CN117427643A - Photocatalytic material based on graphite-phase carbon nitride and preparation method and application thereof - Google Patents
Photocatalytic material based on graphite-phase carbon nitride and preparation method and application thereof Download PDFInfo
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- CN117427643A CN117427643A CN202311754321.6A CN202311754321A CN117427643A CN 117427643 A CN117427643 A CN 117427643A CN 202311754321 A CN202311754321 A CN 202311754321A CN 117427643 A CN117427643 A CN 117427643A
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- JMANVNJQNLATNU-UHFFFAOYSA-N oxalonitrile Chemical compound N#CC#N JMANVNJQNLATNU-UHFFFAOYSA-N 0.000 title claims abstract description 95
- 230000001699 photocatalysis Effects 0.000 title claims abstract description 56
- 239000000463 material Substances 0.000 title claims abstract description 44
- 238000002360 preparation method Methods 0.000 title abstract description 8
- 229910002367 SrTiO Inorganic materials 0.000 claims abstract description 44
- 229910002804 graphite Inorganic materials 0.000 claims abstract description 37
- 239000010439 graphite Substances 0.000 claims abstract description 37
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 claims abstract description 33
- 229910052751 metal Inorganic materials 0.000 claims abstract description 28
- 239000002184 metal Substances 0.000 claims abstract description 28
- 229910052755 nonmetal Inorganic materials 0.000 claims abstract description 11
- 229910052757 nitrogen Inorganic materials 0.000 claims abstract description 7
- 229910052796 boron Inorganic materials 0.000 claims abstract description 3
- 229910052802 copper Inorganic materials 0.000 claims abstract description 3
- 229910052746 lanthanum Inorganic materials 0.000 claims abstract description 3
- 229910052717 sulfur Inorganic materials 0.000 claims abstract description 3
- 238000001816 cooling Methods 0.000 claims description 25
- LFQSCWFLJHTTHZ-UHFFFAOYSA-N Ethanol Chemical compound CCO LFQSCWFLJHTTHZ-UHFFFAOYSA-N 0.000 claims description 22
- 238000010438 heat treatment Methods 0.000 claims description 22
- 238000001354 calcination Methods 0.000 claims description 19
- 238000005406 washing Methods 0.000 claims description 19
- 238000002156 mixing Methods 0.000 claims description 18
- 238000001035 drying Methods 0.000 claims description 17
- 239000000843 powder Substances 0.000 claims description 16
- 238000000034 method Methods 0.000 claims description 14
- 238000001914 filtration Methods 0.000 claims description 13
- DHEQXMRUPNDRPG-UHFFFAOYSA-N strontium nitrate Chemical compound [Sr+2].[O-][N+]([O-])=O.[O-][N+]([O-])=O DHEQXMRUPNDRPG-UHFFFAOYSA-N 0.000 claims description 12
- GRYLNZFGIOXLOG-UHFFFAOYSA-N Nitric acid Chemical compound O[N+]([O-])=O GRYLNZFGIOXLOG-UHFFFAOYSA-N 0.000 claims description 10
- 229910017604 nitric acid Inorganic materials 0.000 claims description 10
- YHWCPXVTRSHPNY-UHFFFAOYSA-N butan-1-olate;titanium(4+) Chemical compound [Ti+4].CCCC[O-].CCCC[O-].CCCC[O-].CCCC[O-] YHWCPXVTRSHPNY-UHFFFAOYSA-N 0.000 claims description 9
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 claims description 8
- QAOWNCQODCNURD-UHFFFAOYSA-N Sulfuric acid Chemical compound OS(O)(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-N 0.000 claims description 8
- 238000000227 grinding Methods 0.000 claims description 8
- 238000001027 hydrothermal synthesis Methods 0.000 claims description 8
- 230000009467 reduction Effects 0.000 claims description 8
- 150000003839 salts Chemical class 0.000 claims description 8
- 159000000008 strontium salts Chemical class 0.000 claims description 8
- 239000002253 acid Substances 0.000 claims description 6
- ORTQZVOHEJQUHG-UHFFFAOYSA-L copper(II) chloride Chemical compound Cl[Cu]Cl ORTQZVOHEJQUHG-UHFFFAOYSA-L 0.000 claims description 6
- 150000007522 mineralic acids Chemical class 0.000 claims description 6
- UBXAKNTVXQMEAG-UHFFFAOYSA-L strontium sulfate Chemical compound [Sr+2].[O-]S([O-])(=O)=O UBXAKNTVXQMEAG-UHFFFAOYSA-L 0.000 claims description 6
- 150000003609 titanium compounds Chemical class 0.000 claims description 6
- JIAARYAFYJHUJI-UHFFFAOYSA-L zinc dichloride Chemical compound [Cl-].[Cl-].[Zn+2] JIAARYAFYJHUJI-UHFFFAOYSA-L 0.000 claims description 6
- XSQUKJJJFZCRTK-UHFFFAOYSA-N Urea Chemical compound NC(N)=O XSQUKJJJFZCRTK-UHFFFAOYSA-N 0.000 claims description 5
- 239000004202 carbamide Substances 0.000 claims description 5
- 230000001476 alcoholic effect Effects 0.000 claims description 4
