CN116161752A - Preparation method of composite electrode and application of composite electrode in nitrate-containing wastewater - Google Patents
Preparation method of composite electrode and application of composite electrode in nitrate-containing wastewater Download PDFInfo
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- 239000002131 composite material Substances 0.000 title claims abstract description 42
- 229910002651 NO3 Inorganic materials 0.000 title claims abstract description 36
- NHNBFGGVMKEFGY-UHFFFAOYSA-N Nitrate Chemical compound [O-][N+]([O-])=O NHNBFGGVMKEFGY-UHFFFAOYSA-N 0.000 title claims abstract description 36
- 239000002351 wastewater Substances 0.000 title claims abstract description 12
- 238000002360 preparation method Methods 0.000 title claims abstract description 10
- KRKNYBCHXYNGOX-UHFFFAOYSA-N citric acid Chemical compound OC(=O)CC(O)(C(O)=O)CC(O)=O KRKNYBCHXYNGOX-UHFFFAOYSA-N 0.000 claims abstract description 28
- 238000000034 method Methods 0.000 claims abstract description 26
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims abstract description 20
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 claims abstract description 15
- 229910052799 carbon Inorganic materials 0.000 claims abstract description 15
- 230000009467 reduction Effects 0.000 claims abstract description 15
- 239000004744 fabric Substances 0.000 claims abstract description 13
- 239000000758 substrate Substances 0.000 claims abstract description 11
- LYCAIKOWRPUZTN-UHFFFAOYSA-N Ethylene glycol Chemical compound OCCO LYCAIKOWRPUZTN-UHFFFAOYSA-N 0.000 claims description 21
- 238000001354 calcination Methods 0.000 claims description 17
- 238000001035 drying Methods 0.000 claims description 16
- QAOWNCQODCNURD-UHFFFAOYSA-N Sulfuric acid Chemical compound OS(O)(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-N 0.000 claims description 14
- 239000000463 material Substances 0.000 claims description 13
- 238000002156 mixing Methods 0.000 claims description 12
- PMZURENOXWZQFD-UHFFFAOYSA-L Sodium Sulfate Chemical compound [Na+].[Na+].[O-]S([O-])(=O)=O PMZURENOXWZQFD-UHFFFAOYSA-L 0.000 claims description 10
- 229910021645 metal ion Inorganic materials 0.000 claims description 10
- GRYLNZFGIOXLOG-UHFFFAOYSA-N Nitric acid Chemical compound O[N+]([O-])=O GRYLNZFGIOXLOG-UHFFFAOYSA-N 0.000 claims description 8
- 239000000499 gel Substances 0.000 claims description 8
- 239000000843 powder Substances 0.000 claims description 8
- 229910052938 sodium sulfate Inorganic materials 0.000 claims description 8
- 235000011152 sodium sulphate Nutrition 0.000 claims description 8
- 229910017604 nitric acid Inorganic materials 0.000 claims description 7
- LFQSCWFLJHTTHZ-UHFFFAOYSA-N Ethanol Chemical compound CCO LFQSCWFLJHTTHZ-UHFFFAOYSA-N 0.000 claims description 6
- 239000002253 acid Substances 0.000 claims description 6
- 238000000227 grinding Methods 0.000 claims description 6
- CJTCBBYSPFAVFL-UHFFFAOYSA-N iridium ruthenium Chemical compound [Ru].[Ir] CJTCBBYSPFAVFL-UHFFFAOYSA-N 0.000 claims description 6
- 239000000725 suspension Substances 0.000 claims description 6
- 239000003792 electrolyte Substances 0.000 claims description 5
- 238000002791 soaking Methods 0.000 claims description 5
- 238000001816 cooling Methods 0.000 claims description 4
- WGCNASOHLSPBMP-UHFFFAOYSA-N hydroxyacetaldehyde Natural products OCC=O WGCNASOHLSPBMP-UHFFFAOYSA-N 0.000 claims description 4
- 239000000126 substance Substances 0.000 claims description 4
- 239000011240 wet gel Substances 0.000 claims description 4
- 229920000557 Nafion® Polymers 0.000 claims description 3
- 230000003647 oxidation Effects 0.000 claims description 3
- 238000007254 oxidation reaction Methods 0.000 claims description 3
- 238000003756 stirring Methods 0.000 claims description 3
- 238000005303 weighing Methods 0.000 claims description 3
- 229910002554 Fe(NO3)3·9H2O Inorganic materials 0.000 claims description 2
- 150000001768 cations Chemical class 0.000 claims description 2
- 239000002738 chelating agent Substances 0.000 claims description 2
- 239000003795 chemical substances by application Substances 0.000 claims description 2
- 238000001704 evaporation Methods 0.000 claims description 2
- 238000004519 manufacturing process Methods 0.000 claims description 2
- 229910052751 metal Inorganic materials 0.000 claims description 2
- 239000002184 metal Substances 0.000 claims description 2
- 238000000643 oven drying Methods 0.000 claims description 2
- 238000006068 polycondensation reaction Methods 0.000 claims description 2
- -1 rare earth cations Chemical class 0.000 claims description 2
- 229910052761 rare earth metal Inorganic materials 0.000 claims description 2
- 239000002904 solvent Substances 0.000 claims description 2
- 230000004913 activation Effects 0.000 claims 1
