Preparation method of activated-carbon multi-point-location supported nano zero-valent iron composite material

A technology of nano-zero-valent iron and composite materials, applied in chemical instruments and methods, physical/chemical process catalysts, metal/metal oxide/metal hydroxide catalysts, etc., can solve the problem of low loading capacity, limited adsorption capacity, activated carbon Poor adsorption selectivity, etc.

Inactive Publication Date: 2017-12-12

BEIJING UNIV OF CHEM TECH

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AI-Extracted Technical Summary

Problems solved by technology

[0004] Activated carbon is a cheap adsorbent that is widely used, and it can still maintain its adsorption capacity after many cycles of operation. However, ordinary activated carbon has poor adsorption selectivity and limited adsorption capacity.

Loading nano-zero-valent iron particles on ordinary activated carbon can increase the surface area of nano-zero-valent iron particles to a certain extent, increase the contact area between nano-zero-valent iron and pollutants, and weaken the agglomeration effect of nano-zero-valent iron particles. Due to the limited loading sites of activated carbon,...

Method used

As shown in Figure 1, the modified activated carbon prepared in the present embodiment is made up of activated carbon and more carbon particles, and the carbon particles present irregular spherical shape, which greatly improves the loading site of activated carbon.

As shown in Figure 5,...

Abstract

The invention provides a method for preparing a composite material of activated carbon loaded with nanometer zero-valent iron, comprising the following steps: Step 1: adding microcrystalline cellulose solution and citric acid to the activated carbon, and hydrothermally reacting to prepare modified activated carbon; Step 2 : Polyethylene glycol is dissolved in ultrapure water to prepare a dispersant solution; Step 3: FeSO4·7H2O is dissolved in the dispersant solution, stirred magnetically under nitrogen protection, and slowly dripped into NaBH4 solution to obtain Activated carbon multi-site loaded nano zero-valent iron composite material. The invention prepares multi-point activated carbon, increases the active sites of activated carbon to a large extent, and effectively improves the loading capacity of nano-zero-valent iron; uses polyethylene glycol solution as a dispersant, so that nano-zero-valent iron particles are evenly loaded on the activated carbon , good dispersion, and improve the catalytic degradation ability of the composite material to pollutants; polyethylene glycol is non-toxic and has good stability, and the residual components will not cause secondary pollution during the repair process.

Application Domain

Metal/metal-oxides/metal-hydroxide catalysts

Technology Topic

Activated carbonNitrogen gas +15

Image

Examples

Experimental program(1)

Example Embodiment

[0017] In the following, with reference to the accompanying drawings, the preparation method of the activated carbon multi-site loaded nano-zero-valent iron composite material provided by the present invention will be described in detail.

[0018] The specific steps of the method of multi-site loading nano-zero-valent iron composite material on activated carbon are as follows:

[0019] Step 1: Weigh 0.5g of dry activated carbon (100 mesh) into 30mL of 12g/L microcrystalline cellulose solution, then add 0.22g of citric acid, ultrasonically disperse in an ultrasonic cleaner for 30min, and then keep at a constant temperature of 25℃ Shake the incubator for 4 hours at a constant temperature. After shaking, place it in a 50mL high-pressure-resistant sealed reactor, react at 220°C for 12 hours, cool to room temperature naturally, wash with absolute ethanol 3 times, centrifuge, and dry in an oven at 75°C for 12 hours. Modified activated carbon;

[0020] Step 2: Dissolve polyethylene glycol (4000) in ultrapure water to prepare a 15g/L dispersant solution;

[0021] Step 3: Weigh 2.48~9.93g FeSO 4 ·7H 2 O was dissolved in 100 mL of the dispersant solution, sealed and placed in an ultrasonic cleaner for ultrasonic dispersion for 30 minutes. Add 1g of the modified activated carbon, and magnetically stir for 30 minutes under the protection of nitrogen. Prepare NaBH 4 Solution (NaBH 4 The molar ratio to Fe is 4:1), poured into a separatory funnel, and slowly dropped into a three-necked flask. After the addition was completed, the reaction was completed after stirring for 30 minutes. After washing with absolute ethanol for 3 times and centrifugal separation, it is freeze-dried in a freeze dryer for 12 hours to obtain a composite material of activated carbon loaded with nano-zero valent iron at multiple sites.

[0022] figure 1 It is the SEM image of the modified activated carbon prepared in the example.

[0023] Such as figure 1 As shown, the modified activated carbon prepared in this embodiment is composed of activated carbon and more carbon particles, and the carbon particles are irregularly spherical, which greatly increases the loading site of activated carbon.

[0024] figure 2 It is the SEM image of the composite material prepared in the example.

[0025] Such as figure 2 As shown, the composite material prepared in this embodiment is composed of modified activated carbon and a large amount of nano-zero-valent iron. The nano-zero-valent iron is filamentous and spherical, and is stably supported on the modified activated carbon with a relatively large loading capacity.

[0026] image 3 It is a TEM image of the composite material prepared in the example.

[0027] Such as image 3 As shown, the nano-zero-valent iron in the composite material prepared in this embodiment is in the form of filaments and spheres, with a size of about 20-50 nm, uniform loading, and good dispersion.

[0028] Figure 4 This is the selected area electron diffraction pattern of the composite material prepared in the example.

[0029] Such as Figure 4 As shown, the composite material prepared in this embodiment is mainly composed of the elements C, O, and Fe, and the mass ratio of nano-zero-valent iron is the highest 41.96%, and the load is relatively large.

[0030] Figure 5 It is the XRD pattern of the composite material prepared in the example.

[0031] Such as Figure 5 As shown, the composite material prepared in this example is composed of modified activated carbon and zero-valent iron, and the peak of zero-valent iron is relatively high and the peak shape is sharp, indicating that the zero-valent iron has a large load on the activated carbon and has good crystallization.

[0032] The preparation method of the activated carbon multi-site loaded nano-zero-valent iron composite material provided by the present invention is not limited to the content described in the above embodiments. The above is only a basic description under the concept of the present invention, but according to the present invention. Any equivalent changes made to the technical solution of the invention shall fall within the protection scope of the present invention.

PUM

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