CN108325543A - A kind of synthetic method of activated carbon supported petal-shaped silver orthophosphate complex phase catalysis material - Google Patents

Abstract

The invention relates to a method for synthesizing an activated carbon-loaded petal-shaped silver phosphate composite photocatalytic material, which is characterized in that: the pretreated activated carbon is placed in a shaker for oscillation, and during the oscillation process, _AgNO3 and H ₃ PO ₄ solution, repeated 5 to 20 times; then the activated carbon was taken out, washed and dried to obtain the activated carbon-loaded petal-shaped silver phosphate composite photocatalytic material. This composite material combines the huge specific surface area of activated carbon and the excellent photocatalytic performance of silver phosphate, has a stronger ability to treat organic pollutants, and is easier to recycle than silver phosphate powder.

Description

Synthesis method of activated carbon-loaded petal-shaped silver phosphate composite photocatalytic material

technical field

The invention relates to a method for synthesizing an active carbon-loaded petal-shaped silver phosphate composite photocatalytic material, which belongs to the field of inorganic non-metallic materials.

Background technique

In today's society, due to the high development of traditional industries and the excessive use of traditional fossil fuels, on the one hand, traditional energy is facing exhaustion, and on the other hand, it has also caused serious air and water pollution. Environmental pollution and the depletion of traditional energy sources have become the two most important problems in human society that need to be solved urgently. In order to alleviate and solve the above problems, it is also necessary to find new energy sources that are easy to obtain and use cleanly, and to control the environmental problems that have occurred so far. The birth of photocatalytic technology has brought hope to solve the above problems, and it is expected to be able to realize the healthy development of human society.

Photocatalysts can absorb light energy, generate free electrons and holes, and then react to become active species, and further react with reactants, thereby realizing the conversion of light energy into chemical energy. Japanese scientists took the lead in discovering that titanium dioxide has the function of photocatalytically splitting water and degrading organic pollutants. Although titanium dioxide has the characteristics of high catalytic activity and good chemical stability, it has been applied to a certain extent at present, but its disadvantages such as absorption only in the ultraviolet region and low quantum efficiency really limit its development.

Research in the field of photocatalysis has gradually shifted its focus to visible light catalytic materials. Researchers have found that narrow bandgap photocatalysts such as CdS, BiVO ₄ , C ₃ N ₄ , and Ag ₃ PO ₄ have a wide absorption range and can be excited by visible light. Among them, Ag ₃ PO ₄ can absorb sunlight with a wavelength of less than 520nm, and has shown extremely superior photocatalytic activity in various organic dye degradation experiments, and its ability to decompose water and produce oxygen is also considerable.

Activated carbon is a kind of adsorbent with huge specific surface area and strong adsorption capacity, which can adsorb organic pollutants in liquid or gas. After Ag ₃ PO ₄ is combined with activated carbon, not only the dispersion of Ag ₃ PO ₄ itself is improved, but also the huge surface area makes the contact between organic pollutants and Ag ₃ PO ₄ more sufficient, thus promoting the photocatalytic reaction.

The patent application number 201310246213.8 reports a preparation method of silver phosphate photocatalyst, the preparation method comprises the following steps: adding silver acetate and phosphoric acid aqueous solution to polyethylene glycol 200 in sequence, adjusting the pH to 5-6, and The reaction is carried out under stirring; after the reaction in the step is completed, the precipitate is collected by centrifugation, washed and dried to obtain the silver phosphate photocatalyst. By adopting the method of the invention, the silver phosphate photocatalyst is obtained as a novel tubular microporous structure, and its photocatalytic activity is relatively high. The patent application number 201210341324.2 reports a preparation method of a visible light-driven nano-silver phosphate catalyst. The present invention prepares a stable nano-silver phosphate photocatalyst by using different light source irradiation and micro-injection of reactants to avoid In addition to the preparation under visible light, the product will decompose. The silver phosphate particles prepared by the method have a spherical cluster structure, the diameter of the monomer is 20-60nm, and the overall diameter is 60-300nm, which is far smaller than the common micron silver phosphate in the market. However, the above-mentioned cases are different from the present application in that the above-mentioned cases are all preparation methods of pure silver phosphate.