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 abstract description 10
- 229910052757 nitrogen Inorganic materials 0.000 abstract description 5
- XKMRRTOUMJRJIA-UHFFFAOYSA-N ammonia nh3 Chemical compound N.N XKMRRTOUMJRJIA-UHFFFAOYSA-N 0.000 abstract description 2
- 239000013543 active substance Substances 0.000 abstract 2
- 238000011065 in-situ storage Methods 0.000 abstract 2
- 239000011149 active material Substances 0.000 abstract 1
- 238000003980 solgel method Methods 0.000 abstract 1
- 239000000243 solution Substances 0.000 description 16
- 238000006722 reduction reaction Methods 0.000 description 13
- 238000005516 engineering process Methods 0.000 description 6
- 239000003344 environmental pollutant Substances 0.000 description 5
- 231100000719 pollutant Toxicity 0.000 description 5
- 238000006243 chemical reaction Methods 0.000 description 4
- 239000011259 mixed solution Substances 0.000 description 4
- 230000008569 process Effects 0.000 description 4
- VWDWKYIASSYTQR-UHFFFAOYSA-N sodium nitrate Chemical compound [Na+].[O-][N+]([O-])=O VWDWKYIASSYTQR-UHFFFAOYSA-N 0.000 description 4
- 238000001179 sorption measurement Methods 0.000 description 4
- 230000009471 action Effects 0.000 description 3
- 239000008367 deionised water Substances 0.000 description 3
- 229910021641 deionized water Inorganic materials 0.000 description 3
- 230000000694 effects Effects 0.000 description 3
- 239000007772 electrode material Substances 0.000 description 3
- 238000000053 physical method Methods 0.000 description 3
- 239000002994 raw material Substances 0.000 description 3
- PUAQLLVFLMYYJJ-UHFFFAOYSA-N 2-aminopropiophenone Chemical compound CC(N)C(=O)C1=CC=CC=C1 PUAQLLVFLMYYJJ-UHFFFAOYSA-N 0.000 description 2
- 230000003197 catalytic effect Effects 0.000 description 2
- 238000005520 cutting process Methods 0.000 description 2
- 238000004821 distillation Methods 0.000 description 2
- 238000000909 electrodialysis Methods 0.000 description 2
- 239000008151 electrolyte solution Substances 0.000 description 2
- 238000005265 energy consumption Methods 0.000 description 2
- 238000005342 ion exchange Methods 0.000 description 2
- 230000000813 microbial effect Effects 0.000 description 2
- 239000000203 mixture Substances 0.000 description 2
- 230000004048 modification Effects 0.000 description 2
- 238000012986 modification Methods 0.000 description 2
- 239000004570 mortar (masonry) Substances 0.000 description 2
- 238000001223 reverse osmosis Methods 0.000 description 2
- 239000004317 sodium nitrate Substances 0.000 description 2
- 235000010344 sodium nitrate Nutrition 0.000 description 2
- 239000007787 solid Substances 0.000 description 2
- KJCVRFUGPWSIIH-UHFFFAOYSA-N 1-naphthol Chemical compound C1=CC=C2C(O)=CC=CC2=C1 KJCVRFUGPWSIIH-UHFFFAOYSA-N 0.000 description 1
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 238000010170 biological method Methods 0.000 description 1
- 230000031018 biological processes and functions Effects 0.000 description 1
- 230000015556 catabolic process Effects 0.000 description 1
- 239000003054 catalyst Substances 0.000 description 1
- 230000008859 change Effects 0.000 description 1
- 239000003638 chemical reducing agent Substances 0.000 description 1
- 239000000356 contaminant Substances 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 238000006731 degradation reaction Methods 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 229910003460 diamond Inorganic materials 0.000 description 1
- 239000010432 diamond Substances 0.000 description 1
- 238000003487 electrochemical reaction Methods 0.000 description 1
- 239000012467 final product Substances 0.000 description 1
- 238000010438 heat treatment Methods 0.000 description 1
- 229910052739 hydrogen Inorganic materials 0.000 description 1
- 239000001257 hydrogen Substances 0.000 description 1
- 230000006872 improvement Effects 0.000 description 1
- 238000009776 industrial production Methods 0.000 description 1
- 239000007788 liquid Substances 0.000 description 1
- 239000007769 metal material Substances 0.000 description 1
- 229910001960 metal nitrate Inorganic materials 0.000 description 1
- 229910044991 metal oxide Inorganic materials 0.000 description 1
- 150000004706 metal oxides Chemical class 0.000 description 1
- 239000008239 natural water Substances 0.000 description 1
- 229910000510 noble metal Inorganic materials 0.000 description 1
- 238000004321 preservation Methods 0.000 description 1
- 238000011946 reduction process Methods 0.000 description 1
- 239000012492 regenerant Substances 0.000 description 1
- 230000001105 regulatory effect Effects 0.000 description 1
- 238000011160 research Methods 0.000 description 1
- 230000004044 response Effects 0.000 description 1
- 230000000630 rising effect Effects 0.000 description 1
