Preparation Method and Application of Modified Silicon Dioxide Particles as Triboelectric Catalysts

Abstract

The present invention discloses a preparation method and application of modified silica particles as triboelectric catalysts. The present invention aims to solve the problems of low sterilization rate of traditional piezoelectric water disinfection materials and the limitation of solar materials by seasons. In the present invention, partial hydrophilic groups are introduced onto the surface of hydrophobic silica, so that while the hydrophobic material generates electron transfer by friction with water, it can ensure effective contact with water to effectively conduct ROS, obtaining material A; then further loading gold nanoparticles on the basis of material A to adjust the Fermi level of the material to obtain material B, and the electron transfer rate of B is further increased on the basis of A. These two-step modifications enable the material to transfer electrons between water and the material using mechanical energy on the one hand, and on the other hand enable the material to have ultra-high electron utilization efficiency, thus effectively combining the advantages of existing water disinfection materials, and obtaining a material with high-efficiency sterilization and a wide range of energy sources without seasonal limitations.

Description

Technical Field

[0001] The present invention provides a preparation method and application of modified silica particles as triboelectric catalysts, relating to a preparation method of triboelectric catalytic materials of modified silica, and particularly relating to its application in interfacial catalytic reactions and water disinfection fields, belonging to the technical field of preparation and application of novel functional materials. Background Art

[0002] Drinking water is contaminated by microorganisms, leading to a series of waterborne diseases such as diarrhea, cholera, dysentery, typhoid, poliomyelitis, etc. For developing regions and vulnerable populations with insufficient or inaccessible sanitation facilities and power grids, the damage even exceeds that of war. Traditional water disinfection methods including chlorination, ultraviolet radiation, and ozonation are chemical and energy-intensive, requiring large, complex, and costly infrastructure for centralized water treatment and distribution. In addition, both chlorination and ozonation may produce harmful by-products, which are statistically related to carcinogenesis. Ultraviolet irradiation requires a long irradiation time and high dose to ensure effective disinfection.

[0003] In regions lacking grid power supply, converting environmental energy such as thermal energy, light energy, and mechanical energy into electrical energy shows great potential in water disinfection. Piezoelectric and triboelectric materials can respond to mechanical energy to generate electrons at the water-solid interface, and such characteristics enable it to disinfect water in situ. However, due to limited charge utilization efficiency, the disinfection efficiency is generally low. Although solar disinfection is a very attractive low-cost method, it also has some disadvantages, such as seasonal limitations and a high risk of microbial regrowth. Therefore, it is crucial to find a water disinfection method that can combine the accessibility of mechanical energy and the high efficiency of solar energy to cope with the increasingly severe water safety situation.

[0004] Triboelectrification is an ancient scientific phenomenon that has been around for 2,000 years, but the discussion about the nature of its carriers has never stopped. For solid-liquid contact electrification, in some early studies, it was generally believed that the carriers of solid-liquid contact electrification were ions. However, recent studies have shown that both electron transfer and ion transfer occur in liquid-solid contact electrification, and sometimes electron transfer even dominates. Although the nature of the carriers is controversial, solid-liquid contact electrification has many applications, such as reducing metals, catalyzing the progress of reactions, promoting self-assembly processes, and removing organic pollutants. Then, whether it is possible to use electron transfer in solid-liquid contact to efficiently disinfect water in situ is lacking in research. The application of liquid-solid contact electrification in the field of water disinfection is very few. As a portable in-situ green disinfection method that is not affected by seasons, such exploration is obviously mismatched. At the same time, further research on the antibacterial mechanism of solid-liquid contact can also provide materials for clarifying the mechanism of solid-liquid contact electrification.