- QGBSISYHAICWAH-UHFFFAOYSA-N dicyandiamide Chemical compound NC(N)=NC#N QGBSISYHAICWAH-UHFFFAOYSA-N 0.000 claims description 4
- 229920000877 Melamine resin Polymers 0.000 claims description 3
- KGBXLFKZBHKPEV-UHFFFAOYSA-N boric acid Chemical compound OB(O)O KGBXLFKZBHKPEV-UHFFFAOYSA-N 0.000 claims description 3
- 239000004327 boric acid Substances 0.000 claims description 3
- JDSHMPZPIAZGSV-UHFFFAOYSA-N melamine Chemical compound NC1=NC(N)=NC(N)=N1 JDSHMPZPIAZGSV-UHFFFAOYSA-N 0.000 claims description 3
- 229910021645 metal ion Inorganic materials 0.000 claims description 3
- 230000035484 reaction time Effects 0.000 claims description 3
- 235000005074 zinc chloride Nutrition 0.000 claims description 3
- 239000011592 zinc chloride Substances 0.000 claims description 3
- 239000010949 copper Substances 0.000 claims description 2
- 235000019441 ethanol Nutrition 0.000 claims description 2
- ZFSLODLOARCGLH-UHFFFAOYSA-N isocyanuric acid Chemical compound OC1=NC(O)=NC(O)=N1 ZFSLODLOARCGLH-UHFFFAOYSA-N 0.000 claims description 2
- FYDKNKUEBJQCCN-UHFFFAOYSA-N lanthanum(3+);trinitrate Chemical compound [La+3].[O-][N+]([O-])=O.[O-][N+]([O-])=O.[O-][N+]([O-])=O FYDKNKUEBJQCCN-UHFFFAOYSA-N 0.000 claims description 2
- WFLYOQCSIHENTM-UHFFFAOYSA-N molybdenum(4+) tetranitrate Chemical compound [N+](=O)([O-])[O-].[Mo+4].[N+](=O)([O-])[O-].[N+](=O)([O-])[O-].[N+](=O)([O-])[O-] WFLYOQCSIHENTM-UHFFFAOYSA-N 0.000 claims description 2
- RXSHXLOMRZJCLB-UHFFFAOYSA-L strontium;diacetate Chemical compound [Sr+2].CC([O-])=O.CC([O-])=O RXSHXLOMRZJCLB-UHFFFAOYSA-L 0.000 claims description 2
- QTBSBXVTEAMEQO-UHFFFAOYSA-N Acetic acid Chemical compound CC(O)=O QTBSBXVTEAMEQO-UHFFFAOYSA-N 0.000 abstract description 30
- 238000010531 catalytic reduction reaction Methods 0.000 abstract description 11
- 238000005215 recombination Methods 0.000 abstract description 9
- 230000006798 recombination Effects 0.000 abstract description 9
- 230000007547 defect Effects 0.000 abstract description 6
- 239000000969 carrier Substances 0.000 abstract description 4
- 230000000052 comparative effect Effects 0.000 description 12
- 238000006243 chemical reaction Methods 0.000 description 7
- 239000002131 composite material Substances 0.000 description 7
- 238000007146 photocatalysis Methods 0.000 description 7
- 238000006722 reduction reaction Methods 0.000 description 7
- 238000006555 catalytic reaction Methods 0.000 description 6
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Chemical compound O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 6
- 239000000919 ceramic Substances 0.000 description 5
- 239000008367 deionised water Substances 0.000 description 5
- 229910021641 deionized water Inorganic materials 0.000 description 5
- 239000004576 sand Substances 0.000 description 5
- 238000012360 testing method Methods 0.000 description 5
- 239000007789 gas Substances 0.000 description 4
- 230000003197 catalytic effect Effects 0.000 description 3
- 239000011941 photocatalyst Substances 0.000 description 3
- 239000004065 semiconductor Substances 0.000 description 3
- CURLTUGMZLYLDI-UHFFFAOYSA-N Carbon dioxide Chemical compound O=C=O CURLTUGMZLYLDI-UHFFFAOYSA-N 0.000 description 2
- 239000003575 carbonaceous material Substances 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 230000005284 excitation Effects 0.000 description 2
- 238000004519 manufacturing process Methods 0.000 description 2
- 230000005012 migration Effects 0.000 description 2
- 238000013508 migration Methods 0.000 description 2
- 238000013032 photocatalytic reaction Methods 0.000 description 2
- 238000006479 redox reaction Methods 0.000 description 2
- 238000000926 separation method Methods 0.000 description 2
- YLZOPXRUQYQQID-UHFFFAOYSA-N 3-(2,4,6,7-tetrahydrotriazolo[4,5-c]pyridin-5-yl)-1-[4-[2-[[3-(trifluoromethoxy)phenyl]methylamino]pyrimidin-5-yl]piperazin-1-yl]propan-1-one Chemical compound N1N=NC=2CN(CCC=21)CCC(=O)N1CCN(CC1)C=1C=NC(=NC=1)NCC1=CC(=CC=C1)OC(F)(F)F YLZOPXRUQYQQID-UHFFFAOYSA-N 0.000 description 1
- 102000004190 Enzymes Human genes 0.000 description 1
- 108090000790 Enzymes Proteins 0.000 description 1
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 description 1
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 1
- 239000001569 carbon dioxide Substances 0.000 description 1
- 229910002092 carbon dioxide Inorganic materials 0.000 description 1
- 239000003054 catalyst Substances 0.000 description 1
- 230000008859 change Effects 0.000 description 1
- 239000003638 chemical reducing agent Substances 0.000 description 1
- 239000013078 crystal Substances 0.000 description 1
