CN116239372B - Preparation method of terahertz material for reducing emission of nitrogen oxides and volatile organic compounds - Google Patents

Abstract

The invention discloses a preparation method of a terahertz material for reducing emission of nitrogen oxides and volatile organic compounds, which comprises the following steps: mixing the raw materials: uniformly mixing silicon dioxide, ferric oxide and calcium tungstate to obtain mixed raw material powder; and (3) melting and crystallizing: melting the mixed raw material powder, cooling and crystallizing, and re-crushing the mixed crystals obtained by crystallizing to obtain mixed crystal powder; and (5) press forming: adding modified graphene oxide and/or nano silicon-based oxide into the mixed crystal powder, and uniformly mixing to obtain terahertz powder; pressing and forming the terahertz powder to obtain a terahertz material block; and (3) heat treatment: placing the terahertz material block into a calciner for sintering, cooling and crushing after the sintering is finished to obtain a terahertz material; and (3) irradiation strengthening treatment: and placing the terahertz material in a terahertz irradiation line environment for irradiation strengthening treatment. When the terahertz material is used for reducing emission of nitrogen oxides and volatile organic compounds by a combustion source, the emission reduction efficiency and stability are good.

Description

Preparation method of terahertz materials that reduce nitrogen oxide and volatile organic compound emissions

Technical field

The present invention relates to the technical field of terahertz materials. Specifically, methods for preparing terahertz materials that reduce nitrogen oxide and volatile organic compound emissions.

Background technique

Nitrogen oxides and volatile organic compounds are the precursors of ozone and secondary PM2.5. To improve ambient air quality, it is necessary to strengthen the emission control of nitrogen oxides and volatile organic compounds. At present, our country mainly uses selective catalytic reduction (SCR) and selective non-catalytic reduction (SNCR) to terminally control the nitrogen oxides generated after combustion of combustion sources, but there is almost no control over the emission of volatile organic compounds from combustion sources. Although the terminal control method can reduce the emissions of nitrogen oxides and volatile organic compounds, it increases energy consumption and ammonia escape, resulting in an increase in carbon emissions, and ammonia escape can cause secondary pollution.

In recent years of exploration, materials that can emit terahertz spectrum have been shown to have a certain role in reducing emissions of nitrogen oxides and volatile organic compounds from combustion sources. For example, patent CN111875819A prepares a terahertz masterbatch for gasoline vehicle emission reduction and fuel saving. It can emit terahertz waves to activate oil fuel, air and coolant, etc., which can reduce vehicle HC by 90% on average and NOx on average. 70%, average fuel saving of 10%, power increase of 8%, which can reduce carbon deposits, extend the life of the three-way catalytic converter, and reduce the contribution of exhaust gas to PM2.5 by 90%.

However, the inventor of the present application has repeatedly tested the above-mentioned terahertz materials in diesel vehicles and other mobile source fuels, and found that its effectiveness in promoting the reduction of nitrogen oxides and volatile organic compounds is unstable. In some tests, the exhaust gas was emitted More harmful substances, with large deviations. Therefore, it is necessary to design a preparation method for terahertz materials that can reduce the emissions of combustion source nitrogen oxides and volatile organic compounds, and make the prepared terahertz materials have more stable combustion source nitrogen oxides and volatile organic compounds to promote the reduction of emissions. efficacy.

Contents of the invention

To this end, the technical problem to be solved by the present invention is to provide a method for preparing a terahertz material that can reduce the emission of nitrogen oxides and volatile organic compounds from combustion sources, so as to solve the problem of existing terahertz materials being used to reduce nitrogen oxides from combustion sources. The problem of poor stability in emission reduction performance when emitting volatile organic compounds.

