KR20170035579A - Photocatalyst containing titanium dioxide supported reduced graphene oxide, and water treatment method using the same - Google Patents
Photocatalyst containing titanium dioxide supported reduced graphene oxide, and water treatment method using the same Download PDFInfo
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- KR20170035579A KR20170035579A KR1020150134604A KR20150134604A KR20170035579A KR 20170035579 A KR20170035579 A KR 20170035579A KR 1020150134604 A KR1020150134604 A KR 1020150134604A KR 20150134604 A KR20150134604 A KR 20150134604A KR 20170035579 A KR20170035579 A KR 20170035579A
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- photocatalyst
- titanium dioxide
- aqueous solution
- organic compound
- graphene oxide
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- 239000011941 photocatalyst Substances 0.000 title claims abstract description 145
- GWEVSGVZZGPLCZ-UHFFFAOYSA-N Titan oxide Chemical compound O=[Ti]=O GWEVSGVZZGPLCZ-UHFFFAOYSA-N 0.000 title claims abstract description 132
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 title claims abstract description 70
- 229910021389 graphene Inorganic materials 0.000 title claims abstract description 65
- 239000004408 titanium dioxide Substances 0.000 title claims abstract description 63
- 238000000034 method Methods 0.000 title claims abstract description 37
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 title abstract description 69
- 150000002894 organic compounds Chemical class 0.000 claims abstract description 83
- 239000007864 aqueous solution Substances 0.000 claims description 76
- 229910010413 TiO 2 Inorganic materials 0.000 claims description 44
- GUTLYIVDDKVIGB-UHFFFAOYSA-N cobalt atom Chemical compound [Co] GUTLYIVDDKVIGB-UHFFFAOYSA-N 0.000 claims description 22
- RTAQQCXQSZGOHL-UHFFFAOYSA-N Titanium Chemical compound [Ti] RTAQQCXQSZGOHL-UHFFFAOYSA-N 0.000 claims description 21
- 229910017052 cobalt Inorganic materials 0.000 claims description 21
- 239000010941 cobalt Substances 0.000 claims description 21
- 239000010936 titanium Substances 0.000 claims description 16
- 229910052719 titanium Inorganic materials 0.000 claims description 16
- 230000001678 irradiating effect Effects 0.000 claims description 15
- MHAJPDPJQMAIIY-UHFFFAOYSA-N Hydrogen peroxide Chemical group OO MHAJPDPJQMAIIY-UHFFFAOYSA-N 0.000 claims description 12
- 239000003795 chemical substances by application Substances 0.000 claims description 11
- 238000001914 filtration Methods 0.000 claims description 9
- -1 lithium aluminum hydride Chemical compound 0.000 claims description 9
- 238000002347 injection Methods 0.000 claims description 7
- 239000007924 injection Substances 0.000 claims description 7
- 238000004519 manufacturing process Methods 0.000 claims description 7
- 239000006185 dispersion Substances 0.000 claims description 6
- 239000012279 sodium borohydride Substances 0.000 claims description 6
- 229910000033 sodium borohydride Inorganic materials 0.000 claims description 6
- 239000003638 chemical reducing agent Substances 0.000 claims description 5
- 238000002156 mixing Methods 0.000 claims description 5
- 239000000203 mixture Substances 0.000 claims description 5
- 238000010438 heat treatment Methods 0.000 claims description 4
- 239000002243 precursor Substances 0.000 claims description 4
- 229910000104 sodium hydride Inorganic materials 0.000 claims description 4
- 229910010082 LiAlH Inorganic materials 0.000 claims description 2
- KEAYESYHFKHZAL-UHFFFAOYSA-N Sodium Chemical compound [Na] KEAYESYHFKHZAL-UHFFFAOYSA-N 0.000 claims description 2
- 239000012280 lithium aluminium hydride Substances 0.000 claims description 2
- 229910052751 metal Inorganic materials 0.000 claims description 2
- 239000002184 metal Substances 0.000 claims description 2
- 239000012312 sodium hydride Substances 0.000 claims description 2
- ISPYQTSUDJAMAB-UHFFFAOYSA-N 2-chlorophenol Chemical compound OC1=CC=CC=C1Cl ISPYQTSUDJAMAB-UHFFFAOYSA-N 0.000 description 49
- 230000000052 comparative effect Effects 0.000 description 20
- VXUYXOFXAQZZMF-UHFFFAOYSA-N titanium(IV) isopropoxide Chemical compound CC(C)O[Ti](OC(C)C)(OC(C)C)OC(C)C VXUYXOFXAQZZMF-UHFFFAOYSA-N 0.000 description 16
- 239000000243 solution Substances 0.000 description 12
- 238000003756 stirring Methods 0.000 description 10
- QTBSBXVTEAMEQO-UHFFFAOYSA-N Acetic acid Chemical compound CC(O)=O QTBSBXVTEAMEQO-UHFFFAOYSA-N 0.000 description 9
- YXFVVABEGXRONW-UHFFFAOYSA-N Toluene Chemical compound CC1=CC=CC=C1 YXFVVABEGXRONW-UHFFFAOYSA-N 0.000 description 9
- 239000012153 distilled water Substances 0.000 description 8
- 238000011156 evaluation Methods 0.000 description 8
- 239000000706 filtrate Substances 0.000 description 8
- 229910052724 xenon Inorganic materials 0.000 description 8
- FHNFHKCVQCLJFQ-UHFFFAOYSA-N xenon atom Chemical compound [Xe] FHNFHKCVQCLJFQ-UHFFFAOYSA-N 0.000 description 8
- 230000031700 light absorption Effects 0.000 description 7
- 238000001179 sorption measurement Methods 0.000 description 7
- UHOVQNZJYSORNB-UHFFFAOYSA-N Benzene Chemical compound C1=CC=CC=C1 UHOVQNZJYSORNB-UHFFFAOYSA-N 0.000 description 6
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 6
- 229910052760 oxygen Inorganic materials 0.000 description 6
- 239000001301 oxygen Substances 0.000 description 6
- 230000001699 photocatalysis Effects 0.000 description 6
- 238000001782 photodegradation Methods 0.000 description 6
- 239000000126 substance Substances 0.000 description 6
- 229910052799 carbon Inorganic materials 0.000 description 5
- LZZYPRNAOMGNLH-UHFFFAOYSA-M Cetrimonium bromide Chemical compound [Br-].CCCCCCCCCCCCCCCC[N+](C)(C)C LZZYPRNAOMGNLH-UHFFFAOYSA-M 0.000 description 4
- LFQSCWFLJHTTHZ-UHFFFAOYSA-N Ethanol Chemical compound CCO LFQSCWFLJHTTHZ-UHFFFAOYSA-N 0.000 description 4
- 238000004833 X-ray photoelectron spectroscopy Methods 0.000 description 4
- 238000002835 absorbance Methods 0.000 description 4
- 230000000694 effects Effects 0.000 description 4
- 238000002474 experimental method Methods 0.000 description 4
- 230000001105 regulatory effect Effects 0.000 description 4
- UFMZWBIQTDUYBN-UHFFFAOYSA-N cobalt dinitrate Chemical compound [Co+2].[O-][N+]([O-])=O.[O-][N+]([O-])=O UFMZWBIQTDUYBN-UHFFFAOYSA-N 0.000 description 3
- 229910001981 cobalt nitrate Inorganic materials 0.000 description 3
- 238000000354 decomposition reaction Methods 0.000 description 3
- 230000003287 optical effect Effects 0.000 description 3
- 239000011148 porous material Substances 0.000 description 3
- 239000002516 radical scavenger Substances 0.000 description 3
- UOCLXMDMGBRAIB-UHFFFAOYSA-N 1,1,1-trichloroethane Chemical compound CC(Cl)(Cl)Cl UOCLXMDMGBRAIB-UHFFFAOYSA-N 0.000 description 2
- 241001465754 Metazoa Species 0.000 description 2
- CTQNGGLPUBDAKN-UHFFFAOYSA-N O-Xylene Chemical compound CC1=CC=CC=C1C CTQNGGLPUBDAKN-UHFFFAOYSA-N 0.000 description 2
- 238000010521 absorption reaction Methods 0.000 description 2
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- 230000003247 decreasing effect Effects 0.000 description 2
- 238000002149 energy-dispersive X-ray emission spectroscopy Methods 0.000 description 2
- 238000005516 engineering process Methods 0.000 description 2