- 230000005684 electric field Effects 0.000 description 1
- 230000002708 enhancing effect Effects 0.000 description 1
- 230000002349 favourable effect Effects 0.000 description 1
- 239000000446 fuel Substances 0.000 description 1
- 229910021389 graphene Inorganic materials 0.000 description 1
- 238000004128 high performance liquid chromatography Methods 0.000 description 1
- 229910052739 hydrogen Inorganic materials 0.000 description 1
- 239000001257 hydrogen Substances 0.000 description 1
- -1 include metal oxides Chemical compound 0.000 description 1
- 229910044991 metal oxide Inorganic materials 0.000 description 1
- 150000004706 metal oxides Chemical class 0.000 description 1
- 229910052976 metal sulfide Inorganic materials 0.000 description 1
- 239000012621 metal-organic framework Substances 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 150000004767 nitrides Chemical class 0.000 description 1
- 231100000956 nontoxicity Toxicity 0.000 description 1
- 239000007800 oxidant agent Substances 0.000 description 1
- 230000033116 oxidation-reduction process Effects 0.000 description 1
- 230000001590 oxidative effect Effects 0.000 description 1
- 229910052760 oxygen Inorganic materials 0.000 description 1
- 239000001301 oxygen Substances 0.000 description 1
- 230000029553 photosynthesis Effects 0.000 description 1
- 238000010672 photosynthesis Methods 0.000 description 1
- 230000008569 process Effects 0.000 description 1
- 239000002994 raw material Substances 0.000 description 1
- 239000000376 reactant Substances 0.000 description 1
- 238000004064 recycling Methods 0.000 description 1
- 238000002336 sorption--desorption measurement Methods 0.000 description 1
- 238000012546 transfer Methods 0.000 description 1
- 230000007704 transition Effects 0.000 description 1
- 229910021642 ultra pure water Inorganic materials 0.000 description 1
- 239000012498 ultrapure water Substances 0.000 description 1
- 238000010792 warming Methods 0.000 description 1
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
- B01J23/00—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00
- B01J23/70—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00 of the iron group metals or copper
- B01J23/76—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00 of the iron group metals or copper combined with metals, oxides or hydroxides provided for in groups B01J23/02 - B01J23/36
- B01J23/78—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00 of the iron group metals or copper combined with metals, oxides or hydroxides provided for in groups B01J23/02 - B01J23/36 with alkali- or alkaline earth metals
-
- 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
- B01J23/00—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00
- B01J23/06—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00 of zinc, cadmium or mercury
-
- 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
-
- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C51/00—Preparation of carboxylic acids or their salts, halides or anhydrides
Abstract
The invention relates to the field of photocatalytic materials, and particularly discloses a graphite-phase carbon nitride-based photocatalytic material, and a preparation method and application thereof. Wherein, the graphite phase carbon nitride-based photocatalytic material is metal doped SrTiO 3 And/or nonmetallic modified graphite phase carbon nitride, wherein the metal is any one of Cu, zn, mo or La, and the nonmetallic is any one of B, S or N. The invention utilizes metal doped SrTiO 3 Heterojunction structure formed by non-metal modified graphite phase carbon nitride and CO catalytic reduction under visible light condition 2 The acetic acid is prepared, and the defects of easy recombination, lower conductivity and the like of photo-generated carriers existing in graphite phase carbon nitride in the prior art are effectively solved, so that the photo-catalytic reduction of CO is caused 2 The efficiency is low.
Description
Technical Field
The invention relates to the field of photocatalytic materials, and particularly discloses a graphite-phase carbon nitride-based photocatalytic material, and a preparation method and application thereof.
Background
To realize CO 2 The conversion into renewable fuel can simultaneously relieve global climate warming and energy crisis, scientists always try to simulate the photosynthesis principle of the nature, solar energy is used as driving force, and a photocatalytic material is used for capturing light energy to CO 2 Reduction treatment is carried out to realize CO 2 Is used for recycling.
