1t-mos2 / fe-biochar composite material and preparation method and application thereof

Abstract

The application relates to a 1T-MoS2 / Fe-biochar composite material and a preparation method and application thereof. Biomass powder and potassium ferrate are stirred in a 80 DEG C water bath, high-temperature calcination is carried out under a nitrogen atmosphere, Fe-biochar is obtained, CH4N2S and (NH4)6Mo7O 24 are dissolved in deionized water, then Fe-biochar is added, hydrothermal reaction is carried out, 2H-MoS2 / Fe-biochar is obtained, the 2H-MoS2 / Fe-biochar is added into a DMF solution, ultrasonic dispersion is carried out, then the 2H-MoS2 / Fe-biochar is transferred into a high-pressure reaction kettle, hydrothermal reaction is carried out, and the 1T-MoS2 / Fe-biochar composite material is obtained. The 1T-MoS2 / Fe-biochar constructed by the application greatly improves the adsorption capacity for single mercury ions or single perfluorooctanoic acid or coexisting mercury ions and perfluorooctanoic acid as an adsorbent.

Description

TECHNICAL FIELD

[0001] The application belongs to the field of adsorption materials, and particularly relates to a 1T-MoS2 / Fe-biochar composite material and a preparation method and application thereof. BACKGROUND

[0002] In recent years, with the continuous advancement of industrialization, industrial wastewater containing a large amount of organic and inorganic pollutants is generated, which seriously pollutes the environment and causes great harm to the environment. The hydrogen atoms on the alkyl chain of the organic perfluorooctanoic acid (PFOA) are replaced by fluorine atoms. Due to its unique chemical and physical properties, such as hydrophobicity, oleophobicity and extraordinary chemical stability, PFOA is widely used as a surfactant, lubricant, flame retardant and polymer additive. The wide industrial application has released PFOA into aquatic systems, which is often detected in drinking water, wastewater and seawater. Mercury (II) is considered to be one of the top ten toxic chemicals, which is usually released in the processes such as mining, manufacturing batteries and electroplating. Due to its non-biodegradable property, mercury (II) can accumulate and cause serious damage to the central nervous system, immune system and kidney function. Therefore, it is very urgent and necessary to remove mercury (II). The coexistence of the organic perfluorooctanoic acid (PFOA) and the inorganic mercury ion (Hg 2+ ) remaining in water has attracted widespread attention. At present, there are more adsorption studies on single pollutants, but there are few co-adsorption studies on organic and inorganic pollutants. SUMMARY

[0003] In order to solve the above-mentioned technical problems, the application provides a co-adsorption composite material 1T-MoS2 / Fe-biochar for an organic and inorganic coexisting pollutant system.

[0004] The technical scheme adopted by the application is that the 1T-MoS2 / Fe-biochar composite material has the following steps in the preparation method:

[0005] 1) Dissolve biomass powder and potassium ferrate in deionized water, uniformly stir in a 80 DEG C water bath, dry overnight, and then put into a tube furnace, high-temperature calcine under a nitrogen atmosphere, grind after cooling, and obtain Fe-biochar;

[0006] 2) Dissolve CH4N2S and (NH4)6Mo7O 24 in deionized water, then add Fe-biochar, stir for 1 h, then transfer the obtained mixture to a 100 mL tetrafluoroethylene-lined high-pressure reaction kettle, and perform hydrothermal reaction, wash the obtained product, dry, and obtain 2H-MoS2 / Fe-biochar;

[0007] 3) 2H-MoS2 / Fe-biochar is added into DMF solution, ultrasonic dispersion is carried out, and then the obtained product is transferred into a high-pressure reaction kettle to carry out hydrothermal reaction, and then the obtained product is washed, dried, and 1T-MoS2 / Fe-biochar composite material is obtained.

[0008] Preferably, in step 1), the biomass powder is pine cone powder, and the preparation method comprises the following steps: crushing the pine cone, washing with deionized water, drying at 60℃ overnight, and grinding.