- TUJKJAMUKRIRHC-UHFFFAOYSA-N hydroxyl Chemical compound [OH] TUJKJAMUKRIRHC-UHFFFAOYSA-N 0.000 description 2
- 230000036244 malformation Effects 0.000 description 2
- 238000012986 modification Methods 0.000 description 2
- 230000004048 modification Effects 0.000 description 2
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- 238000006303 photolysis reaction Methods 0.000 description 2
- 231100000331 toxic Toxicity 0.000 description 2
- 230000002588 toxic effect Effects 0.000 description 2
- 239000008096 xylene Substances 0.000 description 2
- KZEVSDGEBAJOTK-UHFFFAOYSA-N 1-(2,4,6,7-tetrahydrotriazolo[4,5-c]pyridin-5-yl)-2-[5-[2-[[3-(trifluoromethoxy)phenyl]methylamino]pyrimidin-5-yl]-1,3,4-oxadiazol-2-yl]ethanone Chemical compound N1N=NC=2CN(CCC=21)C(CC=1OC(=NN=1)C=1C=NC(=NC=1)NCC1=CC(=CC=C1)OC(F)(F)F)=O KZEVSDGEBAJOTK-UHFFFAOYSA-N 0.000 description 1
- YJLUBHOZZTYQIP-UHFFFAOYSA-N 2-[5-[2-(2,3-dihydro-1H-inden-2-ylamino)pyrimidin-5-yl]-1,3,4-oxadiazol-2-yl]-1-(2,4,6,7-tetrahydrotriazolo[4,5-c]pyridin-5-yl)ethanone Chemical group C1C(CC2=CC=CC=C12)NC1=NC=C(C=N1)C1=NN=C(O1)CC(=O)N1CC2=C(CC1)NN=N2 YJLUBHOZZTYQIP-UHFFFAOYSA-N 0.000 description 1
- ZATJSNLHOCRDEW-UHFFFAOYSA-N 2-chlorophenol titanium Chemical compound [Ti].OC1=CC=CC=C1Cl ZATJSNLHOCRDEW-UHFFFAOYSA-N 0.000 description 1
- IQUPABOKLQSFBK-UHFFFAOYSA-N 2-nitrophenol Chemical compound OC1=CC=CC=C1[N+]([O-])=O IQUPABOKLQSFBK-UHFFFAOYSA-N 0.000 description 1
- CONKBQPVFMXDOV-QHCPKHFHSA-N 6-[(5S)-5-[[4-[2-(2,3-dihydro-1H-inden-2-ylamino)pyrimidin-5-yl]piperazin-1-yl]methyl]-2-oxo-1,3-oxazolidin-3-yl]-3H-1,3-benzoxazol-2-one Chemical compound C1C(CC2=CC=CC=C12)NC1=NC=C(C=N1)N1CCN(CC1)C[C@H]1CN(C(O1)=O)C1=CC2=C(NC(O2)=O)C=C1 CONKBQPVFMXDOV-QHCPKHFHSA-N 0.000 description 1
- 206010007269 Carcinogenicity Diseases 0.000 description 1
- ZAMOUSCENKQFHK-UHFFFAOYSA-N Chlorine atom Chemical compound [Cl] ZAMOUSCENKQFHK-UHFFFAOYSA-N 0.000 description 1
- ISWSIDIOOBJBQZ-UHFFFAOYSA-N Phenol Chemical compound OC1=CC=CC=C1 ISWSIDIOOBJBQZ-UHFFFAOYSA-N 0.000 description 1
- 230000002292 Radical scavenging effect Effects 0.000 description 1
- 208000000453 Skin Neoplasms Diseases 0.000 description 1
- 238000000441 X-ray spectroscopy Methods 0.000 description 1
- 229910021536 Zeolite Inorganic materials 0.000 description 1
- 125000000217 alkyl group Chemical group 0.000 description 1
- PNEYBMLMFCGWSK-UHFFFAOYSA-N aluminium oxide Inorganic materials [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 description 1
- 230000008901 benefit Effects 0.000 description 1
- 230000033228 biological regulation Effects 0.000 description 1
- 230000000711 cancerogenic effect Effects 0.000 description 1
- 150000001721 carbon Chemical group 0.000 description 1
- 231100000315 carcinogenic Toxicity 0.000 description 1
- 231100000260 carcinogenicity Toxicity 0.000 description 1
- 230000007670 carcinogenicity Effects 0.000 description 1
- 239000003054 catalyst Substances 0.000 description 1
- 230000003197 catalytic effect Effects 0.000 description 1
- 238000006555 catalytic reaction Methods 0.000 description 1
- 230000008859 change Effects 0.000 description 1
- 239000000460 chlorine Substances 0.000 description 1
- 229910052801 chlorine Inorganic materials 0.000 description 1
- 150000001805 chlorine compounds Chemical class 0.000 description 1
- 239000000470 constituent Substances 0.000 description 1
- 230000001276 controlling effect Effects 0.000 description 1
- 239000003599 detergent Substances 0.000 description 1
- 201000010099 disease Diseases 0.000 description 1
- 208000037265 diseases, disorders, signs and symptoms Diseases 0.000 description 1
- 230000001747 exhibiting effect Effects 0.000 description 1
- 239000000417 fungicide Substances 0.000 description 1
- 230000009036 growth inhibition Effects 0.000 description 1
- 229910052736 halogen Inorganic materials 0.000 description 1
- 239000004009 herbicide Substances 0.000 description 1
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- 238000005259 measurement Methods 0.000 description 1
- 239000012528 membrane Substances 0.000 description 1
- 239000002071 nanotube Substances 0.000 description 1
- KBJMLQFLOWQJNF-UHFFFAOYSA-N nickel(ii) nitrate Chemical compound [Ni+2].[O-][N+]([O-])=O.[O-][N+]([O-])=O KBJMLQFLOWQJNF-UHFFFAOYSA-N 0.000 description 1
- 125000004430 oxygen atom Chemical group O* 0.000 description 1
- SOQBVABWOPYFQZ-UHFFFAOYSA-N oxygen(2-);titanium(4+) Chemical group [O-2].[O-2].[Ti+4] SOQBVABWOPYFQZ-UHFFFAOYSA-N 0.000 description 1
- 239000000575 pesticide Substances 0.000 description 1
- 238000006552 photochemical reaction Methods 0.000 description 1
- 230000015843 photosynthesis, light reaction Effects 0.000 description 1
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- 239000012855 volatile organic compound Substances 0.000 description 1
- 239000002351 wastewater Substances 0.000 description 1
- 239000010457 zeolite Substances 0.000 description 1
Images
Classifications
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- B01J35/004—
-
- 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
- B01J21/00—Catalysts comprising the elements, oxides, or hydroxides of magnesium, boron, aluminium, carbon, silicon, titanium, zirconium, or hafnium
- B01J21/06—Silicon, titanium, zirconium or hafnium; Oxides or hydroxides thereof
- B01J21/063—Titanium; Oxides or hydroxides thereof
-
- 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
- B01J23/74—Iron group metals
- B01J23/75—Cobalt
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- B01J37/00—Processes, in general, for preparing catalysts; Processes, in general, for activation of catalysts
- B01J37/0009—Use of binding agents; Moulding; Pressing; Powdering; Granulating; Addition of materials ameliorating the mechanical properties of the product catalyst
- B01J37/0018—Addition of a binding agent or of material, later completely removed among others as result of heat treatment, leaching or washing,(e.g. forming of pores; protective layer, desintegrating by heat)
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- B01J37/00—Processes, in general, for preparing catalysts; Processes, in general, for activation of catalysts
- B01J37/02—Impregnation, coating or precipitation
- B01J37/0201—Impregnation
-
- C—CHEMISTRY; METALLURGY
- C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F1/00—Treatment of water, waste water, or sewage
- C02F1/28—Treatment of water, waste water, or sewage by sorption
- C02F1/281—Treatment of water, waste water, or sewage by sorption using inorganic sorbents
-
- C—CHEMISTRY; METALLURGY
- C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F1/00—Treatment of water, waste water, or sewage
- C02F1/28—Treatment of water, waste water, or sewage by sorption
- C02F1/288—Treatment of water, waste water, or sewage by sorption using composite sorbents, e.g. coated, impregnated, multi-layered
-
- C—CHEMISTRY; METALLURGY
- C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F1/00—Treatment of water, waste water, or sewage
- C02F1/30—Treatment of water, waste water, or sewage by irradiation
- C02F1/32—Treatment of water, waste water, or sewage by irradiation with ultraviolet light
-
- C—CHEMISTRY; METALLURGY
- C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F1/00—Treatment of water, waste water, or sewage
- C02F1/72—Treatment of water, waste water, or sewage by oxidation
- C02F1/722—Oxidation by peroxides
-
- C—CHEMISTRY; METALLURGY
- C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F1/00—Treatment of water, waste water, or sewage
- C02F1/72—Treatment of water, waste water, or sewage by oxidation
- C02F1/725—Treatment of water, waste water, or sewage by oxidation by catalytic oxidation
-
- C—CHEMISTRY; METALLURGY
- C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F2305/00—Use of specific compounds during water treatment
- C02F2305/10—Photocatalysts
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- 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
- Y02W—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO WASTEWATER TREATMENT OR WASTE MANAGEMENT
- Y02W10/00—Technologies for wastewater treatment
- Y02W10/30—Wastewater or sewage treatment systems using renewable energies
- Y02W10/37—Wastewater or sewage treatment systems using renewable energies using solar energy
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- Chemical & Material Sciences (AREA)
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- Hydrology & Water Resources (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Life Sciences & Earth Sciences (AREA)
- Environmental & Geological Engineering (AREA)
- Water Supply & Treatment (AREA)
- Materials Engineering (AREA)
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Abstract
Description
The present invention relates to a photocatalyst comprising reduced graphene oxide on which titanium dioxide is supported and a method of water treatment using the same. More particularly, the present invention relates to a photocatalyst containing titanium dioxide supported on graphene oxide (Co-TiO 2 / rGO) reduced with cobalt-doped titanium dioxide The present invention relates to a water treatment method for purifying polluted water by decomposing organic compounds in polluted water by using a photocatalyst having a structure as a photocatalyst and a catalytic reaction of the photocatalyst.
BACKGROUND ART Aromatic organic compounds such as benzene, xylene and toluene are widely used industrially as a solvent, a detergent and the like as highly volatile organic compounds. They are also used in agriculture as organic pesticides such as insecticides, fungicides and herbicides. These organic compounds are toxic to humans, exhibit carcinogenicity, contain growth and developmental damage to animals and plants, induce malformations, and the present manufacturing, use and disposal are strictly regulated. Despite these regulations, however, due to the high cost and low efficiency of conventional water treatment techniques, many industries fail to comply with the above regulatory standards.
Accordingly, various techniques for removing organic compounds present in water have been studied in various ways. For example,
However, since the technologies developed until now include titanium dioxide as a photocatalyst, ultraviolet ray irradiation is required during water treatment. However, there is a problem in that the ultraviolet rays are irradiated with ultraviolet lamps having a high facility cost. In addition, ultraviolet rays irradiated during the water treatment process are harmful to living organisms because they cause diseases such as skin cancer when they are exposed to living organisms.
Therefore, it is urgently required to develop a water treatment photocatalyst that exhibits photocatalytic activity even at a low energy wavelength, such as visible light, and has excellent photodegradation efficiency for organic compounds remaining in water.
Accordingly, an object of the present invention is to provide a photocatalyst exhibiting high photodegradation efficiency for an organic compound remaining in water even at a low energy wavelength in the visible light region.
Another object of the present invention is to provide a method for producing the photocatalyst.
It is still another object of the present invention to provide a water treatment method using the photocatalyst.
Another object of the present invention is to provide a water treatment apparatus including the photocatalyst.
In order to achieve the above object, the present invention provides, in one embodiment,
A cobalt-doped titanium dioxide-supported reduced graphene oxide,
And has a band gap of 2.7 to 2.9 eV in a wavelength range of 400 nm to 800 nm.
In addition, the present invention, in one embodiment,
Obtaining graphene oxide (Co-TiO 2 / GO) carrying cobalt-doped titanium dioxide from a dispersion containing graphene oxide (GO) and cobalt-doped titanium dioxide (Co-TiO 2 ); And
(Co-TiO 2 / GO) doped with titanium dioxide to obtain a reduced graphene oxide (Co-TiO 2 / rGO) carrying cobalt-doped titanium dioxide, thereby preparing a photocatalyst ≪ / RTI >
Further, the present invention, in one embodiment,
Contacting an aqueous solution containing an organic compound with a photocatalyst containing reduced cobalt-doped titanium dioxide-supported reduced graphene oxide (Co-TiO 2 / rGO) and adsorbing the organic compound in the aqueous solution to the photocatalyst; And
Irradiating the photocatalyst on which the organic compound is adsorbed by light irradiation,
Wherein the light has a wavelength of 360 to 850 nm.
In addition, the present invention, in one embodiment,
An injection port into which an aqueous solution containing an organic compound is injected;
A filtration unit adsorbing an organic compound of an aqueous solution injected from the injection port and containing the photocatalyst (Co-TiO 2 / rGO);
An outlet through which the aqueous solution from which the organic compound has been removed is discharged; And
And a light irradiating part for irradiating light to the filtering part.
The photocatalyst according to the present invention has a structure in which cobalt-doped titanium dioxide is supported on reduced graphene oxide, so that an organic compound remaining in the water can be photo-decomposed at a high efficiency even in the wavelength region of visible light, The organic compound can be adsorbed and removed even under the condition not irradiated, so that it can be usefully used as a photocatalyst for water treatment.
1 is an image of a photocatalyst (Co-TiO 2 / rGO) according to the present invention analyzed by a scanning electron microscope (SEM).
2 is an image of an energy dispersive X-ray spectroscopy (EXD) of a photocatalyst (Co-TiO 2 / rGO) according to the present invention.
FIG. 3 is a graph showing X-ray photoelectron spectroscopy (XPS) of each type of photocatalyst.
FIG. 4 is a graph showing absorbance and band gap energy for each type of photocatalyst. FIG. 4 (a) is a graph showing absorbance according to wavelength, and FIG. 4 (b) is a graph showing band gap energy.
5 is a graph showing the removal efficiency of organic compounds according to the pH of each type of photocatalyst.
FIG. 6 is a graph showing the removal efficiency of the organic compound according to the concentration of the organic compound present in the aqueous solution and the water treatment time.
7 is a graph showing the removal efficiency of an organic compound depending on the amount of hydrogen peroxide to be added to the aqueous solution.
FIGS. 8 and 11 are graphs showing removal efficiencies of organic compounds according to the average power during light irradiation for each photocatalyst type. FIG.
9 is a graph showing removal efficiency of organic compounds according to water treatment time for each contact amount of the photocatalyst.
10 is a graph showing equilibrium isotherm data at the time of photocatalytic decomposition according to the types of photocatalysts: (a) is the result obtained by the Langmuir method, (b) Freundlich method.
While the invention is susceptible to various modifications and alternative forms, specific embodiments thereof are shown by way of example in the drawings and will herein be described in detail.
It should be understood, however, that the invention is not intended to be limited to the particular embodiments, but includes all modifications, equivalents, and alternatives falling within the spirit and scope of the invention.
In the present invention, the terms "comprising" or "having ", and the like, specify that the presence of a feature, a number, a step, an operation, an element, a component, But do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, or combinations thereof.
It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory and are intended to provide further explanation of the invention as claimed.
In the present invention, "ultraviolet light (UV light)" refers to light having a shorter wavelength than visible light and a longer wavelength than X-ray. Light having a higher energy than a visible light ray belonging to a wavelength range of about 10 to 390 nm it means.
In the present invention, the term "visible light" means light having a wavelength shorter than that of infrared light and having a wavelength longer than that of ultraviolet light, the light belonging to the wavelength range of about 390 to 820 nm, , Visible light, infrared light, etc.).
The present invention relates to a photocatalyst containing reduced titanium oxide-supported reduced graphene oxide (Co-TiO 2 / rGO) and a water treatment method using the same.
Aromatic organic compounds such as benzene, xylene, toluene and the like contain toxic and carcinogenic substances to humans and exhibit growth inhibition and malformation induction against animals and plants, and their manufacture, use and disposal at present are strictly regulated. However, due to the high cost and low efficiency of conventional water treatment techniques, many industries do not meet the above regulatory standards. To solve this problem, the technologies developed until now include titanium dioxide as a photocatalyst, and ultraviolet rays are required to be irradiated during water treatment. The ultraviolet rays irradiated are not only harmful to an organism but also have a high cost There is a limit.
Accordingly, the present invention provides a photocatalyst comprising reduced graphene oxide on which titanium dioxide is supported, and a water treatment method using the same.
The photocatalyst according to the present invention has a structure in which cobalt-doped titanium dioxide is supported on reduced graphene oxide, so that an organic compound remaining in the water can be photo-decomposed at a high efficiency even in the wavelength region of visible light, The organic compound can be adsorbed and removed even under the condition not irradiated, so that it can be usefully used as a photocatalyst for water treatment.
Hereinafter, the present invention will be described in detail.
The present invention, in one embodiment,
The present invention provides a photocatalyst comprising reduced graphene oxide (Co-TiO 2 / rGO) on which cobalt-doped titanium dioxide is supported.
The photocatalyst according to the present invention has a two-dimensional planar structure such as a honeycomb structure and a honeycomb lattice structure. The photocatalyst can support cobalt-doped titanium dioxide. The reduced graphene oxide, which is complexed with titanium dioxide, rGO). At this time, the titanium dioxide is doped with cobalt to form a chemical bond (Ti-O-Co) in which cobalt and oxygen atoms are common to each other. Due to chemical bonding with the cobalt, photo- the efficiency of the photocatalyst can be increased by increasing the transfer efficiency of the electrons. The titanium dioxide is supported on reduced graphene oxide to form a chemical bond (CO-Ti-O-Co and / or C-Ti-O-Co) between the titanium atom and the carbon atom of the reduced graphene oxide, In the reaction, titanium dioxide is not separated from the reduced graphene oxide surface, and more electrons and holes are formed, thereby increasing photocatalytic activity.
In addition, the photocatalyst may include titanium dioxide, cobalt and reduced graphene oxide as a main component, and titanium dioxide as a main component.
As an example, the photocatalyst may comprise 100 parts by weight of titanium dioxide; 0.1 to 1 part by weight of cobalt; And 1 to 10 parts by weight of reduced graphene oxide; specifically, 100 parts by weight of titanium dioxide; 0.1 to 0.6 parts by weight of cobalt; And 4 to 7 parts by weight of reduced graphene oxide.
The photocatalyst according to the present invention has a large specific surface area and has the above-mentioned component content including titanium dioxide as a main component, which exhibits catalytic activity upon light irradiation. As a result, the photocatalyst exhibits excellent optical activity Lt; / RTI >
For example, titanium dioxide (TiO 2 ), cobalt-doped titanium dioxide (Co-TiO 2 ), iii) titanium dioxide-supported reduced graphene oxide (TiO 2 / rGO), which are conventionally used as photocatalysts, And iv) evaluation of the degree of absorption of the photocatalyst (Co-TiO 2 / rGO) according to the present invention on light in the region of 200 to 800 nm. As a result, The light absorption intensity was about 90% or more and the light absorption intensity was decreased as the wavelength was increased. In this case, the degree of decrease is about 15% in the case of titanium dioxide (TiO 2 ), ii) about 35% in the case of cobalt-doped titanium dioxide (Co-TiO 2 ), and iii) titanium dioxide (TiO 2 / rGO) exhibited an average light absorption intensity of about 20% in the supported reduced graphene oxide (TiO 2 / rGO). Iv) The photocatalyst (Co-TiO 2 / rGO) according to the present invention has an average light absorption of at least about 40%, more specifically at least about 41%, at least about 42%, or at least about 43% Strength. This indicates that the photocatalyst according to the present invention has a structure in which cobalt-doped titanium dioxide is supported on reduced graphene oxide, and the photon energy is reduced and electrons are easily 'charge transitioned'.
As another example, the photocatalyst according to the present invention may have a band gap of 2.7 to 2.9 eV in the wavelength range of 400 nm to 800 nm, specifically 2.75 to 2.85 eV; Or 2.80 to 2.85 eV. Photocatalytic photochemical reaction occurs when electrons are excited from the valence band to the conduction band during the irradiation of light. Electrons are formed in the conduction band and holes are formed in the valence band. The electrons and holes thus formed form the surface of the photocatalyst It can diffuse and participate in the redox reaction and decompose the contaminants remaining in the water. The photocatalyst of the present invention has an advantage that the photoreaction can be performed with high efficiency even at the wavelength of the visible light region (390 to 820 nm) having low energy by reducing the interval between the valence band and the conduction band, that is, the band gap to the above range have.
Meanwhile, the photocatalyst according to the present invention can have a high surface area including pores. The photocatalyst may include pores, including reduced graphene oxide having a two-dimensional planar structure such as a honeycomb structure and a honeycomb lattice structure. Accordingly, contaminants remaining in the water under a condition that a high surface area is not irradiated, So that it can be removed.
At this time, the photocatalyst has an average diameter of 8 to 10 nm, specifically, 8.5 to 9.5 nm; Or 8.5 to 9 nm, wherein the pore volume is 0.1 to 0.3 cm < 3 > / g; 0.2 to 0.3 cm < 3 > / g; Or 0.25 to 0.3 cm < 3 > / g. The average BET specific surface area of the photocatalyst may be 100 to 140 m 2 / g, specifically 100 to 130 m 2 / g; 100 to 120 m < 2 > / g; 115 to 130 m < 2 > / g; 115 to 125 m < 2 > / g; Or from 115 to 120 m < 2 > / g.
In addition, the present invention, in one embodiment,
Obtaining cobalt-doped titanium dioxide-supported graphene oxide from a dispersion containing graphene oxide and cobalt-doped titanium dioxide; And
And heat treating the graphen oxide loaded with titanium dioxide to obtain a reduced graphene oxide carrying titanium dioxide doped with cobalt.
A method of manufacturing a photocatalyst according to the present invention includes the steps of mixing cobalt-doped titanium dioxide (Co-TiO 2 ) and oxidized graphene oxide (GO) the graphene oxide (Co-TiO 2 / GO) to obtain, thus obtained graphene oxide (Co-TiO 2 / GO) by heat-treating the graphene oxide (GO) a photocatalyst of the reduced, and the separation form (Co-TiO 2 / rGO) can be obtained.
Here, the above-mentioned titanium dioxide (Co-TiO 2 ) is not particularly limited and can be used as long as it is doped with cobalt. As an example, in the step of obtaining the titanium dioxide-supported graphene oxide, before the dispersed dispersion of cobalt-doped titanium dioxide (Co-TiO 2 ) and oxidized graphene oxide (GO) A titanium precursor and a metal cobalt (Co) may be sequentially added with water and a reducing agent, and titanium dioxide doped with cobalt may be used.
At this time, the titanium precursor is not particularly limited as long as it is reduced to form titanium dioxide (TiO 2 ). For example, the titanium precursor may be titanium isopropoxide (TIP) or the like.
The reducing agent may be at least one selected from the group consisting of sodium hydride (NaH), sodium borohydride (NaBH 4 ), lithium aluminum hydride (LiAlH 4 ) have. Specifically, sodium borohydride (NaBH 4 ) may be used as the reducing agent.
In the photocatalyst production method of the present invention, the step of heat-treating the graphene oxide (Co-TiO 2 / GO) bearing titanium dioxide is a step of reducing and stripping the oxidized graphene oxide, Can be carried out for 1 to 60 minutes in the temperature range of 400 to 600 캜, which is excellent. Specifically, the heat treatment temperature is 450 to 600 占 폚; 450 to 550 占 폚; Or 475 to 525 < 0 > C. The heat treatment time is 1 to 30 minutes; 20 to 35 minutes; 40 to 60 minutes; Or 1 to 10 minutes.
Further, the present invention, in one embodiment,
Mixing an aqueous solution containing an organic compound with a photocatalyst containing reduced graphene oxide on which cobalt-doped titanium dioxide is supported; and adsorbing an organic compound in an aqueous solution to a photocatalyst; And
Irradiating the photocatalyst on which the organic compound is adsorbed by light irradiation,
Wherein the light has a wavelength of 360 to 850 nm.
In the water treatment method according to the present invention, the organic compound is adsorbed by bringing the photocatalyst of the present invention described above into contact with an aqueous solution containing an organic compound, and irradiated with light having a wavelength in the visible light region to decompose the organic compound, Can be removed with high efficiency.
At this time, the light may be a light having a wavelength of 360 to 850 nm, specifically, 380 to 800 nm; 390 to 820 nm; 400 to 800 nm; 400 to 700 nm; 450 to 750 nm; 500 to 800 nm; 450 to 650 nm; 500 to 720 nm; 380 to 500 nm; And may have a wavelength ranging from 380 to 450 nm.
In order to maximize the adsorption rate of the organic compound and the photocatalyst in the aqueous solution, the pH of the aqueous solution containing the organic compound may be 6 to 8, and the concentration of the organic compound contained in the aqueous solution may be 200 mg or less. Specifically, the pH of the aqueous solution is 5 to 7; 6 to 6.5; 5.0 to 6; 5.5 to 7; 5.5 to 6.5; Or 5.7 to 6.3, and the concentration of the organic compound is 150 mg or less per liter of the aqueous solution containing the organic compound; 140 mg or less; 130 mg or less; Or 115 mg or less.
The contact amount of the photocatalyst in contact with the organic compound in the aqueous solution may be 10 parts by weight or less per 1000 parts by weight of the aqueous solution containing the organic compound in a concentration of 90 to 110 mg / L, and more specifically, 7.5 parts by weight or less per 1000 parts by weight of the aqueous solution; 5 parts by weight or less; 5 to 0.5 parts by weight; 4 to 0.5 parts by weight; Or 3.5 to 0.8 parts by weight. The water treatment method according to the present invention can prevent the photodegradation rate from being lowered due to the shielding effect caused by excessive photocatalyst by controlling the contact amount of the photocatalyst in contact with the organic compound remaining in the aqueous solution within the above range .
In addition, light irradiation can be carried out without particular limitation, provided that the photocatalyst can be irradiated with a sufficient amount of light. As an example, with an average power of 50 to 200 W, in particular between 50 and 150 W; 100 to 200 W; Or an average power of 75 to 125 W.
The type of the organic compound is not particularly limited, but includes, for example, a C 6 -C 14 aryl compound substituted or unsubstituted with C 1 -4 alkyl, nitro, hydroxy, or halogen Aromatic organic compounds and organic chlorides including chlorine, and specifically, toluene, phenol, nitrophenol, chlorophenol (CP), and trichloroethane (TCE , trichloroethane), and the like.
Further, the water treatment method may further include a step of mixing the feedstock with an aqueous solution containing the organic compound before the step of adsorbing the organic compound of the aqueous solution to the photocatalyst. The radicals decomposes the supplied water during the optical hydroxyl radical (· OH -), and form a hydroxyl radical thus formed may serve as a catalyst for decomposing organic compounds which remain in the aqueous solution. The radical supply agent is not particularly limited as long as it can stably form radicals in an aqueous solution by light irradiation. As one example, hydrogen peroxide (H 2 O 2 ) can be used. The radical scavenger may be used in an amount of 0.0001 to 0.1 part by weight based on 100 parts by weight of the aqueous solution containing the organic compound in a concentration of 90 to 110 mg / L, and specifically 0.0005 to 0.1 part by weight, 0.0005 to 0.05 part by weight , Or 0.001 to 0.01 part by weight. In the present invention, by using the radical-supplying agent within the above-mentioned content range, the radical supplying agent is not sufficiently supplied and the effect of improving the water treatment efficiency is insufficient, or the radical formed by photolysis using an excess amount is prevented from reacting with the excess radical- can do.
In addition, the present invention, in one embodiment,
An injection port into which an aqueous solution containing an organic compound is injected;
A filtration unit including a photocatalyst according to the present invention for adsorbing an organic compound in an aqueous solution injected from the injection port;
An outlet through which the aqueous solution from which the organic compound has been removed is discharged; And
And a light irradiating part for irradiating light to the filtering part.
The water treatment apparatus according to the present invention includes a filtration unit including a photocatalyst including reduced graphene oxide on which cobalt-doped titanium dioxide is supported, and can decompose the aromatic organic compound contained in the aqueous solution at a high ratio, The effect of removing the organic compounds remaining in the aqueous solution such as wastewater is excellent.
Although the shape of the water treatment apparatus is not particularly limited, an injection port through which an aqueous solution containing an organic compound is injected is disposed in an upper portion of a filtration unit provided with a adsorption bed including a photocatalyst of the present invention, May have a structure in which a discharge port through which the aqueous solution from which the organic compound is removed through the adsorption bed of the filtration part is located.
The water treatment apparatus may include a light irradiating unit for irradiating light into the filter unit to decompose organic compounds adsorbed on the photocatalyst. If the light irradiating unit is capable of irradiating light having a wavelength of 360 to 850 nm And can be used without particular limitation. For example, the light irradiating unit may be a light emitting device, such as a xenon lamp for irradiating light having a wavelength in the visible light region, which can irradiate light near natural light.
Further, the water treatment apparatus may further comprise: pH and temperature of the aqueous solution to be injected; But it is not limited to the measurement unit for measuring the contact time of the aqueous solution and the nano-zeolite.
Hereinafter, the present invention will be described in more detail with reference to Examples and Experimental Examples.
However, the following Examples and Experimental Examples are merely illustrative of the present invention, and the present invention is not limited to the following Examples and Experimental Examples.
Example One.
First, a dispersion (5 mL) in which oxidized graphene oxide (GO, 20 mg) was dispersed and cetyl trimethylammonium bromide (CTAB, 0.5 g) were placed in ethanol (30 mL) Followed by stirring to prepare Solution A in which graphene oxide was dispersed.
Separately, add distilled water (120 mL) dissolving 1 wt% of cobalt nitrate into a 250 mL flask, add titanium isopropoxide (TIP 7.44 mL) and acetic acid (14.32 mL) And the mixture was stirred for 1 hour. Then, 0.5 M of sodium borohydride (NaBH 4 , 2 mL) was added dropwise to the flask, and the mixture was stirred for 20 minutes to obtain a solution B (C) of titanium dioxide (Ti-O-Co) dispersed in cobalt-doped white .
Solution B was added dropwise to the previously prepared solution A, and distilled water (20 mL) was added thereto, followed by stirring at room temperature for 12 hours. Thereafter, the solution was filtered, the filtrate was washed with distilled water, and dried overnight at 80 ° C. to obtain cobalt-doped titanium dioxide-loaded graphene oxide (Co-TiO 2 / GO). Then, the obtained graphene oxide was sintered at 500 ° C for 5 minutes to obtain a reduced graphene oxide (Co-TiO 2 / rGO) carrying cobalt-doped titanium dioxide as a photocatalyst.
Comparative Example One.
Titanium dioxide (TiO 2 ) was commercially available as a photocatalyst.
Comparative Example 2.
Titanium isopropoxide (TIP 7.44 mL) and acetic acid (14.32 mL) were added to distilled water (120 mL) dissolving 1 wt% of cobalt nitrate in a 250 mL flask. Lt; / RTI > Then, 0.5 M sodium borohydride (NaBH 4 , 2 mL) was added dropwise to the flask and stirred for 20 minutes. When it was confirmed that a white solid was formed, it was filtered and the filtrate was washed with distilled water. Thereafter, the washed filtrate was dried to obtain cobalt-doped titanium dioxide (Co-TiO 2 ) as a photocatalyst.
Comparative Example 3.
First, a dispersion (5 mL) in which oxidized graphene oxide (GO, 20 mg) was dispersed and cetyl trimethylammonium bromide (CTAB, 0.5 g) were placed in ethanol (30 mL) Followed by stirring to prepare Solution A in which graphene oxide was dispersed.
Then, titanium isopropoxide (TIP 7.44 mL) and acetic acid (14.32 mL) were separately added to a 250 mL flask, and the mixture was stirred for 1 hour. Then, 0.5 M of sodium borohydride (NaBH 4 , 2 mL) was added dropwise to the flask and stirred for 20 minutes to prepare a solution B in which titanium dioxide was dispersed.
Solution B was added dropwise to the previously prepared solution A, and distilled water (20 mL) was added thereto, followed by stirring at room temperature for 12 hours. Thereafter, the solution was filtered, the filtrate was washed with distilled water, and dried overnight at 80 ° C to obtain graphene oxide (TiO 2 / GO) bearing titanium dioxide. Then, the obtained graphene oxide was sintered at 500 ° C for 5 minutes to obtain a reduced graphene oxide (TiO 2 / rGO) carrying titanium dioxide as a photocatalyst.
Experimental Example One.
The following experiment was conducted to confirm the constituents of the photocatalyst according to the present invention.
The photocatalyst prepared in Example 1 was subjected to Scanning Electron Microscope (SEM) photographing by confirming the shape and content of the photocatalyst, and the energy dispersal was continuously performed while scanning electron microscope (SEM) X-ray spectroscopy (EDX) was measured. Further, X-ray photoelectron spectroscopy (XPS) was measured on the photocatalyst prepared in Example 1 and Comparative Examples 1 to 3, confirming the binding properties between the components constituting the photocatalyst. The measured results are shown in Figs.
1 and 2, it can be seen that the photocatalyst according to the present invention has a shape in which uniform titanium dioxide particles of about 150 to 200 nm doped with cobalt (Co) are supported on the surface of graphene oxide and fixed. The photocatalyst thus formed was confirmed to contain 48.5 占 1% by weight of titanium element, 45 占 1% by weight of oxygen element, 6 占 1% by weight of carbon element and 0.45 占 0.1% by weight of cobalt element.
3, the photocatalyst prepared in Example 1 showed that the binding energies of Ti2p and O1s, which can confirm the binding properties of the titanium element and the oxygen element, were lower than those of the photocatalysts prepared in Comparative Examples 1 to 3 . This means that the titanium element of the titanium dioxide of the photocatalyst of Example 1 is chemically bonded to the carbon of the reduced graphene oxide, so that the binding energy between the titanium element and the oxygen element is relatively reduced.
In the case of the photocatalyst prepared in Example 1 and Comparative Example 2, the binding energy of Co2p, which can confirm the binding property of cobalt (Co), was found to have a high spin state, and about 796 ± 2 eV and about 781 It can be seen that the doublet peak is weakly present at the binding energy of ± 2 eV. Here, the peak may be a Co 2 +, and cobalt is doped to the photocatalyst of titanium dioxide as representing the Co 3 + oxygen element and cobalt in the titanium dioxide seen that forms a chemically bonded.
From these results, it can be seen that the photocatalyst according to the present invention contains cobalt and reduced graphene oxide mainly composed of titanium dioxide (TiO 2 ) having photocatalytic activity, and titanium dioxide in the form of particles is carried on the surface of reduced graphene (rGO) And has a fixed structure. It is also understood that the cobalt forms a chemical bond with an oxygen element of titanium dioxide, and the titanium element of titanium dioxide forms a chemical bond with an oxygen element bonded with a carbon element and / or a carbon element of graphene oxide.
Experimental Example 2.
The following experiment was conducted to evaluate the optical properties of the photocatalyst according to the present invention.
The photocatalyst prepared in Example 1 and Comparative Examples 1 to 3 was measured for absorbance and band gap in a wavelength region of 200 to 800 nm using a UV-Vis spectrometer (light source: xenon lamp, output: 20 to 200 W) , And the measured results are shown in FIG. 4 and Table 1.
4 (a) is a graph showing the absorbance of the photocatalyst according to a change in wavelength, and FIG. 4 (b) is a graph showing the band gap.
4 (a), the photocatalysts prepared in Example 1 and Comparative Examples 1 to 3 exhibited a light absorption intensity of about 90% or more at a wavelength of 350 nm or less and a wavelength of And the intensity that absorbs light decreases as the size increases. However, the photocatalyst prepared in Comparative Examples 1 to 3 exhibited an average light absorption intensity of about 15%, about 35% and about 20% at a wavelength of 500 nm or more, respectively, whereas the photocatalyst of Example 1 was about 43% Of the average light absorption intensity. This means that the photocatalyst of Example 1 is reduced in excited photon energy and the electrons can easily 'charge transition'.
4 (b) and Table 1, the photocatalysts of Comparative Examples 1 to 3 had bandgaps of about 3.21 eV, 3.15 eV, and 3.07 eV, respectively, while the photocatalyst of Example 1 was about 2.83 eV. This indicates that even when the photocatalyst according to the present invention is irradiated with low energy light such as visible light, the photocatalyst efficiency is excellent.
From these results, it can be seen that the photocatalyst according to the present invention has an excellent photocatalytic effect even in the visible light region of 400 to 800 nm wavelength range.
Experimental Example 3.
