CN112007677A - Nitrogen-doped iron nanotube, and preparation method and application thereof - Google Patents
Nitrogen-doped iron nanotube, and preparation method and application thereof Download PDFInfo
- Publication number
- CN112007677A CN112007677A CN202010722928.6A CN202010722928A CN112007677A CN 112007677 A CN112007677 A CN 112007677A CN 202010722928 A CN202010722928 A CN 202010722928A CN 112007677 A CN112007677 A CN 112007677A
- Authority
- CN
- China
- Prior art keywords
- nitrogen
- fen
- nanotube
- nitrate
- doped iron
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 title claims abstract description 106
- 239000002071 nanotube Substances 0.000 title claims abstract description 59
- 229910052742 iron Inorganic materials 0.000 title claims abstract description 25
- 238000002360 preparation method Methods 0.000 title abstract description 13
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 claims abstract description 54
- 229910002651 NO3 Inorganic materials 0.000 claims abstract description 46
- NHNBFGGVMKEFGY-UHFFFAOYSA-N Nitrate Chemical compound [O-][N+]([O-])=O NHNBFGGVMKEFGY-UHFFFAOYSA-N 0.000 claims abstract description 46
- 229910052757 nitrogen Inorganic materials 0.000 claims abstract description 29
- 239000011148 porous material Substances 0.000 claims abstract description 7
- 238000005844 autocatalytic reaction Methods 0.000 claims abstract description 5
- 238000000034 method Methods 0.000 claims description 18
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 15
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 claims description 12
- 238000001027 hydrothermal synthesis Methods 0.000 claims description 9
- FAPWRFPIFSIZLT-UHFFFAOYSA-M Sodium chloride Chemical compound [Na+].[Cl-] FAPWRFPIFSIZLT-UHFFFAOYSA-M 0.000 claims description 8
- 239000002033 PVDF binder Substances 0.000 claims description 7
- 229910052799 carbon Inorganic materials 0.000 claims description 7
- 230000003197 catalytic effect Effects 0.000 claims description 7
- 229920002981 polyvinylidene fluoride Polymers 0.000 claims description 7
- PXHVJJICTQNCMI-UHFFFAOYSA-N Nickel Chemical compound [Ni] PXHVJJICTQNCMI-UHFFFAOYSA-N 0.000 claims description 6
- 239000006185 dispersion Substances 0.000 claims description 6
- 238000001035 drying Methods 0.000 claims description 6
- 239000000463 material Substances 0.000 claims description 6
- BASFCYQUMIYNBI-UHFFFAOYSA-N platinum Chemical compound [Pt] BASFCYQUMIYNBI-UHFFFAOYSA-N 0.000 claims description 6
- 238000006243 chemical reaction Methods 0.000 claims description 5
- 229940075397 calomel Drugs 0.000 claims description 4
- 239000006229 carbon black Substances 0.000 claims description 4
- 239000011248 coating agent Substances 0.000 claims description 4
- 238000000576 coating method Methods 0.000 claims description 4
- ZOMNIUBKTOKEHS-UHFFFAOYSA-L dimercury dichloride Chemical compound Cl[Hg][Hg]Cl ZOMNIUBKTOKEHS-UHFFFAOYSA-L 0.000 claims description 4
- 239000007789 gas Substances 0.000 claims description 4
- 150000002505 iron Chemical class 0.000 claims description 4
- VCJMYUPGQJHHFU-UHFFFAOYSA-N iron(3+);trinitrate Chemical compound [Fe+3].[O-][N+]([O-])=O.[O-][N+]([O-])=O.[O-][N+]([O-])=O VCJMYUPGQJHHFU-UHFFFAOYSA-N 0.000 claims description 4
- 230000008569 process Effects 0.000 claims description 4
- 238000000197 pyrolysis Methods 0.000 claims description 4
- 239000011780 sodium chloride Substances 0.000 claims description 4
- WQZGKKKJIJFFOK-GASJEMHNSA-N Glucose Natural products OC[C@H]1OC(O)[C@H](O)[C@@H](O)[C@@H]1O WQZGKKKJIJFFOK-GASJEMHNSA-N 0.000 claims description 3
- 229910021578 Iron(III) chloride Inorganic materials 0.000 claims description 3
- 239000007832 Na2SO4 Substances 0.000 claims description 3
- 239000008103 glucose Substances 0.000 claims description 3
- RBTARNINKXHZNM-UHFFFAOYSA-K iron trichloride Chemical group Cl[Fe](Cl)Cl RBTARNINKXHZNM-UHFFFAOYSA-K 0.000 claims description 3
- 238000002156 mixing Methods 0.000 claims description 3
- 229910052759 nickel Inorganic materials 0.000 claims description 3
- QJGQUHMNIGDVPM-UHFFFAOYSA-N nitrogen group Chemical group [N] QJGQUHMNIGDVPM-UHFFFAOYSA-N 0.000 claims description 3
- 229910052697 platinum Inorganic materials 0.000 claims description 3
- 239000012266 salt solution Substances 0.000 claims description 3
- 229910052938 sodium sulfate Inorganic materials 0.000 claims description 3
- 229920002134 Carboxymethyl cellulose Polymers 0.000 claims description 2
- 239000001768 carboxy methyl cellulose Substances 0.000 claims description 2
- 235000010948 carboxy methyl cellulose Nutrition 0.000 claims description 2
- 239000008112 carboxymethyl-cellulose Substances 0.000 claims description 2
- 239000003792 electrolyte Substances 0.000 claims description 2
- 125000002791 glucosyl group Chemical group C1([C@H](O)[C@@H](O)[C@H](O)[C@H](O1)CO)* 0.000 claims description 2
- 150000003839 salts Chemical class 0.000 claims description 2
- 230000000694 effects Effects 0.000 abstract description 6
- 230000007613 environmental effect Effects 0.000 abstract description 4
- 239000008204 material by function Substances 0.000 abstract description 2
- 230000027756 respiratory electron transport chain Effects 0.000 abstract description 2