Photocatalytic reduction of CO 2 The principle of (2) is that under the excitation of light, electrons generated on a valence band of the photocatalyst transition to a conduction band, and holes are remained on the valence band to form electron-hole pairs, wherein the electrons and the holes serve as an oxidant and a reducing agent respectively. The charge formed by excitation is transferred from the bulk phase to the surface, and in the process, charge recombination of the bulk phase and the surface occurs. Finally, the electrons and holes on the surface are contacted with reactants to generate oxidation-reduction reaction, and CO is generated 2 And (5) reduction. The energy band structure of the photocatalyst determines the occurrence of the photocatalytic reaction, and the positions of the valence band and the conduction band determine whether the oxidation-reduction reaction can be performed. Current materials for photocatalytic reduction of carbon dioxide mainly include metal oxides, metal sulfides or metal nitrides, metal organic frameworks, and carbon materials. Among them, carbon materials have been increasingly studied in the field of photocatalysis because of having suitable energy band positions and narrower band gap widths, such as graphene oxide and graphite-phase carbon nitride, which are of great interest because of having the advantages of no toxicity, no harm, wide raw materials, high operability, and the like. However, the graphite phase carbon nitride has the defects of easy recombination of photo-generated carriers, lower conductivity and the like at present, so that the photo-catalytic reduction of CO is caused 2 The efficiency is low. Therefore, a photocatalyst with high catalytic activity and good stability for converting CO through photocatalysis is developed 2 Has great significance.
Disclosure of Invention
Aiming at the defects of easy recombination of photo-generated carriers, lower conductivity and the like in the prior art, the graphite phase carbon nitride has the defects of photo-catalytic reduction of CO 2 The invention provides a photocatalytic material based on graphite phase carbon nitride and a preparation method and application thereof. The invention adopts metal doped SrTiO 3 And non-metal modified graphite phase carbon nitride are compounded to form a heterojunction structure, so that the catalytic activity of the material is improved, and the material is subjected to efficient catalytic reduction of CO 2 The purpose of preparing acetic acid.
In order to achieve the above purpose, the present invention provides the following technical solutions.
The first aspect of the invention provides a photocatalytic material based on graphite-phase carbon nitride, which is metal doped SrTiO 3 And/or nonmetallic modified graphite phase carbon nitride, wherein the metal is any one of Cu, zn, mo or La, and the nonmetallic is any one of B, S or N.
Compared with the prior art, the invention provides a photocatalytic material based on graphite-phase carbon nitride. The invention mixes the metal with SrTiO 3 Combining with non-metal modified graphite phase carbon nitride to form a heterojunction structure, srTiO 3 And a band bend is formed at the interface with graphite phase carbon nitride, so that the transfer rate of electrons is improved, and an electric field in a heterojunction formed by the band bend and the graphite phase carbon nitride is favorable for the recombination of photo-generated electrons and holes in a semiconductor, so that the charge separation efficiency is improved, and the higher oxidation-reduction capability is maintained, so that the efficient catalytic reduction of CO is realized 2 The purpose of preparing acetic acid.
Wherein, the invention utilizes metal doped SrTiO 3 Introducing metal ions into SrTiO 3 Inside, after new charges are generated in the crystal lattice, defects are formed, the separation efficiency of photo-generated carriers is increased, the recombination of photo-generated electrons and holes is reduced, and the semiconductor SrTiO is effectively improved 3 Is to (1) promoteActivity of the enzyme. But metal doped semiconductor SrTiO 3 Can not convert CO 2 And (3) complete catalytic reduction. Based on the method, the nonmetallic modified graphite-phase carbon nitride is also introduced, a new band is created above the valence band of the nonmetallic doped graphite-phase carbon nitride, and electron-hole pair recombination existing in the graphite-phase carbon nitride is inhibited by enhancing the capability of capturing electrons, so that the photocatalytic activity of the nonmetallic doped graphite-phase carbon nitride is enhanced. In the photocatalytic reaction, the photogenerated electrons move from nonmetallic modified graphite phase carbon nitride to SrTiO 3 The surface migration and then migration to the metal surface effectively inhibit the recombination of the photo-generated electrons and holes to promote the photocatalysis efficiency to be greatly improved.
Preferably, the photocatalytic material is Cu-SrTiO 3 Carbon nitride of/S-graphite phase, cu-SrTiO 3 B-graphite phase carbon nitride or Zn-SrTiO 3 Any one of N-graphite phase carbon nitride.
Further preferably, the photocatalytic material is Cu-SrTiO 3 S-graphite phase carbon nitride.