- 238000000926 separation method Methods 0.000 description 1
- 239000010865 sewage Substances 0.000 description 1
- 238000009210 therapy by ultrasound Methods 0.000 description 1
- 238000005406 washing Methods 0.000 description 1
- 239000002699 waste material Substances 0.000 description 1
- 238000003911 water pollution Methods 0.000 description 1
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- C—CHEMISTRY; METALLURGY
- C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F1/00—Treatment of water, waste water, or sewage
- C02F1/46—Treatment of water, waste water, or sewage by electrochemical methods
- C02F1/461—Treatment of water, waste water, or sewage by electrochemical methods by electrolysis
- C02F1/46104—Devices therefor; Their operating or servicing
- C02F1/46109—Electrodes
-
- C—CHEMISTRY; METALLURGY
- C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F1/00—Treatment of water, waste water, or sewage
- C02F1/46—Treatment of water, waste water, or sewage by electrochemical methods
- C02F1/461—Treatment of water, waste water, or sewage by electrochemical methods by electrolysis
- C02F1/467—Treatment of water, waste water, or sewage by electrochemical methods by electrolysis by electrochemical disinfection; by electrooxydation or by electroreduction
- C02F1/4676—Treatment of water, waste water, or sewage by electrochemical methods by electrolysis by electrochemical disinfection; by electrooxydation or by electroreduction by electroreduction
-
- C—CHEMISTRY; METALLURGY
- C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F1/00—Treatment of water, waste water, or sewage
- C02F1/46—Treatment of water, waste water, or sewage by electrochemical methods
- C02F1/461—Treatment of water, waste water, or sewage by electrochemical methods by electrolysis
- C02F1/46104—Devices therefor; Their operating or servicing
- C02F1/46109—Electrodes
- C02F2001/46133—Electrodes characterised by the material
- C02F2001/46138—Electrodes comprising a substrate and a coating
- C02F2001/46142—Catalytic coating
-
- C—CHEMISTRY; METALLURGY
- C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F2101/00—Nature of the contaminant
- C02F2101/10—Inorganic compounds
- C02F2101/16—Nitrogen compounds, e.g. ammonia
- C02F2101/163—Nitrates
-
- C—CHEMISTRY; METALLURGY
- C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F2201/00—Apparatus for treatment of water, waste water or sewage
- C02F2201/46—Apparatus for electrochemical processes
- C02F2201/461—Electrolysis apparatus
- C02F2201/46105—Details relating to the electrolytic devices
- C02F2201/4612—Controlling or monitoring
- C02F2201/46125—Electrical variables
- C02F2201/4614—Current
-
- C—CHEMISTRY; METALLURGY
- C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F2201/00—Apparatus for treatment of water, waste water or sewage
- C02F2201/46—Apparatus for electrochemical processes
- C02F2201/461—Electrolysis apparatus
- C02F2201/46105—Details relating to the electrolytic devices
- C02F2201/4616—Power supply
- C02F2201/4617—DC only
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- Chemical & Material Sciences (AREA)
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- Electrochemistry (AREA)
- General Chemical & Material Sciences (AREA)
- Life Sciences & Earth Sciences (AREA)
- Hydrology & Water Resources (AREA)
- Engineering & Computer Science (AREA)
- Environmental & Geological Engineering (AREA)
- Water Supply & Treatment (AREA)
- Organic Chemistry (AREA)
- Water Treatment By Electricity Or Magnetism (AREA)
- Electrodes For Compound Or Non-Metal Manufacture (AREA)
Abstract
The invention relates to the field of electrochemical water treatment, in particular to a preparation method of a composite electrode and application of the composite electrode in nitrate-containing wastewater. La provided by the invention 0.9 FeO 3 The C composite electrode comprises a hydrophilic conductive carbon cloth substrate and an active substance which is arranged on the surface of the carbon substrate and is generated by dripping or in situ. The active material comprises La 0.9 FeO 3 Fe (b) Ⅱ 。La 0.9 FeO 3 The active layer is prepared by citric acid-assisted sol-gel method, fe Ⅱ The active substance is generated on the surface of the electrode in situ by the constant current electrochemical reduction method provided by the invention. The composite electrode is applied to a water body containing nitrate, can be used for rapidly and effectively electrocatalytically reducing the nitrate into nitrogen or lower-valence ammonia nitrogen, and reduces the pollution of the nitrate to the environment。
Description
Technical Field
The invention relates to the field of electrochemical water treatment, in particular to a preparation method of a composite electrode and application of the composite electrode in nitrate-containing wastewater.