- 239000003054 catalyst Substances 0.000 description 20
- 238000006722 reduction reaction Methods 0.000 description 12
- 230000009467 reduction Effects 0.000 description 11
- 239000002351 wastewater Substances 0.000 description 6
- 238000003917 TEM image Methods 0.000 description 4
- 239000000047 product Substances 0.000 description 4
- 230000010757 Reduction Activity Effects 0.000 description 3
- 230000008901 benefit Effects 0.000 description 3
- 239000002041 carbon nanotube Substances 0.000 description 3
- 229910021393 carbon nanotube Inorganic materials 0.000 description 3
- -1 nitrogenous compound Chemical class 0.000 description 3
- 230000035484 reaction time Effects 0.000 description 3
- 238000010531 catalytic reduction reaction Methods 0.000 description 2
- 239000011258 core-shell material Substances 0.000 description 2
- 230000007423 decrease Effects 0.000 description 2
- 238000012851 eutrophication Methods 0.000 description 2
- 239000000203 mixture Substances 0.000 description 2
- 238000012986 modification Methods 0.000 description 2
- 230000004048 modification Effects 0.000 description 2
- 239000002086 nanomaterial Substances 0.000 description 2
- 239000002105 nanoparticle Substances 0.000 description 2
- 238000005554 pickling Methods 0.000 description 2
- 230000001105 regulatory effect Effects 0.000 description 2
- 239000000243 solution Substances 0.000 description 2
- 241000195493 Cryptophyta Species 0.000 description 1
- 239000011865 Pt-based catalyst Substances 0.000 description 1
- 230000002378 acidificating effect Effects 0.000 description 1
- 230000009471 action Effects 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 230000008033 biological extinction Effects 0.000 description 1
- 238000010170 biological method Methods 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 238000000354 decomposition reaction Methods 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 230000006866 deterioration Effects 0.000 description 1
- 238000011161 development Methods 0.000 description 1
- 239000010411 electrocatalyst Substances 0.000 description 1
- 238000002474 experimental method Methods 0.000 description 1
- 239000012467 final product Substances 0.000 description 1
- 229910001385 heavy metal Inorganic materials 0.000 description 1
- 231100000053 low toxicity Toxicity 0.000 description 1
- 239000002082 metal nanoparticle Substances 0.000 description 1
- 239000011943 nanocatalyst Substances 0.000 description 1
- 150000002823 nitrates Chemical class 0.000 description 1
- 229910000510 noble metal Inorganic materials 0.000 description 1
- 235000015097 nutrients Nutrition 0.000 description 1
- 150000002926 oxygen Chemical class 0.000 description 1
- 238000004806 packaging method and process Methods 0.000 description 1
- 102000004169 proteins and genes Human genes 0.000 description 1
- 108090000623 proteins and genes Proteins 0.000 description 1
- 230000009257 reactivity Effects 0.000 description 1
- 238000011160 research Methods 0.000 description 1
- 238000001179 sorption measurement Methods 0.000 description 1
- 241000894007 species Species 0.000 description 1
- 230000000087 stabilizing effect Effects 0.000 description 1
- 239000002352 surface water Substances 0.000 description 1
- 238000012546 transfer Methods 0.000 description 1
- 238000005406 washing Methods 0.000 description 1
Images
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- B01J27/00—Catalysts comprising the elements or compounds of halogens, sulfur, selenium, tellurium, phosphorus or nitrogen; Catalysts comprising carbon compounds
- B01J27/24—Nitrogen compounds
-
- B01J35/23—
-
- B01J35/33—
-
- B01J35/618—
-
- B01J35/633—
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- B01J37/00—Processes, in general, for preparing catalysts; Processes, in general, for activation of catalysts
- B01J37/08—Heat treatment
- B01J37/082—Decomposition and pyrolysis
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- B01J37/00—Processes, in general, for preparing catalysts; Processes, in general, for activation of catalysts
- B01J37/08—Heat treatment
- B01J37/10—Heat treatment in the presence of water, e.g. steam
-
- 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
Abstract
The invention belongs to the field of environment functional materials, and provides a preparation method of a nitrogen-doped iron (FeN) nanotube and an electrocatalysis application thereof. In the nitrogen-doped iron nanotube, FeN active sites are dispersedly encapsulated in a tubular NC shell layer. The preparation method comprises the steps of growing the nitrogen-doped iron nanotube by Fe autocatalysis, and dispersedly encapsulating FeN active sites in a tubular NC shell layer. The FeN nanotube has high specific surface area, large pore volume, wide pore size distribution, high density and high stability of FeN active sites and one-dimensional electron transfer channels; the working electrode prepared from the FeN nanotube has high denitrification performance in the environmental field, the nitrate removal rate can reach 88-96%, and the nitrogen selectivity is 85-91%; high denitrification activity and nitrogen selectivity are still maintained in a wide pH value range and after a plurality of electrocatalysis cycles.