The invention provides a preparation method of the photocatalytic material based on graphite phase carbon nitride, which comprises the following steps:
firstly, grinding a nitrogen source in an inert atmosphere, heating to 500-550 ℃, preserving heat for 3-5 hours, and cooling to obtain carbon nitride powder;
dispersing the carbon nitride powder in an inorganic acid solution, adjusting the pH value to be 4-5, performing hydrothermal reaction at 150-200 ℃, filtering, washing and drying to obtain nonmetal modified graphite phase carbon nitride, wherein the inorganic acid solution is any one of sulfuric acid solution, nitric acid solution or boric acid solution;
dispersing strontium salt and metal salt in an acid solution, and uniformly mixing to obtain a first solution; mixing alcoholic solution containing titanium compound with the first solution uniformly, reacting at 200-300 deg.C in inert atmosphere, cooling, filtering, washing, and drying to obtain metal doped SrTiO 3 Wherein the metal salt is any one of copper chloride, zinc chloride, molybdenum nitrate or lanthanum nitrate;
step four, under the inert atmosphere, the following steps are carried outPrecalcination of non-metal modified graphite phase carbon nitride at 200-250 ℃, cooling to 50-80 ℃, adding the metal doped SrTiO 3 And heating to 400-500 ℃ for secondary calcination, and cooling to obtain the graphite-phase carbon nitride-based photocatalytic material.
Preferably, in the first step, the nitrogen source is any one of urea, melamine, cyanuric acid or dicyandiamide.
Preferably, in the first step, the grinding time is 20min-30min.
Preferably, in the first step, the temperature is raised in a temperature programming manner, and the temperature raising rate of the temperature programming is 10 ℃/min-15 ℃/min.
Preferably, in the second step, the mass-volume ratio of the carbon nitride powder to the inorganic acid solution with the concentration of 0.1mol/L-0.2mol/L is 1g:3mL-5mL.
Preferably, in the second step, the hydrothermal reaction time is 2-4 h.
Preferably, in the second step, the washing is carried out by adopting deionized water for 2-3 times and then adopting absolute ethyl alcohol for 2-3 times.
Preferably, in the second step, the drying temperature is 70-90 ℃ and the drying time is 6-10 h.
Preferably, in the third step, the strontium salt is any one of strontium nitrate, strontium sulfate or strontium acetate.
Preferably, in step three, sr in the strontium salt 2+ And the molar ratio of metal ions in the metal salt is 1-1.2:1.
Preferably, in the third step, the acid solution is a nitric acid solution with the mass concentration of 3% -5%.
Preferably, in the third step, the volume ratio of the total mass of the strontium salt and the metal salt to the acid solution is 1g to 5mL to 7mL.
Preferably, in the third step, the alcohol solution containing the titanium compound comprises tetrabutyl titanate and absolute ethyl alcohol, wherein the mass volume ratio of the tetrabutyl titanate to the absolute ethyl alcohol is 1g:3mL-5mL.
Preferably, in the third step, the volume ratio of the alcoholic solution containing the titanium compound to the first solution is 1-1.1:1.
Preferably, in the third step, the reaction time is 4-8 h.
Preferably, in the third step, the washing is performed 2-4 times by using absolute ethyl alcohol.
Preferably, in the third step, the drying temperature is 50-80 ℃ and the drying time is 4-8 h.
Preferably, in the fourth step, the pre-calcining time is 1h-3h.
Preferably, in the fourth step, the non-metal modified graphite phase carbon nitride and the metal doped SrTiO 3 The mass ratio of (2) is 1-2:1.5-2.
Preferably, in the fourth step, the time of the secondary calcination is 3-5 h.
Preferably, in the fourth step, the temperature of the pre-calcination and the secondary calcination is raised by adopting a temperature programming mode, wherein the temperature raising rate of the pre-calcination is 4 ℃/min-8 ℃/min, and the temperature raising rate of the secondary calcination is 5 ℃/min-10 ℃/min.
The third aspect of the invention provides an application of the composite material based on visible light catalysis in the field of photocatalysis.
In summary, the invention provides a photocatalytic material based on graphite-phase carbon nitride, a preparation method and application thereof, and SrTiO doped with metal 3 The heterojunction structure is formed by the non-metal modified graphite phase carbon nitride, so that the defects that the photo-generated carrier is easy to generate recombination, the conductivity is low and the like in the existing graphite phase carbon nitride material are effectively solved, and the photo-catalytic reduction of CO is caused 2 The efficiency is low. CO catalytic reduction by using the photocatalysis material provided by the invention 2 The method for preparing acetic acid has high catalytic efficiency and good product selectivity.
Drawings
FIG. 1 shows the photocatalytic reduction of CO by the graphite-phase carbon nitride-based photocatalytic material obtained in example 1 and comparative examples 1-3 2 And (5) a change chart of the obtained acetic acid content.
Detailed Description
The following description of the technical solutions in the embodiments of the present invention will be clear and complete, and it is obvious that the described embodiments are only some embodiments of the present invention, but not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.