Background
Nitrate is one of the main pollutants in water bodies. Currently, common methods for removing nitrate from water are generally classified into physical methods, chemical methods, and biological methods. The physical method is a method for removing nitrate in water through a physical process, and comprises adsorption, distillation, ion exchange, reverse osmosis, electrodialysis and the like. Wherein, the modified adsorption material can improve the adsorption capacity, but needs to consume a large amount of adsorption material; the ion exchange method also needs a large amount of regenerant, and effluent water can be discharged after being treated; the distillation method has high energy consumption and is only suitable for treating a small amount of water; the reverse osmosis and electrodialysis methods have good nitrate removal effect, but have high cost, and subsequent waste liquid is difficult to treat. Furthermore, physical methods only adsorb or transfer nitrate, and are not capable of chemically removing nitrate contaminants. The biological process converts nitrate into nitrogen through microbial denitrification so as to remove nitrate pollution, and has the advantages of stable effect, low cost, nitrogen as a final product and little influence on environment, but also has the defects of easy influence on the operation environment and microbial growth and the like. As a novel water pollution treatment technology, the electrocatalytic reduction technology can realize the conversion of nitrate into nitrogen or ammonia nitrogen with lower valence, and thoroughly realize the removal of nitrate.
In recent years, the electrocatalytic reduction technology is widely applied to the treatment of nitrate pollution due to the advantages of high efficiency, no secondary pollution and the like. The reduction of nitrate occurs at the cathode surface. The principle is that in an electrochemical reaction device, direct current is applied to an electrode, and nitrate pollutants in a water body can undergo reduction reaction on a catalytic layer on the surface of a cathode. Compared with biological denitrification and physical separation, the electrocatalytic reduction technology relies on electrolytic reaction on the surface of an electrode to directly reduce (the pollutants directly obtain electrons on a cathode and reduce) or indirectly reduce (reducing hydrogen is generated in the electrolytic process) the pollutants, and has the advantages of high efficiency, low cost and no need of externally adding a reducing agent.
The physicochemical properties of the electrode material, electrolyte solution and wastewater are three major factors affecting the efficiency of electrocatalytic reduction. The choice of electrode material directly affects the degradation efficiency of nitrate. On the one hand, the reduction performance of different electrodes on nitrate is greatly different. On the other hand, the electrodes also determine the current efficiency, stability and durability. The pretreatment of the electrode material is an essential key link, and the step is to lay a solid foundation for subsequent researches. The electrode is activated by adopting a constant current electrochemical reduction method, and before the surface is electrically activated, the electrode has a large overpotential, so that the response is slow and the energy consumption is increased. After pretreatment, the electrode surface is activated, so that the original electrode surface with higher stability and reproducibility is obtained. For higher reduction rates and lower costs in the nitrate reduction process, metal oxides are used instead of noble metals.
Disclosure of Invention
The invention aims to provide a preparation method of a composite electrode and application of the composite electrode in nitrate-containing wastewater so as to solve the problems in the prior art.
In order to solve the technical problems, the invention provides the following technical scheme: a preparation method of a composite electrode and application thereof in nitrate-containing wastewater comprise the following steps:
step 1: weighing La (NO) 3 ) 3 ·6H 2 O、Fe(NO 3 ) 3 ·9H 2 O, mixing citric acid as chelating agent and glycol as polycondensation agent in pure water, stirring at room temperature to obtain gel containing rare earth cations and metal cations;
step 2: drying the gel for the first time, and evaporating the water in the gel to enable the material to be in a wet gel state; then the wet gel-like material is dried for the second time to obtain a dry gel-like material;
step 3: grinding the dry gel material, and calcining at high temperature to obtain a powdery material; grinding at high temperatureCalcining for the second time, and cooling to obtain La 0.9 FeO 3 A powder;
step 4: treating a hydrophilic conductive carbon cloth substrate by adopting a wet chemical oxidation method, mixing a nitric acid solution and a sulfuric acid solution to obtain a mixed acid solution, and soaking the carbon cloth in the mixed acid solution;
step 5: la is subjected to 0.9 FeO 3 Mixing powder, ethanol as solvent and Nafion solution for 1 hr, mixing to obtain suspension, dripping the suspension onto carbon cloth substrate, and oven drying to obtain La 0.9 FeO 3 -C composite electrode.