[0009] Preferably, in step 1), the high-temperature calcination is high-temperature calcination at 700℃ for 2h, and the heating rate is 5℃ / min.

[0010] Preferably, in step 2), the hydrothermal reaction is hydrothermal reaction at 180℃ for 24h.

[0011] Preferably, in step 3), the hydrothermal reaction is hydrothermal reaction at 200℃ for 8h.

[0012] The 1T-MoS2 / Fe-biochar composite material provided by the application is used as an adsorbent to adsorb organic pollutants in wastewater or inorganic pollutants in wastewater or co-adsorb organic pollutants and inorganic pollutants in wastewater.

[0013] Preferably, the organic pollutants are PFOA; and the inorganic pollutants are Hg 2+ .

[0014] Preferably, the method is as follows: 1T-MoS2 / Fe-biochar composite material is added into wastewater containing PFOA and / or Hg 2+ , and adsorption is carried out for 2-60min.

[0015] Preferably, the initial concentration of PFOA in the wastewater is 50-800mg·L -1 , the initial concentration of Hg 2+ is 50-800mg·L -1 , and the initial pH value is 4.

[0016] Preferably, the amount of 1T-MoS2 / Fe-biochar composite material added is 1mg·mL -1 .

[0017] The beneficial effects of the application are as follows:

[0018] 1、The biomass adopts pine cones, and the pine cones naturally falling off are converted into biochar, which is very low in price and has no pollution. The biochar is rich in a large number of hydroxyl and carboxyl functional groups, and is pyrolyzed to generate stable carbonaceous materials. Moreover, the pyrolyzed materials have good specific surface area and large pore diameter, and have great potential for adsorption of organic pollutants and heavy metal ions. Meanwhile, the introduction of potassium ferrate expands the pore diameter and is beneficial to solid-liquid separation of the adsorbent, and also achieves the effect of one-step negative magnetism on the biochar.

[0019] 2, MoS2 is rarely studied in the adsorption field, and the conversion of 2H into 1T phase is rarely studied in the adsorption field. In the application, 2H is converted into 1T, which can expand the interlayer spacing, improve the adsorption capacity, and increase the specific surface area. Meanwhile, the stability of the composite adsorbent is also enhanced.

[0020] 3, The 1T-MoS2 / Fe-biochar constructed in the application greatly improves the adsorption capacity of single mercury ions or single perfluorooctanoic acid or coexistence of mercury ions and perfluorooctanoic acid as an adsorbent. BRIEF DESCRIPTION OF DRAWINGS

[0021] Figure 1 is the SEM diagram of BC (left) and Fe-BC (right).

[0022] Figure 2 is the SEM diagram of 1T-MoS2 / Fe-BC.

[0023] Figure 3 is the X-ray diffraction diagram of Fe-BC, 2H-MoS2, 1T-MoS2, 2H-MoS2 / Fe-BC and 1T-MoS2 / Fe-BC.

[0024] Figure 4 is the nitrogen adsorption-desorption curve of BC, Fe-BC and 1T-MoS2 / Fe-BC.

[0025] Figure 5 is the adsorption efficiency of Fe-BC, 2H-MoS2, 1T-MoS2, 2H-MoS2 / Fe-BC and 1T-MoS2 / Fe-BC on Hg 2+ .

[0026] Figure 6 is the adsorption efficiency of Fe-BC, 2H-MoS2, 1T-MoS2, 2H-MoS2 / Fe-BC and 1T-MoS2 / Fe-BC on PFOA.

[0027] Figure 7 is the adsorption kinetics curve of 1T-MoS2 / Fe-BC on Hg 2+ and Hg 2+ &PFOA.

[0028] Figure 8 Adsorption kinetics curves of 1T-MoS2 / Fe-BC for PFOA and PFOA&Hg 2+ .

[0029] Figure 9 Adsorption isotherms of 1T-MoS2 / Fe-BC for Hg 2+ and Hg 2+ &PFOA (25℃, PH=4, PFOA coexistence concentration 10, 50mg·L -1 ).

