CN111468133B - Preparation method of potassium niobate/alpha-ferric oxide heterogeneous photocatalyst - Google Patents
Preparation method of potassium niobate/alpha-ferric oxide heterogeneous photocatalyst Download PDFInfo
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- 239000011941 photocatalyst Substances 0.000 title claims abstract description 42
- 238000002360 preparation method Methods 0.000 title claims abstract description 27
- UKDIAJWKFXFVFG-UHFFFAOYSA-N potassium;oxido(dioxo)niobium Chemical compound [K+].[O-][Nb](=O)=O UKDIAJWKFXFVFG-UHFFFAOYSA-N 0.000 title claims abstract description 11
- UQSXHKLRYXJYBZ-UHFFFAOYSA-N iron oxide Inorganic materials [Fe]=O UQSXHKLRYXJYBZ-UHFFFAOYSA-N 0.000 title claims abstract description 6
- 229910000859 α-Fe Inorganic materials 0.000 claims abstract description 69
- 238000001027 hydrothermal synthesis Methods 0.000 claims abstract description 29
- QTBSBXVTEAMEQO-UHFFFAOYSA-N Acetic acid Chemical compound CC(O)=O QTBSBXVTEAMEQO-UHFFFAOYSA-N 0.000 claims abstract description 24
- 239000000843 powder Substances 0.000 claims abstract description 20
- 238000000034 method Methods 0.000 claims abstract description 17
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- 238000003756 stirring Methods 0.000 claims abstract description 15
- 238000001035 drying Methods 0.000 claims abstract description 14
- 238000005406 washing Methods 0.000 claims abstract description 14
- 229960000583 acetic acid Drugs 0.000 claims abstract description 12
- 238000001354 calcination Methods 0.000 claims abstract description 12
- 239000012362 glacial acetic acid Substances 0.000 claims abstract description 12
- 239000007795 chemical reaction product Substances 0.000 claims abstract description 7
- 238000001816 cooling Methods 0.000 claims abstract description 7
- 239000007864 aqueous solution Substances 0.000 claims abstract description 5
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- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Chemical compound O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 23
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- 239000000047 product Substances 0.000 claims description 12
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- GUCVJGMIXFAOAE-UHFFFAOYSA-N niobium atom Chemical compound [Nb] GUCVJGMIXFAOAE-UHFFFAOYSA-N 0.000 claims description 9
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- JZQOJFLIJNRDHK-CMDGGOBGSA-N alpha-irone Chemical compound CC1CC=C(C)C(\C=C\C(C)=O)C1(C)C JZQOJFLIJNRDHK-CMDGGOBGSA-N 0.000 claims description 5
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- CURLTUGMZLYLDI-UHFFFAOYSA-N Carbon dioxide Chemical compound O=C=O CURLTUGMZLYLDI-UHFFFAOYSA-N 0.000 description 4
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- PYWVYCXTNDRMGF-UHFFFAOYSA-N rhodamine B Chemical compound [Cl-].C=12C=CC(=[N+](CC)CC)C=C2OC2=CC(N(CC)CC)=CC=C2C=1C1=CC=CC=C1C(O)=O PYWVYCXTNDRMGF-UHFFFAOYSA-N 0.000 description 2
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- B01J35/39—
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- 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
- B01J23/84—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 arsenic, antimony, bismuth, vanadium, niobium, tantalum, polonium, chromium, molybdenum, tungsten, manganese, technetium or rhenium
- B01J23/847—Vanadium, niobium or tantalum or polonium
- B01J23/8474—Niobium
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- C—CHEMISTRY; METALLURGY
- C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F1/00—Treatment of water, waste water, or sewage
- C02F1/30—Treatment of water, waste water, or sewage by irradiation
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- C—CHEMISTRY; METALLURGY
- C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F2101/00—Nature of the contaminant
- C02F2101/30—Organic compounds
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- C—CHEMISTRY; METALLURGY
- C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F2101/00—Nature of the contaminant
- C02F2101/30—Organic compounds
- C02F2101/38—Organic compounds containing nitrogen
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- C—CHEMISTRY; METALLURGY
- C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- 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
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- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
- Y02E60/30—Hydrogen technology
- Y02E60/36—Hydrogen production from non-carbon containing sources, e.g. by water electrolysis
Abstract
The invention discloses a preparation method of a potassium niobate/alpha-ferric oxide heterogeneous photocatalyst, which comprises the steps of firstly preparing KNbO 3 (ii) a Then KNbO 3 Adding the powder to FeCl 3 ·6H 2 O and Na 2 SO 4 Adding glacial acetic acid into the aqueous solution, uniformly stirring, adding the mixture into a reaction kettle, carrying out hydrothermal reaction, cooling, washing and drying the reaction product, and finally calcining to obtain KNbO 3 /α‑Fe 2 O 3 A heterogeneous photocatalyst. The preparation method has the advantages of simple preparation process, low reaction temperature, short reaction time and low material cost, is suitable for industrial production, and the KNbO obtained by the method 3 /α‑Fe 2 O 3 The heterogeneous photocatalyst has many active sites, high separation efficiency of photon-generated carriers and excellent performance of photocatalytic degradation of dyes.
