Application of Cu3Fe4(vO4)6 as photocatalyst in environmental governance and preparation method thereof

Abstract

The application discloses application of Cu3Fe4(VO4)6 as a photocatalyst in environmental governance and a preparation method thereof, and belongs to the technical field of photocatalysts.The Cu3Fe4(VO4)6 includes three kinds of morphologies of rod-shaped particles, irregular frame shapes and multi-edge prisms.The Cu3Fe4(VO4)6 with three new morphologies is prepared as a high-activity visible light catalyst, has a large catalytic surface area, is suitable for deep treatment of industrial wastewater and treatment of other toxic and harmful and refractory organic pollutants, and has potential for solving environmental pollution problems.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of photocatalysts, and particularly relates to application of Cu3Fe4(VO4)6 as a photocatalyst in environmental governance and a preparation method thereof. BACKGROUND

[0002] Photocatalytic technology has potential application prospects in solar energy and environmental governance. With the progress of global industrialization science and technology and the rapid development of social economy, the large-scale discharge of industrial wastewater has become a serious problem of environmental pollution. Traditional wastewater treatment methods often have difficulty in completely degrading organic matter, leading to water pollution. Photocatalytic technology provides a green and efficient solution for wastewater treatment.

[0003] Photocatalytic wastewater treatment technology is to produce active free radicals by the interaction of energy-carrying photons and the surface of photocatalysts, and then degrade organic matter in wastewater. Photocatalysts usually use semiconductor materials such as titanium dioxide (TiO2), which has high adsorption and catalytic activity on the surface. When light irradiates the surface of the photocatalyst, it will excite the electrons, making them jump to the conduction band to form an electron-hole pair. These active free radicals have strong redox ability and can oxidize and decompose organic matter in organic wastewater into harmless substances, thereby achieving wastewater purification. However, TiO2 only has catalytic performance under ultraviolet light.

[0004] Compared with traditional physical and chemical treatment methods, photocatalytic wastewater treatment technology has many advantages. First, photocatalytic process does not require additional oxidizing or reducing agents, and only needs light to carry out catalytic reaction, thus saving energy and chemical reagent use. Second, the photocatalytic reaction rate is fast and the degradation efficiency is high, which can completely degrade harmful substances in organic wastewater in a short time, thereby avoiding secondary pollution. In addition, the photocatalytic process does not require high temperature and pressure conditions, and is simple to operate, easy to implement and maintain.

[0005] However, photocatalytic wastewater treatment technology also has some challenges and problems. First, the selection of photocatalysts plays an important role in photocatalytic efficiency. Second, the photocatalytic process is greatly affected by factors such as light conditions, catalyst concentration, and wastewater properties. Finally, photocatalytic wastewater treatment technology has problems of high cost and complex equipment in application.

[0006] Therefore, it is still an urgent task and a great challenge to further explore new high-activity photocatalysts, especially photocatalysts with visible light catalytic activity, to study the photocatalytic reaction mechanism, and ultimately to improve the photocatalytic efficiency. SUMMARY

[0007] The application aims to provide a preparation method of Cu3Fe4(VO4)6 and application of the Cu3Fe4(VO4)6 in industrial wastewater treatment.

[0008] To achieve the above-mentioned purpose, the application adopts the technical scheme of:

[0009] The application of the Cu3Fe4(VO4)6 as a photocatalyst is characterized in that the morphology of the Cu3Fe4(VO4)6 includes rod-shaped particles, irregular frame-shaped and polygonal prism-shaped.

[0010] The application provides a preparation method of Cu3Fe4(VO4)6, and the preparation method of the rod-shaped particles and the irregular frame-shaped Cu3Fe4(VO4)6 in claim 1 comprises the following steps:

[0011] In step A, FeCl3·6H2O is weighed and dissolved in water, CuO is weighed and dissolved in dilute nitric acid, and NH4VO3 is weighed and dissolved in water.

[0012] In step B, the three kinds of dissolved solutions are mixed, and after mixing, stirring, heating and evaporation are performed until the solution volume is 50-60% of the volume of the hydrothermal reaction container, and the PH value is adjusted to 6 or 7.

[0013] In step C, the adjusted solution is poured into the hydrothermal reaction container, and the hydrothermal reaction container is placed in a drying box for heating reaction.

[0014] In step D, the solution after the reaction is completed is poured into a clean beaker and washed with water and alcohol.

[0015] In step E, the washed solution is subjected to suction filtration, and after suction filtration, the culture dish is placed in a drying box for drying.

[0016] In step F, the dried powder is ground in a mortar, and after grinding, the powder is placed in a crucible, and the crucible is placed in a muffle furnace for calcination.

[0017] In step G, after calcination is completed, the powder is ground, and the sample Cu3Fe4(VO4)6 is obtained.