Further, in the step 1, the molar concentration ratio of glycol, citric acid and metal ions in the solution is (7-8): 2-1): 0.95-1; the concentration of the metal ions is 0.2-0.3 mol/L.
Further, in step 1, the metal ions include La Ⅲ And Fe (Fe) Ⅲ ，La Ⅲ And Fe (Fe) Ⅲ The molar concentration ratio is (0.8-0.9): 1.
further, in step 1, the molar concentration ratio of ethylene glycol, citric acid and metal ions in the solution is preferably 8:2:0.95; the metal ion concentration is preferably 0.2375mol/L.
In the step 2, the primary drying temperature is 70-80 ℃ and the time is 10-12 hours; preferably, the drying temperature is 80℃and the drying time is 10 hours.
In the step 2, the secondary drying temperature is 100-120 ℃ and the drying time is 10-12 h; preferably, the drying temperature is 120 ℃ and the drying time is 10 hours.
Further, in the step 3, the primary calcination condition is that the temperature is raised at a rate of 5 ℃/min, the calcination temperature is 300-350 ℃, the preferred temperature is 300 ℃, and the calcination time is 2-3 h, preferably 2h; the secondary calcination condition is that the temperature is raised at a rate of 5 ℃/min, the calcination temperature is 700-750 ℃, the preferred temperature is 700 ℃, and the calcination time is 2-3 h, and the preferred time is 2h.
Further, in the step 4, the mixed acid solution is prepared by mixing nitric acid with the mass concentration of 10% with sulfuric acid with the mass concentration of 10% according to a volume ratio of 3:1, mixing; the soaking time is 20-24 hours, preferably 24 hours.
Further, in the step 5, the drying temperature is 70-80 ℃; preferably 80 ℃.
Further, the La 0.9 FeO 3 The application method of the-C composite electrode comprises the following steps: by La of 0.9 FeO 3 The C composite electrode is used as a cathode, the reticular ruthenium iridium electrode is used as an anode, 50mM sodium sulfate solution is used as electrolyte, and constant current density of 15mA/cm is continuously introduced for 10 hours 2 The composite electrode is activated by direct current. In nitrate-containing wastewater to activate La 0.9 FeO 3 The composite electrode of-C is used as a cathode, a netlike ruthenium iridium electrode is used as an anode, 50mM sodium sulfate solution is used as electrolyte, the distance between the anode and the cathode is controlled to be 0.5-1.5 cm, and 15mA/cm is introduced 2 The direct current carries out electrocatalytic reduction of nitrate, the temperature is 20-30 ℃ and the time is 180min.
Compared with the prior art, the invention has the following beneficial effects: the invention prepares La for the first time 0.9 FeO 3 The C composite electrode can more effectively and rapidly electrically catalyze the reduction of nitrate into nitrogen, and reduce the pollution of nitrate to the environment. The surface of the electrode is treated by current to promote the change of the catalytic active site of nitrate, so that the original electrode surface with high stability and good reproducibility is obtained, and the electrode surface is suitable for removing nitrate in natural water and sewage without regulating pH. The invention precisely controls the microstructure of the catalyst surface through a series of electrochemical parameters, has the characteristics of green, mild, environment-friendly, simple, low-cost, easy operation and the like, has wide raw material sources and low production cost, and is suitable for industrial production.
Drawings
The accompanying drawings are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate the invention and together with the embodiments of the invention, serve to explain the invention. In the drawings:
FIG. 1 is a diagram of La in the present invention 0.9 FeO 3 -C a flow chart for the preparation of the composite electrode;
FIG. 2 is La prepared in example 1 0.9 FeO 3 -C composite electrode electro-active siteXRD patterns before and after the treatment;
FIG. 3 is La 0.9 FeO 3 -C effect graph of electrochemical reduction of nitrate by composite electrode.
Detailed Description
The following description of the embodiments of the present invention will be made clearly and completely with reference to the accompanying drawings, in which it is apparent that the embodiments described are only some embodiments of the present invention, but not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.