[0005] In summary, in view of the deficiencies of the prior art, the purpose of the present invention is to provide a preparation method of modified silica particles as triboelectric catalysts and their application in water disinfection. On the one hand, an electron transfer channel between the solid material and water is established through triboelectrification to optimize the electron transfer ability of the material under the action of mechanical force; on the other hand, through the supporting interaction between Au and SiO 2 at the nanoscale, the band gap of the piezoelectric material is regulated, its conductivity is regulated, and electron migration is accelerated. Thereby significantly enhancing the catalytic performance of the material and realizing an efficient and low-energy water disinfection strategy. Summary of the Invention

[0006] The purpose of the present invention is to address the deficiencies of existing piezoelectric catalytic materials and applications, and propose a preparation method of a triboelectric catalyst of modified silica particles and its application in water disinfection. An electron transfer channel between the solid material and water is established through triboelectrification to optimize the electron transfer ability of the material under the action of mechanical force, and through the supporting interaction between Au and SiO 2 at the nanoscale, the band gap of the piezoelectric material is regulated, its conductivity is regulated, and electron migration is accelerated, thereby significantly improving the sterilization efficiency of the material.

[0007] To achieve this purpose, the preparation method of a triboelectric catalyst of modified silica particles and its application in water disinfection described in the present invention has the following technical solutions and steps:

[0008] 1) Synthesize silica nanoparticles using TEOS, ammonia water, and ethanol;

[0009] 2) Add the silica nanoparticles to an aqueous solution containing dodecylethyldimethylammonium bromide to form a large number of solid wax droplets containing silica nanoparticles, filter, wash, and vacuum dry to obtain Janus hydrophobically modified silica;

[0010] 3) Add the dried Janus hydrophobically modified silica powder to a methanol solution containing an appropriate amount of APTES, and mix it with a chloroform solution dissolved with paraffin to release amino-modified silica nanoparticles, wash and dry to obtain a powder;

[0011] 4) Disperse the powder obtained in step 3) in a solution containing a hydrophobic modification material, and after modification, amphiphilic Janus silica can be obtained, wash and dry under vacuum;

[0012] 5) Mix an ethanol solution containing silica JPs with an aqueous suspension of gold nanoparticles, and then oscillate in a shaking bath to obtain modified silica particles.

[0013] Preferably, the hydrophobic modification material described in step 4) is a fluorinated or alkylated reagent.

[0014] Preferably, the hydrophobic modification material described in step 4) is at least one of n-octyltrichlorosilane, dodecyltrichlorosilane, tetradecyltrichlorosilane, hexadecyltrichlorosilane, octadecyltrichlorosilane, butyltrichlorosilane, pentyltrichlorosilane, n-octyltrichlorosilane and n-decyltrichlorosilane.

[0015] Preferably, the concentration of the modifier in the hydrophobic modification material described in step 4) is controlled at 0.01 - 0.80 μL / mg.

[0016] Preferably, the concentration of the aqueous suspension of gold nanoparticles described in step 5) is 0.1 wt% - 10 wt%.

[0017] Preferably, the particle size of the silica nanoparticles described in step 1) is 100 - 300 nm.

[0018] This application also relates to the application of the preparation method of modified silica particles as triboelectric catalysts in disinfection. The modified silica particles are placed in a liquid containing bacteria, and mechanical force is introduced to stimulate the piezoelectric catalytic reaction.

[0019] Preferably, the mechanical force is one or more of ball milling method, ultrasonic method, stirring method, air flow method and water flow method.

[0020] Compared with other technologies, the advantages of the present invention are as follows: (1) The triboelectric catalyst of the modified silica particles provided by the present invention has a simple operation process, low cost and is easy to mass-produce. (2) The present invention connects some hydrophilic groups to the hydrophobic silica surface, so that while the hydrophobic material generates electron transfer by friction with water, it can ensure effective contact with water and effectively conduct ROS, improving the conduction efficiency of ROS. (3) The synthesized gold-loaded modified silica particle triboelectric catalyst of the present invention further improves the electron transfer rate on the traditional triboelectric material, thereby further improving the catalytic activity and being able to kill bacteria in water very efficiently. (4) The present invention effectively combines the advantages of existing water disinfection materials to obtain a material with high bactericidal efficiency and a wide range of energy sources without seasonal restrictions. Description of the Drawings

