt nitrate and 0.0050 mol of thiourea in 35 mL of deionized water and stirring for 20 minutes to mix the solution evenly to obtain a precursor solution;

[0044] (3) Transfer the precursor solution to a 50 mL autoclave and add 2*2 cm 2 The pretreated nickel foam (thickness 1 mm) was reacted at 185 ° C for 9 h, cooled naturally to room temperature, washed repeatedly with deionized water, and finally dried at 60 ° C for 12 h to obtain Co 9 S 8 / CoS / Ni 3 S 2 @NF Composites 3.

[0045] Application Example 1

[0046] 0.3g / L PMS, 0.5*0.5cm 2 NF (thickness 1mm) and composite material 1 Figure 2 The grouped experimental system shown in the figure was that each system was added into a 200-mL conical flask containing 100 mL of LOM solution (10 mg / L, pH=5.60). The conical flask was placed in a constant temperature oscillating reactor at a rotation speed of 200 rpm and a temperature of room temperature. At a predetermined time interval, 2 mL of the reaction solution was collected, filtered through a 0.22 μm membrane, and the concentration change of LOM at the maximum absorption wavelength of 283 nm was immediately detected by a UV-visible spectrophotometer.

[0047] The results are as follows Figure 2 As shown, it can be seen that in Co 9 S 8 / CoS / Ni 3 S 2 When NF composite material 1 and 0.3 g / LPMS were present at the same time, LOM removal rate was 76% within 60 min, while only PMS, NF, Co 9 S 8 / CoS / Ni 3 S 2 @NF composite material 1, the LOM concentration remained basically unchanged under the reaction conditions, indicating that Co 9 S 8 / CoS / Ni 3 S 2 @NF composite material 1 has a high efficiency in removing LOM by activating PMS.

[0048] Application Example 2

[0049] Repeated cycle degradation experiments were conducted to investigate the stability of the material. 9 S 8 / CoS / Ni 3 S 2 @NF composite material 1 was rinsed with deionized water and then dried at 60°C overnight for the next reaction.

[0050] The results are as follows Figure 3 As shown, it can be seen that although Co 9 S 8 / CoS / Ni 3 S 2 The catalytic efficiency of @NF decreased slightly, but after 4 consecutive cycles, nearly 71.8% of LOM was still removed within 60 min. 9 S 8 / CoS / Ni 3 S 2 @NF has excellent reuse effect.

[0051] Application Example 3

[0052] In order to study the dissolution of metal ions in the catalytic reaction system, the solutions after the catalytic degradation reaction in Application Examples 1 and 2 were tested using a high-resolution plasma optical emission spectrometer (ICP-OES). Figure 4As shown, a small amount of Co ions are leached out, and the Co ion leaching amount before and after the cycle reaction (0.340 and 0.183 mg / L) is lower than the standard (1 mg / L) of "China Copper-Nickel-Cobalt Industry Pollutant Emission Standard" (GB25467-2010), indicating that the composite material is green, low-toxic and environmentally friendly.

[0053] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for preparing a double cobalt nickel composite material based on nickel foam, characterized in that: The method comprises the following steps: (1) Pre-treating the nickel foam NF to remove oxides and impurities in the nickel foam; (2) mixing cobalt salt and thiourea in deionized water to obtain a precursor solution, wherein the molar volume ratio of the cobalt salt, thiourea and deionized water is 0.0015 mol: 0.0040-0.050 mol: 30-40 mL; (3) Adding the pretreated nickel foam to the precursor solution, reacting at 175-185° C. for 7-9 hours, cooling to room temperature, washing, and drying to obtain a double cobalt nickel composite material Co9S8 / CoS / Ni3S2@NF based on nickel foam.

2. The preparation method according to claim 1, characterized in that In step (1), the pretreatment is specifically to perform ultrasonic treatment with acetone, 12 mol / L hydrochloric acid and ethanol solution in sequence, each for 10 minutes, and then perform ultrasonic treatment with deionized water three times, each for 5 minutes, and then dry the nickel foam in a vacuum oven at 80° C. for 12 hours to obtain the pretreated nickel foam.

3. The preparation method according to claim 1, characterized in that: In step (2), the cobalt salt is cobalt nitrate hexahydrate.

4. The preparation method according to claim 1, characterized in that: In step (3), pre-treated nickel foam with a thickness of 1 mm and a surface area of ​​2*2 cm on both sides is added to 30~40 mL of the precursor solution. 2 .

5. The preparation method according to claim 1, characterized in that: In step (3), the washing and drying are as follows: washing repeatedly with deionized water and then drying at 60° C. for 12 h.

6. The preparation method according to claim 1, characterized in that: In the Co9S8 / CoS / Ni3S2@NF, the loading mass of Co9S8 / CoS / Ni3S2 on NF is 21 mg / cm 2 .

7. The dual cobalt-nickel composite material Co9S8 / CoS / Ni3S2@NF with nickel foam as the substrate obtained by the preparation method according to any one of claims 1 to 6.

8. Use of the double cobalt nickel composite material Co9S8 / CoS / Ni3S2@NF based on nickel foam as claimed in claim 7 in activating persulfate to degrade antibiotics in water.

9. The use according to claim 8, characterized in that The antibiotics include fluoroquinolone antibiotics.

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