Description
Technical Field
The invention relates to the field of photocatalysis, in particular to a preparation method of a potassium niobate/alpha-ferric oxide heterogeneous photocatalyst.
Background
First use of TiO by Japanese scientists since the last 70 s 2 Since the photocatalytic material is successfully used for realizing the photodecomposition of water, the semiconductor photocatalytic technology attracts more and more attention of domestic and foreign scientists. Through a photocatalysis technology, solar energy can be successfully converted into chemical energy, such as organic fuels like hydrogen prepared by photocatalytic water decomposition and carbon dioxide reduced by photocatalysis. Besides the application in the energy field, the photocatalysis technology can also be applied in the environmental fields of sewage treatment, indoor air purification and the like. Therefore, the photocatalytic technology is considered to be a green technology which has great development prospect and successfully utilizes solar energy. Although having a wide application prospect, the large-scale industrial application of the photocatalytic technology still faces a great challenge, and the low solar energy conversion efficiency is a key factor for restricting the photocatalytic technology from being practical.
The spontaneous polarization field in the ferroelectric material is proved to be capable of effectively driving the separation of photo-generated charges, inhibiting the recombination among the photo-generated charges and improving the photocatalytic efficiency, and is receiving more and more attention of research workers. Ferroelectric KNbO in recent years 3 Because of their typical ferroelectric properties, crystals have been successfully used as photocatalysts for the degradation of organic dyes, photolysis water and photoreduction of carbon dioxide. However, the forbidden band width is large (3.2 eV), and only visible light can be absorbed, so that visible light in a solar spectrum cannot be fully utilized, and meanwhile, the separation efficiency of internal photo-generated carriers needs to be further improved.
Disclosure of Invention
To overcome ferroelectric KNbO 3 The invention provides a method for preparing a potassium niobate/alpha-iron oxide heterogeneous photocatalyst by constructing KNbO 3 /α-Fe 2 O 3 Heterojunction utilizing alpha-Fe while promoting separation of photogenerated carriers 2 O 3 Good response to visible light, expanded spectral absorption range of photocatalyst, simple preparation process, and the prepared KNbO 3 /α-Fe 2 O 3 The heterogeneous photocatalyst has high-efficiency performance of photodegradation of organic dyes, and the photocatalytic effect of the heterogeneous photocatalyst is far superior to that of pure-phase KNbO 3 And alpha-Fe 2 O 3 。
In order to achieve the purpose, the invention adopts the following technical scheme:
a preparation method of a potassium niobate/alpha-ferric oxide heterogeneous photocatalyst comprises the following steps:
the method comprises the following steps: preparation of KNbO by hydrothermal reaction 3 Powder;
step two: KNbO obtained in the first step 3 Adding the powder to FeCl 3 ·6H 2 O and Na 2 SO 4 Adding glacial acetic acid into the aqueous solution, uniformly stirring, carrying out hydrothermal reaction, cooling, washing and drying the reaction product, and finally calcining to obtain KNbO 3 /α-Fe 2 O 3 A heterogeneous photocatalyst.
Further, KNbO in the step one 3 Powder bodyThe preparation method comprises the following steps: dissolving KOH in deionized water, adding niobium powder, fully stirring on a magnetic stirrer, then transferring to a polytetrafluoroethylene lining reaction kettle, carrying out hydrothermal reaction for 12 hours at 150 ℃, fully washing the obtained product with deionized water until the pH value is neutral, and finally drying for 12 hours at 60 ℃ to obtain KNbO 3 And (3) powder.
Further, KOH was dissolved in deionized water to obtain a KOH solution with a concentration of 15mol/L, and the mass of KOH and the mass of niobium powder were 12.624.
