CN115254173B - Graphite-phase carbon nitride photocatalyst, and preparation method, system and application thereof - Google Patents
Graphite-phase carbon nitride photocatalyst, and preparation method, system and application thereof Download PDFInfo
- Publication number
- CN115254173B CN115254173B CN202211049603.1A CN202211049603A CN115254173B CN 115254173 B CN115254173 B CN 115254173B CN 202211049603 A CN202211049603 A CN 202211049603A CN 115254173 B CN115254173 B CN 115254173B
- Authority
- CN
- China
- Prior art keywords
- graphite
- carbon nitride
- phase carbon
- photocatalyst
- dispersion liquid
- 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.)
- Active
Links
- JMANVNJQNLATNU-UHFFFAOYSA-N oxalonitrile Chemical compound N#CC#N JMANVNJQNLATNU-UHFFFAOYSA-N 0.000 title claims abstract description 156
- 239000011941 photocatalyst Substances 0.000 title claims abstract description 62
- 238000002360 preparation method Methods 0.000 title claims abstract description 18
- 238000006243 chemical reaction Methods 0.000 claims abstract description 77
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims abstract description 75
- 230000001699 photocatalysis Effects 0.000 claims abstract description 27
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 claims abstract description 25
- 239000001257 hydrogen Substances 0.000 claims abstract description 25
- 229910052739 hydrogen Inorganic materials 0.000 claims abstract description 25
- 238000004519 manufacturing process Methods 0.000 claims abstract description 20
- 239000006185 dispersion Substances 0.000 claims description 73
- 239000007788 liquid Substances 0.000 claims description 66
- 238000000034 method Methods 0.000 claims description 12
- GSEJCLTVZPLZKY-UHFFFAOYSA-N Triethanolamine Chemical compound OCCN(CCO)CCO GSEJCLTVZPLZKY-UHFFFAOYSA-N 0.000 claims description 7
- 239000003054 catalyst Substances 0.000 claims description 6
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 abstract description 54
- 229910002804 graphite Inorganic materials 0.000 abstract description 52
- 239000010439 graphite Substances 0.000 abstract description 52
- 230000004048 modification Effects 0.000 abstract description 14
- 238000012986 modification Methods 0.000 abstract description 14
- 230000000694 effects Effects 0.000 abstract description 11
- 230000035484 reaction time Effects 0.000 abstract description 9
- 238000012360 testing method Methods 0.000 abstract description 3
- 238000001816 cooling Methods 0.000 description 23
- 230000000052 comparative effect Effects 0.000 description 13
- 230000001276 controlling effect Effects 0.000 description 11
- 238000001228 spectrum Methods 0.000 description 11
- 238000005485 electric heating Methods 0.000 description 10
- 238000001914 filtration Methods 0.000 description 10
- 238000001035 drying Methods 0.000 description 9
- 238000005086 pumping Methods 0.000 description 9
- 238000003860 storage Methods 0.000 description 9
- 238000000354 decomposition reaction Methods 0.000 description 8
- 238000005406 washing Methods 0.000 description 8
- 238000001027 hydrothermal synthesis Methods 0.000 description 7
- 238000002156 mixing Methods 0.000 description 7
- 239000000243 solution Substances 0.000 description 5
- 238000010586 diagram Methods 0.000 description 4
- 238000010438 heat treatment Methods 0.000 description 4
- 238000010335 hydrothermal treatment Methods 0.000 description 4
- 239000000463 material Substances 0.000 description 4
- 238000011084 recovery Methods 0.000 description 4
- 239000002270 dispersing agent Substances 0.000 description 3
- 239000012530 fluid Substances 0.000 description 3
- 125000000524 functional group Chemical group 0.000 description 3
- 230000007246 mechanism Effects 0.000 description 3
- 239000002245 particle Substances 0.000 description 3
- 238000010008 shearing Methods 0.000 description 3
- QGZKDVFQNNGYKY-UHFFFAOYSA-N Ammonia Chemical compound N QGZKDVFQNNGYKY-UHFFFAOYSA-N 0.000 description 2
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 2
- 229910052799 carbon Inorganic materials 0.000 description 2
- 230000003197 catalytic effect Effects 0.000 description 2
- 239000011259 mixed solution Substances 0.000 description 2
- 229910052757 nitrogen Inorganic materials 0.000 description 2
- 229910052760 oxygen Inorganic materials 0.000 description 2
- 239000011148 porous material Substances 0.000 description 2
- 239000000843 powder Substances 0.000 description 2
- 230000008569 process Effects 0.000 description 2
- OWYWGLHRNBIFJP-UHFFFAOYSA-N Ipazine Chemical group CCN(CC)C1=NC(Cl)=NC(NC(C)C)=N1 OWYWGLHRNBIFJP-UHFFFAOYSA-N 0.000 description 1
- 238000002441 X-ray diffraction Methods 0.000 description 1
- 230000009471 action Effects 0.000 description 1
- 239000007864 aqueous solution Substances 0.000 description 1
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 238000009835 boiling Methods 0.000 description 1
- 239000000470 constituent Substances 0.000 description 1
- 239000000356 contaminant Substances 0.000 description 1
- 230000007797 corrosion Effects 0.000 description 1
- 238000005260 corrosion Methods 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 230000032798 delamination Effects 0.000 description 1
- 238000009792 diffusion process Methods 0.000 description 1
- 238000011156 evaluation Methods 0.000 description 1
- 238000002474 experimental method Methods 0.000 description 1
- 239000007789 gas Substances 0.000 description 1
- 229910001385 heavy metal Inorganic materials 0.000 description 1
- 239000012535 impurity Substances 0.000 description 1
- 150000002500 ions Chemical class 0.000 description 1
- 231100000956 nontoxicity Toxicity 0.000 description 1
- 230000003647 oxidation Effects 0.000 description 1
- 238000007254 oxidation reaction Methods 0.000 description 1
- 239000001301 oxygen Substances 0.000 description 1
- 238000007146 photocatalysis Methods 0.000 description 1
- 238000013033 photocatalytic degradation reaction Methods 0.000 description 1
- 238000013032 photocatalytic reaction Methods 0.000 description 1
