Nitrogen-modified perovskite composite molecular sieve photocatalyst, and preparation method and application method thereof

A technology of composite molecular sieve and photocatalyst, which is applied in the field of photocatalyst and its preparation, can solve the problems of insufficient utilization of visible light, high electron-hole recombination rate, and large energy consumption, so as to promote rapid catalytic degradation and increase the absorbable area , Improve the effect of contact area

Active Publication Date: 2020-04-21
SOUTHEAST UNIV
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  • Abstract
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  • Claims
  • Application Information

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Problems solved by technology

Although the biodegradation method has a mature treatment process and low cost, it is only suitable for the treatment of low-concentration aromatic compounds; chemical oxidation and advanced oxidation technology methods refer to adding a certain amount of oxidants (oxygen, hydrogen peroxide, Ozone, etc.), under certain conditions, a strong oxidizing agent is produced, so that the aromatic compound is oxidized and degraded, and finally completely mineralized into carbon dioxide and water
Although this method has a good treatment effect, it is difficult to recover the oxidant and the operation cost is expensive, which affects its use; the adsorption method is a more effective method for the treatment of aromatic compounds, mainly using porous materials to adsorb pollutants in wastewater, wastewater The pollutants in the adsorbent will enter the interior of the adsorbent through the pore structure of the adsorbent, and then the adsorbent can be treated to a certain extent, so that the adsorbent can be recycled
However, the equipment investment is large, the reusability of the adsorbent is low and the regeneration problem needs to be solved; the cold plasma treatment wastewater technology is a new wastewater treatment technology that combines high-energy electron radiation, ozone oxidation and ultraviolet photolysis. , but this method consumes a lot of energy; nano photocatalysis technology has mild reaction conditions, can use ultraviolet light and sunlight and other conditions, directly and indirectly convert pollutants into CO2, water and other harmless substances, consumes little energy and does not produce Secondary pollution
Commonly used photocatalysts such as TiO2 have disadvantages such as wide band gap, inability to make full use of visible light, and low quantum efficiency, while perovskite catalysts have narrow band gap and small band gap, which is a good photocatalyst, but calcium Titanium has the problem of high electron-hole recombination rate, and it does not respond well to a wide range of visible light.

Method used

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  • Nitrogen-modified perovskite composite molecular sieve photocatalyst, and preparation method and application method thereof

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0026] Weigh 2.1646g of lanthanum nitrate, 2.02g of ferric nitrate, 0.3g of urea and 0.9012g of MCM-41 in a three-necked flask according to the molar ratio of 1:1:1:3, add 50mL of distilled water to dissolve, stir well to form A liquid; according to tartaric acid: The molar ratio of lanthanum nitrate is 1:1, add 0.7505g of tartaric acid, add 15mL of distilled water, dissolve and stir evenly to form B liquid. Slowly add liquid B to liquid A under stirring, react and polymerize into a sol in a water bath at 80°C, dry overnight to obtain a xerogel, and calcinate at 700°C for 4 hours at a rate of 2°C / min to obtain the catalyst N-LaFeO 3 @MCM-41-1.

[0027] Incorporation of N-LaFeO in the photocatalytic reactor 3 @MCM-41-1 catalyst, methanol and bisphenol A wastewater for photocatalytic reaction, the volume ratio of methanol and bisphenol A wastewater is 1:8, the dosage of photocatalyst in the mixture of methanol and bisphenol A wastewater per liter 0.20g; first carry out 30min d...

Embodiment 2

[0029] Weigh 2.1646g of lanthanum nitrate, 2.02g of ferric nitrate, 0.9g of urea and 2.1028g of MCM-41 in a three-necked flask according to the molar ratio of 1:1:3:7, add 50mL of distilled water to dissolve, and stir to form A liquid; : The molar ratio of lanthanum nitrate is 2:1, add 1.3409g malic acid, add 30mL distilled water, dissolve and stir to form B liquid evenly. Slowly add liquid B to liquid A under stirring, react and polymerize in a water bath at 80°C to form a sol, dry overnight to obtain a xerogel, and calcinate at 700°C for 4 hours at a rate of 2°C / min to obtain the catalyst N-LaFeO 3 @MCM-41-2.