[0018] Further improvement of the technical scheme of the application is that in step A, the molar amount ratio of FeCl3·6H2O, CuO and NH4VO3 is 4:3:6, and the amount ratio of CuO and nitric acid is 3 mol / 200 mL.

[0019] Further improvement of the technical scheme of the present application is that in step B, when the pH value is adjusted to 7, the morphology of Cu3Fe4(VO4)6 is irregular frame shape, and when the pH value is adjusted to 6, the morphology of Cu3Fe4(VO4)6 is rod-shaped particle, and the solution used for adjusting the pH value includes sodium hydroxide solution.

[0020] Further improvement of the technical scheme of the present application is that in step C, the temperature of the drying box is adjusted to 170-190 DEG C, and the reaction time is 11-13 h, and in step D, the washing with water is performed 3-5 times, and the washing with alcohol is performed 3-5 times.

[0021] Further improvement of the technical scheme of the present application is that in step E, the drying temperature is 60-70 DEG C, and the time is 6-7 h, and in step F, the calcination temperature is 700-750 DEG C, and the calcination time is 2-3 h.

[0022] A preparation method of Cu3Fe4(VO4)6, characterized in that the preparation method of the Cu3Fe4(VO4)6 with the multi-edge prism morphology in claim 1 comprises the following steps:

[0023] Step S1, a certain amount of iron chloride, copper oxide and ammonium metavanadate are weighed and put into a mortar for grinding and mixing;

[0024] Step S2, the ground powder is loaded into a crucible for compaction and pre-burning in a muffle furnace;

[0025] Step S3, after the pre-burning is completed, the medicine is put into a mortar for thorough grinding, and after the grinding is completed, the medicine is loaded into a crucible for sintering;

[0026] Step S4, after the sintering is completed, the medicine is put into a mortar for grinding into powder, and the obtained powder is Cu3Fe4(VO4)6.

[0027] Further improvement of the technical scheme of the present application is that in step S1, the molar amount ratio of FeCl3·6H2O, CuO and NH4VO3 is 4:3:6.

[0028] Further improvement of the technical scheme of the present application is that in step S2, the pre-burning temperature is 360-390 DEG C, and the pre-burning time is 2-2.5 h, and in step S3, the sintering temperature is 790 DEG C, and the sintering time is 6-7 h.

[0029] Further improvement of the technical scheme of the present application is that the photocatalyst is applied to an industrial wastewater treatment process.

[0030] Due to the adoption of the above technical scheme, the present application has the following technical effects:

[0031] The application prepares three new morphologies of Cu3Fe4(VO4)6, in the preparation of Cu3Fe4(VO4)6 by a hydrothermal method, different two morphologies can be obtained by changing pH, a polygonal prism morphology is obtained by a solid sintering method, the three morphologies have large catalytic surface area and high visible light catalytic activity, are suitable for the deep treatment of industrial wastewater and the treatment of other toxic and harmful, refractory organic pollutants, have the potential to solve the problem of environmental pollution, and have significant social significance especially in the application to the treatment of industrial wastewater. BRIEF DESCRIPTION OF DRAWINGS

[0032] Figure 1 is an SEM image of Cu3Fe4(VO4)6 in a rod-like particle morphology;

[0033] Figure 2 is an SEM image of Cu3Fe4(VO4)6 in an irregular frame shape;

[0034] Figure 3 is an SEM image of Cu3Fe4(VO4)6 in a polygonal prism shape;

[0035] Figure 4 is an XRD image of the sample Cu3Fe4(VO4)6 prepared in Example 1 and the XRD image of Cu3Fe4(VO4)6;

[0036] Figure 5 is an XRD image of the sample Cu3Fe4(VO4)6 prepared in Example 3 and the XRD image of Cu3Fe4(VO4)6. DETAILED DESCRIPTION

[0037] The application will be further described in detail below in combination with specific embodiments:

[0038] Example 1

[0039] A preparation method of Cu3Fe4(VO4)6, comprising the following steps:

[0040] Step A, weigh 1.0812g of iron chloride hexahydrate, stir and dissolve with water, weigh 0.2387g of copper oxide, stir and dissolve with 2mL of nitric acid, and weigh 0.7019g of ammonium metavanadate, stir and dissolve with water.

[0041] Step B, mix the three dissolved solutions, after mixing, stir and heat to evaporate to about 25mL, and adjust the pH value to 6.

[0042] Step C, pour the adjusted solution into a hydrothermal reaction container, the solution accounts for 50% of the solution volume of the hydrothermal kettle, place the hydrothermal reaction container in a drying box, adjust the temperature of the drying box to 180℃, and react for 12h.

[0043] Step D, pour the solution into a clean beaker, wash the solution with water 3 times, and wash with alcohol 3 times.