The raw materials used in the invention and the sources thereof are as follows:
the carbon cloth substrate is purchased from sandisk science and technology limited, su, model WOS1011; duPont 5% Nafion solution purchased from Sankino technologies Inc., model D520; the mesh ruthenium iridium electrode is made of Yu Mingxuan metal materials, the specification is a diamond hole with the thickness of 1mm and the aperture of 1mm multiplied by 3mm; la (NO) 3 ) 3 ·6H 2 O (CAS number 10277-43-7), fe (NO) 3 ) 3 ·9H 2 O (CAS number 7782-61-8), citric acid (CAS number 77-92-9), ethylene glycol (CAS number 107-21-1), sodium sulfate (CAS number 7757-82-6), nitric acid (CAS number 7697-37-2), sulfuric acid (CAS number 7757-82-6) were all purchased from Ala-dine.
Example 1
(1)La 0.9 FeO 3 Preparation of the powder
2.4300g La (NO) 3 ) 3 ·6H 2 O and 2.5191g Fe (NO) 3 ) 3 ·9H 2 Dissolving O solid powder in 25.0000mL deionized water to obtain a metal nitrate mixed solution, and uniformly stirring at room temperature; at the same time, 5.2500g of citric acid is dissolved in 25.0000mL of deionized water, and after being fully and uniformly stirred, the mixture is poured into the nitrate mixed solution of the metal ions, and the mixture is continuously and fully and uniformly stirred, and then 5.6000mL of ethylene glycol is slowly added. The metal ion concentration is 0.2375mol/L, wherein La (NO 3 ) 3 ·6H 2 The concentration of O is 0.1125mol/L，Fe(NO 3 ) 3 ·9H 2 The concentration of O is 0.1250mol/L; the concentration of the citric acid is 0.5000mol/L; the concentration of ethylene glycol was 2.0000mol/L. Placing the mixed solution in an oven at 80 ℃ for heat preservation for 10 hours to dry all the water to obtain wet gel; drying the wet gel at 120 ℃ for 10 hours to obtain xerogel; grinding the obtained xerogel by using a mortar, and calcining the xerogel in a muffle furnace at 300 ℃ for 2 hours, wherein the temperature rising rate of the muffle furnace is 5 ℃/min; cooling the obtained powdery material, further grinding with a mortar, calcining in a muffle furnace at 700 ℃ for 3 hours, heating the muffle furnace at a speed of 5 ℃/min, and cooling to obtain La 0.9 FeO 3 And (3) powder.
(2) Pretreatment of carbon substrates
The carbon cloth substrate needs to be subjected to a series of pretreatment including cutting, wet chemical oxidation treatment and ultrasonic water washing. Cutting the carbon cloth into squares with side length of 2cm by utilizing tools such as scissors or blades; nitric acid with the mass concentration of 10% and sulfuric acid solution with the mass concentration of 10% are mixed according to the volume ratio of 3:1, soaking the carbon cloth in the mixed solution for 24 hours, and carrying out ultrasonic treatment under the condition of deionized water until the water is clear so as to ensure that no residual nitric acid and sulfuric acid exist.
(3)La 0.9 FeO 3 Preparation of the-C composite electrode
Accurately weighing 0.0030g of La prepared in the step (1) 0.9 FeO 3 Adding 1.2000mL of ethanol solution and 0.0060mL of naphthol solution into the powder, uniformly mixing the suspension for 1 hour, uniformly dripping the suspension on the carbon cloth substrate prepared in the step (2) by using a tool such as a pipette or a dropper, and drying the carbon cloth substrate at 80 ℃.
Example 2
Under the condition of normal temperature and normal pressure, sodium sulfate and sodium nitrate are used as raw materials to simulate the waste water. And 3.57mM sodium nitrate is used as a target pollutant, and 50mM sodium sulfate solution is used as electrolyte solution, so that the simulated wastewater is obtained.
In the present invention, a two-electrode system is used, comprising a piece of cathode and a piece of anode, the anode-to-cathode distance being 1.5cm. To a side length of 2cmLa 0.9 FeO 3 The composite electrode C is used as a cathode, a reticular ruthenium iridium electrode with the side length of 2cm is used as an anode, 50mM sodium sulfate solution is used as electrolyte, and the constant current density is 15mA/cm after 10 hours of continuous feeding 2 The composite electrode is activated by direct current. The activated electrode was placed in 50mL of simulated wastewater to be treated and placed in a reactor. At normal temperature and pressure, the current density is 15mA/cm 2 The direct current performs an electrocatalytic reaction. After 180min of reaction, the reduction rate of nitrate in water can reach 85.6+/-0.6%.