In order to solve the above technical problems, the present invention provides the following technical solutions:

A method for preparing terahertz materials that reduces nitrogen oxide and volatile organic compound emissions, including the following steps:

Step (1), mixing raw materials: Mix silica, ferric oxide and calcium tungstate evenly to obtain mixed raw material powder;

Step (2), melt crystallization: melt the mixed raw material powder and then cool it for crystallization, and re-pulverize the mixed crystal obtained by crystallization to obtain mixed crystal powder;

Step (3), pressing and molding: add modified graphene oxide and/or nano silicon-based oxide to the mixed crystal powder, mix evenly to obtain terahertz powder; press and mold the terahertz powder to obtain a terahertz material block ;

Step (4), heat treatment: Place the terahertz material block in a calcining furnace for sintering. After the sintering is completed, it is cooled and pulverized to obtain the terahertz material;

Step (5), radiation strengthening treatment: Place the terahertz material in a terahertz radiation line environment for radiation strengthening treatment.

In the above-mentioned preparation method of terahertz materials for reducing nitrogen oxide and volatile organic matter emissions, in step (1), the mass ratio of silicon dioxide, ferric oxide and calcium tungstate is: (3～5): (1 ~3): (1~2); Silica, ferric oxide and calcium tungstate are all passed through a 200 mesh sieve.

In the above-mentioned preparation method of terahertz materials for reducing nitrogen oxide and volatile organic matter emissions, in step (2), the melting temperature is 1600-1800°C and the melting time is 1-1.5h; the mixed crystal is crushed and passed through a 300-mesh sieve to obtain Mix crystal powder.

In the above-mentioned preparation method of terahertz materials that reduce nitrogen oxides and volatile organic matter emissions, in step (3), the pressing pressure is 3 to 5 MPa, the holding time is 10 to 20 min; the pressing temperature is room temperature;

When modified graphene oxide is added to the mixed crystal powder, the mass ratio of the mixed crystal powder to modified graphene oxide is 5 to 8:1;

When nano-silicon-based oxide is added to the mixed crystal powder, the mass ratio of the mixed crystal powder to nano-silicon-based oxide is 3 to 5:1;

When modified graphene oxide and nano-silicon-based oxide are added to the mixed crystal powder, the ratio of the mass of the mixed crystal powder to the sum of the masses of modified graphene oxide and nano-silicon-based oxide is: 2 to 5:1 , and the mass ratio of modified graphene oxide and nano silicon-based oxide is 1:2~3.

The above-mentioned preparation method of terahertz materials for reducing nitrogen oxide and volatile organic compound emissions, the preparation method of modified graphene oxide in step (3) is:

Step (A-1), ultrasonically disperse graphene oxide in dimethyl sulfoxide to obtain a graphene oxide dispersion;

Step (A-2): Add silica gel and N,N'-diisopropylcarbodiimide to the graphene oxide dispersion, and place it in a water bath for heating reaction;

Step (A-3): The product obtained by the reaction is washed with water and methanol in sequence and then dried to obtain modified graphene oxide.

In the above-mentioned preparation method of terahertz materials for reducing nitrogen oxide and volatile organic matter emissions, in step (A-1), the mass fraction of graphene oxide in the graphene oxide dispersion is 15 to 20 wt%;

In step (A-2), the mass ratio of graphene oxide, silica gel and N,N'-diisopropylcarbodiimide is: 1: (15～20): (2～4); heating The reaction temperature is 30~40℃, and the heating reaction time is 30~60min.

The above-mentioned preparation method of terahertz materials for reducing nitrogen oxide and volatile organic compound emissions, the preparation method of nanometer silicon-based oxide in step (3) is:

Step (B-1): Disperse magnesium sulfate and ethyl orthosilicate evenly in water to obtain a mixed dispersion; add inorganic acid to the mixed dispersion to react, adjust the pH to neutral after the reaction is completed, and let it stand. Obtain mixed system A;

Step (B-2): Add acetone to mixed system A and stir, then add vinyltriethoxysilane and continue stirring. After stirring, mixed system B is obtained;

Step (B-3): dry the mixed system B to obtain nanometer silicon-based oxide.