Example 1
The embodiment provides a photocatalytic material Cu-SrTiO based on graphite phase carbon nitride 3 The S-graphite phase carbon nitride specifically comprises the following steps:
grinding 5g of urea for 25min in an inert atmosphere, transferring into a ceramic crucible, heating to 530 ℃ in a sand bath at a heating rate of 12 ℃/min, preserving heat for 4h, and cooling to room temperature to obtain carbon nitride powder;
dispersing 5g of carbon nitride powder in 20mL of 0.1mol/L sulfuric acid solution, adjusting the pH to 4.5, transferring the system into a polytetrafluoroethylene-lined high-pressure reaction kettle, performing hydrothermal reaction at 180 ℃ for 3 hours, filtering, washing with deionized water for 3 times, washing with absolute ethyl alcohol for 3 times, and drying at 80 ℃ for 8 hours to obtain S-graphite phase carbon nitride;
dispersing 3g of strontium nitrate and 1.8g of copper chloride in 25mL of 3% nitric acid solution, and uniformly mixing to obtain a first solution; mixing 26mL of absolute ethanol solution containing 8g of tetrabutyl titanate with the first solution uniformly, reacting for 6 hours at 250 ℃ in an inert atmosphere, cooling to room temperature, filtering, washing for 3 times by adopting absolute ethanol, and drying for 5 hours at 60 ℃ to obtain Cu-SrTiO 3 ；
Step four, under an inert atmosphere, 2g of S-graphite phase carbon nitride is preheated to 240 ℃ at a speed of 6 ℃/min, after 2h of precalcination, 3.5g of Cu-SrTiO is added when cooling to 70 DEG C 3 Uniformly mixing, heating to 450 ℃ at the heating rate of 8 ℃/min, performing secondary calcination for 4 hours, and cooling to room temperature to obtain the composite material Cu-SrTiO based on visible light catalysis 3 S-graphite phase carbon nitride.
Example 2
The embodiment provides a photocatalytic material Zn-SrTiO based on graphite phase carbon nitride 3 The N-graphite phase carbon nitride specifically comprises the following steps:
grinding 5g of melamine for 20min in an inert atmosphere, transferring into a ceramic crucible, heating to 500 ℃ in a sand bath at a heating rate of 10 ℃/min, preserving heat for 5h, and cooling to room temperature to obtain carbon nitride powder;
dispersing 5g of carbon nitride powder in 15mL of 0.2mol/L nitric acid solution, adjusting the pH to 4.2, transferring the system into a polytetrafluoroethylene-lined high-pressure reaction kettle, performing hydrothermal reaction at 150 ℃ for 4 hours, filtering, washing with deionized water for 3 times, washing with absolute ethyl alcohol for 3 times, and drying at 70 ℃ for 10 hours to obtain N-graphite phase carbon nitride;
dispersing 3g of strontium sulfate and 2g of zinc chloride in 30mL of 4% nitric acid solution, and uniformly mixing to obtain a first solution; mixing 30mL of absolute ethanol solution containing 8.5g of tetrabutyl titanate with the first solution uniformly, reacting for 8 hours at 200 ℃ in an inert atmosphere, cooling to room temperature, filtering, washing for 3 times by adopting absolute ethanol, and drying for 8 hours at 50 ℃ to obtain Zn-SrTiO 3 ；
Step four, under the inert atmosphere, 2g of the N-graphite phase carbon nitride is heated to 250 ℃ at 8 ℃/min for precalcination, after precalcination for 1.5 hours, 3.5g of the Cu-SrTiO is added when cooling to 70 DEG C 3 Uniformly mixing, heating to 500 ℃ at the heating rate of 10 ℃/min, carrying out secondary calcination for 3.5 hours, and cooling to room temperature to obtain the composite material Zn-SrTiO based on visible light catalysis 3 N-graphite phase carbon nitride.
Example 3
The embodiment provides a photocatalytic material Cu-SrTiO based on graphite phase carbon nitride 3 The method comprises the following steps of:
grinding 5g of dicyandiamide for 30min in an inert atmosphere, transferring the dicyandiamide into a ceramic crucible, heating to 550 ℃ in a sand bath at a heating rate of 10 ℃/min, preserving heat for 4h, and cooling to room temperature to obtain carbon nitride powder;
dispersing 5g of carbon nitride powder in 20mL of 0.15mol/L boric acid solution, adjusting the pH to 4.8, transferring the system into a polytetrafluoroethylene-lined high-pressure reaction kettle, performing hydrothermal reaction at 200 ℃ for 4 hours, filtering, washing with deionized water for 3 times, washing with absolute ethyl alcohol for 3 times, and drying at 80 ℃ for 8 hours to obtain B-graphite phase carbon nitride;
dispersing 3g of strontium nitrate and 1.8g of copper chloride in 25mL of 3% nitric acid solution, and uniformly mixing to obtain a first solution; mixing 26mL of absolute ethanol solution containing 8g of tetrabutyl titanate with the first solution uniformly, reacting for 6 hours at 250 ℃ in an inert atmosphere, cooling to room temperature, filtering, washing for 3 times by adopting absolute ethanol, and drying for 5 hours at 60 ℃ to obtain Cu-SrTiO 3 ；
Step four, under the inert atmosphere, 2g of the N-graphite phase carbon nitride is heated to 210 ℃ at a speed of 7 ℃/min for precalcination, after precalcination for 3 hours, 3.5g of the Cu-SrTiO is added when cooling to 70 DEG C 3 Uniformly mixing, heating to 500 ℃ at the heating rate of 10 ℃/min, performing secondary calcination for 4 hours, and cooling to room temperature to obtain the composite material Cu-SrTiO based on visible light catalysis 3 B-graphite phase carbon nitride.