It is noted that relational terms such as first and second, and the like are used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Moreover, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus.
Finally, it should be noted that: the foregoing description is only a preferred embodiment of the present invention, and the present invention is not limited thereto, but it is to be understood that modifications and equivalents of some of the technical features described in the foregoing embodiments may be made by those skilled in the art, although the present invention has been described in detail with reference to the foregoing embodiments. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.
Claims (10)
1. A preparation method of a composite electrode is characterized by comprising the following steps: the method comprises the following steps:
step 1: weighing La (NO) 3 ) 3 ·6H 2 O、Fe(NO 3 ) 3 ·9H 2 O, mixing citric acid as chelating agent and glycol as polycondensation agent in pure water, and roomStirring uniformly at a temperature to obtain gel containing rare earth cations and metal cations;
step 2: drying the gel for the first time, and evaporating the water in the gel to enable the material to be in a wet gel state; then the wet gel-like material is dried for the second time to obtain a dry gel-like material;
step 3: grinding the dry gel material, and calcining for the first time to obtain a powdery material; grinding, calcining again, and cooling to obtain La 0.9 FeO 3 A powder;
step 4: treating a hydrophilic conductive carbon cloth substrate by adopting a wet chemical oxidation method, mixing a nitric acid solution and a sulfuric acid solution to obtain a mixed acid solution, and soaking the carbon cloth in the mixed acid solution;
step 5: la is subjected to 0.9 FeO 3 Mixing powder, ethanol as solvent, nafion solution, and ultrasonic stirring to obtain suspension, dripping the suspension onto carbon cloth substrate, and oven drying to obtain La 0.9 FeO 3 -C composite electrode.
2. The method for preparing a composite electrode according to claim 1, wherein: in the step 1, the molar concentration ratio of glycol, citric acid and metal ions in the solution is (7-8): 2-1): 0.95-1; the concentration of metal ions is 0.2-0.3 mol/L; the metal ion comprises La Ⅲ And Fe (Fe) Ⅲ ，La Ⅲ And Fe (Fe) Ⅲ The molar concentration ratio is (0.8-0.9): 1.
3. the method for preparing a composite electrode according to claim 1, wherein: in the step 2, the primary drying temperature is 70-80 ℃ and the time is 10-12 h; the secondary drying temperature is 100-120 ℃, and the drying time is 10-12 h.
4. The method for preparing a composite electrode according to claim 1, wherein: in the step 3, the primary calcination condition is that the temperature is raised at a speed of 5 ℃/min, the calcination temperature is 300-350 ℃, and the calcination time is 2-3 h; the secondary calcination condition is that the temperature is raised at the speed of 5 ℃/min, the calcination temperature is 700-750 ℃, and the calcination time is 2-3 h.
5. The method for preparing a composite electrode according to claim 1, wherein: in the step 4, the mixed acid solution is prepared by mixing nitric acid and sulfuric acid according to a volume ratio of 3:1, mixing; the soaking time is 20-24 hours.
6. The method for preparing a composite electrode according to claim 1, wherein: in the step 5, the drying temperature is 70-80 ℃.
7. A composite electrode produced by the method for producing a composite electrode according to any one of claims 1 to 6.
8. The use of a composite electrode according to claim 7, wherein: the application method of the activated composite electrode comprises the following steps of adding La into nitrate-containing wastewater 0.9 FeO 3 The C composite electrode is used as a cathode, the netlike ruthenium iridium electrode is used as an anode, the sodium sulfate solution is used as electrolyte, and direct current is introduced to perform electrocatalytic reduction of nitrate.
9. The use of a composite electrode according to claim 8, wherein: the activation method of the composite electrode comprises the following steps: sodium sulfate solution is used as electrolyte, la 0.9 FeO 3 And C, using the composite electrode as a cathode, using a netlike ruthenium iridium electrode as an anode, and continuously introducing direct current to activate the composite electrode.
10. The use of a composite electrode according to claim 8, wherein: the direct current density is 15mA/cm 2 The method comprises the steps of carrying out a first treatment on the surface of the The electrocatalytic reduction temperature is 20-30 ℃ and the time is 180min; the distance between the anode and the cathode is 0.5-1.5 cm.