[0030] Figure 10 Adsorption isotherms of 1T-MoS2 / Fe-BC for PFOA and PFOA&Hg 2+ (25℃, PH=4, Hg 2+ coexistence concentration 10, 50mg·L -1 ). DETAILED DESCRIPTION

[0031] Example 1 1T-MoS2 / Fe-biochar composite material (1T-MoS2 / Fe-BC)

[0032] (I) Preparation method

[0033] 1) Pineal gland was crushed and washed with deionized water for 2-3 times, and then dried in an oven at 60℃ overnight to obtain pineal powder. 2g of pineal powder and 0.8g of potassium ferrate were dissolved in 40mL of deionized water, and the mixed solution was stirred uniformly in a water bath at 80℃. After drying in an oven at 60℃ overnight, it was put into a tube furnace and calcined at 700℃ (heating rate 5℃ / min) under nitrogen atmosphere for 2h. Finally, the obtained solid was ground into powder using a corundum mortar to obtain black powder solid, which was labeled as Fe-biochar, marked as Fe-BC.

[0034] 2) 0.228g CH4N2S and 0.1235g (NH4)6Mo7O 24 were taken and added to 30mL of deionized water. After stirring and dissolving, 0.35g of Fe-BC was added and stirred for 1h. Then the mixed solution was transferred to a 100mL tetrafluoroethylene lined autoclave and hydrothermal reaction was carried out at 180℃ for 24h. After cooling, it was washed with deionized water and anhydrous ethanol for three times and dried at 60℃ to obtain black powder solid, which was labeled as 2H-MoS2 / Fe-BC.

[0035] 3) Take 150 mg of 2H-MoS2 / Fe-BC and add it to 30 mL of DMF solution, ultrasonic dispersion for 15 min, then transfer it to a high-pressure reaction kettle, and carry out hydrothermal reaction at 200°C in an oven for 8 h. After washing the product, dry it at 60°C to obtain 1T-MoS2 / Fe-biochar composite material, marked as 1T-MoS2 / Fe-BC.

[0036] (B) Characterization

[0037] Figure 1 SEM images of BC (left) and Fe-BC (right) can be seen, and the successful loading of potassium ferrate and the obvious increase in pore size can be seen.

[0038] Figure 2 SEM images and mapping images of 1T-MoS2 / Fe-BC can be seen, and after loading 1T-MoS2, a flower-like structure appears on the biochar, and the mapping element distribution shows a large amount of Mo and S elements, proving the successful composite of 1T-MoS2 / Fe-BC.

[0039] Figure 3 X-ray diffraction patterns of Fe-BC, 2H-MoS2, 1T-MoS2, 2H-MoS2 / Fe-BC and 1T-MoS2 / Fe-BC can be seen. The diffraction peaks of 1T-MoS2 / Fe-BC at 2θ = 8.4, 32.7, 35.3, 58.2° are attributed to the peaks of MoS2, indicating that MoS2 is successfully loaded on Fe-BC. Comparing the peak width of 2H-MoS2 / Fe-BC (d = 9.8 nm) and 1T-MoS2 / Fe-BC (d = 10.5 nm). It shows that the interlayer distance becomes larger when 2H changes to 1T phase, which can provide more active sites and improve the adsorption performance.

[0040] Figure 4 Nitrogen adsorption-desorption curves of BC, Fe-BC, 1T-MoS2 / Fe-BC can be seen, and the specific surface area and average pore size of the composite adsorbent 1T-MoS2 / Fe-BC are 517.99 m 2 / g, 6.905 nm, the specific surface area and pore size have been greatly improved

[0041] Example 2 Application

[0042] Application of 1T-MoS2 / Fe-biochar composite material as adsorbent in single adsorption of organic pollutants in wastewater or single adsorption of inorganic pollutants in wastewater or co-adsorption of organic and inorganic pollutants coexisting in wastewater

[0043] Adsorption performance evaluation: All adsorption experiments were carried out in batch mode at room temperature (25℃). The adsorption mode was to use 1T-MoS2 / Fe-BC to adsorb PFOA and Hg in water in a shaking box. 2+ The results were detected by fluorescence spectrometer and inductively coupled plasma emission spectrometer.