Comparative example 1
This comparative example provides a photocatalytic material Cu-SrTiO 3 The method specifically comprises the following steps:
dispersing 3g of strontium nitrate and 1.8g of copper chloride in 25mL of 3% nitric acid solution, and uniformly mixing to obtain a first solution; mixing 26mL of absolute ethanol solution containing 8g of tetrabutyl titanate with the first solution uniformly, reacting for 6 hours at 250 ℃ in an inert atmosphere, cooling to room temperature, filtering, washing for 3 times by adopting absolute ethanol, and drying for 5 hours at 60 ℃ to obtain Cu-SrTiO 3 。
Comparative example 2
The comparative example provides a photocatalytic material S-graphite phase carbon nitride based on graphite phase carbon nitride, which specifically comprises the following steps:
grinding 5g of urea for 25min in an inert atmosphere, transferring into a ceramic crucible, heating to 530 ℃ in a sand bath at a heating rate of 12 ℃/min, preserving heat for 4h, and cooling to room temperature to obtain carbon nitride powder;
dispersing 5g of carbon nitride powder in 20mL of 0.1mol/L sulfuric acid solution, adjusting the pH to 4.5, transferring the system into a polytetrafluoroethylene-lined high-pressure reaction kettle, performing hydrothermal reaction at 180 ℃ for 3 hours, filtering, washing with deionized water for 3 times, washing with absolute ethyl alcohol for 3 times, and drying at 80 ℃ for 8 hours to obtain S-graphite phase carbon nitride;
comparative example 3
This comparative example provides a photocatalytic material Cu-SrTiO based on graphite-phase carbon nitride 3 The graphite phase carbon nitride specifically comprises the following steps:
grinding 5g of urea for 25min in an inert atmosphere, transferring into a ceramic crucible, heating to 530 ℃ in a sand bath at a heating rate of 12 ℃/min, preserving heat for 4h, and cooling to room temperature to obtain carbon nitride powder;
dispersing 3g of strontium nitrate and 1.8g of copper chloride in 25mL of 3% nitric acid solution, and uniformly mixing to obtain a first solution; mixing 26mL of absolute ethanol solution containing 8g of tetrabutyl titanate with the first solution uniformly, reacting for 6 hours at 250 ℃ in an inert atmosphere, cooling to room temperature, filtering, washing for 3 times by adopting absolute ethanol, and drying for 5 hours at 60 ℃ to obtain Cu-SrTiO 3 ；
Step four, under an inert atmosphere, 2g of the carbon nitride powder is preheated to 240 ℃ at a speed of 6 ℃ per minute, after 2h of precalcination, 3.5g of the Cu-SrTiO is added when the temperature is cooled to 70 DEG C 3 Uniformly mixing, heating to 450 ℃ at the heating rate of 8 ℃/min, performing secondary calcination for 4 hours, and cooling to room temperature to obtain the graphite-phase carbon nitride-based photocatalytic material Cu-SrTiO 3 Graphite phase carbon nitride.
In order to further embody the technical effects of the invention, the invention carries out the photocatalytic reduction of CO on the composite materials obtained in the examples 1-3 and the composite materials obtained in the comparative examples 1-3 2 The specific operation of the acetic acid production test is shown in the test examples, and the test results are shown in table 1 and fig. 1.
Test examples
Dispersing 0.1g of the graphite-phase carbon nitride-based photocatalytic material prepared in examples 1 to 3 and comparative examples 1 to 3 in 100mL of ultrapure water, charging into a 5L sealed reactor provided with a gas inlet and outlet, opening the gas inlet and outlet, and subjecting high-purity CO to a reaction 2 Gas and its preparation methodIntroducing into the reactor for 20min to remove oxygen in water and air in the reactor, and introducing CO 2 The gas and the high-purity hydrogen are kept for 30min until the pressure in the reactor is 0.8MPa, so that the catalyst and CO are reacted 2 And (3) reaching adsorption-desorption balance, carrying out photocatalysis reaction by taking a 20W LED lamp (lambda=450 nm) as a visible light source, detecting the concentration of acetic acid in the product by utilizing high performance liquid chromatography, and calculating the yield of the obtained acetic acid.
TABLE 1 photocatalytic reduction of CO for the composite materials obtained in examples and comparative examples 2 Test results for acetic acid production
As can be seen from Table 1, the photocatalytic material based on graphite-phase carbon nitride obtained in example 1 of the present invention is effective for catalytic reduction of CO 2 The yield of acetic acid obtained in 5h can be as high as 972.7. Mu. Mol. Catalytic reduction of CO according to comparative example 1 and comparative example 2 2 As can be seen from the case of (a), the metal-doped SrTiO forming the heterojunction structure 3 And the catalysis efficiency of the nonmetal modified graphite phase carbon nitride is obviously better than that of a single component, which also proves that the photocatalysis material provided by the invention has higher catalysis activity.