In order to evaluate the water treatment efficiency according to the water treatment condition of the photocatalyst according to the present invention and the water treatment efficiency according to the kind of the photocatalyst at the optimum condition, the following experiment was performed.
(1) Evaluation of removal efficiency of organic compounds according to pH of aqueous solution
(100 mL) containing 2-chlorophenol (CP) at a concentration of 10 mg / L as an organic compound and a photocatalyst (50 mg) prepared in Example 1 and Comparative Examples 1 to 3 were added to a 250 mL flask, (2-chlorophenol (2-CP)) in the aqueous solution was removed by light irradiation with a xenon lamp (wavelength: 390 to 820 nm, output: 100 W) while stirring for 8 hours. Then, the photocatalyst was filtered and the concentration of 2-chlorophenol (2-CP) in the filtrate was measured to derive the removal rate of 2-chlorophenol (2-CP). At this time, the pH of the aqueous solution was adjusted in the range of
Referring to FIG. 5, the photocatalyst according to the present invention was found to remove organic compounds in aqueous solution at a high removal rate.
Specifically, the water treatment method of the present invention showed a removal rate of about 60% or more in the pH range of 4 to 8 when the organic compound was 2-chlorophenol (2-CP), and more than about 80% High removal rate.
From these results, it can be seen that the water treatment method according to the present invention shows high water treatment efficiency when the pH of the aqueous solution to be treated is adjusted to 5 to 7.
(2) Evaluation of removal efficiency of organic compounds according to water treatment time
An aqueous solution (100 mL, pH 6) containing 2-chlorophenol (CP) as an organic compound and a photocatalyst (50 mg) prepared in Example 1 and Comparative Examples 1 to 3 were added to a 250 mL flask Then, 2-chlorophenol (2-CP) in the aqueous solution was removed by light irradiation with a xenon lamp (wavelength: 390 to 820 nm, output: 100 W) while stirring for 12 hours. At this time, the removal rate of 2-chlorophenol (2-CP) was measured by taking an aqueous solution into which the photocatalyst was added at intervals of 2 hours based on the point of time when the photocatalyst was added, CP) was measured. The concentration of the aqueous solution containing 2-chlorophenol (2-CP) was evaluated by adjusting the concentration to 10 mg / L, 20 mg / L, 40 mg / L and 60 mg / L. The result is shown in Fig.
Referring to FIG. 6, it was confirmed that the removal rate of 2-chlorophenol (2-CP) was about 45% or more when the water treatment time exceeded 2 hours or more. Further, as the contact time with the residual 2-chlorophenol (2-CP) in the aqueous solution became longer, the removal rate of the organic compound was increased. After about 6 hours, the increase in the removal rate was slowed, Chlorophenol (2-CP) in the aqueous solution showed a high removal rate of about 80% or more regardless of the concentration of the 2-chlorophenol (2-CP) dissolved in the aqueous solution.
From these results, it can be seen that the water treatment method according to the present invention can remove the organic compounds remaining in the aqueous solution with high efficiency when carried out for 2 hours or more, specifically 6 hours or more.
(3) Radical Evaluation of removal efficiency of organic compounds according to the amount of supply agent used
An aqueous solution (100 mL, pH 6) containing 2-chlorophenol (2-CP) and a photocatalyst (50 mg) prepared in Example 1 were added to a 250 mL flask at a concentration of 100 mg / L as an organic compound (2-chlorophenol (2-CP) solution was removed by light irradiation with a xenon lamp (wavelength: 390 to 820 nm, output: 100 W) while stirring for 600 minutes. Then, the photocatalyst was filtered and the concentration of 2-chlorophenol (2-CP) in the filtrate was measured to derive the removal rate of 2-chlorophenol (2-CP). At this time, hydrogen peroxide (H 2 O 2 , concentration: 30% by volume), which is a radical supply agent, was added to the aqueous solution containing 2-chlorophenol (2-CP) in an amount of 0.001, 0.01, 0.1 , 0.5 and 1 part by weight, respectively, and the removal rate of the aqueous solution to which hydrogen peroxide was not added was also measured as a control. The measured results are shown in Table 2 and Figure 7
Table 2 and FIG. 7 show that the removal efficiency of 2-chlorophenol (2-CP) in comparison with the case where 0.001 to 0.01 part by weight of hydrogen peroxide (H 2 O 2 ) . In contrast, when the radical scavenging agent is added in an amount of 0.1 part by weight or more based on 100 parts by weight of the aqueous solution, the removal efficiency of 2-chlorophenol (2-CP) is decreased compared with the case where the radical scavenger is not added . This is because the radical-supplying agent has a function of promoting the photodegradation of 2-chlorophenol (2-CP) by forming a radical upon irradiation, but when an excessive amount of the radical-supplying agent is used, radicals are formed and residual radical- The activity of the radical is lowered.
From these results, it can be understood that the water treatment method according to the present invention improves the removal efficiency of the organic compound in the aqueous solution when 0.0001 to 0.1 part by weight of the radical-supplying agent is added to 100 parts by weight of the aqueous solution containing the organic compound.
(4) Evaluation of removal efficiency of organic compounds according to light irradiation average power
(100 mL, pH 6) containing 2-chlorophenol (2-CP) at a concentration of 100 mg / L as an organic compound and an aqueous solution (100 mL, pH 6) prepared in Example 1 and Comparative Examples 1 to 3 (50 mg) were each added thereto, followed by light irradiation with a xenon lamp (wavelength: 390 to 820 nm) while stirring for 8 hours to remove 2-chlorophenol (2-CP) in the aqueous solution. Then, the photocatalyst was filtered and the concentration of 2-chlorophenol (2-CP) in the filtrate was measured to derive the removal rate of 2-chlorophenol (2-CP). At this time, the average output power was adjusted to be 20 W, 40 W, 60 W, 100 W and 200 W, respectively, and the obtained results are shown in FIG.
8, the photocatalyst of Example 1 showed an efficiency of removing about 60% or more of 2-chlorophenol (2-CP) at an average power of 60 W, and a removal efficiency of about 85.2 ± 2% Respectively.
From these results, it can be seen that the water treatment method according to the present invention has an excellent efficiency of removing organic compounds at an average output of 50 W or more.
(5) Photocatalyst Evaluation of removal efficiency of organic compounds according to usage
An aqueous solution (100 mL, pH 6) containing 2-chlorophenol (2-CP) and a photocatalyst prepared in Example 1 were introduced into a 250 mL flask at a concentration of 100 mg / L as an organic compound, 2-chlorophenol (2-CP) in the aqueous solution was removed by light irradiation with a xenon lamp (wavelength: 390 to 820 nm, output: 100 W) with stirring for 600 minutes. Then, the photocatalyst was filtered and the concentration of 2-chlorophenol (2-CP) in the filtrate was measured to derive the removal rate of 2-chlorophenol (2-CP). At this time, 0.25 g to 3 g of each photocatalyst was added to 1 L of the aqueous solution, and the results obtained are shown in Table 3 and FIG.
As shown in Table 3 and FIG. 9, the water treatment method according to the present invention increases the removal rate of 2-chlorophenol (2-CP) as the amount of photocatalyst added to an aqueous solution containing an organic compound increases at a concentration of 100 mg / The removal rate of 2-chlorophenol (2-CP) remained constant at over 98% after 500 minutes of water treatment when 2 ㎎ or more of photocatalyst was added to 1 L of aqueous solution.
From these results, it can be understood that the water treatment method according to the present invention can remove the organic compound with high efficiency by using 10 parts by weight or less of the organic compound in 1000 parts by weight of the aqueous solution containing 100 mg / L of the organic compound.
Experimental Example 4.