[0044] Step E, the washed solution is filtered, and then put into a petri dish and dried in a drying oven at 60°C for 6h.

[0045] Step F, the dried powder is ground in a mortar, and then put into a crucible and calcined in a muffle furnace at 700°C for 2h.

[0046] Step G, after calcination, the powder is ground to obtain the sample Cu3Fe4(VO4)6.

[0047] The obtained sample Cu3Fe4(VO4)6 is detected, Figure 1 for its SEM image, Figure 4 for the XRD pattern of the sample and the comparison of Cu3Fe4(VO4)6 XRD pattern.

[0048] Sample morphology: As can be seen from the figure, under the conditions, rod-like Cu3Fe4(VO4)6 secondary particles are formed, which are composed of irregularly shaped and unevenly sized Cu3Fe4(VO4)6 primary small particle crystals connected by interfaces to form rod-like Cu3Fe4(VO4)6 secondary particles.

[0049] The prepared product is Cu3Fe4(VO4)6 verified by XRD pattern.

[0050] Example 2

[0051] A method for preparing Cu3Fe4(VO4)6, comprising the following steps:

[0052] Step A, weigh 1.0812g of iron chloride hexahydrate and dissolve with water, weigh 0.2387g of copper oxide and dissolve with 2mL of nitric acid, weigh 0.7019g of ammonium metavanadate and dissolve with water.

[0053] Step B, mix the three dissolved solutions, then stir and heat to evaporate to about 25mL, and adjust the pH to 7.

[0054] Step C, pour the adjusted solution into a hydrothermal reaction container, the solution accounts for 50% of the hydrothermal reaction kettle, put the hydrothermal reaction container into a drying oven, adjust the temperature of the drying oven to 180°C, and react for 12h.

[0055] Step D, pour the completed reaction solution into a clean beaker, wash the solution with water 3 times, and wash with alcohol 3 times.

[0056] Step E, the washed solution is filtered by suction, and then is placed in a culture dish and dried in a drying oven at 60°C for 6h.

[0057] Step F, the dried powder is ground in a mortar, and then is placed in a crucible and calcined in a muffle furnace at 700°C for 2h.

[0058] Step G, after calcination, the powder is ground, and Cu3Fe4(VO4)6is obtained.

[0059] The obtained sample Cu3Fe4(VO4)6is detected, Figure 2 and its SEM image is obtained.

[0060] Sample morphology: As can be seen from the figure, the morphology of the Cu3Fe4(VO4)6powder formed under the above experimental conditions is irregular frame shape, the edges of the frame are relatively smooth, and other Cu3Fe4(VO4)6unformed small particles are attached to it.

[0061] Example 3

[0062] Step S1, 1.0812g of iron chloride hexahydrate, 0.2387g of copper oxide and 0.7019g of ammonium metavanadate are weighed and mixed by grinding in a mortar.

[0063] Step S2, the ground powder is loaded into a crucible and compacted, and then is pre-fired in a muffle furnace at 380°C for 2h.

[0064] Step S3, after pre-firing, the medicine is placed in a mortar and ground thoroughly, and then is sintered in a crucible at 790°C for 6h.

[0065] Step S4, after sintering, the medicine is ground into powder in a mortar, and the obtained powder is Cu3Fe4(VO4)6.

[0066] The obtained sample Cu3Fe4(VO4)6is detected, Figure 3 and its SEM image is obtained, Figure 5 and its XRD image is obtained.

[0067] Sample morphology: As can be seen from the figure, the morphology of the Cu3Fe4(VO4)6powder obtained by this method is a multi-edge prism, the edges of the Cu3Fe4(VO4)6grains are relatively sharp, the particles are relatively distinct, and the length in a certain direction is relatively large, showing obvious prismatic shape. Figure 5 As can be seen from the figure, the product obtained by this preparation method is Cu3Fe4(VO4)6.

[0068] Comparative Example 1

[0069] The reaction steps and the amount of reactants of the present comparative example are the same as those of Example 1, except that the pH value of the adjusted solution in Step B of the present comparative example is 8, and then the final product obtained in Step G is detected, and it is found from the XRD pattern that the product is not Cu3Fe4(V04)6.

[0070] Comparative Example 2

[0071] The reaction steps and the amount of reactants of the present comparative example are the same as those of Example 1, except that the pH value of the adjusted solution in Step B of the present comparative example is 5.5, and then the final product obtained in Step G is detected, and it is found from the XRD pattern that the product is not Cu3Fe4(V04)6.

[0072] Comparative Example 3

[0073] The reaction steps of the present comparative example are the same as those of Example 1, except that the final volume of the mixed solution in Step B of the present comparative example is 35 mL, which is about 70% of the volume of the hydrothermal reaction vessel, and it is found that after the heating reaction in Step C is completed, the hydrothermal reaction vessel is opened, and no solid is produced, and the reaction fails.