The foregoing description of the preferred embodiments of the invention is not intended to be limiting, but rather is intended to cover all modifications, equivalents, or alternatives falling within the spirit and principles of the invention.
Claims (10)
1. A photocatalytic material based on graphite phase carbon nitride is characterized in that the photocatalytic material is metal doped SrTiO 3 And/or nonmetallic modified graphite phase carbon nitride, wherein the metal is any one of Cu, zn, mo or La, and the nonmetallic is any one of B, S or N.
2. The photocatalytic material based on graphite phase carbon nitride according to claim 1, characterized in that it is Cu-SrTiO 3 Carbon nitride of/S-graphite phase, cu-SrTiO 3 B-graphite phase carbon nitride or Zn-SrTiO 3 Any one of N-graphite phase carbon nitride.
3. A method for preparing a photocatalytic material based on graphite-phase carbon nitride according to any one of claims 1 or 2, characterized in that: the method comprises the following steps:
firstly, grinding a nitrogen source in an inert atmosphere, heating to 500-550 ℃, preserving heat for 3-5 hours, and cooling to obtain carbon nitride powder;
dispersing the carbon nitride powder in an inorganic acid solution, adjusting the pH value to 4-5, performing hydrothermal reaction at 150-200 ℃, filtering, washing and drying to obtain nonmetal modified graphite phase carbon nitride; wherein the inorganic acid solution is any one of sulfuric acid solution, nitric acid solution or boric acid solution;
dispersing strontium salt and metal salt in an acid solution, and uniformly mixing to obtain a first solution; mixing alcoholic solution containing titanium compound with the first solution uniformly, reacting at 200-300 deg.C in inert atmosphere, cooling, filtering, washing, and drying to obtain metal doped SrTiO 3 The method comprises the steps of carrying out a first treatment on the surface of the Wherein the metal salt is any one of copper chloride, zinc chloride, molybdenum nitrate or lanthanum nitrate;
step four, pre-calcining the non-metal modified graphite phase carbon nitride at 200-250 ℃ in an inert atmosphere, and adding the metal doped SrTiO when cooling to 50-80 DEG C 3 And heating to 400-500 ℃ for secondary calcination, and cooling to obtain the graphite-phase carbon nitride-based photocatalytic material.
4. A method for preparing a photocatalytic material based on graphite-phase carbon nitride as set forth in claim 3, characterized in that: in the first step, the nitrogen source is any one of urea, melamine, cyanuric acid or dicyandiamide; and/or
In the first step, the temperature is raised in a temperature programming mode, and the temperature raising rate of the temperature programming is 10 ℃/min-15 ℃/min.
5. A method for preparing a photocatalytic material based on graphite-phase carbon nitride as set forth in claim 3, characterized in that: in the second step, the mass volume ratio of the carbon nitride powder to the inorganic acid solution with the concentration of 0.1mol/L-0.2mol/L is 1g:3mL-5mL; and/or
In the second step, the time of the hydrothermal reaction is 2-4 h.
6. A method for preparing a photocatalytic material based on graphite-phase carbon nitride as set forth in claim 3, characterized in that: in the third step, the strontium salt is any one of strontium nitrate, strontium sulfate or strontium acetate; and/or
In the third step, sr in the strontium salt 2+ And the molar ratio of metal ions in the metal salt is 1-1.2:1.
7. A method for preparing a photocatalytic material based on graphite-phase carbon nitride as set forth in claim 3, characterized in that: in the third step, the acid solution is nitric acid solution with the mass concentration of 3% -5%; and/or
In the third step, the volume ratio of the total mass of the strontium salt and the metal salt to the acid solution is 1g to 5mL-7mL; and/or
In the third step, the alcohol solution containing the titanium compound comprises tetrabutyl titanate and absolute ethyl alcohol, wherein the mass volume ratio of the tetrabutyl titanate to the absolute ethyl alcohol is 1g:3mL-5mL.
8. The method for preparing a photocatalytic material based on graphite-phase carbon nitride as set forth in claim 7, wherein: in the third step, the volume ratio of the alcoholic solution containing the titanium compound to the first solution is 1-1.1:1; and/or
In the third step, the reaction time is 4-8 h.
9. A method for preparing a photocatalytic material based on graphite-phase carbon nitride as set forth in claim 3, characterized in that: in the fourth step, the pre-calcination time is 1h-3h; and/or
Step fourIn the non-metal modified graphite phase carbon nitride and the metal doped SrTiO 3 The mass ratio of (2) is 1-2:1.5-2; and/or
In the fourth step, the secondary calcination time is 3-5 h; and/or
In the fourth step, the temperature of the pre-calcination and the secondary calcination is raised by adopting a temperature programming mode, wherein the temperature raising rate of the pre-calcination is 4 ℃/min-8 ℃/min, and the temperature raising rate of the secondary calcination is 5 ℃/min-10 ℃/min.
10. A photocatalytic material based on graphite-phase carbon nitride according to any one of claims 1 or 2 for photocatalytic CO 2 Application in reduction.
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