- 239000002994 raw material Substances 0.000 description 1
- 238000005215 recombination Methods 0.000 description 1
- 230000006798 recombination Effects 0.000 description 1
- 230000009467 reduction Effects 0.000 description 1
- 230000001105 regulatory effect Effects 0.000 description 1
- 229920006395 saturated elastomer Polymers 0.000 description 1
- 239000010865 sewage Substances 0.000 description 1
- 229910001220 stainless steel Inorganic materials 0.000 description 1
- 239000010935 stainless steel Substances 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- 238000006557 surface reaction Methods 0.000 description 1
- 238000010998 test method Methods 0.000 description 1
- BFKJFAAPBSQJPD-UHFFFAOYSA-N tetrafluoroethene Chemical group FC(F)=C(F)F BFKJFAAPBSQJPD-UHFFFAOYSA-N 0.000 description 1
- 239000002351 wastewater Substances 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
-
- B01J35/39—
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
- C01B3/00—Hydrogen; Gaseous mixtures containing hydrogen; Separation of hydrogen from mixtures containing it; Purification of hydrogen
- C01B3/02—Production of hydrogen or of gaseous mixtures containing a substantial proportion of hydrogen
- C01B3/04—Production of hydrogen or of gaseous mixtures containing a substantial proportion of hydrogen by decomposition of inorganic compounds, e.g. ammonia
- C01B3/042—Decomposition of water
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
- C01B2203/00—Integrated processes for the production of hydrogen or synthesis gas
- C01B2203/02—Processes for making hydrogen or synthesis gas
- C01B2203/0266—Processes for making hydrogen or synthesis gas containing a decomposition step
- C01B2203/0277—Processes for making hydrogen or synthesis gas containing a decomposition step containing a catalytic decomposition step
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
- C01B2203/00—Integrated processes for the production of hydrogen or synthesis gas
- C01B2203/10—Catalysts for performing the hydrogen forming reactions
- C01B2203/1041—Composition of the catalyst
- C01B2203/1088—Non-supported catalysts
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
- Y02E60/30—Hydrogen technology
- Y02E60/36—Hydrogen production from non-carbon containing sources, e.g. by water electrolysis
Abstract
The invention discloses a graphite-phase carbon nitride photocatalyst, a preparation method, a system and application thereof. The invention carries out continuous rapid hydrothermal modification on graphite phase carbon nitride based on a continuous reaction system, the modification time is between (25.2 and 50.3) s, and the test result of photocatalytic water splitting hydrogen production shows that the activity is improved by 5.2 times compared with that before modification, and the invention has the advantages of short reaction time and good performance of graphite phase carbon nitride photocatalyst.
Description
Technical Field
The invention belongs to the technical field of hydrogen production by photocatalytic water splitting, and particularly relates to a graphite phase carbon nitride photocatalyst, and a preparation method, a system and application thereof.
Background
Graphite phase carbon nitride (g-C) 3 N 4 ) The photocatalyst with visible light photocatalytic reaction activity has the advantages of good thermal/chemical stability, no toxicity, no pollution and the like, and is widely studied in the application fields of photocatalytic decomposition of water, photocatalytic degradation of organic wastewater, photocatalytic reduction of heavy metal ions and the like. In g-C 3 N 4 In applications for removing organic contaminants, due to pure g-C 3 N 4 The specific surface area is small, the visible light utilization efficiency is low, the conductivity is low, the photon-generated carrier recombination efficiency is high, the number of interface (photo) reaction active sites is small, the surface reaction kinetics speed is slow, the oxidation capability is moderate, and the catalytic activity is low. Thus, it is necessary to pass through the pair g-C 3 N 4 Targeted toModified to enhance its photocatalytic properties.
In a number of modification processes, the modification is carried out on g-C 3 N 4 Hydrothermal post-treatment is an effective and green method. Wherein g-C 3 N 4 Dispersing in pure water for hydrothermal treatment, and modifying to obtain g-C 3 N 4 The photocatalyst has more excellent photocatalytic activity mainly because of (1) the large increase of the specific surface area; (2) g-C 3 N 4 Carbon and nitrogen vacancies; (3) the introduction of surface oxygen-containing functional groups. The above hydrothermal treatment is usually carried out in a sealed tetrafluoroethylene lining, the hydrothermal temperature is usually 100-190 ℃, the treatment time is usually 6-8 hours, and the higher the hydrothermal temperature is, the longer the time is g-C 3 N 4 The lower the yield.
Disclosure of Invention
The invention aims to solve the technical problem of providing a graphite phase carbon nitride photocatalyst, and a preparation method, a system and application thereof, aiming at the defects of the prior art. The invention modifies graphite phase carbon nitride based on rapid high-temperature hydrothermal reaction of a continuous reaction system to obtain the graphite phase carbon nitride photocatalyst, and has the advantages of short modification time, high reaction temperature, less decomposition of graphite phase carbon nitride and good photocatalyst performance.
In order to solve the technical problems, the invention adopts the following technical scheme:
a preparation method of a graphite-phase carbon nitride photocatalyst comprises the following steps:
dispersing graphite-phase carbon nitride in water to obtain graphite-phase carbon nitride dispersion liquid;
adding the graphite-phase carbon nitride dispersion liquid and preheated water into a reaction zone, and reacting for 25.2-50.3 s at 260-300 ℃ to obtain the graphite-phase carbon nitride photocatalyst.