[0074] The optical properties of the Cu3Fe4(V04)6samples in three forms prepared in the example are characterized:

[0075] In this experiment, a xenon lamp is used as a visible light source, tetracycline is used as a target degradation product, and copper iron vanadate powders prepared by different methods are used to degrade tetracycline. The degradation efficiency is used to represent the efficiency of photocatalysis. The specific operation steps are as follows: weigh 0.05 g of copper iron alum powder, put it into a quartz tube, add 15 mL of 0.02 mmol tetracycline solution, put in 2 magnetic sub-particles, and then put the test tube into a photochemical reaction instrument, and open the circulating cooling water. After stirring for 60 min under light shielding condition to reach adsorption / desorption equilibrium, open the xenon lamp light source. After irradiation for a certain time, the test tube is taken out, the solution is poured into a centrifuge tube at a certain mark, a high-speed centrifuge is used at a speed of 9000 r / min for 7 min to obtain supernatant, and then a visible spectrophotometer is used to measure the absorbance at the maximum absorption wavelength, and the degradation rate is calculated according to the following formula:

[0076] D = C / C0

[0077] In the formula, D is the photocatalytic efficiency; C0is the absorbance of the initial tetracycline solution at the maximum absorption wavelength; and C is the absorbance of the tetracycline solution at the maximum absorption wavelength (the same absorption wavelength) after irradiation for a certain time.

[0078]

[0079]

[0080] Therefore, the three morphologies of Cu3Fe4(VO4)6 prepared by the application have visible light catalytic activity.

Claims

1. A method for preparing Cu3Fe4(VO4)6, characterized in that: The preparation method of rod-like particles and irregular frame-like Cu3Fe4(VO4)6 comprises the following steps: Step A, weighing ferric chloride and stirring and dissolving it with water, weighing copper oxide and stirring and dissolving it with dilute nitric acid, and weighing ammonium metavanadate and stirring and dissolving it with water; In step A, the molar ratio of FeCl3·6H2O, CuO, and NH4VO3 is 4:3:6, and the ratio of CuO to nitric acid is 3 mol / 200 mL; Step B, mixing the three dissolved solutions, stirring, heating and evaporating the solution until the volume is 50-60% of the volume of the hydrothermal reaction vessel, and adjusting the pH value to 6 or 7; When the pH value is adjusted to 7 in step B, the morphology of Cu3Fe4(VO4)6 is an irregular frame shape, and when the pH value is adjusted to 6, the morphology of Cu3Fe4(VO4)6 is rod-shaped particles. The solution used to adjust the pH includes a sodium hydroxide solution. Step C, pouring the adjusted solution into a hydrothermal reaction vessel, and placing the hydrothermal reaction vessel in a drying oven for heating reaction; In step C, the temperature of the drying oven is adjusted to 170°C-190°C, the reaction time is 11-13 hours, and in step D, the mixture is washed with water 3-5 times and with alcohol 3-5 times; Step D: Pour the reaction solution into a clean beaker and wash with water and alcohol; Step E: Filter the washed solution, put it into a culture dish after filtration, and put the culture dish into a drying oven for drying; In step E, the drying temperature is 60°C-70°C and the time is 6-7 hours. In step F, the calcination temperature is 700°C-750°C and the calcination time is 2-3 hours. Step F, grinding the dried powder in a mortar, putting the ground powder into a crucible, and placing the crucible into a muffle furnace for calcination; Step G: After the calcination is completed, grind it into powder to obtain the sample Cu3Fe4(VO4)6.

2. A method for preparing Cu3Fe4(VO4)6, characterized in that: The preparation method of Cu3Fe4(VO4)6 with polygonal prism morphology comprises the following steps: Step S1, weighing a certain amount of ferric chloride, copper oxide and ammonium metavanadate, putting them into a mortar and grinding and mixing; In step S1, the molar ratio of FeCl3·6H2O, CuO and NH4VO3 is 4:3:6; Step S2: putting the ground powder into a crucible, compacting it, and placing it in a muffle furnace for pre-sintering; In step S2, the pre-firing temperature is 360-390°C and the pre-firing time is 2-2.5 hours. In step S3, the sintering temperature is 790°C and the sintering time is 6-7 hours. Step S3: After the pre-firing is completed, the medicine is placed in a mortar and fully ground. After the grinding is completed, the medicine is placed in a crucible and sintered; Step S4: After sintering is completed, the drug is placed in a mortar and ground into powder, and the obtained powder is Cu3Fe4(VO4)6.

3. Application of Cu3Fe4(VO4)6 as a photocatalyst, characterized by: The Cu3Fe4(VO4)6 photocatalyst prepared according to claim 1 or claim 2 is applied to an industrial wastewater treatment process.

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