In the above-mentioned preparation method of terahertz materials for reducing nitrogen oxide and volatile organic matter emissions, in step (B-1), the mass ratio of magnesium sulfate, ethyl orthosilicate and water is 1: (1～1.5): ( 2~3); The amount of inorganic acid added is such that the pH of the mixed dispersion is 4~5; the reaction time is 4~6h, and the standing time is 16~24h;

The volume ratio of acetone in step (B-2) and water in step (B-1) is 1:8~10, and the volume ratio of vinyltriethoxysilane and acetone is 1.5~2:1; add acetone The final stirring time is 1 to 1.5 hours, and the stirring time after adding vinyltriethoxysilane is 2 to 3 hours;

In step (B-3), the drying temperature is 60-70°C, and the drying time is 12-24 hours.

In the above-mentioned preparation method of terahertz materials for reducing nitrogen oxide and volatile organic matter emissions, in step (4), the sintering temperature is 1100-1300°C, the sintering time is 1-2 hours; the particle size of the terahertz material is 10-50 μm.

In the above-mentioned preparation method of terahertz materials for reducing nitrogen oxide and volatile organic compound emissions, in step (5), the conditions for radiation strengthening treatment are: first irradiate for 1 to 3 hours in the 2.3×10 ¹¹ frequency band, and then irradiate at 5.5× Radiation treatment is performed in the 10 ¹¹ frequency band for 1 to 3 hours, followed by irradiation treatment in the 2.3×10 ¹² frequency band for 1 to 3 hours, and finally irradiation treatment in the 5.5×10 ¹² frequency band for 1 to 3 hours.

The technical solution of the present invention achieves the following beneficial technical effects:

1. In the present invention, three terahertz materials with relatively close melting points are first melted and mixed, and then modified graphene oxide and/or nano silicon-based oxide are added to prepare terahertz materials with high emissivity, and the terahertz materials are When the material is used in combustion sources to reduce emissions of nitrogen oxides and volatile organic compounds, its emission reduction performance is stable.

2. In the present invention, graphene oxide is modified and used, which can effectively improve the emissivity of the prepared terahertz material and the stability of its emission reduction energy efficiency. This may be because: the silicone-bonded graphene oxide can It can better synergize with terahertz materials such as silicon dioxide, ferric oxide, and calcium tungstate to mutually stimulate the radiation properties of terahertz materials, and ultimately obtain terahertz materials with high emissivity.

3. Compared with ordinary silicon dioxide, the nano silicon-based oxide in the present invention has a special lattice structure, which makes the terahertz material have a higher emissivity; and the nano silicon prepared by the preparation method of the present invention In the presence of calcium tungstate-based oxide, the terahertz material can maintain a high emissivity under different conditions of use, and when modified graphite oxide is added to the terahertz material, the nano-silicon-based oxide and modified The synergistic effect of graphite oxide makes the above effects of calcium tungstate more obvious.

Detailed ways

Example 1

In this embodiment, a method for preparing a terahertz material that reduces nitrogen oxide and volatile organic compound emissions includes the following steps:

Step (1), mixing of raw materials: Mix silica, ferric oxide and calcium tungstate evenly to obtain mixed raw material powder; the mass ratio of silica, ferric oxide and calcium tungstate is 3:2: 1; Silica, ferric oxide and calcium tungstate are all passed through a 200 mesh sieve.

Step (2), melting and crystallizing: Melt the mixed raw material powder at a temperature of 1750°C for 1 hour, then cool and crystallize, re-pulverize the mixed crystals obtained by crystallization and pass through a 300-mesh sieve to obtain mixed crystal powder;

Step (3), compression molding: add modified graphene oxide to the mixed crystal powder, the mass ratio of the mixed crystal powder to modified graphene oxide is 5:1, mix evenly to obtain terahertz powder; add terahertz powder The powder is maintained at room temperature and under a pressure of 5MPa for 10 min, and then pressed and molded to obtain a terahertz material block;

Step (4), heat treatment: Place the terahertz material block in a calcining furnace for sintering. The sintering temperature is 1200°C and the sintering time is 2 hours. After the sintering is completed, it is cooled and pulverized to obtain the terahertz material. The particle size of the terahertz material is 10～50μm;

Step (5), radiation strengthening treatment: place the terahertz material in a terahertz radiation line environment for radiation strengthening treatment; the conditions for radiation strengthening treatment are: first irradiate for 1 to 3 hours in the 2.3×10 ¹¹ frequency band , then radiate for 1 to 3 hours under the 5.5×10 ¹¹ frequency band, then 1 to 3 hours under the 2.3×10 ¹² frequency band, and finally 1 to 3 hours under the 5.5×10 ¹² frequency band.