Further, in the graphite-phase carbon nitride dispersion, the dosage ratio of the graphite-phase carbon nitride to water is 1 to 10g:1mL.
Further, the volume flow ratio of the graphite-phase carbon nitride dispersion liquid to the preheated water is 1:4.
further, the reaction pressure in the reaction zone is 15-25 MPa.
A system for preparing the graphite-phase carbon nitride photocatalyst comprises a material conveying system, a preheating system, a mixed reaction system and a cooling recovery system; the material conveying system comprises a plunger pump and a advection pump, the mixed reaction system comprises a T-shaped three-way mixer and a reaction zone, and the cooling recovery system comprises a double pipe heat exchanger, a back pressure valve and a collecting device;
the advection pump is connected with the preheater, the plunger pump and the preheater are both connected with the inlet of the T-shaped three-way mixer, the outlet of the T-shaped three-way mixer is connected with the inlet of the reaction zone, and the outlet of the reaction zone is connected with the collecting device through a pipeline and a back pressure valve; the double pipe heat exchanger is arranged outside the pipeline.
A catalyst prepared according to the method described above.
Use of a catalyst prepared according to the method described above for photocatalytic decomposition of water to produce hydrogen.
Further, dispersing a photocatalyst in a triethanolamine solution, adding Pt, and carrying out hydrogen production; wherein the dosage ratio of the photocatalyst to the triethanolamine solution is 20mg:80mL of triethanolamine solution was 10% by volume.
Further, the addition amount of Pt was 1% by weight of the photocatalyst.
Compared with the prior art, the invention has the following beneficial effects:
the continuous rapid hydrothermal reaction of the invention modifies graphite-phase carbon nitride, the reaction time is between 25.2 and 50.3s, and the test result of photocatalytic water splitting hydrogen production activity by using the photocatalyst shows that the activity is improved by 5.2 times compared with that before modification, and the invention has the advantages of short reaction time and good performance of the graphite-phase carbon nitride photocatalyst. The reaction mechanism of the invention is as follows: in the continuous rapid hydrothermal modification treatment process, after the graphite phase carbon nitride dispersion liquid is mixed with high-temperature high-pressure water, the reaction temperature is reached, and g-C is formed at the reaction temperature 3 N 4 Partial decomposition to produce ammonia gas, partial conversion of water into water vapor to form solid-liquid three-phase system, and high temperature and high pressure fluid to realize g-C 3 N 4 Stripping of photocatalystLayer and shear, increase g-C 3 N 4 The number of pores and the specific surface area of the powder destroy g-C 3 N 4 Is a conjugated structure of (a). The invention utilizes the saturated vapor pressure, thermal diffusion coefficient, low density, surface tension and viscosity of a hydrothermal system under high temperature and high pressure to modify graphite phase carbon nitride, thereby avoiding the problems of poor improving effect, excessive decomposition of graphite phase carbon nitride and the like of the existing method. The preparation method of the invention has the advantages of time saving, simple and repeatable operation and wide popularization and application values.
Further, in the invention, the temperature of the graphite-phase carbon nitride dispersion liquid is raised to 260-300 ℃ by mixing with high-temperature preheated water under the pressure of 19MPa, and the volume flow of the graphite-phase carbon nitride dispersion liquid and the high-temperature preheated water is controlled, so that the reaction time is between (25.2-50.3) s, and the reaction time is shortened.
The system of the invention can realize continuous reaction of the graphite phase carbon nitride photocatalyst, improves the catalytic performance of the catalyst, has simple structure and is easy to realize.
The catalyst has higher photocatalytic performance and can be applied to hydrogen production by photocatalytic decomposition of water.
Drawings
FIG. 1 is a continuous rapid hydrothermal reaction system of the present invention.
FIG. 2 is a graph comparing the hydrogen production rate curves of the photocatalyst of example 1 and comparative example 1.
FIG. 3 is a bar graph of hydrogen generating activity of the photocatalysts of examples 1-4.
FIG. 4 is a bar graph of normalized yields for the photocatalysts of example 1 and examples 7-10.
Fig. 5 is an XRD spectrum of the photocatalyst of example 1 and comparative example 1.
FIG. 6 shows XPS high-resolution spectra of C1s, N1s and O1s of CN-280/5-9 of example 1 and CN-30/5-9 of comparative example 1 and XPS full spectra of CN-280/5-9. Wherein, (a) is the XPS high-resolution spectrum of C1s of CN-280/5-9 of example 1 and CN-30/5-9 of comparative example 1, (b) is the XPS high-resolution spectrum of N1s of CN-280/5-9 of example 1 and CN-30/5-9 of comparative example 1, (C) is the XPS high-resolution spectrum of O1s of CN-280/5-9 of example 1 and CN-30/5-9 of comparative example 1, and (d) is the XPS full spectrum of CN-280/5-9 of example 1;
FIG. 7 is a schematic diagram of a continuous rapid thermal modification of graphite phase carbon nitride mechanism. Wherein, (a) is a reaction system, (b) is an enlarged view of a circle in the graph (a), and (c) and (d) are schematic diagrams of a delamination effect and a shearing effect occurring at the circle in the graph (b).
In the figure, 1 is graphite phase carbon nitride dispersion liquid, 2 is water, 3 is a plunger pump, 4 is a horizontal flow pump, 5 is a preheater, 6 is a T-shaped three-way mixer, 7 is a reaction zone, 8 is a double pipe heat exchanger, 9 is a back pressure valve, and 10 is a collecting device.