[0021] Figure 1 is the effect curve of the modified silica material prepared by the present invention for killing E. coli;

[0022] Figure 2 is the transmission electron microscope photo and element distribution map of the modified silica material loaded with gold nanoparticles prepared by the present invention;

[0023] Figure 3 is the picture of the E. coli killing effect of the modified silica material loaded with gold nanoparticles prepared by the present invention;

[0024] Figure 4 Pictures showing the killing effects of the modified silica material loaded with gold nanoparticles prepared in the present invention against S. aureus, S. epidermidis, K. pneumoniae and P. aeruginosa;

[0025] Figure 5 EPR pictures of the prepared modified silica material loaded with gold nanoparticles and the reference group. Detailed implementation manners

[0026] The following further illustrates the detailed implementation manners of the present invention in combination with the drawings and technical solutions.

[0027] A preparation method of a modified silica particle triboelectric catalyst comprises the following steps:

[0028] 1) According to the method, add an appropriate amount of TEOS, ammonia water and ethanol into a beaker to synthesize 100 - 300 nm silica.

[0029] 2) Add the powder obtained in the previous step into an aqueous solution containing dodecylethyldimethylammonium bromide according to a ratio of 1:30 to 1:50, incubate at 65°C - 85°C for 30 min, then stir vigorously at a speed of 10000 - 20000 rpm for 100 - 140 s, and then cool to room temperature to form a large number of solid wax droplets containing silica nanoparticles. Filter, wash and dry in vacuum to obtain Janus hydrophobic modified silica.

[0030] 3) Add the dried powder into a methanol solution containing an appropriate amount of APTES, stir at room temperature for 10 - 14 h, dissolve the paraffin in chloroform at 30 - 40°C to release the amino-modified silica nanoparticles, and wash and dry.

[0031] 4) Disperse the obtained powder in a toluene solution containing octyltrichlorosilane, and then stir at 20 - 30°C and 100 - 200 rpm for 1 - 3 h to form amphiphilic silica. Finally, collect by centrifugation, wash 3 times with ethanol, and then dry in vacuum.

[0032] 5) Mix an ethanol solution containing silica JPs with an equal amount of a citrate-stabilized gold nanoparticle aqueous suspension, and then oscillate in a shaking bath at 20 - 40°C and 100 - 200 rpm for 10 - 14 h.

[0033] 6) Weigh 0.005 - 0.05 g of iron-based composite piezoelectric catalyst powder, place it in the bacterial solution, and test its performance. The specific operation is as follows: Weigh 0.005 - 0.05 g of iron-based composite piezoelectric catalyst powder, add it to 0.1 - 1 mL of bacterial solution, and introduce mechanical force to stimulate the piezoelectric catalytic reaction for 0.01 - 4 h. The test for the water disinfection ability uses the typical Gram-negative bacterium - Escherichia coli, with an initial bacterial density of 10 4 - 10 8 colonies, a vortex frequency of 300 - 800 rpm, and a power of 50 - 80 W.

[0034] In one embodiment, a preparation method of a modified silica particle triboelectric catalyst is as follows:

[0035] 1) According to the method, add appropriate amounts of TEOS, ammonia water, and ethanol to a beaker to synthesize 200 nm silica.

[0036] 2) Add the powder obtained in the previous step to an aqueous solution containing dodecylethyldimethylammonium bromide in a ratio of 1:40, incubate at 75 °C for 30 min, then stir vigorously at a speed of 15000 rpm for 120 s, and then cool to room temperature to form a large number of solid wax droplets containing silica nanoparticles. Filter, wash, and vacuum dry to obtain Janus hydrophobic modified silica.

[0037] 3) Add the dried powder to a methanol solution containing an appropriate amount of APTES, stir at room temperature for 12 h, dissolve the paraffin in chloroform at 32 °C to release the amino-modified silica nanoparticles, wash, and dry.

[0038] 4) Disperse the obtained powder in a toluene solution containing octyltrichlorosilane, and then stir at 25 °C and 150 rpm for 2 h to form amphiphilic silica. Finally, collect by centrifugation, wash 3 times with ethanol, and then dry under vacuum.

[0039] 5) Mix the ethanol solution containing silica JPs with an equal amount of citrate-stabilized gold nanoparticle aqueous suspension, and then oscillate in a shaking bath at 28 °C and 150 rpm for 12 hours.

[0040] 6) Weigh 0.005 - 0.05 g of iron-based composite piezoelectric catalyst powder, place it in the bacterial solution, and test its performance. The specific operation is as follows: Weigh 0.005 - 0.05 g of iron-based composite piezoelectric catalyst powder, add it to 0.1 - 1 mL of bacterial solution, and introduce mechanical force to stimulate the piezoelectric catalytic reaction for 0.01 - 4 h. The test for the water disinfection ability uses the typical Gram-negative bacterium - Escherichia coli, with an initial bacterial density of 10 6Colonies, vortex frequency is 500 rpm, power is 60 W.

[0041] In one embodiment, the hydrophobic modification material is at least one of n-octyltrichlorosilane, dodecyltrichlorosilane, tetradecyltrichlorosilane, hexadecyltrichlorosilane, octadecyltrichlorosilane, butyltrichlorosilane, pentyltrichlorosilane, n-octyltrichlorosilane, and n-decyltrichlorosilane.

[0042] In one embodiment, 1) Modify the silica particles according to a modifier concentration of 0.2 μL / mg, wash them three times with ethanol, and dry them under vacuum.

[0043] 2) Collect the dried powder and dry it at 60 °C for 2 h to obtain the modified silica material product.

[0044] 3) Weigh 50 mg of the modified silica particles and add 0.5 mL of 10 4 CFU / mL of E. coli.

[0045] 4) Oscillate the powder in step 3) under vortex conditions of 500 rpm for 4 h. Since the material is hydrophobic, no further treatment is required. Directly weigh the clarified solution and spread it on a plate, and culture it at 37 °C for 16 - 24 h. The removal effect is shown in Figure 1 .

[0046] 5) It can be seen from the appendix Figure 1 that the prepared Janus SiO 2 -F material can effectively kill E. coli under vortex action. When the reaction time is 4 h, the removal rate of E. coli can reach 99.99%.

[0047] In one embodiment, 1) Modify the silica particles according to a modifier concentration of 0.2 μL / mg, wash them three times with ethanol, and dry them under vacuum.

[0048] 2) Oscillate the citrate-stabilized gold nanoparticle solution (5 wt%) with an appropriate amount of the particles in step 2) at 28 °C for 12 h. After washing with deionized water and ethanol and drying under vacuum, gold nanoparticle-loaded modified silica particles are obtained. The transmission electron microscopy characterization results are shown in the appendix Figure 2 .

[0049] 3) Weigh 5 mg of the loaded modified silica particles and add 0.5 mL of 10 6 CFU / mL of E. coli.

[0050] 4) Oscillate the powder in step 3) under vortex conditions of 500 rpm for 15 min. Weigh the clarified solution and spread it on a plate, and culture it at 37 °C for 16 - 24 h. The removal effect is shown in Figure 3 .

[0051] 5) As shown in the appendix Figure 3 It can be seen that the prepared Janus SiO 2 -Au-F material can effectively kill E. coli under the action of vortex. When the reaction time is 15 min, the removal rate of E. coli can reach 99.9999%.

[0052] 6) As shown in the appendix Figure 2 From the transmission electron microscope images, it can be known that the prepared gold nanoparticles are deposited on the surface of 200 nm silica particles. From the EDX-Mapping images, it can be seen that Si and F elements are evenly distributed on the surface of the material, while Au is dispersed on the surface.

[0053] In one embodiment, 1) Modify silica particles at a modifier concentration of 0.1 μL / mg, wash them three times with ethanol, and dry them under vacuum.

[0054] 2) Oscillate the citrate-stabilized gold nanoparticle solution (5 wt%) with an appropriate amount of the particles in step 2) at 28 °C for 12 h. After washing with deionized water and ethanol and drying under vacuum, gold nanoparticle-loaded modified silica particles are obtained.

[0055] 3) Weigh 5 mg of the loaded modified silica particles and add 0.5 mL of 10 6 CFU / mL of S. aureus, S. epidermidis, K. pneumoniae, and P. aeruginosa respectively.

[0056] 4) Oscillate the powder in step 3) under vortex conditions at 500 rpm for 15 min. Weigh the clarified solution and coat it on a plate, and culture it at 37 °C for 16 - 24 h. The removal effect is shown in Figure 4 .

[0057] 5) As shown in the appendix Figure 4 It can be seen that the prepared Janus SiO 2 -Au-F material can effectively kill S. aureus, S. epidermidis, K. pneumoniae, and P. aeruginosa under the action of vortex. When the reaction time is 15 min, the removal rate of E. coli can reach 99.9999%, and the material has broad-spectrum antibacterial properties.

[0058] 6) From the EPR experimental results in the appendix, it can be known that the Janus SiO Figure 5 -Au-F material can effectively generate oxidizing substances. When an external force is applied, as shown in the appendix 2 -Au-F, it can be seen that a strong oxidation peak DMPOX of DMPO appears in the EPR. Figure 5 It can be seen that a strong oxidation peak DMPOX of DMPO appears in the EPR.

Claims

1. Preparation method of modified silica particles as triboelectric catalysts, Characterized in that, Comprising the following steps: 1) Synthesize silica nanoparticles using TEOS, ammonia water and ethanol; 2) Add the silica nanoparticles into an aqueous solution containing dodecylethyldimethylammonium bromide to form a large number of solid wax droplets containing silica nanoparticles, filter, wash and vacuum dry to obtain Janus hydrophobically modified silica; 3) Add the dried Janus hydrophobically modified silica powder into a methanol solution containing an appropriate amount of APTES, and mix it with a chloroform solution dissolved with paraffin wax, thereby releasing amino-modified silica nanoparticles, wash and dry to obtain a powder; 4) Disperse the powder obtained in step 3) in a solution containing a hydrophobic modification material to form amphiphilic silica, wash and dry under vacuum to obtain silica JPs; the hydrophobic modification material is at least one of octyltrichlorosilane, dodecyltrichlorosilane, tetradecyltrichlorosilane, hexadecyltrichlorosilane, octadecyltrichlorosilane, butyltrichlorosilane, pentyltrichlorosilane, octyltrichlorosilane and decyltrichlorosilane; 5) Mix the ethanol solution containing silica JPs with an aqueous suspension of gold nanoparticles, and then oscillate in a shaking bath to obtain modified silica particles.

2. Preparation method of modified silica particles as triboelectric catalysts according to claim 1, Characterized in that, The hydrophobic modification material described in step 4) is a fluorinated or alkylated reagent.

3. Preparation method of modified silica particles as triboelectric catalysts according to claim 1, Characterized in that, The concentration of the modifier in the hydrophobic modification material described in step 4) is controlled at 0.01 - 0.80 μL / mg.

4. Preparation method of modified silica particles as triboelectric catalysts according to claim 1, Characterized in that, The concentration of the aqueous suspension of gold nanoparticles described in step 5) is 0.1wt% - 10wt%.

5. Preparation method of modified silica particles as triboelectric catalysts according to claim 1, Characterized in that, The particle size of the silica nanoparticles described in step 1) is 100 - 300nm.

6. Application of the preparation method of modified silica particles as triboelectric catalysts according to claim 1 in disinfection, Characterized in that, Place the modified silica particles described in claim 1 in a liquid containing fungi, and introduce mechanical force to stimulate the piezoelectric catalytic reaction.

7. Application of the preparation method of modified silica particles as triboelectric catalysts according to claim 6 in disinfection, Characterized in that, The mechanical force is one or more of ball milling method, ultrasonic method, stirring method, air flow method and water flow method.

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