The preparation method of the modified graphene oxide added in step (3) of this embodiment is:

Step (A-1), ultrasonically disperse graphene oxide in dimethyl sulfoxide to obtain a graphene oxide dispersion; the mass fraction of graphene oxide in the graphene oxide dispersion is 20wt%;

Step (A-2), add silica gel and N,N'-diisopropylcarbodiimide to the graphene oxide dispersion, and place it in a water bath for heating reaction; graphene oxide, silica gel and N,N' -The mass ratio of the three diisopropylcarbodiimides is: 1:15:2, the temperature of the heating reaction is 38°C, and the time of the heating reaction is 50min;

Step (A-3): The product obtained by the reaction is washed with water and methanol in sequence and then dried to obtain modified graphene oxide.

The infrared emissivity of the terahertz material prepared in this example reached 91.3%. The terahertz material prepared in this example was added to the coolant of gasoline vehicles and diesel vehicles for repeated tests. It was found that after adding the terahertz material, The amount of nitrogen oxides and volatile organic compounds emitted by combustion of gasoline and diesel vehicles has been significantly reduced; terahertz materials have stable and good performance in promoting the emission reduction of nitrogen oxides and volatile organic compounds.

Example 2

In this embodiment, a method for preparing a terahertz material that reduces nitrogen oxide and volatile organic compound emissions includes the following steps:

Step (1), raw material mixing: mix silica, ferric oxide and calcium tungstate evenly to obtain mixed raw material powder; the mass ratio of silica, ferric oxide and calcium tungstate is 5:3: 2; Silica, ferric oxide and calcium tungstate are all passed through a 200 mesh sieve.

Step (2), melting and crystallizing: melt the mixed raw material powder at a temperature of 1600°C for 1.5 hours, then cool and crystallize, re-pulverize the mixed crystals obtained by crystallization and pass through a 300-mesh sieve to obtain mixed crystal powder;

Step (3), compression molding: add nano silicon-based oxide to the mixed crystal powder, the mass ratio of the mixed crystal powder and nano silicon-based oxide is 5:1, mix evenly to obtain terahertz powder; add the terahertz powder The powder is maintained at room temperature and under a pressure of 3MPa for 20 min, and then pressed and molded to obtain a terahertz material block;

Step (4), heat treatment: Place the terahertz material block in a calcining furnace for sintering. The sintering temperature is 1300°C and the sintering time is 1 hour. After the sintering is completed, it is cooled and pulverized to obtain the terahertz material. The particle size of the terahertz material is 10～50μm;

Step (5), radiation strengthening treatment: place the terahertz material in a terahertz radiation line environment for radiation strengthening treatment; the conditions for radiation strengthening treatment are: first, irradiation treatment in the 2.3×10 ¹¹ frequency band for 1 to 3 hours , then radiate for 1 to 3 hours under the 5.5×10 ¹¹ frequency band, then 1 to 3 hours under the 2.3×10 ¹² frequency band, and finally 1 to 3 hours under the 5.5×10 ¹² frequency band.