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Citations (12)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DK209781A (en) * | 1980-05-13 | 1981-11-14 | British Petroleum Co | ELECTRODES PROCEDURE FOR THEIR PREPARATION AND THEIR USE IN ELECTROCHEMICAL CELLS |
| CN1913208A (en) * | 2006-07-17 | 2007-02-14 | 昆明理工大学 | Middle-temp. solid oxide fuel cell system material and its cell and preparation method |
| US20070080061A1 (en) * | 2005-06-21 | 2007-04-12 | Gorte Raymond J | Solid-state electrochemical nox sensors |
| CN103050572A (en) * | 2012-12-06 | 2013-04-17 | 燕山大学 | Perovskite/graphene composite membrane electrode manufacturing method |
| US20200208282A1 (en) * | 2020-01-08 | 2020-07-02 | Jiangsu Provincial Academy Of Environmental Science | Titanium Sub-oxide/Ruthenium Oxide Composite Electrode And Preparation Method And Application Thereof |
| CN111362247A (en) * | 2020-03-12 | 2020-07-03 | 东莞理工学院 | Carbon-coated sodium super-ion conductor Na3Fe2(PO4)3/C composite material and preparation method and application thereof |
| CN112501640A (en) * | 2020-12-10 | 2021-03-16 | 东莞理工学院 | Battery system for converting nitrate wastewater into ammonia |
| US20210309544A1 (en) * | 2020-04-03 | 2021-10-07 | Tongji University | Nitrate removal from water bodies using electrocatalytic hydrogen evolution and catalytic hydrogenation |
| CN113788516A (en) * | 2021-09-27 | 2021-12-14 | 江南大学 | Application of transition metal carbonate nano material in electrocatalytic reduction reaction of nitrate |
| CN114054032A (en) * | 2021-11-23 | 2022-02-18 | 东莞理工学院 | Preparation method and application of strontium perovskite catalytic cathode |
| CN114195228A (en) * | 2021-12-14 | 2022-03-18 | 中南大学 | Wastewater organic pollutant degradation system based on perovskite three-dimensional electrode |
| CN115010217A (en) * | 2022-04-18 | 2022-09-06 | 陕西科技大学 | Preparation method and application of three-dimensional composite electrode for efficiently removing nitrate in water through electro-catalysis |
Patent Citations (12)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DK209781A (en) * | 1980-05-13 | 1981-11-14 | British Petroleum Co | ELECTRODES PROCEDURE FOR THEIR PREPARATION AND THEIR USE IN ELECTROCHEMICAL CELLS |
| US20070080061A1 (en) * | 2005-06-21 | 2007-04-12 | Gorte Raymond J | Solid-state electrochemical nox sensors |
| CN1913208A (en) * | 2006-07-17 | 2007-02-14 | 昆明理工大学 | Middle-temp. solid oxide fuel cell system material and its cell and preparation method |
| CN103050572A (en) * | 2012-12-06 | 2013-04-17 | 燕山大学 | Perovskite/graphene composite membrane electrode manufacturing method |
| US20200208282A1 (en) * | 2020-01-08 | 2020-07-02 | Jiangsu Provincial Academy Of Environmental Science | Titanium Sub-oxide/Ruthenium Oxide Composite Electrode And Preparation Method And Application Thereof |
| CN111362247A (en) * | 2020-03-12 | 2020-07-03 | 东莞理工学院 | Carbon-coated sodium super-ion conductor Na3Fe2(PO4)3/C composite material and preparation method and application thereof |
| US20210309544A1 (en) * | 2020-04-03 | 2021-10-07 | Tongji University | Nitrate removal from water bodies using electrocatalytic hydrogen evolution and catalytic hydrogenation |
| CN112501640A (en) * | 2020-12-10 | 2021-03-16 | 东莞理工学院 | Battery system for converting nitrate wastewater into ammonia |
| CN113788516A (en) * | 2021-09-27 | 2021-12-14 | 江南大学 | Application of transition metal carbonate nano material in electrocatalytic reduction reaction of nitrate |
| CN114054032A (en) * | 2021-11-23 | 2022-02-18 | 东莞理工学院 | Preparation method and application of strontium perovskite catalytic cathode |
| CN114195228A (en) * | 2021-12-14 | 2022-03-18 | 中南大学 | Wastewater organic pollutant degradation system based on perovskite three-dimensional electrode |
| CN115010217A (en) * | 2022-04-18 | 2022-09-06 | 陕西科技大学 | Preparation method and application of three-dimensional composite electrode for efficiently removing nitrate in water through electro-catalysis |
Non-Patent Citations (2)
| Title |
|---|
| 李熔;宋长忠;赵旭;冒冉;: "Pd/rGO/C电极催化还原硝酸盐", 环境工程学报, no. 02, 5 February 2016 (2016-02-05) * |
| 胡桓铭等: "Ｌａ０．９５ＦｅＯ３－δ／Ｃ复合电极制备工艺对 氧还原和氧析出催化性能的影响", 《上海交通大学学报》, 30 September 2021 (2021-09-30), pages 1049 - 1057 * |
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