The patent application number 201410001356.7 reports a preparation method of an exfoliated hydrotalcite-supported silver phosphate catalyst. The specific steps are as follows: dissolve uracil in NaOH solution, add silver nitrate, stir until the solution is clear and transparent, add dry commercially available Or self-made hydrotalcite powder, stirred, precipitated and separated, and dried; put the dried product in a microwave oven, and microwave irradiated; added the microwave irradiated product into the phosphoric acid solution, stirred, precipitated and separated, and dried to obtain An exfoliated hydrotalcite-supported silver phosphate catalyst. The patent application number 201410156228.X reports a preparation method of halloysite-loaded silver phosphate photocatalyst, the specific steps are as follows: add halloysite into nitric acid solution to obtain acid-treated halloysite, and mix 4-8g The acid-treated halloysite is placed in a vacuum filter bottle, mixed with silver nitrate ethanol solution in a vacuum state, let the silver nitrate fully enter the halloysite tube, continue to stir for 2-3 hours, separate solid and liquid, vacuum 70-80°C Drying; add the product obtained by drying into 50mL of sodium dihydrogen phosphate solution with a concentration of 0.5-1.5mol/L, stir for 4-5 hours, separate solid and liquid, wash, and dry at 100-105°C to obtain a Halloysite supported silver phosphate photocatalyst. The patent application number 201410259216.X reports a preparation method of a supported silver phosphate photocatalyst. The specific steps are as follows: Weigh 80-100g of porous hydroxyapatite that has been ground and passed through a 40-mesh sieve, and fill it in the top and bottom with valve control. In the glass tube; respectively prepare 200 mL of HNO ₃ solution with a concentration of 0.01-0.1 mol/L, NaNO ₃ solution with a concentration of 0.01-0.1 mol/L and AgNO ₃ solution with a concentration of 0.2-0.8 mol/L; The glass tube of porous hydroxyapatite is vertical, open the upper and lower valves, inject HNO ₃ solution into the tube from the bottom, when the solution can immerse the porous hydroxyapatite, discharge the HNO ₃ solution, keep the bottom valve open, and inject NaNO ₃ from the top solution, let the NaNO ₃ solution flow out from the bottom after injecting it from the top, then close the bottom valve, inject the AgNO ₃ solution from the top and soak for 20-30 minutes, release the AgNO ₃ solution from the bottom, and wash the particles in the glass tube with deionized water and dry Then a loaded silver phosphate photocatalyst is obtained. The above case and this application all belong to the preparation of supported silver phosphate photocatalyst, but the carrier, loading process, and size and appearance of silver phosphate involved in this application are completely different, and the final photocatalytic activity is also very different.

This application is different from the above reports. This application obtains petal-shaped silver phosphate composite photocatalytic material supported by activated carbon by repeatedly spraying AgNO ₃ solution and H ₃ PO ₄ solution on the surface of activated carbon. This photocatalyst has broad application prospects in the field of degradation of organic pollutants.

Contents of the invention

The invention mainly relates to a synthesis method of a petal-shaped silver phosphate composite photocatalytic material supported by activated carbon, and the specific content of the invention is as follows.

1. Weigh 10~20g of activated carbon, ultrasonically clean it, dry it, then calcinate and activate it in a muffle furnace at 400~500°C for 1~2h, and then place it in a shaking table for oscillation; during the oscillation process, first spray 3mmol/L evenly on the surface of the activated carbon AgNO ₃ solution, the control spraying speed is about 5~10mL/min, spraying 2min each time; then evenly spray 1mmol/L H ₃ PO ₄ solution on the surface of activated carbon, controlling the spraying speed is about 5~10mL/min, each time Spray for 2 minutes, and repeat this process 5 to 20 times; then take out the activated carbon, wash it with deionized water for 3 to 5 times, and dry it to obtain a petal-shaped silver phosphate composite photocatalytic material loaded with activated carbon.

2. The ultrasonic cleaning temperature is room temperature, the frequency is 20kHz, and the power is 5kW.

3. The drying method of activated carbon before loading is blast drying, the drying temperature is 100~150℃, and the drying time is 3~5h.

4. The oscillation mode of the shaking table is orbital oscillation, the orbital frequency is 50~400r/min, and the oscillation amplitude is 20~30mm.

5. The drying method of activated carbon after loading is as follows: first blow dry with N ₂ for 5~10min, and the flow rate of N ₂ is 0.2~0.5m ³ /min; .