Description
Technical Field
The invention belongs to the field of environment functional materials, and particularly relates to a nitrogen-doped iron nanotube, a preparation method and an electrocatalysis application thereof.
Background
The excessive nutrient-rich oxygen salts such as nitrogen elements in the water body cause excessive propagation of algae and other plankton, and cause serious eutrophication of surface water bodies such as sea, river and river basin, which causes disorder of the water body ecological system, extinction of biological species and formation of a large area of dead water area, and the eutrophication of the water body has become one of the most serious environmental challenges facing the world. NO3 -Is the final product of the decomposition of nitrogenous organic matters through inorganic action, is the most stable nitrogenous compound in an aerobic environment, has high fluidity and high solubility, and is a key link for maintaining nitrogen balance in an ecological system. For effectively reducing NO in water body3 -Content, finding a NO with low cost, effectiveness, convenient operation and wide application range3 -The removal technology becomes an important problem which needs to be solved at present. With the rapid development of multifunctional nano materials, electrocatalytic technology and renewable energy sources (such as wind energy and solar energy) in recent years, the reduction of nano electrocatalytic nitrate into harmless nitrogen is rapidly developing into the most promising denitrification technology capable of replacing the traditional biological method.
Fe has the advantages of rich reserves, low cost, low toxicity and the like, is often used for preparing cathode electro-catalysts, and can effectively replace noble metal nano-catalysts for catalyzing the reduction of nitrates. Fe-based catalyst exhibits high NO due to its excellent electron donating ability3 -Reduction activity, however, the products formed are mostly ammonium ions (NH)4 +) Result in N2The selectivity is poor, and the problems of poor stability and poor acid-base tolerance exist in the electrocatalysis process of the catalyst. Carbon nanotubes are reported as an effective support for dispersing and stabilizing metal nanoparticles due to their unique geometry, significant surface area, and high electrical conductivity. However, Fe supported on the surface of the carbon nanotube is easy to leak in an acidic environment, which results in reduction of active sites of the catalyst and deterioration of catalytic stability.
Disclosure of Invention
The invention provides a method for preparing a denitrification catalyst, which aims at overcoming the defects of high cost, poor nitrate removal performance, low nitrogen selectivity and poor acid-base tolerance of the existing denitrification catalyst. The invention aims to solve the technical problem of providing a nitrogen-doped iron nanotube, which combines the advantages of an electrochemical reduction method, can control the multi-electron transfer of nitrate reduction by adjusting the porous structure of the nanotube, and selectively reduces nitrate in a water body into nitrogen.
In view of the technical problems of the present invention, studies have shown that Fe-C-N formed by doping N and Fe to a carbon nanotube structure can exhibit redox activity and cycle stability comparable to those of Pt-based catalysts. The invention encapsulates the N-doped Fe nano-particles in the nano-tube without influencing NO3 -The reduction performance is improved at the same time2Selectivity, and the FeN nanotube shows high stability and acid-base tolerance in the electrocatalysis process. The invention adopts a Fe autocatalysis method to prepare the FeN nanotube, regulates the growth process of the nanotube by adjusting the gradient Fe doping amount, and prepares the porous FeN nanotube with a larger active interface for electrocatalysis of NO3 -And (4) reducing. The nanotube with high pore structure provides rich nitrate adsorption sites and one-dimensional electron transfer channels, and the high-density FeN active sites provide strong NO3 -The reducing power, the nanotube packaging structure provides effective acid-base tolerance, and the graphitized NC shell layer provides high conductivity. The porous FeN nanotubes of the invention exhibit high NO3 -The reduction performance, high stability and effective acid-base tolerance, and can be specifically applied to the treatment of pickling wastewater and deplating wastewater. The research result of the paper is to reasonably construct the protein with high NO3 -The reduction activity, high cost effectiveness, low environmental impact of FeN nanotubes provides a new direction.