Detailed Description
The technical scheme of the invention is further described in detail below with reference to the accompanying drawings and the examples.
The invention discloses a preparation method of a graphite phase carbon nitride photocatalyst for photocatalytic hydrogen production, which comprises the following steps: through a continuous reaction system, the graphite-phase carbon nitride dispersion liquid and high-temperature preheated water are mixed in a reaction section and undergo rapid high-temperature high-pressure hydrothermal reaction, and continuous rapid high-temperature high-pressure hydrothermal post-treatment is carried out on the graphite-phase carbon nitride, so that the more efficient graphite-phase carbon nitride photocatalyst is obtained.
Specifically, referring to fig. 1, the continuous reaction system includes: the device comprises a material conveying system, a preheating system, a mixed reaction system and a cooling recovery system. The material conveying system comprises a plunger pump 3 and a advection pump 4, the preheating system comprises a preheater 5, the mixed reaction system comprises a T-shaped three-way mixer 6 and a reaction zone 7, and the cooling recovery system comprises a double pipe heat exchanger 8, a back pressure valve 9 and a collecting device 10. The advection pump 4 is connected with the preheater 5, the plunger pump 3 and the preheater 5 are connected with the inlet of the T-shaped three-way mixer 6, the outlet of the T-shaped three-way mixer 6 is connected with the inlet of the reaction zone 7, the outlet of the reaction zone 7 is connected with the collecting device 10 through a pipeline and a back pressure valve 9, and a sleeve heat exchanger 8 is arranged outside one section of pipeline. The reaction zone 7 is internally provided with an electric heating wire for heating.
The graphite-phase carbon nitride dispersion liquid 1 is conveyed by a advection pump 3, the water 2 is conveyed by a plunger pump 4, the volume flow rate of the graphite-phase carbon nitride dispersion liquid is (9-18) mL/min, and the volume flow rate ratio of the graphite-phase carbon nitride dispersion liquid to the plunger pump is 1:4.
the water 2 fed by the plunger pump 4 is heated to (300-340) deg.c after passing through the preheating system 5, and then enters the mixing reaction system to react with the graphite-phase carbon nitride. The purpose of preheating is to ensure the temperature of the reaction.
The graphite phase carbon nitride dispersion liquid and high temperature preheated water are mixed in a T-shaped three-way mixer 6 and then flow into a reaction zone 7 for reaction, the reaction time is between (25.2 and 50.3) s, the reaction temperature is between (260 and 300), and the pressure is between (15 and 25) MPa.
And cooling the high-temperature mixed solution to normal temperature through a double pipe heat exchanger 8, collecting, filtering and drying the high-temperature mixed solution through a collecting device 10 after flowing through a back pressure valve 9, and obtaining a modified graphite-phase carbon nitride sample.
Continuous rapid high-temperature hydrothermal reaction occurs in the reaction zone 7, specifically, the aim of rapid temperature rise is achieved by mixing graphite phase carbon nitride dispersion liquid and high-temperature preheating water, and the reaction temperature is between (260) and (300); controlling the reaction time by controlling the volume flow rate (volume flow rate unit is mL/min) of the graphite phase carbon nitride dispersion liquid and water, wherein the reaction time is between (25.2 and 50.3) s; in order to prevent the boiling of the aqueous solution in the pipeline and the damage of the pipeline, the reaction pressure is controlled to be (15-25) MPa by adjusting the back pressure valve 9. Specifically, the reaction temperature may be 260 ℃, 280 ℃, 290 ℃ or 300 ℃; the volume flow ratio of the graphite phase carbon nitride dispersion liquid to the high-temperature preheated water is 1: the volume flow rate of the graphite phase carbon nitride dispersion liquid can be 9mL/min, 12mL/min, 13.5mL/min, 15mL/min or 18mL/min, and the corresponding reaction time is respectively 50.3s, 37.7s, 33.6s, 30.2s and 25.2s. The graphite-phase carbon nitride is subjected to continuous rapid high-temperature hydrothermal treatment at a temperature higher than the decomposition temperature of the graphite-phase carbon nitride, so that the graphite-phase carbon nitride is modified on the premise of not decomposing, and the modified graphite-phase carbon nitride is endowed with good photocatalytic activity.
Preferably, the mass volume ratio of the graphite phase carbon nitride to the dispersant (water) is (1-10): 1, the mass unit of graphite phase carbon nitride is mg, the mass unit of dispersing agent is mL, and the dispersing agent is water.
The invention changes a continuous reaction system into a continuous reaction system, and carries out rapid heating by mixing graphite phase carbon nitride dispersion liquid and high-temperature preheated water, designs a double-pipe heat exchanger for rapid cooling, has higher reaction temperature and greatly reduces the time required for heating and cooling. And (3) after the graphite-phase carbon nitride particles react for tens of seconds in the cylindrical reactor, collecting and filtering the graphite-phase carbon nitride particles through a back pressure valve, and finally obtaining the modified graphite-phase carbon nitride particles.
The present invention will be specifically described with reference to examples, which are not intended to limit the present invention.
The graphite phase carbon nitride photocatalyst for sewage treatment is prepared by the method of the invention, and is concretely as follows.