Description of drawings

Fig. 1 is the SEM image of the activated carbon-loaded petal-shaped silver phosphate composite photocatalytic material prepared under the process conditions of Example 1.

Fig. 2 is the degradation curve of Rhodamine B (0.5g/L, 400ml) of 1g mass of activated carbon-loaded petal-shaped silver phosphate composite photocatalytic material prepared under the process conditions of Example 1.

Detailed ways

The present invention will be described in detail below in conjunction with examples, and the present invention is not limited by these examples.

Example 1

Weigh 10g of activated carbon and ultrasonically clean it at room temperature with an ultrasonic frequency of 20kHz and an ultrasonic power of 5kW, air-dry it at 110°C for 3h, then calcinate and activate it in a muffle furnace at 400°C for 2h; 200r/min, the oscillation amplitude is 20mm; during the oscillation process, first spray 3mmol/L AgNO ₃ solution evenly on the surface of the activated carbon, control the spraying speed to about 5mL/min, and spray 2min each time; then spray 1mmol/L evenly on the surface of the activated carbon H ₃ PO ₄ solution, the spraying speed is controlled to be about 5mL/min, each spraying is 2min, and this is repeated 10 times; then the activated carbon is taken out and washed with deionized water for 3 times; N ₂ is blown dry for 5 min, and the flow rate of N ₂ is 0.2m ³ /min; and then vacuum-dried at 80°C for 12h, vacuum degree = 180Pa, to obtain petal-shaped silver phosphate multi-phase photocatalytic material supported by activated carbon.

Example 2

Weigh 10g of activated carbon and ultrasonically clean it at room temperature with an ultrasonic frequency of 20kHz and an ultrasonic power of 5kW, air-dry it at 100°C for 4h, then calcinate and activate it in a muffle furnace at 400°C for 1h; 200r/min, the oscillation amplitude is 20mm; during the oscillation process, first spray 3mmol/L AgNO ₃ solution evenly on the surface of the activated carbon, control the spraying speed to about 7mL/min, and spray 2min each time; then spray 1mmol/L evenly on the surface of the activated carbon H ₃ PO ₄ solution, the spraying speed is controlled to be about 7mL/min, each spraying is 2min, and this is repeated 12 times; then the activated carbon is taken out and washed with deionized water for 3 times; N ₂ is blown dry for 10 min, and the flow rate of N ₂ is 0.5m ³ /min; then vacuum-dried at 80°C for 12h, vacuum degree = 150Pa, to obtain petal-shaped silver phosphate multi-phase photocatalytic material supported by activated carbon.

Example 3

Weigh 15g of activated carbon and ultrasonically clean it at room temperature with an ultrasonic frequency of 20kHz and an ultrasonic power of 5kW, air-dry it at 120°C for 3h, then calcinate and activate it in a muffle furnace at 450°C for 1.5h; The vibration amplitude is 200r/min, and the oscillation amplitude is 30mm; during the oscillation process, first spray 3mmol/L AgNO ₃ solution evenly on the surface of the activated carbon, control the spraying speed to about 8mL/min, and spray 2min each time; then spray 1mmol/L AgNO 3 solution evenly on the surface of the activated carbon L of H ₃ PO ₄ solution, the spraying speed is controlled _to be about 8mL/min, each spraying is 2min, and this is repeated 5 times; then the activated carbon is taken out and washed ₃ times with deionized water; 0.5m ³ /min; then vacuum-dried at 90°C for 10h, vacuum degree = 180Pa, to obtain a petal-shaped silver phosphate multi-phase photocatalytic material supported by activated carbon.

Example 4

Weigh 15g of activated carbon and ultrasonically clean it at room temperature with an ultrasonic frequency of 20kHz and an ultrasonic power of 5kW, air-dry it at 130°C for 4h, then calcinate and activate it in a muffle furnace at 450°C for 2h; 200r/min, the oscillation amplitude is 25mm; during the oscillation process, first spray 3mmol/L AgNO ₃ solution evenly on the surface of activated carbon, control the spraying speed to about 8mL/min, spray 2min each time; then spray 1mmol/L evenly on the surface of activated carbon H ₃ PO ₄ solution, the spraying speed is controlled to be about 8mL/min, each spraying is 2min, and this is repeated 10 times; then the activated carbon is taken out and washed with deionized water for 3 times; N ₂ is blown dry for 10 min, and the flow rate of N ₂ is 0.5m ³ /min; then vacuum-dried at 90°C for 12h, vacuum degree = 160Pa, to obtain petal-shaped silver phosphate multi-phase photocatalytic material supported by activated carbon.