[0030] Incorporation of N-LaFeO in the photocatalytic reactor 3 @MCM-41-2 catalyst, methanol and benzonitrile wastewater for photocatalytic reaction, the volume ratio of methanol and benzonitrile wastewater is 1:16, and the dosage of photocatalyst in the mixture of methanol and benzonitrile wastewater is 0.60g per liter ;First carry out 30min dark adsorption reactio...

Embodiment 3

[0032] Weigh 2.1646g of lanthanum nitrate, 2.02g of ferric nitrate, 0.6g of urea and 1.502g of MCM-41 in a three-necked flask according to the molar ratio of 1:1:2:5, add 50mL of distilled water to dissolve and stir evenly to form A liquid; The molar ratio of lanthanum is 3:1, add 1.3512g lactic acid as a complexing agent, add 45mL distilled water, dissolve and stir evenly to form B liquid. Slowly add liquid B to liquid A under stirring, react and polymerize into a sol in a water bath at 80°C, dry overnight to obtain a xerogel, and calcinate at 700°C for 4 hours at a rate of 2°C / min to obtain the catalyst N-LaFeO 3 @MCM-41-3.

[0033] Incorporation of N-LaFeO in the photocatalytic reactor 3 @MCM-41-3 catalyst, methanol and p-methoxybenzonitrile wastewater for photocatalytic reaction, the volume ratio of methanol and p-methoxybenzonitrile wastewater is 1:12, per liter of methanol and p-methoxybenzonitrile wastewater The dosage of the photocatalyst in the mixture is 0.40g; fir...

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Abstract

The invention discloses a nitrogen-modified perovskite composite molecular sieve photocatalyst, and a preparation method and an application method thereof. The photocatalyst is N-LaFeO3@MCM-41. The preparation method of the photocatalyst comprises the following steps: weighing lanthanum nitrate, ferric nitrate, urea and MCM-41 according to a molar ratio of 1:1:(1-3):(3-7), adding water for dissolving, and stirring to form a solution A; adding water to dissolve a complexing agent, and stirring to form a solution B, wherein the molar ratio of the complexing agent to lanthanum nitrate is (1-4):1;slowly adding the solution B into the solution A, polymerizing to form a sol, and drying and calcining the sol to obtain the photocatalyst. The ivention further provides the application method of thephotocatalyst for treating aromatic compound organic wastewater. The photocatalyst can efficiently degrade aromatic compound organic wastewater, the preparation method is convenient to operate and low in cost, secondary pollution is avoided when the photocatalyst is applied to aromatic compound organic wastewater, energy is saved, and the environment is protected.

Description

technical field [0001] The invention relates to a photocatalyst, a preparation method and an application method thereof, in particular to a photocatalyst of a nitrogen-modified perovskite composite molecular sieve, a preparation method and an application method thereof. Background technique [0002] Aromatic compounds are a class of compounds with a benzene ring structure. They are stable in structure, difficult to decompose, and highly toxic. Aromatic compounds come from lignin and secondary metabolic processes of higher plants on the one hand, and various chemical products synthesized in industry on the other hand, such as pesticides, herbicides, dyes, explosives, etc. Aromatic compounds such as benzene, benzonitriles and phenols are being manufactured in millions of tons per year. These compounds are widely used in fuels and industrial solvents, and they are used in the production of pharmaceuticals together with polycyclic aromatic compounds and chlorinated biphenyls. ,...

Claims

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Application Information

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Patent Type & AuthorityApplications(China)
IPC IPC(8): B01J29/76C02F1/30C02F1/72C02F101/30C02F101/34C02F101/38
CPCB01J29/76C02F1/30C02F1/725B01J2229/18C02F2101/30C02F2305/10C02F2101/38C02F2101/345Y02W10/37B01J23/83B01J23/005B01J35/39B01J35/647
Inventor吴敏刘颖厉明升王传传李志豪赵颖丹张仲琨
OwnerSOUTHEAST UNIV