[0044] (I) Adsorption kinetics experiment:

[0045] 5mg of adsorbent was added to 5mL of water solution containing PFOA and / or Hg 2+ , and the initial pH value of the solution was adjusted to 4. Liquid samples were collected at time intervals of 2, 5, 8, 10, 15, 20, 30, 40 and 60min, and after adsorption, the mixture was filtered through a 0.45μm hydrophilic nylon filter to explore the adsorption kinetics.

[0046] The adsorbents used were: Fe-BC, 2H-MoS2, 1T-MoS2, 2H-MoS2 / Fe-BC, 1T-MoS2 / Fe-BC.

[0047] The water adsorption system was: single adsorption system 1: 50mg·L -1 Hg 2+

[0048] Single adsorption system 2: 100mg·L -1 PFOA

[0049] Coexisting system 1: 50mg·L -1 Hg 2+ and 10mg·L -1 PFOA

[0050] Coexisting system 2: 100mg·L -1 PFOA and 10mg·L -1 Hg 2+

[0051] Figure 5 The adsorption efficiency of 5mL single adsorption system 1 (50mg·L -1 Hg 2+ ) adsorbed by 5mg of Fe-BC, 2H-MoS2, 1T-MoS2, 2H-MoS2 / Fe-BC and 1T-MoS2 / Fe-BC for 20min.

[0052] Figure 6 The adsorption efficiency of 5mL single adsorption system 2 (100mg·L -1adsorption efficiency of 1T-MoS2 / Fe-BC for 20 min.

[0053] By Figure 5 and Figure 6 It can be seen that the composite adsorbent 1T-MoS2 / Fe-BC adsorbs Hg 2+ and PFOA greatly improves the adsorption efficiency, and the adsorption efficiency is 88.46%, 98.49% respectively.

[0054] Figure 7 is the adsorption kinetics curve of 1T-MoS2 / Fe-BC with an addition amount of 5 mg to 5 mL single adsorption system 1 (50 mg·L -1 Hg 2+ ) and coexisting system 1 (50 mg·L -1 Hg 2+ and 10 mg·L -1 PFOA), the results show that it conforms to the pseudo-second-order kinetics model.

[0055] Figure 8 is the adsorption kinetics curve of 1T-MoS2 / Fe-BC with an addition amount of 5 mg to 5 mL single adsorption system 2 (100 mg·L -1 PFOA) and coexisting system 2 (100·mg L -1 PFOA and 10 mg·L -1 Hg 2+ ), the results show that it conforms to the pseudo-second-order kinetics model.

[0056] (II) Adsorption isotherm experiment:

[0057] 5 mg of 1T-MoS2 / Fe-BC was added to 5 mL of aqueous solution adsorption system containing PFOA and / or Hg 2+ , and the initial pH value of the solution was adjusted to 4. After shaking adsorption for 20 min, the liquid sample was collected, and after adsorption, the mixture was filtered through a 0.45 μm hydrophilic nylon filter to explore the adsorption isotherm.

[0058] The aqueous solution adsorption system uses: single adsorption system 1: 50-800 mg·L -1 Hg 2+