Example 5

Weigh 15g of activated carbon and ultrasonically clean it at room temperature with an ultrasonic frequency of 20kHz and an ultrasonic power of 5kW, air-dry it at 120°C for 5h, then calcinate and activate it in a muffle furnace at 500°C for 1h; 200r/min, the oscillation amplitude is 30mm; during the oscillation process, first spray 3mmol/L AgNO ₃ solution evenly on the surface of the activated carbon, control the spraying speed to about 10mL/min, and spray 2min each time; then spray 1mmol/L evenly on the surface of the activated carbon H ₃ PO ₄ solution, the spraying speed is controlled to be about 10mL/min, each spraying is 2min, and this is repeated 15 times; then the activated carbon is taken out and washed 5 times with deionized water; N ₂ is blown dry for 10 min, and the flow rate of N ₂ is 0.5m ³ /min; then vacuum-dried at 100°C for 10h, vacuum degree = 160Pa, to obtain petal-shaped silver phosphate composite photocatalytic material supported by activated carbon.

Example 6

Weigh 20g of activated carbon and ultrasonically clean it at room temperature with an ultrasonic frequency of 20kHz and an ultrasonic power of 5kW, air-dry at 150°C for 5h, and then calcinate and activate it in a muffle furnace at 500°C for 2h; 300r/min, the oscillation amplitude is 30mm; during the oscillation process, first spray 3mmol/L AgNO ₃ solution evenly on the surface of the activated carbon, control the spraying speed to about 10mL/min, and spray 2min each time; then spray 1mmol/L evenly on the surface of the activated carbon H ₃ PO ₄ solution, the spraying speed is controlled to be about 10mL/min, each spraying is 2min, and this is repeated 20 times; then the activated carbon is taken out and washed 5 times with deionized water; N ₂ is blown dry for 10 min, and the flow rate of N ₂ is 0.5m ³ /min; then vacuum-dried at 100°C for 12h, vacuum degree = 180Pa, to obtain a petal-shaped silver phosphate composite photocatalytic material supported on activated carbon.

Claims (5)

1. A method for synthesizing active carbon-loaded petal-shaped silver phosphate composite photocatalytic materials, characterized in that: 10-20 g of activated carbon is ultrasonically cleaned, dried, and then calcined and activated in a muffle furnace at 400-500 °C for 1-2 hours. Then place it in a shaking table and oscillate; during the oscillating process, spray 3mmol/L AgNO ₃ solution evenly on the surface of the activated carbon, control the spraying speed to about 5-10mL/min, and spray 2min each time; then spray 1mmol/L AgNO 3 solution evenly on the surface of the activated carbon. L of H ₃ PO ₄ solution, control the spraying speed to about 5~10mL/min, spray 2min each time, repeat this way 5~20 times; then take out the activated carbon, wash it with deionized water 3~5 times, after drying, The activated carbon-loaded petal-shaped silver phosphate composite photocatalytic material was obtained. 2. the synthetic method of a kind of gac-loaded petal-shaped silver phosphate composite photocatalytic material as claimed in claim 1, is characterized in that ultrasonic cleaning temperature is room temperature, frequency 20kHz, power 5kW. 3. A kind of synthetic method of activated carbon-loaded petal-shaped silver phosphate composite photocatalytic material as claimed in claim 1, characterized in that the drying method of the activated carbon before loading is blast drying, the drying temperature is 100 ~ 150 ° C, and the drying time is 3 ~5h. 4. A kind of synthetic method of active carbon loading petal-shaped silver phosphate composite photocatalytic material as claimed in claim 1, it is characterized in that the mode of shaker oscillation is cyclotron oscillation, and the cyclotron frequency is 50 ~ 400r/min, and the oscillation amplitude is 20 ~30mm. 5. A kind of synthetic method of active carbon loaded petal-shaped silver phosphate composite photocatalytic material as claimed in claim 1, it is characterized in that the drying method of activated carbon after loading is: at first N ₂ Dry 5～10min, _N Flow rate is 0.2 ~0.5m ³ /min; then vacuum dry at 80~100℃ for 10~12h, vacuum degree <200Pa.