In one aspect, the invention provides a nitrogen-doped iron nanotube, wherein nitrogen-doped iron (FeN) active sites are dispersedly encapsulated in a tubular carbon Nanotube (NC) shell layer.
Preferably, the specific surface area of the FeN nanotube is not less than 1500m2(ii)/g, pore volume of not less than 0.2cm3/g。
The invention provides a preparation method of the nitrogen-doped iron nanotube, wherein the nitrogen-doped iron nanotube grows by Fe autocatalysis, and FeN active sites are dispersedly encapsulated in a tubular NC shell layer, and the preparation method comprises the following specific steps:
(1) putting a nitrogen source and a carbon source into water, uniformly mixing to form a uniform dispersion system, and adding a ferric salt solution with the weight percentage of 5-35% into the uniform dispersion system to carry out hydrothermal reaction, wherein: nitrogen source: the molar ratio of the carbon source to the ferric salt is (0.4-1.0) to (2.2-3.6) to (0.4-2.0), the temperature of the hydrothermal reaction is controlled to be 120-160 ℃, and the time of the hydrothermal reaction is 6-12 h;
(2) drying the product obtained in step (1), for example in an oven; then placing the mixture into a tubular furnace for roasting, wherein the pyrolysis atmosphere is nitrogen, the gas flow rate is 90-120mL/min, and pyrolyzing the mixture for 1-4h at 400-1200 ℃ to react to obtain the FeN nanotube.
For example, the weight percentage of the iron salt solution is 5-30%, 20-35%, 25-35%, etc., such as 5, 10, 15, 20, 25, 30, 35%, etc.
Nitrogen source in step (1): the molar ratio of carbon source to iron salt may be adjusted within the range of (0.4-1.0) to (2.2-3.6) to (0.4-2.0), for example, 1: 5: 1,1: 5: 3,1: 5: 5,1: 4: 2,1: 4: 3,1: 4: 4,1: 3: 1,1: 3: 2,1: 3: 3,2: 5: 1,2: 6: 3, and so on.
The temperature and time of the hydrothermal reaction in step (1) may be adjusted together, for example, the temperature and time of the hydrothermal reaction are 120 ℃ and 8 hours, 120 ℃ and 10 hours, 120 ℃ and 12 hours, 130 ℃ and 10 hours, 140 ℃ and 8 hours, 140 ℃ and 12 hours, 150 ℃ and 8 hours, 160 ℃ and 10 hours, and the like, respectively.
Preferably, the temperature range for drying in step (2) is 80-140 ℃. E.g., 80, 90, 95, 100, 102, 105, 110, 115, 120, 125, 130, 135, 140 ℃, etc.
The gas flow rate of the pyrolysis gas in the step (2) can be adjusted according to actual conditions, for example, 90, 92, 100, 103, 105, 108, 110, 112, 113, 115, 118, 120mL/min, and the like are adopted.
In step (2), the pyrolysis reaction temperature and time can be 400-1200 ℃ and 1-4h, respectively, and the time required for higher temperature is generally shorter, for example, 400 ℃ is preferably used for 4h, 800 ℃ can be used for 2-3h, 1000 ℃ can be used for 3, 3.5 or 4h, etc.
Preferably, the iron salt is ferric chloride or ferric nitrate.
Preferably, the carbon source is glucose or carboxymethyl cellulose.
In a preferred embodiment of the invention, the nitrogen source is g-C3N4。
On the other hand, the invention provides the application of the nitrogen-doped iron nanotube in electrocatalytic denitrification, namely coating a FeN nanotube catalyst, carbon black and polyvinylidene fluoride (PVDF) on a nickel screen (0.6-1.2cm) x (0.6-1.2cm) to prepare a working electrode according to the mass-volume ratio of (1-4mg) to (0.3-0.6mg) to (30-70 mu L), and forming a three-electrode system by taking a platinum electrode as a counter electrode and a calomel electrode as a reference electrode; the three-electrode system is placed in a water body containing nitrate for denitrification treatment.
The FeN nanotube catalytic material can be a FeN nanotube. The addition amount of Fe is selected, preferably, 20-35% of the mass of the FeN nanotube, for example, 25%, 30%, 35%, and the like.
In the present invention, the FeN nanotube catalytic material, carbon black and polyvinylidene fluoride (PVDF) may be in the ratio of (1-4mg) to (0.3-0.6mg) to (30-70. mu.L). For example, the ratio of the three is 1mg:0.3mg: 30. mu.L, 1mg:0.3mg: 60 μ L, 1mg:0.4mg:30 μ L, 1mg:0.6mg:50 μ L, 3mg:0.3mg:40 μ L, 1mg:0.1mg:10 μ L, 1mg:0.2mg:20 μ L, 1mg:0.25mg:15 μ L, 2mg:0.3mg:35 μ L, and so forth.
Preferably, the concentration of the nitrate in the nitrate-containing water body is 20-100 mgN/L. For example, 20, 40, 50, 60, 80, 85, 90mgN/L, etc. are used.
Preferably, the water contains Na2SO4And NaCl. Wherein Na2SO4The concentration of (A) is 0.05-0.2 mol/L. E.g., 0.07, 0.10, 0.11, 0.12, 0.14, 0.15, 0.18, 0.20mol/L, etc.; aCl at a concentration of 0.02-0.12mol/L, e.g., 0.02, 0.04, 0.06, 0.08, 0.10, 0.12mol/L, etc。
Preferably, the applied voltage is from-1.1 to-1.8V, e.g., -1.1, -1.3, -1.4, -1.5, -1.6, -1.7 volts, and so on.
Preferably, the denitrification time is 1-20 h. E.g., 1, 4, 6, 8, 10, 12, 13, 15, 17, 19 hours, etc.
The invention has the following beneficial effects:
the invention provides a preparation method of a nitrogen-doped iron nanotube, which not only grows a FeN nanotube by Fe autocatalysis, but also is NO3 -The reduction of (a) provides electrons, and improves the reactivity, stability and acid-base tolerance of the catalyst. By adjusting the Fe doping amount (5, 15, 25 and 35 percent), the porous structure and the specific surface area of the catalyst can be regulated and controlled, and the NO can be further regulated and catalyzed3 -The electron-donating capability of reduction is improved, and the target product N is improved2Selectivity of (a); the FeN nanotube has high specific surface area (2245 m)2Per g), large pore volume (0.4 cm)3/g), broad pore size distribution, high density of FeN active sites, and one-dimensional electron transport channels, thereby modulating N2Selectivity (91%) and NO3 -Removal (96%); the FeN-25 still maintains high electrocatalytic reduction activity and N after a plurality of continuous electrocatalytic cycles in the pH range of 5-112The selectivity shows that the nanotube wrapping structure can effectively protect FeN active sites, and greatly enhances the cycle stability and the acid-base tolerance of the nanotube catalyst; the FeN nano tube constructed by the invention shows high NO3 -The reduction activity, high nitrogen selectivity, high stability and effective acid-base tolerance, and simultaneously has high cost benefit and low environmental impact, and can be specifically applied to the treatment of pickling wastewater and deplating wastewater. The high denitrification activity and nitrogen selectivity are still maintained in a wide pH value range and after multiple electrocatalysis cycles, and the nanotube catalyst has effective acid-base tolerance and high cycle stability.
Drawings
FIG. 1 is a TEM image of FeN-5 in example 1 of the present invention.
FIG. 2 is a TEM image of FeN-15 in example 1 of the present invention.
FIG. 3 is a TEM image of FeN-25 in example 1 of the present invention.
FIG. 4 is a TEM image of FeN-35 in example 1 of the present invention.
Fig. 5 shows the nitrate removal rate and nitrogen selectivity of FeN-X (X ═ 5, 15, 25, 35) and NC in example 1 of the present invention.
Fig. 6 is a plot of FeN-X (X ═ 5, 15, 25, 35) and NC over time for the reduction of nitrate at different concentrations catalyzed by example 1 of the invention.
FIG. 7 is a graph showing the time course of FeN-25 catalyzing the reduction of nitrate with different concentrations in example 1 of the present invention.
FIG. 8 is a graph showing the effect of pH on the nitrate removal rate and nitrogen selectivity of FeN-25 in example 1 of the present invention.
Detailed Description
The present invention is further illustrated by the following examples, which are intended to be illustrative of the invention and are not to be construed as limiting the invention.
Example 1
1. The preparation method of the nitrogen-doped iron nanotube comprises the following specific steps:
(1) g to C3N4Adding (0.8mol) and glucose (3.4mol) into water, uniformly mixing to form a uniform dispersion system, adding a ferric chloride (1.2mol) solution into the uniform dispersion system, carrying out ultrasonic reaction for 3h, moving into a hydrothermal reaction kettle, reacting for 12h at 120 ℃, repeatedly centrifuging, washing, and drying in a vacuum oven at 80 ℃ for 6 h.
(2) And (2) pyrolyzing the product obtained in the step (1) in a tubular furnace in nitrogen (80mL/min) atmosphere at the high temperature of 800 ℃ for 2h to obtain the core-shell FeN nanotube catalytic material.
2. The obtained nuclear shell nitrogen-doped iron metal nano material is applied to electrocatalytic denitrification
Coating the FeN nanotube catalytic material (2mg) of carbon black and polyvinylidene fluoride (PVDF) on a nickel screen (1.2cm multiplied by 1cm) according to the weight ratio of 8:1:1, respectively drying at 60 ℃ and 120 ℃ for 6h and 10h to prepare a working electrode, taking a platinum electrode as a counter electrode, and calomel as a calomel electrodeThe electrode is a reference electrode to form a three-electrode system. The system is placed in a mixed electrolyte Na with the initial concentration of nitrate of 50mgN/L2SO4And 20mL of a reaction solution containing NaCl at concentrations of 0.1mol/L and 0.05mol/L, respectively. After the electrocatalytic reaction for 9 hours, the selectivity of the nitrogen is 98 percent, and the removal rate of the nitrate is 96 percent.
As can be seen from FIG. 1, FeN-5 has a core-shell structure.
As can be seen in FIG. 2, FeN-15 forms a prototype structure of nanotubes.
As can be seen from FIG. 3, a nanotube structure is grown from FeN-25, and Fe active sites are dispersedly encapsulated in the nanotube.
As can be seen from FIG. 4, the Fe nanoparticles in the FeN-35 nanotubes are aggregated.
As can be seen from fig. 5, the prepared FeN-25 nanotubes exhibited the highest nitrogen selectivity and nitrate removal rate with the increase of the Fe doping amount.
As can be seen from FIG. 6, the removal efficiency of the catalyst for nitrate is gradually increased with the increase of the Fe doping amount in the FeN catalyst, and the FeN-25 has the highest cost performance.
As can be seen from fig. 7, as the nitrate concentration decreases, the time required to remove nitrate gradually decreases, indicating that the catalyst has more efficient removal performance for low concentrations of nitrate.
As can be seen from FIG. 8, FeN-25 still maintains high electrocatalytic activity and N in the pH range of 5 to 112And selectivity shows that the FeN nanotube has high acid-base tolerance.
Example 2
The method for preparing the nitrogen-doped iron nanotube and catalytically reducing nitrate was as in example 1, except that the doping amount of Fe during the preparation of the FeN catalyst was 5 wt%, the nitrogen selectivity of the prepared catalyst FeN-5 was 50%, and the removal rate of nitrate was 62%.
Example 3
The method for preparing the nitrogen-doped iron nanotube and catalytically reducing nitrate was as in example 1, except that the doping amount of Fe was 35 wt% during the preparation of the FeN catalyst, the nitrogen selectivity of the prepared catalyst FeN-35 was 86%, and the removal rate of nitrate was 91%.
Example 4
The preparation of the nitrogen-doped iron nanotube and the method for catalytic reduction of nitrate are as in example 1, except that the initial concentration of nitrate is 100mgN/L, the reaction time is 18h, the nitrogen selectivity of the prepared FeN-25 catalyst is 91%, and the removal rate of nitrate is 94%.
Example 5
The preparation of the nitrogen-doped iron nanotube and the method for catalytic reduction of nitrate are as in example 1, except that the system selects the nitrate with the concentration of 20mgN/L, the coating amount of the nano catalytic material is 5mg, the reaction time is 3h, the nitrogen selectivity of the prepared FeN-25 catalyst is 97%, and the removal rate of the nitrate is 100%.
Example 6
The method for preparing the nitrogen-doped iron nanotube and catalytically reducing the nitrate is as in example 1, except that the system selects a deplating wastewater sample for an electro-catalytic denitrification experiment, firstly, nano zero-valent iron is used for removing heavy metals in the wastewater sample, then, the concentration of the nitrate is diluted to 40mgN/L, the pH value is adjusted to be close to 5, the reaction time is 4 hours, the nitrogen selectivity of the prepared FeN-25 catalyst is 90%, and the removal rate of the nitrate is 100%.
The embodiments described above are presented to enable a person having ordinary skill in the art to make and use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without the use of the inventive faculty. Therefore, the present invention is not limited to the embodiments described herein, and those skilled in the art should make improvements and modifications within the scope of the present invention based on the disclosure of the present invention.
Claims (10)
1. The nitrogen-doped iron nanotube is characterized in that FeN active sites are dispersedly encapsulated in a tubular NC shell layer.
2. The method of claim 1The nitrogen-doped iron nanotube is characterized in that the specific surface area of the FeN nanotube is not less than 1500m2Per g, pore volume not less than 0.2cm3/g。
3. The method for preparing the nitrogen-doped iron nanotube of claim 1, wherein the nitrogen-doped iron nanotube is grown by Fe autocatalysis, and the FeN active sites are dispersedly encapsulated in the tubular NC shell layer, and the method comprises the following specific steps:
(1) putting a nitrogen source and a carbon source into water, uniformly mixing to form a uniform dispersion system, and adding a ferric salt solution with the weight percentage of 5-35% into the uniform dispersion system to carry out hydrothermal reaction, wherein: nitrogen source: the molar ratio of the carbon source to the ferric salt is (0.4-1.0) to (2.2-3.6) to (0.4-2.0), the temperature of the hydrothermal reaction is controlled to be 120-160 ℃, and the time of the hydrothermal reaction is 6-12 h;
(2) and (2) drying the product obtained in the step (1), then placing the product in a tubular furnace for roasting, wherein the pyrolysis atmosphere is nitrogen, the gas flow rate is 90-120mL/min, and pyrolyzing the product at 400-1200 ℃ for 1-4h for reaction to obtain the FeN nanotube.
4. The method according to claim 3, wherein the drying temperature in the step (2) is in the range of 80 to 140 ℃.
5. The method according to claim 3, wherein the iron salt is ferric chloride or ferric nitrate.
6. The method according to claim 3, wherein the carbon source is glucose or carboxymethyl cellulose.
7. The process according to claim 3, wherein the nitrogen source is g-C3N4。
8. The use of the nitrogen-doped iron nanotubes of claim 1 in electrocatalytic denitrification, wherein: coating a FeN nanotube catalytic material, carbon black and polyvinylidene fluoride on a nickel screen according to the mass volume ratio of (1-4mg) to (0.3-0.6mg) to (30-70 mu L) to prepare a working electrode, and forming a three-electrode system by using a platinum electrode as a counter electrode and a calomel electrode as a reference electrode; the three-electrode system is placed in a water body containing nitrate for denitrification treatment.
9. Use according to claim 8, characterized in that: the concentration of the nitrate in the water containing the nitrate is 0-100 mgN/L.
10. Use according to claim 8, characterized in that: the nitrate-containing water body also contains mixed electrolyte, wherein Na2SO4The concentration of the sodium chloride is 0.05-0.2mol/L, the concentration of NaCl is 0.02-0.12mol/L, the applied voltage is-1.1-1.8V, and the denitrification time is 1-20 h.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010722928.6A CN112007677A (en) | 2020-07-24 | 2020-07-24 | Nitrogen-doped iron nanotube, and preparation method and application thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010722928.6A CN112007677A (en) | 2020-07-24 | 2020-07-24 | Nitrogen-doped iron nanotube, and preparation method and application thereof |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN112007677A true CN112007677A (en) | 2020-12-01 |
Family
ID=73499619
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202010722928.6A Pending CN112007677A (en) | 2020-07-24 | 2020-07-24 | Nitrogen-doped iron nanotube, and preparation method and application thereof |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN112007677A (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113233551A (en) * | 2021-05-20 | 2021-08-10 | 燕山大学 | Preparation method of catalytic reduction nitrate electrode and resource utilization technology thereof |
| CN114436371A (en) * | 2022-01-25 | 2022-05-06 | 中南大学 | Vanadium-titanium magnetite-based electrode and preparation method and application thereof |
| CN116371446A (en) * | 2023-04-19 | 2023-07-04 | 中国科学院生态环境研究中心 | Iron-nitrogen compound-carbon nano tube composite material, preparation method and application |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105355934A (en) * | 2015-10-31 | 2016-02-24 | 哈尔滨工业大学 | Preparation method of nitrogen-doped carbon nanotubes |
| KR20170088145A (en) * | 2016-01-22 | 2017-08-01 | 한국과학기술연구원 | Method of preparing non-platinum catalyst for fuel cell |
| CN108339562A (en) * | 2018-02-11 | 2018-07-31 | 济南大学 | A kind of preparation method and products obtained therefrom of the azotized carbon nano pipe of iron ion doping |
| CN108493461A (en) * | 2018-05-08 | 2018-09-04 | 大连理工大学 | A kind of N adulterates the catalyst and preparation method thereof of porous carbon coating Fe, Co bimetal nano particles |
| CN110465319A (en) * | 2019-08-23 | 2019-11-19 | 江西夏氏春秋环境股份有限公司 | A kind of preparation method and application of the copper palladium bimetal nano catalysis material of N doping |
-
2020
- 2020-07-24 CN CN202010722928.6A patent/CN112007677A/en active Pending
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105355934A (en) * | 2015-10-31 | 2016-02-24 | 哈尔滨工业大学 | Preparation method of nitrogen-doped carbon nanotubes |
| KR20170088145A (en) * | 2016-01-22 | 2017-08-01 | 한국과학기술연구원 | Method of preparing non-platinum catalyst for fuel cell |
| CN108339562A (en) * | 2018-02-11 | 2018-07-31 | 济南大学 | A kind of preparation method and products obtained therefrom of the azotized carbon nano pipe of iron ion doping |
| CN108493461A (en) * | 2018-05-08 | 2018-09-04 | 大连理工大学 | A kind of N adulterates the catalyst and preparation method thereof of porous carbon coating Fe, Co bimetal nano particles |
| CN110465319A (en) * | 2019-08-23 | 2019-11-19 | 江西夏氏春秋环境股份有限公司 | A kind of preparation method and application of the copper palladium bimetal nano catalysis material of N doping |
Non-Patent Citations (3)
| Title |
|---|
| JING WANG ET AL.: "Nitrogen-doped iron for selective catalytic reduction of nitrate to dinitrogen", 《SCIENCE BULLETIN》 * |
| YUE LAN ET AL.: "Fe/Fe3C nanoparticle-decorated N-doped carbon nanofibers for improving the nitrogen selectivity of electrocatalytic nitrate reduction", 《JOURNAL OF MATERIALS CHEMISTRY A》 * |
| ZHAN XU ET AL.: "Pea-like Fe/Fe3C Nanoparticles Embedded in Nitrogen-Doped Carbon Nanotubes with Tunable Dielectric/Magnetic Loss and Efficient Electromagnetic Absorption", 《ACS APPLIED MATERIALS & INTERFACES》 * |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113233551A (en) * | 2021-05-20 | 2021-08-10 | 燕山大学 | Preparation method of catalytic reduction nitrate electrode and resource utilization technology thereof |
| CN114436371A (en) * | 2022-01-25 | 2022-05-06 | 中南大学 | Vanadium-titanium magnetite-based electrode and preparation method and application thereof |
| CN114436371B (en) * | 2022-01-25 | 2023-10-03 | 中南大学 | Vanadium titano-magnetite-based electrode and preparation method and application thereof |
| CN116371446A (en) * | 2023-04-19 | 2023-07-04 | 中国科学院生态环境研究中心 | Iron-nitrogen compound-carbon nano tube composite material, preparation method and application |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN112007677A (en) | Nitrogen-doped iron nanotube, and preparation method and application thereof | |
| CN110479329B (en) | Preparation and application of phosphorus-doped cobalt telluride nano material | |
| CN111992233A (en) | Core-shell nitrogen-doped iron metal nanoparticle, preparation method and electrocatalysis application thereof | |
| CN111036247B (en) | Cobalt-iron oxide-cobalt phosphate electrocatalytic oxygen evolution composite material and preparation method and application thereof | |
| CN110975899B (en) | Preparation method and application of cobalt phosphide nanosheet composite material with carbon particle intercalation | |
| CN109675632A (en) | A kind of carbon-based ZIF composite catalyst and preparation method thereof and the application in electro-catalysis reduction carbon dioxide reaction | |
| CN113385203A (en) | Preparation method of core-shell structure bimetal phosphide nano-array | |
| CN113373471B (en) | For electrocatalytic reduction of CO2Preparation method and application of indium-based catalyst for preparing low-carbon alcohol | |
| CN111498952B (en) | Porous carbon iron-nickel alloy foam nickel electrode and preparation method and application thereof | |
| CN111282588A (en) | Catalyst for hydrogen evolution by electrolyzing water and preparation method and application thereof | |
| CN110400939A (en) | A kind of preparation method of biomass nitrating porous carbon oxygen reduction catalyst | |
| CN113896299B (en) | electro-Fenton reaction cathode material of ferromanganese layered double metal hydroxide loaded biochar, and preparation method and application thereof | |
| Zhang et al. | Melamine-assisted synthesis of paper mill sludge-based carbon nanotube/nanoporous carbon nanocomposite for enhanced electrocatalytic oxygen reduction activity | |
| CN112919593B (en) | Preparation method of graphene-coated cobalt Prussian blue nanocrystalline composite material, method for preparing working electrode by using graphene-coated cobalt Prussian blue nanocrystalline composite material and application of graphene-coated cobalt Prussian blue nanocrystalline composite material | |
| CN110071300B (en) | Preparation method of transition metal/nitrogen-doped carbon fiber electrocatalyst | |
| CN111330620A (en) | Intercalation type graphite-like carbon nitride composite material, preparation method and application thereof | |
| CN111068717A (en) | Ruthenium simple substance modified sulfur-doped graphene two-dimensional material and preparation and application thereof | |
| CN113054209A (en) | Directly-grown carbon nanotube-based non-noble metal fuel cell catalyst and preparation method thereof | |
| CN110902770A (en) | Fe based on carbon cloth3O4/C, Fe/C, preparation and application thereof | |
| CN114725328B (en) | Nitrogen-doped biomass-derived porous carbon-loaded Fe 3 O 4 Fe composite material, preparation method and application thereof | |
| CN110010912A (en) | A kind of catalyst of fuel cell and its preparation method and application | |
| CN115180690A (en) | Nitrogen-doped graphene-coated metal copper nano-catalyst and preparation method thereof | |
| CN114744220A (en) | In-situ S-doped Fe-NxPreparation method and application of modified mesoporous carbon-oxygen reduction catalyst | |
| CN108911048B (en) | Preparation method of multi-scale salient point electrode | |
| CN113502497A (en) | Electrocatalyst with low-temperature plasma regulation and control performance and preparation method and application thereof |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| WD01 | Invention patent application deemed withdrawn after publication |
Application publication date: 20201201 |
|
| WD01 | Invention patent application deemed withdrawn after publication |