Novel magnetic composite catalyst and preparation method thereof
阅读说明：本技术 一种新型磁性复合催化剂及制备方法 (Novel magnetic composite catalyst and preparation method thereof ) 是由 马国峰 祁蓝钰 张鸿龄 于 2021-10-21 设计创作，主要内容包括：用于光催化降解有机废水催化剂及制备方法,涉及一种处理废水催化剂及制备方法,通过热聚合法制备g-C-(3)N-(4)；然后通过两步原位法回流煅烧法构建ZnCo-(2)O-(4)/g-C-(3)N-(4)复合物；最后通过机械球磨法原位制备出Co-(78)Si-(8)B-(14)/ZnCo-(2)O-(4)/g-C-(3)N-(4)磁性复合催化剂。本发明制备出集吸附-催化-光催化-磁分离于一体的催化剂,解决/g-C-(3)N-(4)催化剂光生载流子的分离效率低及难以分离回收及有机物高效去除问题。(A catalyst for photocatalytic degradation of organic wastewater and a preparation method thereof, relates to a wastewater treatment catalyst and a preparation method thereof, and g-C is prepared by a thermal polymerization method 3 N 4 (ii) a Then a two-step in-situ reflux calcination method is used for constructing ZnCo 2 O 4 /g‑C 3 N 4 A complex; finally preparing Co in situ by a mechanical ball milling method 78 Si 8 B 14 /ZnCo 2 O 4 /g‑C 3 N 4 Magnetic composite catalyst. The invention prepares the catalyst integrating adsorption-catalysis-photocatalysis-magnetic separation, and solves the problem of g-C 3 N 4 The separation efficiency of the catalyst photon-generated carriers is low, the separation and the recovery are difficult, and the organic matters are highEffectively removing the problem.)
1. The catalyst for photocatalytic degradation of organic wastewater and the preparation method thereof are characterized in that the method is a novel amorphous Co catalyst78Si8B14/ZnCo2O4/g-C3N4The magnetic composite catalyst and the preparation method thereof comprise the following steps:
(1) preparation of g-C by thermal polymerization3N4: weighing 5-20 g of urea, introducing the urea into a quartz crucible, tightly wrapping the urea with tinfoil, placing the wrapped urea in a muffle furnace, calcining the urea for 1-5 hours at the temperature of 500 plus materials and 700 ℃, weighing 1-3 g of solid products in the quartz crucible after the reaction is finished, placing the solid products in a 500 ml beaker, adding 300 plus materials and 450 ml of deionized water, continuously performing ultrasonic treatment for 5-15 hours, and placing the quartz crucible in a drying box for drying for 8-12 hours at the temperature of 90 ℃ to obtain g-C3N4；
(2) Method for constructing ZnCo by two-step in-situ reflux calcination2O4/g-C3N4: first, 10-15 g Zn (NO) is weighed3)2And 15-25 g Co (NO)3)2Dissolving in 100 ml of deionized water, slowly dropwise adding 1 mol/L sodium hydroxide solution into a beaker until the pH value of the solution is adjusted to 10, and magnetically stirring for 10-60 minutes to form a uniformly distributed black solution; then 1-3 g of g-C3N4Transferring the black solution and the black solution into a three-neck flask, slowly heating to 100 ℃ for 0.5-2 hours, washing, centrifuging, drying, collecting and placing the product in a muffle furnace again to heat to 200-400 ℃ for calcining for 1-3 hours after the reflux reaction is finished to obtain ZnCo2O4/g-C3N4A complex;
(3) in-situ preparation of Co by mechanical ball milling method78Si8B14/ZnCo2O4/g-C3N4Magnetic composite catalyst: all equipment is a star ball mill: 1) the simple substance raw materials used in the test are powders of Co, Si and B, the granularity is 200 meshes, the purity is not lower than 99.99 percent (mass percent), stainless steel is selected as a ball milling medium, and three stainless steel balls are used in the test, wherein 800 stainless steel balls with the radius of 2 mm, 300 stainless steel balls with the radius of 5 mm and 20 stainless steel balls with the radius of 10 mm are used respectively; 2) accurately weighed Co, Si, B powder and ZnCo2O4/g-C3N4Putting the compound into a ball milling tank, putting the stainless steel balls into the ball milling tank, sealing the ball milling tank, vacuumizing by using a vacuum pump, filling high-purity argon as protective gas, repeatedly performing the steps for 5-6 times to ensure the purity of the argon in the ball milling tank, and finally checking whether a gas valve is screwed down to prevent gas leakage(ii) a 3) Fixing the ball milling tank on the star type ball mill, covering a protective cover, starting the star type ball mill to operate, enabling the ball milling speed of the test to be 200-times/min, stopping for 1 hour, enabling the ball milling time to be 30-80 hours, after the star type ball mill operates for a set time, waiting until the ball milling tank is cooled, opening an air valve of the ball milling tank, discharging argon in the ball milling tank, opening the ball milling tank, taking out the prepared Co78Si8B14/ZnCo2O4/g-C3N4Magnetic composite catalyst.
2. The method for preparing a catalyst for photocatalytic degradation of organic wastewater according to claim 1, wherein the amount of Co powder added is 10 to 20 g, the amount of Si powder added is 1 to 5 g, and the amount of B powder added is 3 to 9 g.
3. The method for preparing a catalyst for the electrocatalytic degradation of organic wastewater according to claim 1, wherein the ZnCo is added to the solution of the organic wastewater2O4/g-C3N4The amount of the compound added is 5-15 g.
Technical Field
The invention relates to a catalyst for treating wastewater and a preparation method thereof, in particular to a catalyst for photocatalytic degradation of organic wastewater and a preparation method thereof.
Background
With conventional TiO2In contrast, g-C of organic two-dimensional layers3N4The photocatalytic hydrogen production is seriously hindered by the defects of low price, proper energy band, stable property, poor conductivity, fast carrier recombination, narrow photoresponse range and the like. Therefore, people improve g-C by regulating morphology, doping elements, loading a cocatalyst, constructing a heterojunction and the like3N4The photocatalytic performance of (a). Wherein, the construction of the heterojunction not only can improve the separation efficiency of photon-generated carriers, but also can expand the light absorption rangeAnd is an effective strategy for improving the activity of the catalyst.
However, the industrial application of the g-C3N4 photocatalysis technology to sewage treatment needs to solve a more critical problem, namely the recovery problem of the photocatalyst. In the process of degrading sewage by using g-C3N4, in order to improve the catalytic performance of the photocatalyst, the photocatalyst is often required to be prepared into powder with large specific surface area, so that the recovery difficulty after degradation is increased. Therefore, the development or optimization of the prior art to prepare a novel catalyst which is low in cost, short in time consumption, renewable, recyclable and free of secondary pollution is a major problem in the field at present.
Disclosure of Invention
The invention aims to provide a catalyst for photocatalytic degradation of organic wastewater and a preparation method thereof78Si8B14、ZnCo2O4And g-C3N4In combination, g-C is first prepared by a thermal polymerization process3N4Then a two-step in-situ method reflux calcination method is used for constructing ZnCo2O4/g-C3N4Finally, preparing Co in situ by a mechanical ball milling method78Si8B14/ZnCo2O4/g-C3N4The magnetic composite catalyst integrates adsorption-catalysis-photocatalysis-magnetic separation and solves the problem of/g-C3N4The separation efficiency of the catalyst photon-generated carriers is low, the separation and the recovery are difficult, and the organic matters are removed efficiently.
The purpose of the invention is realized by the following technical scheme:
a catalyst for photocatalytic degradation of organic wastewater and a preparation method thereof, and the method is used for preparing novel amorphous Co with high catalytic activity78Si8B14/ZnCo2O4/g-C3N4A method of magnetically complexing a catalyst, the method comprising the process of:
(1) preparation of g-C by thermal polymerization3N4: weighing 5-20 g of urea, introducing the urea into a quartz crucible, tightly wrapping the urea with tinfoil, placing the wrapped urea in a muffle furnace, and calcining for 1-5 hours at the temperature of 500-Then (c) is performed. After the reaction is finished, weighing 1-3 g of solid product in the quartz crucible, putting the solid product in a 500 ml beaker, adding 300-450 ml of deionized water, continuously carrying out ultrasonic treatment for 5-15 hours, and then putting the solid product in a drying oven for drying for 8-12 hours at 90 ℃ to obtain g-C3N4；
(2) Method for constructing ZnCo by two-step in-situ reflux calcination2O4/g-C3N4: first, 10-15 g Zn (NO) is weighed3)2And 15-25 g Co (NO)3)2Dissolving in 100 ml of deionized water, slowly dropwise adding 1 mol/L sodium hydroxide solution into a beaker until the pH value of the solution is adjusted to 10, and magnetically stirring for 10-60 minutes to form a uniformly distributed black solution. Then 1-3 g of g-C3N4The mixture was transferred to a three-necked flask together with the black solution, and the temperature was slowly raised to 100 ℃ for 0.5 to 2 hours. After the reflux reaction is finished, washing, centrifuging, drying and collecting the resultant, placing the resultant in a muffle furnace again, heating to 200-400 ℃ and calcining for 1-3 hours to obtain ZnCo2O4/g-C3N4A complex;
(3) in-situ preparation of Co by mechanical ball milling method78Si8B14/ZnCo2O4/g-C3N4Magnetic composite catalyst: all the devices are star ball mills; 1) the simple substance raw materials used in the test are powders of Co, Si and B, the granularity is 200 meshes, and the purity is not lower than 99.99 percent (mass percentage). Stainless steel is selected as a ball milling medium, and three stainless steel balls, namely 800 stainless steel balls with the radius of 2 mm, 300 stainless steel balls with the radius of 5 mm and 20 stainless steel balls with the radius of 10 mm are used in the test; 2) accurately weighed Co, Si, B powder and ZnCo2O4/g-C3N4Putting the compound into a ball milling tank, putting the stainless steel balls into the ball milling tank, and sealing the ball milling tank. Then, vacuumizing by using a vacuum pump, filling high-purity argon as protective gas, repeatedly performing the steps for 5-6 times to ensure the purity of the argon in the final ball-milling filling, and finally checking whether a gas valve is screwed down to prevent gas leakage; 3) fixing the ball milling tank on a star-type ball mill, covering a protective cover, and starting up the ball milling tank to operate. The ball milling speed of the test is 200 plus 500 r/min, and the test is operated1 hour and 30 to 80 hours of ball milling. After the star-type ball mill runs for a set time, cooling the ball milling tank, opening an air valve of the ball milling tank, discharging argon in the ball milling tank, opening the ball milling tank, and taking out the prepared Co78Si8B14/ZnCo2O4/g-C3N4Magnetic composite catalyst.
The invention has the advantages and effects that:
1. the invention relates to novel amorphous Co78Si8B14/ZnCo2O4/g-C3N4Magnetic composite catalyst integrating ZnCo2O4Adsorptivity of, amorphous Co78Si8B14The catalyst has high catalytic activity and magnetism, has the characteristics of integrating adsorption, catalysis, photocatalysis and magnetic separation, can be separated and recovered, can efficiently remove organic matters, and has no secondary pollution.
2. The method has the advantages of simple operation, easy equipment acquisition, simple process flow and low investment cost, and the prepared catalyst does not need to be additionally added with other oxidants in the process of photocatalytic degradation of organic wastewater, thereby being beneficial to large-scale industrial application.
Detailed Description
The present invention will be described in detail with reference to examples.
Example 1
The invention provides a novel amorphous Co78Si8B14/ZnCo2O4/g-C3N4The magnetic composite catalyst and the preparation method thereof comprise the following steps:
(1) preparation of g-C by thermal polymerization3N4: 10 g of urea were weighed into a quartz crucible, tightly wrapped with a tin foil, placed in a muffle furnace, and calcined at 550 ℃ for 3 hours. After the reaction is finished, weighing 2 g of solid product in the quartz crucible, putting the solid product into a 500 ml beaker, adding 350 ml of deionized water, continuously performing ultrasonic treatment for 10 hours, putting the mixture into a drying oven, drying the mixture for 10 hours at 90 ℃ to obtain g-C3N4；
(2) Two-step methodMethod for constructing ZnCo by using bit method reflux calcination method2O4/g-C3N4: first, 10 g of Zn (NO) is weighed3)2And 20 g Co (NO)3)2Dissolving in 100 ml of deionized water, slowly dropwise adding 1 mol/L sodium hydroxide solution into a beaker until the pH value of the solution is adjusted to 10, and magnetically stirring for 30 minutes to form a uniformly distributed black solution. Then 2 g of g-C3N4The resulting mixture was transferred to a three-necked flask together with the black solution, and the temperature was slowly raised to 100 ℃ for 1.5 hours. After the reflux reaction is finished, washing, centrifuging, drying and collecting the resultant, putting the resultant in a muffle furnace again, heating to 300 ℃ and calcining for 2 hours to obtain ZnCo2O4/g-C3N4A complex;
(3) in-situ preparation of Co by mechanical ball milling method78Si8B14/ZnCo2O4/g-C3N4Magnetic composite catalyst: all the devices are star ball mills; 1) the simple substance raw materials used in the test are powders of Co, Si and B, the granularity is 200 meshes, and the purity is not lower than 99.99 percent (mass percentage). Stainless steel is selected as a ball milling medium, and three stainless steel balls, namely 800 stainless steel balls with the radius of 2 mm, 300 stainless steel balls with the radius of 5 mm and 20 stainless steel balls with the radius of 10 mm are used in the test; 2) accurately weighed Co, Si, B powder and ZnCo2O4/g-C3N4Putting the compound into a ball milling tank, putting the stainless steel balls into the ball milling tank, and sealing the ball milling tank. Then, vacuumizing by using a vacuum pump, filling high-purity argon as protective gas, repeatedly performing the steps for 5 times to ensure the purity of the argon in the final ball-milling filling, and finally checking whether a gas valve is screwed to prevent gas leakage; 3) fixing the ball milling tank on a star-type ball mill, covering a protective cover, and starting up the ball milling tank to operate. The ball milling speed of the test is 3000 r/min, the operation time is 1 hour, the rest time is 1 hour, and the ball milling time is 60 hours. After the star-type ball mill runs for a set time, cooling the ball milling tank, opening an air valve of the ball milling tank, discharging argon in the ball milling tank, opening the ball milling tank, and taking out the prepared Co78Si8B14/ZnCo2O4/g-C3N4Magnetic composite catalyst.
Example 2
The invention provides a novel amorphous Co78Si8B14/ZnCo2O4/g-C3N4The magnetic composite catalyst and the preparation method thereof comprise the following steps:
(1) preparation of g-C by thermal polymerization3N4: 15 g of urea were weighed into a quartz crucible, tightly wrapped with tinfoil, placed in a muffle furnace and calcined at 600 ℃ for 2 hours. After the reaction is finished, weighing 3 g of solid product in the quartz crucible, putting the solid product into a 500 ml beaker, adding 400 ml of deionized water, continuously performing ultrasonic treatment for 15 hours, putting the mixture into a drying oven, drying the mixture for 9 hours at 90 ℃ to obtain g-C3N4；
(2) Method for constructing ZnCo by two-step in-situ reflux calcination2O4/g-C3N4: first, 15 g of Zn (NO) is weighed3)2And 20 g Co (NO3)2Dissolving in 100 ml of deionized water, slowly dropwise adding 1 mol/L sodium hydroxide solution into a beaker until the pH value of the solution is adjusted to 10, and magnetically stirring for 50 minutes to form a uniformly distributed black solution. Then 3 g of g-C3N4The resulting mixture was transferred to a three-necked flask together with the black solution, and the temperature was slowly raised to 100 ℃ for 2 hours. After the reflux reaction is finished, washing, centrifuging, drying and collecting the resultant, putting the resultant in a muffle furnace again, heating to 400 ℃ and calcining for 2 hours to obtain ZnCo2O4/g-C3N4A complex;
(3) in-situ preparation of Co by mechanical ball milling method78Si8B14/ZnCo2O4/g-C3N4Magnetic composite catalyst: all the devices are star ball mills; 1) the simple substance raw materials used in the test are powders of Co, Si and B, the granularity is 200 meshes, and the purity is not lower than 99.99 percent (mass percentage). Stainless steel is selected as a ball milling medium, and three stainless steel balls, namely 800 stainless steel balls with the radius of 2 mm, 300 stainless steel balls with the radius of 5 mm and 20 stainless steel balls with the radius of 10 mm are used in the test; 2) accurately weighed Co, Si, B powder and ZnCo2O4/g-C3N4Putting the compound into a ball milling tank, putting the stainless steel balls into the ball milling tank, and sealing the ball milling tank. Then, vacuumizing by using a vacuum pump, filling high-purity argon as protective gas, repeatedly performing the steps for 5 times to ensure the purity of the argon in the final ball-milling filling, and finally checking whether a gas valve is screwed to prevent gas leakage; 3) fixing the ball milling tank on a star-type ball mill, covering a protective cover, and starting up the ball milling tank to operate. The ball milling speed of the test is 500 rpm, the operation time is 1 hour, the rest time is 1 hour, and the ball milling time is 50 hours. After the star-type ball mill runs for a set time, cooling the ball milling tank, opening an air valve of the ball milling tank, discharging argon in the ball milling tank, opening the ball milling tank, and taking out the prepared Co78Si8B14/ZnCo2O4/g-C3N4Magnetic composite catalyst.
Example 3
The invention provides a novel amorphous Co78Si8B14/ZnCo2O4/g-C3N4The magnetic composite catalyst and the preparation method thereof comprise the following steps:
(1) preparation of g-C by thermal polymerization3N4: 5-20 g of urea was weighed into a quartz crucible, tightly wrapped with tinfoil, placed in a muffle furnace and calcined at 600 ℃ for 3 hours. After the reaction is finished, weighing 1-3 g of solid product in the quartz crucible, putting the solid product in a 500 ml beaker, adding 450 ml of deionized water, continuously performing ultrasonic treatment for 10 hours, putting the mixture in a drying oven for drying for 12 hours at 90 ℃ to obtain g-C3N4；
(2) Method for constructing ZnCo by two-step in-situ reflux calcination2O4/g-C3N4: first, 15 g of Zn (NO) is weighed3)2And 25 g Co (NO)3)2Dissolving in 100 ml of deionized water, slowly dropwise adding 1 mol/L sodium hydroxide solution into a beaker until the pH value of the solution is adjusted to 10, and magnetically stirring for 60 minutes to form a uniformly distributed black solution. Then 3 g of g-C3N4Transferring the black solution into a three-neck flask together with the black solution, slowly heating to 100 ℃, and flowing for 2 hoursThen (c) is performed. After the reflux reaction is finished, washing, centrifuging, drying and collecting the resultant, putting the resultant in a muffle furnace again, heating to 300 ℃ and calcining for 3 hours to obtain ZnCo2O4/g-C3N4A complex;
(3) in-situ preparation of Co by mechanical ball milling method78Si8B14/ZnCo2O4/g-C3N4Magnetic composite catalyst: all the devices are star ball mills; 1) the simple substance raw materials used in the test are powders of Co, Si and B, the granularity is 200 meshes, and the purity is not lower than 99.99 percent (mass percentage). Stainless steel is selected as a ball milling medium, and three stainless steel balls, namely 800 stainless steel balls with the radius of 2 mm, 300 stainless steel balls with the radius of 5 mm and 20 stainless steel balls with the radius of 10 mm are used in the test; 2) accurately weighed Co, Si, B powder and ZnCo2O4/g-C3N4Putting the compound into a ball milling tank, putting the stainless steel balls into the ball milling tank, and sealing the ball milling tank. Then, vacuumizing by using a vacuum pump, filling high-purity argon as protective gas, repeatedly performing the step 6 times to ensure the purity of the argon in the final ball-milling filling, and finally checking whether a gas valve is screwed to prevent gas leakage; 3) fixing the ball milling tank on a star-type ball mill, covering a protective cover, and starting up the ball milling tank to operate. The ball milling speed of the test is 500 rpm, the operation time is 1 hour, the rest time is 1 hour, and the ball milling time is 80 hours. After the star-type ball mill runs for a set time, cooling the ball milling tank, opening an air valve of the ball milling tank, discharging argon in the ball milling tank, opening the ball milling tank, and taking out the prepared Co78Si8B14/ZnCo2O4/g-C3N4Magnetic composite catalyst.