Example 1
The embodiment provides a preparation method of a graphite phase carbon nitride photocatalyst for photocatalytic hydrogen production, which comprises the following steps:
step one, dispersing 3g of graphite-phase Carbon Nitride (CN) in 600mL of pure water to obtain graphite-phase carbon nitride dispersion liquid 1;
step two, placing the graphite-phase carbon nitride dispersion liquid in the step one into a storage bin;
pumping graphite-phase carbon nitride dispersion liquid at a volume flow rate of 9mL/min, and controlling the volume flow rate ratio of the graphite-phase carbon nitride dispersion liquid to water to be 1:4, and adjusting the back pressure valve 8 to enable the pipeline pressure to be 19MPa;
step four, adjusting the power of the preheater 5 and the electric heating wire on the wall surface of the reaction zone 7, so that the temperature of the reaction zone 7 after the water 2 and the graphite phase carbon nitride dispersion liquid 1 are mixed is kept at 280 ℃, and the sample flows out of the reaction zone 7 after staying for 50.3 s;
step five, the system after the reaction in the step four is cooled by water through a double pipe heat exchanger 8, filtered, washed and dried to obtain a graphite phase carbon nitride photocatalyst which is recorded as CN-280/5-9; according to CN-T/c-m c ，CN-T/c-m c Wherein T represents the temperature of the hydrothermal treatment, c represents the concentration of the dispersion in mg/mL, m c Representing the volume flow mL/min of the graphite phase carbon nitride dispersion.
Example 2
This example is the same as example 1, except that the temperature in reaction zone 7 after mixing water 2 with graphite-phase carbon nitride dispersion 1 is maintained at 260 ℃.
Example 3
This example is the same as example 1, except that the temperature in reaction zone 7 after mixing water 2 with graphite-phase carbon nitride dispersion 1 is maintained at 290 ℃.
Example 4
This example is the same as example 1, except that the temperature in reaction zone 7 after mixing water 2 with graphite-phase carbon nitride dispersion 1 is maintained at 300 ℃.
Comparative example 1
This comparative example is the same as example 1 except that the preheater 5 and the heating wire on the wall of the reaction zone 7 are in a non-powered state, and the experiment is performed at room temperature of 30 ℃.
Example 5
The embodiment provides a preparation method of a graphite phase carbon nitride photocatalyst for photocatalytic hydrogen production, which comprises the following steps:
step one, dispersing 0.6g of graphite-phase Carbon Nitride (CN) in 600mL of pure water to obtain graphite-phase carbon nitride dispersion liquid;
step two, placing the graphite-phase carbon nitride dispersion liquid in the step one into a storage bin;
pumping graphite-phase carbon nitride dispersion liquid at a volume flow rate of 9mL/min, and controlling the volume flow rate ratio of the graphite-phase carbon nitride dispersion liquid to water to be 1:4, and adjusting the back pressure valve 9 to enable the pipeline pressure to be 19MPa;
step four, adjusting the power of the preheater 5 and the electric heating wire on the wall surface of the reaction zone 7, so that the temperature of the reaction zone 7 after the water 2 and the graphite phase carbon nitride dispersion liquid 1 are mixed is kept at 280 ℃, and the sample flows out of the reaction zone 7 after staying for 50.3 s;
and fifthly, cooling the reacted system in the step four by water cooling through a double pipe heat exchanger 8, filtering, washing and drying to obtain the graphite phase carbon nitride photocatalyst, which is marked as CN-280/1-9.
Example 6
The embodiment provides a preparation method of a graphite phase carbon nitride photocatalyst for photocatalytic hydrogen production, which comprises the following steps:
step one, dispersing 6g of graphite-phase Carbon Nitride (CN) in 600mL of pure water to obtain graphite-phase carbon nitride dispersion liquid;
step two, placing the graphite-phase carbon nitride dispersion liquid in the step one into a storage bin;
pumping graphite-phase carbon nitride dispersion liquid at a volume flow rate of 9mL/min, and controlling the volume flow rate ratio of the graphite-phase carbon nitride dispersion liquid to water to be 1:4, adjusting the back pressure valve to enable the pipeline pressure to be 19MPa;
step four, adjusting the power of the preheater 5 and the electric heating wire on the wall surface of the reaction zone 7, so that the temperature of the reaction zone 7 after the water 2 and the graphite phase carbon nitride dispersion liquid 1 are mixed is kept at 280 ℃, and the sample flows out of the reaction zone 7 after staying for 50.3 s;
and fifthly, cooling the reacted system in the step four by water cooling through a double pipe heat exchanger, filtering, washing and drying to obtain the graphite phase carbon nitride photocatalyst, which is marked as CN-280/10-9.
Example 7
The embodiment provides a preparation method of a graphite phase carbon nitride photocatalyst for photocatalytic hydrogen production, which comprises the following steps:
step one, dispersing 3g of graphite-phase Carbon Nitride (CN) in 600mL of pure water to obtain graphite-phase carbon nitride dispersion liquid;
step two, placing the graphite-phase carbon nitride dispersion liquid in the step one into a storage bin;
pumping graphite-phase carbon nitride dispersion liquid at a volume flow rate of 12mL/min, and controlling the volume flow rate ratio of the graphite-phase carbon nitride dispersion liquid to water to be 1:4, adjusting the back pressure valve to enable the pipeline pressure to be 19MPa;
step four, adjusting the power of the preheater 5 and the electric heating wire on the wall surface of the reaction zone 7, so that the temperature of the reaction zone 7 after the water 2 and the graphite phase carbon nitride dispersion liquid 1 are mixed is kept at 300 ℃, and the sample flows out of the reaction zone 7 after staying for 37.7 s;
and fifthly, cooling the reacted system in the step four by water cooling through a double pipe heat exchanger, filtering, washing and drying to obtain the graphite phase carbon nitride photocatalyst, which is marked as CN-280/5-12.