The following experiment was conducted to evaluate the water treatment efficiency of the photocatalyst according to the present invention.
(1) Water
A 250 mL flask was placed where natural light including ultraviolet light and visible light was irradiated and 2-chlorophenol (2-CP, 5 to 150 ppm) was dissolved in distilled water (100 mL) Photocatalyst (50 mg) prepared in Examples 1 to 3 was added, and the mixture was stirred at 30 ± 1 ° C for 8 hours to carry out photodegradation. At this time, the pH of the solution in which 2-chlorophenol (2-CP) was dissolved was 6, and the wavelength of light was 390 to 820 nm at the time of photodegradation and the output was 100 W. The decomposition efficiency of 2-chlorophenol (2-CP) according to the photo-decomposition reaction was derived according to Langmuir absorption isotherm and Freundlich adsorption isotherm. Respectively.
10 (a), the photocatalyst prepared in Example 1 has an adsorption capacity of about 111.3 ± 5 mg / g to 2-chlorophenol (2-CP) remaining in an aqueous solution, 3 showed that the adsorption capacity of the photocatalyst was about 19.2 ± 2 mg / g, 34.2 ± 2 mg / g and 28.4 ± 2 mg / g, respectively.
10 (b), the photocatalyst prepared in Example 1 exhibited an isothermal adsorption line for 2-chlorophenol (2-CP) at a concentration of 100 mg / g or less. The removal rate of 2-chlorophenol (2-CP) was higher than that of 2-chlorophenol (2-CP) It takes 8 ± 0.2 hours to complete decomposition.
(2) Water
First, the same procedure as in Example 1 was carried out except that nickel nitrate was used instead of cobalt nitrate in Example 1 to prepare a nickel-doped titanium dioxide- to obtain a reduction of graphene oxide (Ni-TiO 2 / rGO) as a photocatalyst.
Thereafter, an aqueous solution (100 mL, pH 6) containing 2-chlorophenol (2-CP) as an organic compound was added to a 250 mL flask, and titanium dioxide (TiO 2 ); The photocatalyst (Co-TiO 2 / rGO) prepared in Example 1; And 50 mg of each of the previously prepared photocatalyst (Ni-TiO 2 / rGO). The aqueous solution containing the photocatalyst was irradiated with light with a xenon lamp (wavelength: 390 to 820 nm, output: 20 to 200 W) while stirring for 8 hours to remove 2-chlorophenol (2-CP) in the aqueous solution. At this time, the concentration of the aqueous solution containing 2-chlorophenol (2-CP) was adjusted to 60 mg / L, and the obtained results are shown in Table 4 and FIG.
Table 4 and FIG. 11 show that the water treatment method according to the present invention uses a photocatalyst (Co-TiO 2 / rGO) containing titanium dioxide doped with cobalt and a photocatalyst containing titanium Chlorophenol (2-CP) removal rate was about 2.65 times higher than that when Ni-TiO 2 / rGO was used. This means that the cobalt-doped photocatalyst can provide optimized energy to form electrons and holes (holes) used to decompose organic compounds at an average power condition of 25 to 200 W. [
From these results, it can be seen that the photocatalyst according to the present invention contains graphene oxide in which titanium dioxide doped with cobalt is reduced so that the organic compound remaining in the aqueous solution can be efficiently decomposed in a wavelength range of 360 to 850 nm including visible light Is excellent.
Claims (15)
Wherein the photocatalyst has a band gap of 2.7 to 2.9 eV in a wavelength range of 400 nm to 800 nm.
100 parts by weight of titanium dioxide;
0.1 to 1 part by weight of cobalt; And
And 1 to 10 parts by weight of reduced graphene oxide.
A method for producing a photocatalyst, comprising the step of heat treating graphene oxide (Co-TiO 2 / GO) carrying titanium dioxide to obtain reduced graphene oxide (Co-TiO 2 / rGO) carrying cobalt-doped titanium dioxide .
Prior to the step of obtaining titanium dioxide-supported graphene oxide (Co-TiO 2 / GO)
Adding a reducing agent to a mixture comprising a titanium precursor and a metal cobalt to dope titanium dioxide with cobalt.
The reducing agent is at least one selected from the group consisting of sodium hydride (NaH), sodium borohydride (NaBH 4 ), lithium aluminum hydride (LiAlH 4 ) Method of manufacturing photocatalyst.
Wherein the heat treatment is performed in a temperature range of 400 to 600 占 폚.
And the heat treatment time is 1 to 60 minutes.
Irradiating the photocatalyst on which the organic compound is adsorbed by light irradiation,
Wherein the light has a wavelength of 360 to 850 nm.
Wherein the pH of the aqueous solution containing the organic compound is from 5 to 7.
Prior to the step of adsorbing the organic compound of the aqueous solution to the photocatalyst,
Further comprising mixing a radical-supplying agent in an aqueous solution containing an organic compound.
Wherein the radical-supplying agent is hydrogen peroxide.
Wherein the content of the radical-supplying agent is 0.0001 to 0.1 part by weight per 100 parts by weight of the aqueous solution containing the organic compound.
Wherein the contact amount of the photocatalyst is 10 parts by weight or less based on 1000 parts by weight of the aqueous solution containing the organic compound.
Wherein the light irradiation is performed with an average power of 50 W to 200 W. < Desc / Clms Page number 19 >
A filtration unit containing the photocatalyst according to claim 1 for adsorbing an organic compound of an aqueous solution injected from the injection port;
An outlet through which the aqueous solution from which the organic compound has been removed is discharged; And
And a light irradiating part for irradiating light to the filtering part.
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| KR1020150134604A KR101818814B1 (en) | 2015-09-23 | 2015-09-23 | Photocatalyst containing titanium dioxide supported reduced graphene oxide, and water treatment method using the same |
| PCT/KR2015/012525 WO2017051979A1 (en) | 2015-09-23 | 2015-11-20 | Photocatalyst having high visible-light activity |
| US15/761,548 US10668458B2 (en) | 2015-09-23 | 2015-11-20 | Photocatalyst having high visible-light activity |
| US16/679,351 US10695758B2 (en) | 2015-09-23 | 2019-11-11 | Photocatalyst having high visible-light activity |
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR20190069906A (en) * | 2017-12-12 | 2019-06-20 | 울산대학교 산학협력단 | Photocatalyst containing Barium doped Bismuth ferrite, and water treatment method using the same |
| US20210206670A1 (en) * | 2019-09-27 | 2021-07-08 | Auburn University | Compositions and methods for removal of per- and polyfluoroalkyl substances (pfas) |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR20130021173A (en) | 2011-08-22 | 2013-03-05 | 한국기초과학지원연구원 | Apparatus and method for wastewater treatment using photocatalyst |
| KR20140119334A (en) | 2013-03-29 | 2014-10-10 | 한국에너지기술연구원 | Flat Type Photocatalytic Apparatus by Using Self-Grown Nanotubular TiO2 on Titanium Foil and Mesh Substrates |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR20130021173A (en) | 2011-08-22 | 2013-03-05 | 한국기초과학지원연구원 | Apparatus and method for wastewater treatment using photocatalyst |
| KR20140119334A (en) | 2013-03-29 | 2014-10-10 | 한국에너지기술연구원 | Flat Type Photocatalytic Apparatus by Using Self-Grown Nanotubular TiO2 on Titanium Foil and Mesh Substrates |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR20190069906A (en) * | 2017-12-12 | 2019-06-20 | 울산대학교 산학협력단 | Photocatalyst containing Barium doped Bismuth ferrite, and water treatment method using the same |
| US20210206670A1 (en) * | 2019-09-27 | 2021-07-08 | Auburn University | Compositions and methods for removal of per- and polyfluoroalkyl substances (pfas) |
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