Further, feCl in step two 3 ·6H 2 O and Na 2 SO 4 1.
Further, feCl in step two 3 ·6H 2 O and KNbO 3 The molar ratio of (0.4-10) to (1).
Further, glacial acetic acid is added in the second step, so that the concentration of the glacial acetic acid in the solution is 0.06mol/L.
Furthermore, the hydrothermal reaction temperature in the second step is 120 ℃, and the hydrothermal reaction time is 8h.
Furthermore, the calcination temperature in the second step is 500 ℃, and the calcination time is 2h.
Compared with the prior art, the invention has the following beneficial technical effects:
the invention adopts a two-step hydrothermal method to prepare samples, has low temperature and short time of hydrothermal reaction, is suitable for industrialized production, and adopts ferroelectric KNbO 3 Introducing alpha-Fe to the surface of the powder 2 O 3 And construct KNbO 3 /α-Fe 2 O 3 The heterojunction utilizes a built-in electric field of the heterojunction to promote photon-generated carrier separation and inhibit electron-hole recombination on one hand; on the other hand, the use of a narrow band gap of alpha-Fe 2 O 3 Good response to visible light, expanded spectral absorption range of photocatalyst and finally obtained KNbO 3 /α-Fe 2 O 3 The heterojunction photocatalyst has high-efficiency performance of photodegrading organic pollutants, and the photodegrading efficiency of the heterojunction photocatalyst is far higher than that of pure-phase KNbO 3 And alpha-Fe 2 O 3 The heterojunction photocatalyst is expected to be applied to sewage treatmentAnd the like.
Drawings
FIG. 1 shows different KNbOs 3 With FeCl 3 ·6H 2 XRD pattern of heterogeneous photocatalyst prepared with molar ratio of O; (a) KNbO 3 ；(b)KNbO 3 /α-Fe 2 O 3 -0.4；(c)KNbO 3 /α-Fe 2 O 3 -2；(d)KNbO 3 /α-Fe 2 O 3 -10；
FIG. 2 shows different KNbO 3 With FeCl 3 ·6H 2 An ultraviolet-diffuse reflection absorption spectrogram of the heterogeneous photocatalyst prepared by the molar ratio of O; (a) KNbO 3 ；(b)α-Fe 2 O 3 ；(c)KNbO 3 /α-Fe 2 O 3 -0.4；(d))KNbO 3 /α-Fe 2 O 3 -2；(e)KNbO 3 /α-Fe 2 O 3 -10；
FIG. 3 shows different KNbO 3 With FeCl 3 ·6H 2 Scanning photo picture of heterogeneous photocatalyst prepared by molar ratio of O; (a) alpha-Fe 2 O 3 ；(b)KNbO 3 /α-Fe 2 O 3 -0.4；(c)KNbO 3 /α-Fe 2 O 3 -2；(d)KNbO 3 /α-Fe 2 O 3 -10；
FIG. 4 shows different KNbO 3 With FeCl 3 ·6H 2 A rhodamine B degradation curve of the heterogeneous photocatalyst prepared by the molar ratio of O; (a) KNbO 3 ；(b)α-Fe 2 O 3 ；(c)KNbO 3 /α-Fe 2 O 3 -0.4；(d)KNbO 3 /α-Fe 2 O 3 -2；(e)KNbO 3 /α-Fe 2 O 3 -10；
FIG. 5 is a different KNbO 3 With FeCl 3 ·6H 2 Linear fitting of the photodegradation rate of the heterogeneous photocatalyst prepared by the molar ratio of O; (a) KNbO 3 ；(b)α-Fe 2 O 3 ；(c)KNbO 3 /α-Fe 2 O 3 -0.4；(d)KNbO 3 /α-Fe 2 O 3 -2；(e)KNbO 3 /α-Fe 2 O 3 -10；
FIG. 6 is KNbO 3 /α-Fe 2 O 3 The photocatalysis mechanism of the heterojunction is shown schematically.
Detailed Description
Embodiments of the invention are described in further detail below:
KNbO 3 /α-Fe 2 O 3 The preparation method of the heterogeneous photocatalyst comprises the following steps:
the method comprises the following steps: preparation of KNbO 3 : after 12.624g KOH was dissolved in 15ml deionized water, 0.874g niobium powder was added, stirred well on a magnetic stirrer for 30min, and then transferred to a 50ml Teflon lined reactor for hydrothermal reaction at 150 ℃ for 12h. Fully washing the obtained product with deionized water until the pH value is neutral, and finally drying the product for 12 hours at 60 ℃ to obtain KNbO 3 Powder;
step two: mixing the 0.2g KNbO obtained in the step one 3 Adding the powder to FeCl 3 ·6H 2 O and Na 2 SO 4 In 25ml of an aqueous solution of (1), feCl is held 3 ·6H 2 O and Na 2 SO 4 1, while adjusting FeCl to a molar ratio of 1 3 ·6H 2 O and KNbO 3 In a molar ratio of 0.4 to 10, to obtain a series of different alpha-Fe 2 O 3 A mass fraction of a heterojunction photocatalyst; adding 1.5ml of glacial acetic acid into the solution, and stirring for 30 minutes; stirring uniformly, adding into a 50ml reaction kettle with a polytetrafluoroethylene lining, carrying out hydrothermal reaction at 120 ℃ for 8h, cooling, washing and drying the reaction product, and calcining at 500 ℃ for 2h to obtain KNbO 3 /α-Fe 2 O 3 A heterogeneous photocatalyst.
The present invention is described in further detail below with reference to examples:
comparative example 1
Hydrothermal method for preparing KNbO 3 The method comprises the following specific steps:
the method comprises the following steps: weighing 12.624g KOH and dissolving in 15ml deionized water;
step two: adding 0.874g of niobium powder into the solution, and fully stirring the mixture for 30min on a magnetic stirrer;
step three: the obtained solution was transferred to a 50ml teflon-lined reaction vessel and subjected to hydrothermal reaction at 150 ℃ for 12 hours.
Step four: after the reaction is finished and cooled, the obtained product is fully washed by deionized water until the pH value is neutral, and finally dried for 12 hours at 60 ℃ to obtain KNbO 3 And (3) powder.
Comparative example 2
Preparation of pure alpha-Fe by hydrothermal method 2 O 3 The method comprises the following specific steps:
the method comprises the following steps: weighing 3g FeCl 3 ·6H 2 Dissolving O in 25ml deionized water;
step two: to the above solution was added 1.578g of Na 2 SO 4 To make FeCl 3 ·6H 2 O and Na 2 SO 4 The molar ratio of (1) is 1, and the mixture is fully stirred on a magnetic stirrer;
step three: adding 1.5ml of glacial acetic acid into the solution, and stirring for 30 minutes;
step four: the resulting solution was transferred to a 50ml teflon lined reactor and subjected to hydrothermal reaction at 120 ℃ for 8h.
Step four: after the reaction is finished and cooled, fully washing the obtained product with deionized water until the pH value is neutral, and finally drying at 60 ℃ for 12 hours for later use;
step five: placing the obtained powder in a crucible, calcining for 2h at 500 ℃ to obtain alpha-Fe 2 O 3 。
Example 1
Preparation of KNbO by two-step hydrothermal method 3 /α-Fe 2 O 3 -x, wherein x =0.4,x is FeCl 3 ·6H 2 O and KNbO 3 The method comprises the following specific steps:
the method comprises the following steps: preparation of KNbO 3 : KOH is dissolved in deionized water, then niobium powder is added, the mixture is fully stirred on a magnetic stirrer, and then the mixture is transferred to a lining reaction kettle made of 50ml of polytetrafluoroethylene to carry out hydrothermal reaction for 12 hours at the temperature of 150 ℃. Fully washing the obtained product with deionized water until the pH value is neutral, and finally drying the product for 12 hours at 60 ℃ to obtain KNbO 3 And (3) powder.
Step two: mixing the 0.2g KNbO obtained in the step one 3 Adding the powder to FeCl 3 ·6H 2 O and Na 2 SO 4 In 25ml of deionized water, feCl was held 3 ·6H 2 O and Na 2 SO 4 1, while adjusting FeCl to a molar ratio of 1 3 ·6H 2 O and KNbO 3 Is 0.4; adding 1.5ml of glacial acetic acid into the solution, and stirring for 30 minutes; stirring uniformly, adding into a 50ml reaction kettle with a polytetrafluoroethylene lining, carrying out hydrothermal reaction at 120 ℃ for 8h, cooling, washing and drying the reaction product, and calcining at 500 ℃ for 2h to obtain KNbO 3 /α-Fe 2 O 3 -0.4 heterogeneous photocatalyst.
Example 2
Preparation of KNbO by two-step hydrothermal method 3 /α-Fe 2 O 3 -x, wherein x =2,x is FeCl 3 ·6H 2 O and KNbO 3 The method comprises the following specific steps:
the method comprises the following steps: preparation of KNbO 3 : KOH is dissolved in deionized water, then niobium powder is added, the mixture is fully stirred on a magnetic stirrer, and then the mixture is transferred to a lining reaction kettle made of 50ml of polytetrafluoroethylene to carry out hydrothermal reaction for 12 hours at the temperature of 150 ℃. Fully washing the obtained product with deionized water until the pH value is neutral, and finally drying the product for 12 hours at 60 ℃ to obtain KNbO 3 And (3) powder.
Step two: 0.2g of KNbO obtained in the first step 3 Adding the powder to FeCl 3 ·6H 2 O and Na 2 SO 4 In 25ml of deionized water, feCl was held 3 ·6H 2 O and Na 2 SO 4 1, while adjusting FeCl to 1 3 ·6H 2 O and KNbO 3 In a molar ratio of 2; adding 1.5ml of glacial acetic acid into the solution, and stirring for 30 minutes; stirring uniformly, adding into a 50ml reaction kettle with a polytetrafluoroethylene lining, carrying out hydrothermal reaction at 120 ℃ for 8h, cooling, washing and drying the reaction product, and calcining at 500 ℃ for 2h to obtain KNbO 3 /α-Fe 2 O 3 -2 heterogeneous photocatalyst.
Example 3
Preparation of KNbO by two-step hydrothermal method 3 /α-Fe 2 O 3 -x, wherein x =10,x is FeCl 3 ·6H 2 O and KNbO 3 The method comprises the following specific steps:
the method comprises the following steps: preparation of KNbO 3 : KOH is dissolved in deionized water, then niobium powder is added, the mixture is fully stirred on a magnetic stirrer and then transferred into a lining reaction kettle made of 50ml of polytetrafluoroethylene, and the hydrothermal reaction is carried out for 12 hours at the temperature of 150 ℃. Fully washing the obtained product with deionized water until the pH value is neutral, and finally drying the product for 12 hours at 60 ℃ to obtain KNbO 3 And (3) powder.
Step two: 0.2g of KNbO obtained in the first step 3 Adding the powder to FeCl 3 ·6H 2 O and Na 2 SO 4 In 25ml of deionized water, feCl was held 3 ·6H 2 O and Na 2 SO 4 1, while adjusting FeCl to a molar ratio of 1 3 ·6H 2 O and KNbO 3 In a molar ratio of 10; adding 1.5ml of glacial acetic acid into the solution, and stirring for 30 minutes; stirring uniformly, adding into a 50ml reaction kettle with a polytetrafluoroethylene lining, carrying out hydrothermal reaction at 120 ℃ for 8h, cooling, washing and drying the reaction product, and calcining at 500 ℃ for 2h to obtain KNbO 3 /α-Fe 2 O 3 -10 heterogeneous photocatalysts.
As can be seen from FIG. 1, feCl is added with the preparation process 3 ·6H 2 O and KNbO 3 Gradually increasing the molar ratio of alpha-Fe 2 O 3 At KNbO 3 /α-Fe 2 O 3 The mass fraction in the heterojunction increases with it, at KNbO 3 /α-Fe 2 O 3 -10 is capable of observing membership to KNbO simultaneously 3 And alpha-Fe 2 O 3 FIG. 2 demonstrates the dependence on alpha-Fe 2 O 3 Increase in mass fraction, KNbO 3 /α-Fe 2 O 3 The visible light absorption capability of the heterojunction photocatalyst is obviously improved, and the scanning photograph of figure 3 also proves that the alpha-Fe 2 O 3 Is grown in KNbO 3 The surfaces of the cube and forming a heterostructure. In addition, alpha-Fe can be observed 2 O 3 At KNbO 3 The surfaces of the cubic blocks are not obviously agglomerated and are in a rough form of hairy antler, so that the photocatalyst can provide more reaction active sites and improve the photocatalytic efficiency, and the effect is attributed to the fact that the weak acid glacial acetic acid is added in the preparation process and can control Fe 3+ Slow hydrolysis occurs. As shown in FIG. 4, KNbO can be found by testing the degradation of the organic dye rhodamine B under simulated sunlight 3 /α-Fe 2 O 3 -2 and KNbO 3 /α-Fe 2 O 3 -10 heterojunction photocatalysts show advantages over pure KNbO 3 And alpha-Fe 2 O 3 The photodegradation efficiency of, wherein KNbO 3 /α-Fe 2 O 3 The photodegradability of-10 is optimal. Calculation of the photodegradation rate by kinetic modeling, as shown in FIG. 5 and Table 1, it can be found that KNbO 3 /α-Fe 2 O 3 The degradation rate of-10 is KNbO 3 273.5 times of that of pure alpha-Fe 2 O 3 3.3 times of that of the dye, the percentage of degradation of the dye is close to 100% under 15 minutes of light.
TABLE 1 photodegradation rate tables of different photocatalysts
This is well documented in KNbO 3 Surface of (2) is loaded with alpha-Fe 2 O 3 And the two are formed into a heterojunction structure, which is an effective strategy for developing high-efficiency photocatalysts. On the one hand by using alpha-Fe 2 O 3 The strong absorption of visible light widens the spectrum absorption range of the photocatalyst, and on the other hand, the built-in electric field of the heterostructure is utilized to promote the migration of photon-generated carriers, and electrons are removed from KNbO 3 Conduction band transfer to alpha-Fe 2 O 3 Conduction band of from alpha-Fe 2 O 3 Valence band transfer to KNbO 3 Thereby realizing effective separation of electrons and holes, inhibiting electron-hole recombination and improving the photocatalytic efficiency.
KNbO prepared by the invention 3 /α-Fe 2 O 3 Heterogeneous natureThe photocatalyst has simple preparation process, low temperature of hydrothermal reaction and short time, is suitable for industrial production, and the prepared KNbO 3 /α-Fe 2 O 3 The heterogeneous photocatalyst has many active sites, high separation efficiency of photon-generated carriers, high performance of photodegradation of organic dyes and is expected to be applied to the fields of sewage treatment and the like.
Claims (5)
1. A preparation method of a potassium niobate/alpha-ferric oxide heterogeneous photocatalyst is characterized by comprising the following steps:
the method comprises the following steps: preparation of KNbO by hydrothermal reaction 3 Powder, KNbO 3 The preparation method of the powder comprises the following steps: dissolving KOH in deionized water to obtain a KOH solution with the concentration of 15mol/L, then adding niobium powder, wherein the mass of the KOH and the mass of the niobium powder are 12.624/0.874, fully stirring on a magnetic stirrer, then transferring to a lining reaction kettle made of polytetrafluoroethylene, carrying out hydrothermal reaction for 12h under the condition of 150 ℃, fully washing an obtained product with deionized water until the pH value is neutral, and finally drying for 12h at 60 ℃, thus obtaining KNbO 3 Powder;
step two: KNbO obtained in the step one 3 Adding the powder to FeCl 3 •6H 2 O and Na 2 SO 4 Adding glacial acetic acid into the aqueous solution to ensure that the concentration of the glacial acetic acid in the aqueous solution is 0.06mol/L, uniformly stirring, carrying out hydrothermal reaction, cooling, washing and drying the reaction product, and finally calcining to obtain KNbO 3 /α-Fe 2 O 3 A heterogeneous photocatalyst.
2. The method for preparing potassium niobate/alpha-iron oxide heterogeneous photocatalyst according to claim 1, wherein FeCl is adopted in the second step 3 •6H 2 O and Na 2 SO 4 1.
3. The method for preparing potassium niobate/alpha-iron oxide heterogeneous photocatalyst according to claim 1, wherein FeCl in step two 3 •6H 2 O and KNbO 3 The molar ratio of (0.4 to 10) to (1).
4. The preparation method of the potassium niobate/alpha-iron oxide heterogeneous photocatalyst according to claim 1, wherein the hydrothermal reaction temperature in the second step is 120 ℃, and the hydrothermal reaction time is 8h.
5. The preparation method of the potassium niobate/alpha-iron oxide heterogeneous photocatalyst according to claim 1, wherein in the second step, the calcination temperature is 500 ℃, and the calcination time is 2h.
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| CN110429260A (en) * | 2019-08-07 | 2019-11-08 | 深圳大学 | Titanium niobate/transition metal oxide nano fiber negative electrode material preparation method |
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| CN110429260A (en) * | 2019-08-07 | 2019-11-08 | 深圳大学 | Titanium niobate/transition metal oxide nano fiber negative electrode material preparation method |
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