Example 8
The embodiment provides a preparation method of a graphite phase carbon nitride photocatalyst for photocatalytic hydrogen production, which comprises the following steps:
step one, dispersing 3g of graphite-phase Carbon Nitride (CN) in 600mL of pure water to obtain graphite-phase carbon nitride dispersion liquid;
step two, placing the graphite-phase carbon nitride dispersion liquid in the step one into a storage bin;
pumping graphite-phase carbon nitride dispersion liquid at a volume flow rate of 13.5mL/min, and controlling the volume flow rate ratio of the graphite-phase carbon nitride dispersion liquid to water to be 1:4, adjusting the back pressure valve to enable the pipeline pressure to be 19MPa;
step four, adjusting the power of the preheater 5 and the electric heating wire on the wall surface of the reaction zone 7, so that the temperature of the reaction zone 7 after the water 2 and the graphite-phase carbon nitride dispersion liquid 1 are mixed is kept at 300 ℃, and the sample flows out of the reaction zone 7 after staying for 33.6 s;
and fifthly, cooling the reacted system in the step four by water cooling through a double pipe heat exchanger, filtering, washing and drying to obtain the graphite phase carbon nitride photocatalyst, which is recorded as CN-280/5-13.5.
Example 9
The embodiment provides a preparation method of a graphite phase carbon nitride photocatalyst for photocatalytic hydrogen production, which comprises the following steps:
step one, dispersing 3g of graphite-phase Carbon Nitride (CN) in 600mL of pure water to obtain graphite-phase carbon nitride dispersion liquid;
step two, placing the graphite-phase carbon nitride dispersion liquid in the step one into a storage bin;
pumping graphite-phase carbon nitride dispersion liquid at a volume flow rate of 15mL/min, and controlling the volume flow rate ratio of the graphite-phase carbon nitride dispersion liquid to water to be 1:4, adjusting the back pressure valve to enable the pipeline pressure to be 19MPa;
step four, adjusting the power of the preheater 5 and the electric heating wire on the wall surface of the reaction zone 7, so that the temperature of the reaction zone 7 after the water 2 and the graphite phase carbon nitride dispersion liquid 1 are mixed is kept at 300 ℃, and the sample flows out of the reaction zone 7 after staying for 30.2 s;
and fifthly, cooling the reacted system in the step four by water cooling through a double pipe heat exchanger, filtering, washing and drying to obtain graphite phase carbon nitride photocatalysis, which is marked as CN-280/5-15.
Example 10
The embodiment provides a preparation method of a graphite phase carbon nitride photocatalyst for photocatalytic hydrogen production, which comprises the following steps:
step one, dispersing 3g of graphite-phase Carbon Nitride (CN) in 600mL of pure water to obtain graphite-phase carbon nitride dispersion liquid;
step two, placing the graphite-phase carbon nitride dispersion liquid in the step one into a storage bin;
pumping graphite-phase carbon nitride dispersion liquid at a volume flow rate of 18mL/min, and controlling the volume flow rate ratio of the graphite-phase carbon nitride dispersion liquid to water to be 1:4, adjusting the back pressure valve to enable the pipeline pressure to be 19MPa;
step four, adjusting the power of the preheater 5 and the electric heating wire on the wall surface of the reaction zone 7, so that the temperature of the reaction zone 7 after the water 2 and the graphite phase carbon nitride dispersion liquid 1 are mixed is kept at 300 ℃, and the sample flows out of the reaction zone 7 after staying for 25.2 s;
and fifthly, cooling the reacted system in the step four by water cooling through a double pipe heat exchanger, filtering, washing and drying to obtain the graphite phase carbon nitride photocatalyst, which is marked as CN-280/5-18.
Example 11
The embodiment provides a preparation method of a graphite phase carbon nitride photocatalyst for photocatalytic hydrogen production, which comprises the following steps:
step one, dispersing 2g of graphite-phase Carbon Nitride (CN) in 600mL of pure water to obtain graphite-phase carbon nitride dispersion liquid;
step two, placing the graphite-phase carbon nitride dispersion liquid in the step one into a storage bin;
pumping graphite-phase carbon nitride dispersion liquid at a volume flow rate of 10mL/min, and controlling the volume flow rate ratio of the graphite-phase carbon nitride dispersion liquid to water to be 1:4, regulating the back pressure valve to enable the pipeline pressure to be 15MPa;
step four, adjusting the power of the preheater 5 and the electric heating wire on the wall surface of the reaction zone 7, so that the temperature of the reaction zone 7 after the water 2 and the graphite phase carbon nitride dispersion liquid 1 are mixed is kept at 270 ℃, and the sample flows out of the reaction zone 7 after staying for 45.3 s;
and fifthly, cooling the reacted system in the step four by water cooling through a double pipe heat exchanger, filtering, washing and drying to obtain the graphite phase carbon nitride photocatalyst.
Example 12
The embodiment provides a preparation method of a graphite phase carbon nitride photocatalyst for photocatalytic hydrogen production, which comprises the following steps:
step one, dispersing 4g of graphite-phase Carbon Nitride (CN) in 600mL of pure water to obtain graphite-phase carbon nitride dispersion liquid;
step two, placing the graphite-phase carbon nitride dispersion liquid in the step one into a storage bin;
pumping graphite-phase carbon nitride dispersion liquid at a volume flow rate of 16mL/min, and controlling the volume flow rate ratio of the graphite-phase carbon nitride dispersion liquid to water to be 1:4, adjusting the back pressure valve to enable the pipeline pressure to be 25MPa;
step four, adjusting the power of the preheater 5 and the electric heating wire on the wall surface of the reaction zone 7, so that the temperature of the reaction zone 7 after the water 2 and the graphite-phase carbon nitride dispersion liquid 1 are mixed is kept at 300 ℃, and the sample flows out of the reaction zone 7 after staying for 28.3 s;
and fifthly, cooling the reacted system in the step four by water cooling through a double pipe heat exchanger, filtering, washing and drying to obtain the graphite phase carbon nitride photocatalyst.