The preparation method of the nano silicon-based oxide added in step (3) of this embodiment is:

Step (B-1): Disperse magnesium sulfate and ethyl orthosilicate evenly in water to obtain a mixed dispersion; add inorganic acid to the mixed dispersion to react, adjust the pH to neutral after the reaction is completed, and let it stand. Obtain mixed system A; the mass ratio of magnesium sulfate, ethyl orthosilicate and water is 1:1.5:3; the amount of inorganic acid added is such that the pH of the mixed dispersion is 4 as a standard; the reaction time is 5h, let stand The time is 20h;

Step (B-2), add acetone to mixed system A and stir for 1.5h, then add vinyltriethoxysilane and continue stirring for 3h. After stirring, mixed system B is obtained; acetone and step (B-1) The volume ratio of water is 1:10, and the volume ratio of vinyltriethoxysilane to acetone is 1.5:1;

Step (B-3): Dry the mixed system B at 70°C for 24 hours to obtain nanometer silicon-based oxide.

The infrared emissivity of the terahertz material prepared in this example reached 92.5%. The terahertz material prepared in this example was added to the coolant of gasoline vehicles and diesel vehicles for repeated tests. It was found that after adding the terahertz material, The amount of nitrogen oxides and volatile organic compounds emitted by the combustion of gasoline vehicles and diesel vehicles has been significantly reduced; the terahertz material has a stable and good performance in promoting the emission reduction of nitrogen oxides and volatile organic compounds, but the stability of its performance is different from the embodiment 1 is slightly better than 1.

Example 3

In this embodiment, a method for preparing a terahertz material that reduces nitrogen oxide and volatile organic compound emissions includes the following steps:

Step (1), mixing of raw materials: Mix silica, ferric oxide and calcium tungstate evenly to obtain mixed raw material powder; the mass ratio of silica, ferric oxide and calcium tungstate is 4:1: 1; Silica, ferric oxide and calcium tungstate are all passed through a 200 mesh sieve.

Step (2), melting and crystallizing: Melt the mixed raw material powder at a temperature of 1800°C for 1 hour, then cool and crystallize, re-pulverize the mixed crystals obtained by crystallization and pass through a 300-mesh sieve to obtain mixed crystal powder;

Step (3), compression molding: add modified graphene oxide and nano-silicon-based oxide to the mixed crystal powder, and the mass ratio of the mixed crystal powder to modified graphene oxide and nano-silicon-based oxide is 5:1. The mass ratio of modified graphene oxide and nano-silicon-based oxide is 1:2; after mixing evenly, terahertz powder is obtained; the terahertz powder is maintained at room temperature and 4MPa pressure for 15 min, and pressed and molded to obtain terahertz powder block of material;

Step (4), heat treatment: Place the terahertz material block in a calcining furnace for sintering. The sintering temperature is 1100°C and the sintering time is 2 hours. After the sintering is completed, it is cooled and pulverized to obtain the terahertz material. The particle size of the terahertz material is 10～50μm;

Step (5), radiation strengthening treatment: place the terahertz material in a terahertz radiation line environment for radiation strengthening treatment; the conditions for radiation strengthening treatment are: first, irradiation treatment in the 2.3×10 ¹¹ frequency band for 1 to 3 hours , then radiate for 1 to 3 hours under the 5.5×10 ¹¹ frequency band, then 1 to 3 hours under the 2.3×10 ¹² frequency band, and finally 1 to 3 hours under the 5.5×10 ¹² frequency band.

The preparation method of the modified graphene oxide added in step (3) of this embodiment is the same as that of Example 1, and the preparation method of the nano silicon-based oxide added is the same as that of Example 2.

The infrared emissivity of the terahertz material prepared in this example reached 95.8%. The terahertz material prepared in this example was added to the coolant of gasoline vehicles and diesel vehicles for repeated tests. It was found that after adding the terahertz material, The amount of nitrogen oxides and volatile organic compounds emitted by the combustion of gasoline vehicles and diesel vehicles has been significantly reduced; the terahertz material has a stable and good performance in promoting the emission reduction of nitrogen oxides and volatile organic compounds, but the stability of its performance is different from the embodiment 2 compared to better.

Comparative example 1

The only difference between this comparative example and Example 1 is that in step (3), commercially available graphene oxide is used instead of the modified graphene oxide in Example 1.

The infrared emissivity of the terahertz material prepared in this comparative example reached 85.6%. The terahertz material prepared in this comparative example was added to the coolant of gasoline vehicles and diesel vehicles for repeated tests. It was found that after adding the terahertz material, The amounts of nitrogen oxides and volatile organic compounds emitted by combustion of gasoline vehicles and diesel vehicles are both reduced, but the reduction amplitudes vary greatly in different tests; the stability of their emission reduction performance is significantly worse than that of Example 1.

Comparative example 2

The only difference between this comparative example and Example 2 is that commercially available nano-silica is added in step (3) instead of the nano-silicon-based oxide in Example 2.

The infrared emissivity of the terahertz material prepared in this comparative example reached 81.9%. The terahertz material prepared in this comparative example was added to the coolant of gasoline vehicles and diesel vehicles for repeated tests. It was found that after adding the terahertz material, The amounts of nitrogen oxides and volatile organic compounds emitted by combustion of gasoline vehicles and diesel vehicles are both reduced, but the reduction amplitudes vary greatly in different tests; the stability of their emission reduction performance is significantly worse than that of Example 2.

Comparative example 3

The only difference between this comparative example and Example 3 is that: in step (1), the raw materials are mixed: silica and ferric oxide are mixed evenly to obtain mixed raw material powder; the mass ratio of silica and ferric oxide is: 4:2; both silica and ferric oxide pass through a 200 mesh sieve.

The infrared emissivity of the terahertz material prepared in this comparative example reached 89.7%. The terahertz material prepared in this comparative example was added to the coolant of gasoline vehicles and diesel vehicles for repeated tests. It was found that after adding the terahertz material, The amounts of nitrogen oxides and volatile organic compounds emitted by combustion of gasoline vehicles and diesel vehicles are both reduced, but the reduction amplitudes vary greatly in different tests; the stability of their emission reduction performance is significantly worse than that of Example 1.

Obviously, the above-mentioned embodiments are only examples for clear explanation and are not intended to limit the implementation. For those of ordinary skill in the art, other different forms of changes or modifications can be made based on the above description. An exhaustive list of all implementations is neither necessary nor possible. The obvious changes or modifications derived therefrom are still within the protection scope of the claims of this patent application.

Claims (8)

1. The preparation method of the terahertz material for reducing the emission of nitrogen oxides and volatile organic compounds is characterized by comprising the following steps of:

step (1), mixing the raw materials: uniformly mixing silicon dioxide, ferric oxide and calcium tungstate to obtain mixed raw material powder;

step (2), melting and crystallizing: melting the mixed raw material powder, cooling and crystallizing, and re-crushing the mixed crystals obtained by crystallizing to obtain mixed crystal powder;

step (3), compression molding: adding modified graphene oxide and/or nano silicon-based oxide into the mixed crystal powder, and uniformly mixing to obtain terahertz powder; pressing and forming the terahertz powder to obtain a terahertz material block;

step (4), heat treatment: placing the terahertz material block into a calciner for sintering, cooling and crushing after the sintering is finished to obtain a terahertz material;

step (5), irradiation strengthening treatment: placing the terahertz material in a terahertz irradiation line environment for irradiation strengthening treatment;

in the step (3), when the modified graphene oxide is added into the mixed crystal powder, the mass ratio of the mixed crystal powder to the modified graphene oxide is 5-8:1;

when the nano silicon-based oxide is added into the mixed crystal powder, the mass ratio of the mixed crystal powder to the nano silicon-based oxide is 3-5:1;

when the modified graphene oxide and the nano silicon-based oxide are added into the mixed crystal powder, the ratio of the mass of the mixed crystal powder to the sum of the mass of the modified graphene oxide and the mass of the nano silicon-based oxide is as follows: 2-5:1, and the mass ratio of the modified graphene oxide to the nano silicon-based oxide is 1:2-3;

the preparation method of the modified graphene oxide in the step (3) comprises the following steps:

step (A-1), ultrasonically dispersing graphene oxide in dimethyl sulfoxide to obtain graphene oxide dispersion liquid;