[0059] Single adsorption system 2: 50-800 mg·L -1 PFOA

[0060] Coexisting system 1: 50-800 mg·L -1 Hg 2+ and 10 mg·L -1 PFOA

[0061] Coexisting system 2: 50-800 mg·L -1 Hg 2+ and 50 mg·L -1 PFOA

[0062] Coexisting system 3: 50-800 mg·L -1 PFOA and 10 mg·L -1 Hg 2+

[0063] Coexisting system 4: 50-800 mg·L -1 PFOA and 50 mg·L -1 Hg 2+

[0064] Figure 9 is the adsorption curve of 1T-MoS2 / Fe-BC with the addition amount of 5 mg to 5 mL single adsorption system 1 (Hg 2+ ), coexisting system 1 (Hg 2+ &PFOA 10 ppm) and coexisting system 2 (Hg 2+ &PFOA 50 ppm). The maximum adsorption amount of 1T-MoS2 / Fe-BC prepared by the application to Hg 2+ is 454.55 mg L -1 , the maximum adsorption amount to Hg 2+ &PFOA 10 ppm is 526.32 mg L -1 , and the maximum adsorption amount to Hg 2+ &PFOA 50 ppm is 714.28 mg L -1 . It can be seen that the adsorption amount is greatly improved when Hg 2+ and PFOA coexist, and the adsorption process is a Langmuir model, which is a monolayer adsorption.

[0065] Figure 10 is the adsorption curve of 1T-MoS2 / Fe-BC with the addition amount of 5 mg to 5 mL single adsorption system 2 (PFOA), coexisting system 3 (PFOA&Hg 2+ 10 ppm) and coexisting system 4 (PFOA&Hg 2+ 50 ppm). The maximum adsorption amount of 1T-MoS2 / Fe-BC prepared by the application to PFOA is 312.5 mg L -1 , the maximum adsorption amount to PFOA&Hg 2+ 10 ppm is 333.33 mg L -1 , and the maximum adsorption amount to PFOA&Hg 2+ 50 ppm is 370.37 mg L -1 . It can be seen that the adsorption amount is greatly improved when Hg 2+The adsorption capacity gradually increased when PFOA coexisted, and the adsorption process was a monolayer adsorption following Langmuir model.

Claims

1. Use of 1T-MoS2 / Fe-biochar composite in the co-adsorption of organic and inorganic pollutants in wastewater, characterized in that, The method is as follows: the organic pollutant is PFOA; and the inorganic pollutant is Hg 2+ , in wastewater containing PFOA and Hg 2+ , 1T-MoS2 / Fe-biochar composite material is added, and adsorption is performed for 2-60 min; The preparation method of the 1T-MoS2 / Fe-biochar composite material comprises the following steps: 1) Biomass powder and potassium ferrate are dissolved in deionized water, stirred uniformly in a water bath at 80 DEG C, dried overnight, and then put into a tube furnace for high-temperature calcination under a nitrogen atmosphere, cooled, and ground to obtain Fe-biochar; 2) CH4N2S and (NH4)6Mo7O 24 Dissolved in deionized water, then Fe-biochar was added, stirred for 1 h; the resulting mixture was transferred to a 100 mL polytetrafluoroethylene-lined autoclave for hydrothermal reaction, the resulting product was washed, dried, and 2H-MoS2 / Fe-biochar was obtained; 3) 2H-MoS2 / Fe-biochar is added to a DMF solution, ultrasonically dispersed, transferred to a high-pressure reaction kettle, and subjected to hydrothermal reaction, and the obtained product is washed, dried, and 1T-MoS2 / Fe-biochar composite material is obtained.

2. Use according to claim 1, characterized in that, In step 1), the biomass powder is pinecone powder, and the preparation method comprises the following steps: pinecone bodies are crushed, washed with deionized water, dried at 60 DEG C overnight, and ground.

3. Use according to claim 1, characterized in that, In step 1), the high-temperature calcination is high-temperature calcination at 700 DEG C for 2 h, and the heating rate is 5 DEG C / min.

4. Use according to claim 1, characterized in that, In step 2), the hydrothermal reaction is hydrothermal reaction at 180 DEG C for 24 h.

5. The use according to claim 1, characterized in that, In step 3), the hydrothermal reaction is hydrothermal reaction at 200 DEG C for 8 h.

6. Use according to claim 1, characterized in that, The initial concentration of PFOA in the adjusted wastewater was 50-800 mg·L -1 , Hg 2+ The initial concentration of PFOA in the adjusted wastewater was 50-800 mg·L -1 , and the initial pH value was 4.

7. Use according to claim 6, characterized in that, The 1T-MoS2 / Fe-biochar composite is added in an amount of 1 mg·mL -1 .

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