Evaluation of performance:
FIG. 1 is a schematic diagram of a continuous rapid thermal hydrothermal reaction system from which all of the example and comparative example photocatalysts of the present invention were prepared.
FIG. 2 is a graph comparing the hydrogen production rate curves of the photocatalyst of example 1 and comparative example 1, wherein the photocatalytic water splitting hydrogen production test method comprises: 20mg of the photocatalyst was dispersed in 80mL of a 10vol% triethanolamine solution, pt (1 wt% of the photocatalyst) was added as a cocatalyst, and the amount of hydrogen produced in the photocatalytic system was measured. As can be seen from FIG. 2, relative to pure g-C 3 N 4 (i.e., raw material CN, corresponding to reaction temperature of 30 ℃ C.) the photocatalyst of the invention hasThe average photocatalytic hydrogen production rate and the activity are obviously improved.
FIG. 3 is a bar graph showing hydrogen generating activity of the photocatalysts of examples 1 to 4 under the same test conditions as FIG. 2. As can be seen from FIG. 3, the samples treated at 260 ℃, 280 ℃, 290 ℃ and 300 ℃ have higher hydrogen-generating activity than the photocatalyst of comparative example 1, and have higher photocatalytic performance.
FIG. 4 is a bar graph of normalized yields of the photocatalysts of example 1 and examples 7-10. As can be seen from FIG. 4, the yield of the product is significantly improved with increasing flow rate.
FIG. 5 is an XRD spectrum of the photocatalyst of example 1 and comparative example 1. As can be seen from FIG. 5, the XRD spectra of CN-280/5 and CN-30/5 are substantially identical, indicating that the structure of the graphite phase carbon nitride is not changed during the hydrothermal reaction.
The XPS high-resolution spectra of C1s, N1s and O1s of CN-280/5 of example 1 and CN-30/5 of comparative example 1 are shown in the order of (a) to (C) in FIG. 6, and the XPS full spectrum of CN-280/5 of example 1 is shown in the order of (d) in FIG. 6. From the high resolution spectrum, g-C can be seen 3 N 4 The binding energy position of each functional group is not obviously moved, and no new peak appears, which indicates that the continuous rapid hydrothermal modification does not introduce new functional groups into the photocatalyst. Meanwhile, as can be seen from fig. 6 (b), the sample MCN-280/5 of example 1 has a peak area of c=n-C/N- (C) 3 greater than MCN-30/5, which indicates that the number of the bridge structures N- (C) 3 of the heptazine ring is somewhat reduced as the hydrothermal modification proceeds, which may be caused by the shearing action of the g-C3N4 photocatalyst by the high-temperature and high-pressure fluid during the continuous rapid high-temperature hydrothermal modification treatment. As shown in FIG. 6 (d), no other impurity peak than O, N, C appears in CN-280/5, indicating that the influence of the constituent elements (Fe, cr, ni, etc.) on the sample due to corrosion of the stainless steel pipeline can be eliminated under this condition.
In fig. 7, (a), (b), (c) and (d) are schematic diagrams of continuous rapid hydrothermal modified graphite phase carbon nitride mechanism. As can be seen from FIG. 7, in the continuous rapid high temperature hydrothermal modification treatment, the graphite phase carbon nitride dispersion is mixed with high temperature and high pressure water to reach a set temperature, and g-C is formed at the set temperature 3 N 4 Partial decomposition to produce ammonia gas, partial conversion of water into water vapor to form solid-liquid-gas three-phase system, and high temperature and high pressure fluid to realize g-C 3 N 4 Stripping and shearing of photocatalyst, and increasing g-C 3 N 4 The number of pores and the specific surface area of the powder destroy g-C 3 N 4 Is a conjugated structure of (a).
The foregoing description is only a preferred embodiment of the present invention, and is not intended to limit the present invention, and any simple modification, variation and equivalent structural changes of the above embodiment according to the technical matter of the present invention still fall within the scope of the technical solution of the present invention.
Claims (7)
1. The preparation method of the graphite-phase carbon nitride photocatalyst is characterized by comprising the following steps of:
dispersing graphite-phase carbon nitride in water to obtain graphite-phase carbon nitride dispersion liquid;
adding graphite-phase carbon nitride dispersion liquid and preheated water into a reaction zone, and reacting at 260-300 ℃ for 25.2-50.3 s to obtain a graphite-phase carbon nitride photocatalyst; the reaction pressure of the reaction zone is 15-25 MPa.
2. The method for preparing a graphite-phase carbon nitride photocatalyst according to claim 1, wherein the graphite-phase carbon nitride dispersion liquid has a graphite-phase carbon nitride to water dosage ratio of 1 to 10mg:1mL.
3. The method for preparing a graphite-phase carbon nitride photocatalyst according to claim 1, wherein the volume flow ratio of the graphite-phase carbon nitride dispersion to the preheated water is 1:4.
4. a catalyst prepared according to the method of any one of claims 1-3.
5. Use of a catalyst prepared according to the method of any one of claims 1-3 for photocatalytic water splitting to produce hydrogen.
6. The use according to claim 5, wherein the hydrogen production is carried out by dispersing the photocatalyst in a triethanolamine solution, adding Pt; wherein the dosage ratio of the photocatalyst to the triethanolamine solution is 20mg:80mL of triethanolamine solution was 10% by volume.