step (A-2), adding silica gel and N, N' -diisopropylcarbodiimide into graphene oxide dispersion liquid, and placing in a water bath for heating reaction;

step (A-3), cleaning a product obtained by the reaction with water and methanol in sequence, and drying to obtain modified graphene oxide;

the preparation method of the nano silicon-based oxide in the step (3) comprises the following steps:

step (B-1), placing magnesium sulfate and tetraethoxysilane into water to be uniformly dispersed to obtain mixed dispersion liquid; adding inorganic acid into the mixed dispersion liquid for reaction, adjusting the pH value to be neutral after the reaction is completed, and standing to obtain a mixed system A;

adding acetone into the mixed system A for stirring, then adding vinyl triethoxysilane, continuing stirring, and obtaining a mixed system B after stirring is finished;

and (B-3) drying the mixed system B to obtain the nano silicon-based oxide.

2. The method for producing a terahertz material for reducing the emission of nitrogen oxides and volatile organic compounds according to claim 1, wherein in step (1), the mass ratio of silica, ferric oxide, and calcium tungstate is: (3-5) (1-3) (1-2); the silicon dioxide, ferric oxide and calcium tungstate are all sieved by a 200-mesh sieve.

3. The method for producing terahertz material for reducing the emission of nitrogen oxides and volatile organic compounds according to claim 1, characterized in that in step (2), the melting temperature is 1600 to 1800 ℃ and the melting time is 1 to 1.5h; and (3) crushing the mixed crystals, and sieving the crushed mixed crystals with a 300-mesh sieve to obtain mixed crystal powder.

4. The method for producing a terahertz material for reducing the emission of nitrogen oxides and volatile organic compounds according to claim 1, wherein in step (3), the pressure of compression molding is 3 to 5MPa, and the dwell time is 10 to 20min; the press molding temperature is room temperature.

5. The method for producing a terahertz material for reducing the emission of nitrogen oxides and volatile organic compounds according to claim 1, wherein in step (a-1), the mass fraction of graphene oxide in the graphene oxide dispersion liquid is 15 to 20wt%;

in the step (A-2), the mass ratio of graphene oxide, silica gel and N, N' -diisopropylcarbodiimide is as follows: 1: (15-20): (2-4); the temperature of the heating reaction is 30-40 ℃, and the time of the heating reaction is 30-60 min.

6. The method for producing a terahertz material for reducing the emission of nitrogen oxides and volatile organic compounds according to claim 1, wherein in step (B-1), the mass ratio of magnesium sulfate, tetraethyl orthosilicate, and water is 1: (1-1.5): (2-3); the addition amount of the inorganic acid is such that the pH of the mixed dispersion is from 4 to 5; the reaction time is 4-6 h, and the standing time is 16-24 h;

the ratio of the volume of acetone in step (B-2) to the volume of water in step (B-1) was 1: 8-10, wherein the volume ratio of the vinyl triethoxysilane to the acetone is 1.5-2:1; the stirring time after adding acetone is 1 to 1.5 hours, and the stirring time after adding vinyl triethoxysilane is 2 to 3 hours;

in the step (B-3), the drying temperature is 60-70 ℃ and the drying time is 12-24 h.

7. The method for preparing a terahertz material for reducing the emission of nitrogen oxides and volatile organic compounds according to claim 1, wherein in step (4), the sintering temperature is 1100-1300 ℃ and the sintering time is 1-2 h; the grain diameter of the terahertz material is 10-50 mu m.

8. The method for producing a terahertz material for reducing the emission of nitrogen oxides and volatile organic compounds according to claim 1, wherein in step (5), the irradiation strengthening treatment conditions are: first at 2.3X10 ¹¹ Radiation treatment for 1-3 h under frequency band, then at 5.5X10 ¹¹ The radiation treatment is carried out for 1 to 3 hours under the frequency band, and then the radiation treatment is carried out at 2.3X10 ¹² Radiation treatment for 1-3 h under frequency band, and finally at 5.5X10 ¹² And carrying out radiation treatment for 1-3 h under the frequency band.