7. The method according to claim 6, wherein Pt is added in an amount of 1% by weight of the photocatalyst.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202211049603.1A CN115254173B (en) | 2022-08-30 | 2022-08-30 | Graphite-phase carbon nitride photocatalyst, and preparation method, system and application thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202211049603.1A CN115254173B (en) | 2022-08-30 | 2022-08-30 | Graphite-phase carbon nitride photocatalyst, and preparation method, system and application thereof |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN115254173A CN115254173A (en) | 2022-11-01 |
| CN115254173B true CN115254173B (en) | 2023-07-07 |
Family
ID=83755198
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202211049603.1A Active CN115254173B (en) | 2022-08-30 | 2022-08-30 | Graphite-phase carbon nitride photocatalyst, and preparation method, system and application thereof |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN115254173B (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN116020516B (en) * | 2023-01-17 | 2023-10-20 | 齐鲁工业大学(山东省科学院) | Graphite-phase carbon nitride photocatalyst with controllable size and preparation method thereof |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114632535A (en) * | 2022-03-31 | 2022-06-17 | 国家电投集团山西铝业有限公司 | Graphite-phase carbon nitride photocatalyst for sewage treatment and preparation method thereof |
Family Cites Families (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4279663A (en) * | 1979-01-12 | 1981-07-21 | American Can Company | Reactor system and pump apparatus therein |
| CN107297217B (en) * | 2017-06-01 | 2020-04-28 | 西安交通大学 | Porous thin-layer graphite-phase carbon nitride-supported platinum photocatalyst and preparation method and application thereof |
| CN111085238A (en) * | 2020-01-10 | 2020-05-01 | 生态环境部华南环境科学研究所 | Hollow tubular graphite phase carbon nitride photocatalyst containing nitrogen defects and preparation method and application thereof |
| CN111729683B (en) * | 2020-07-14 | 2023-01-31 | 广东石油化工学院 | Oxygen-doped graphite-like phase carbon nitride photocatalyst and preparation method and application thereof |
| CN112973761B (en) * | 2021-03-18 | 2022-10-18 | 宁夏大学 | Graphite phase carbon nitride composite material and preparation method and application thereof |
| CN113680373A (en) * | 2021-09-28 | 2021-11-23 | 中化学朗正环保科技有限公司 | Graphite phase carbon nitride photocatalyst for sewage treatment and preparation method and application thereof |
| CN114839310A (en) * | 2022-03-11 | 2022-08-02 | 青岛科技大学 | Method for preparing p-toluenesulfonate from liquid-phase sulfur trioxide |
-
2022
- 2022-08-30 CN CN202211049603.1A patent/CN115254173B/en active Active
Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114632535A (en) * | 2022-03-31 | 2022-06-17 | 国家电投集团山西铝业有限公司 | Graphite-phase carbon nitride photocatalyst for sewage treatment and preparation method thereof |
Also Published As
| Publication number | Publication date |
|---|---|
| CN115254173A (en) | 2022-11-01 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN111054421B (en) | Graphite-like carbon nitride doped modified microsphere catalyst and preparation method and application thereof | |
| Zhao et al. | In situ preparation of highly stable polyaniline/W18O49 hybrid nanocomposite as efficient visible light photocatalyst for aqueous Cr (VI) reduction | |
| CN115254173B (en) | Graphite-phase carbon nitride photocatalyst, and preparation method, system and application thereof | |
| CN103877959B (en) | Hydrogenated titanium dioxide nanotube/nano-particle composite photocatalytic material and preparation method thereof | |
| CN101024188A (en) | Halogen-oxide photocatalytic material and preparing method | |
| CN109835897B (en) | Metal/heteroatom modified distiller's grain-based activated carbon and preparation method thereof | |
| CN111054417A (en) | High-efficiency iron monatomic Fenton catalyst, and synthesis method and application thereof | |
| CN106824253A (en) | A kind of support type ozone catalyst and preparation and application for dyeing waste water biochemistry pre-treatment | |
| CN111359652A (en) | Carbon nitride-based nickel-gold bimetallic supported catalyst and preparation method thereof | |
| CN101935085A (en) | Microwave oxidized waste water treatment system and waste water treatment method | |
| CN111054377B (en) | Manganese oxide nanowire-supported ferroferric oxide magnetic Fenton catalyst, and one-step synthesis method and application thereof | |
| CN102794186A (en) | Oxyhalide photo-catalytic material and preparation method thereof | |
| CN117427641B (en) | Low-temperature ceramic catalyst and preparation method and application thereof | |
| CN111733486A (en) | Carbon fiber film for high-efficiency persulfate catalysis and preparation method thereof | |
| CN110918099A (en) | Method for treating hexavalent chromium-containing wastewater through photocatalytic reduction of nickel oxide-nickel cobaltate-black titanium dioxide composite | |
| CN110775972B (en) | Method, system and application for preparing modified activated carbon by two-stage reduction pyrolysis of organic solid waste | |
| CN113231059A (en) | Composite catalyst for electron beam sewage treatment and preparation method and application thereof | |
| CN102513091A (en) | Preparation method for graphene self-assembled nanometer bismuth vanadate photocatalyst | |
| CN215288133U (en) | Treatment device for organic wastewater difficult to degrade | |
| Jia et al. | gC 3 N 4-modified Zr-Fc MOFs as a novel photocatalysis-self-Fenton system toward the direct hydroxylation of benzene to phenol | |
| CN109876816A (en) | A kind of micro ware auxiliary catalysis wet oxidation nanocatalyst and its application | |
| CN105749954A (en) | Metal-free hydrogenation catalyst and application of metal-free hydrogenation catalyst in catalyzing 1,5-dinitronaphthalene hydrogenation reaction | |
| CN102489291A (en) | Method for preparing expanded graphite load nanometer bismuth vanadate photochemical catalyst | |
| CN112808290B (en) | Enol-ketone covalent organic framework/graphite phase carbon nitride composite photocatalyst and preparation method and application thereof | |
| CN107649184B (en) | Perfusion silica gel/nanogold composite microspheres 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 | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |