Double-function composite nano material and preparation method and application thereof
阅读说明：本技术 一种双功能复合纳米材料及其制备方法和用途 (Double-function composite nano material and preparation method and application thereof ) 是由 王毅 连雨萌 张盾 于 2021-09-08 设计创作，主要内容包括：本发明涉及模拟酶技术以及光催化,具体说是一种双功能复合纳米材料(溴化银、钼酸银复合物)及其制备方法和用途。通过银盐、钼盐与CTAB通过一步沉淀法获得双功能复合纳米材料。本发明制备的纳米材料具有合成方法简单、成本低、性能优异、可重复利用等优点,在纳米材料催化氧化领域中具有广阔的应用前景。(The invention relates to a mimic enzyme technology and photocatalysis, in particular to a bifunctional composite nano material (silver bromide and silver molybdate compound) and a preparation method and application thereof. The bifunctional composite nano material is obtained by a one-step precipitation method through silver salt, molybdenum salt and CTAB. The nano material prepared by the invention has the advantages of simple synthesis method, low cost, excellent performance, reusability and the like, and has wide application prospect in the field of nano material catalytic oxidation.)
1. A preparation method of a bifunctional composite nano material is characterized by comprising the following steps: the bifunctional composite nano material is obtained by a one-step precipitation method through silver salt, molybdenum salt and CTAB.
2. The method for preparing the bifunctional composite nanomaterial according to claim 1, wherein:
mixing silver salt, molybdenum salt and CTAB powder, adding deionized water to obtain a mixed solution, magnetically stirring the mixed solution in a dark environment for 1-2 hours, cleaning and centrifuging the obtained material, and drying the obtained composite material at 60-80 ℃ for 6-8 hours in vacuum after centrifugation to finally obtain the silver and molybdenum containing nano composite material; wherein the molar ratio of the molybdenum salt to CTAB is 1: 1.
3. The method for preparing the bifunctional composite nanomaterial according to claim 1, wherein:
adding silver salt into distilled water for magnetic stirring to obtain a silver-containing solution, sequentially adding molybdenum salt and CTAB into distilled water for magnetic stirring to obtain a molybdenum-containing mixed solution, slowly dropwise adding the molybdenum-containing mixed solution into the silver-containing solution, and carrying out magnetic stirring for 1-2 hours in a dark environment after dropwise adding to react.
4. A process for the preparation of the bifunctional nanocomposite material as claimed in claim 2, characterized in that: and after the magnetic stirring reaction in the dark environment, sequentially washing the reaction product by absolute ethyl alcohol and distilled water for 2 to 3 times respectively, washing the reaction product, centrifuging the reaction product, collecting yellow precipitates, drying the yellow precipitates in vacuum at 60 to 80 ℃ for 6 to 8 hours, and grinding the dried powder to obtain the bifunctional composite nanomaterial.
5. A process for the preparation of a bifunctional nanocomposite material as claimed in any of claims 1 to 3, characterized in that: the silver salt is silver nitrate; the molybdenum salt is ammonium molybdate.
6. The bifunctional nanocomposite prepared as claimed in claim 1, wherein: the bifunctional composite nanomaterial containing silver and molybdenum irregular nano spherical particles prepared by the method of claim 1.
7. Use of the bifunctional nanocomposite material of claim 6, wherein: the silver-molybdenum containing bifunctional composite nano material is applied to degradation of dyes under the condition of visible light as a mimic enzyme or a photocatalyst.
8. Use of the bifunctional nanocomposite material according to claim 7, wherein: the silver-molybdenum containing bifunctional composite nano material is used as a mimic enzyme material and is applied to catalytic oxidation-reduction reaction of a substrate under an acidic condition.
9. Use of the bifunctional nanocomposite material according to claim 8, wherein: the substrates are TMB and H2O2。
10. Use of the bifunctional nanocomposite material according to claim 7, wherein: the dye is rhodamine B and/or tetracycline hydrochloride (TC).
Technical Field
The invention relates to a mimic enzyme technology and photocatalysis, in particular to a bifunctional composite nano material (silver bromide and silver molybdate compound) and a preparation method and application thereof.
Background
Active enzymes such as HRP contained in organisms have high catalytic activity and specificity, and can be used for organic synthesis, biosensors, environmental management, wastewater treatment,Has more applications in the medical field. The enzyme-like catalytic activity of the nano enzyme comes from the nano structure of the nano enzyme, and a catalytic group or natural enzyme is not required to be additionally introduced; the natural enzyme is easily influenced by temperature and pH, and compared with the nanometer enzyme, the stability is higher, the cost is lower and the catalytic activity is adjustable, so the development of the mimic enzyme material is particularly important. The semiconductor photocatalyst has the characteristics of high efficiency, stability and environmental friendliness. Among a series of semiconductor photocatalyst materials, TiO2No poison, stable structure and high activity, but TiO2Can only be excited by ultraviolet light and has great limitation in practical application. Platinum/titanium dioxide nanoparticles (Pt/TiO)2NPs) have peroxidase-like activity and can rapidly catalyze hydrogen peroxide (H)2O2) Oxidation of 3,3 ', 5, 5' -Tetramethylbenzidine (TMB) color development. The single semiconductor material has limited performance, and has the defects of high recombination rate of photo-generated electrons and holes, poor absorption to visible light and the like, and the composite semiconductor photocatalyst greatly weakens the defects.
In recent years, more and more nanomaterials or nanocomposites have been investigated with mimic enzymatic properties, such as UsAuNPs/MOF [1 ]]、CuO-HCSs[2]、CuS/GO[3]Etc.; there are also an increasing number of semiconductor heterojunction materials that have been shown to have photocatalytic activity, such as Ag3PO4/TiO2[4]And the like. Compared with the method for obtaining the natural enzyme, the mimic enzyme material has the advantages of reduced material cost, simple and convenient synthesis method, easy realization of unit operation, excellent durability, stability, biocompatibility and reusability; the inherent defects of the nano enzyme exist, the weak visible light response of the nano enzyme limits the application of bactericidal activity, and the nano composite material needs to be modified to have photocatalysis capability. Compared with a single semiconductor photocatalyst, the composite photocatalyst improves the band gap width, and the separation efficiency of the photoproduction electrons and the holes is also greatly improved; the photocatalytic activity under visible light and the enzyme-like activity in dark environments have a synergistic effect in bactericidal applications. Therefore, the development of a high-efficiency catalyst with photocatalytic and mimic enzyme activities has important significance in improving the utilization rate of the catalyst and the application of environmental problemsAnd (5) defining.
1.HU WEN-CHAO,YOUNIS M R,ZHOU YUE,et al(2020)In situ fabrication of ultrasmall gold nanoparticles/2D MOFs hybrid as nanozyme for antibacterial therapy.Small,2000553.
2.XI JU-QUN,WEO GEN,AN LAN-FANG,et al(2019)Copper/carbon hybrid nanozyme:tuning catalytic activity by the copper state for antibacterial therapy.Nano Letter 19(11):7645-7654.
3.WANG WAN-SHUN,LI BING-LIN,YANG HUI-LI,et al(2020)Efficient elimination of multidrug-resistant bacteria using copper sulfide nanozymes anchored to graphene oxide nanosheets.Nano Res 13(8):2156-2164.
4.LIU HUAN,LI DAO-RONG,YANG XIN-LI,et al(2019)Fabrication and characterization of Ag3PO4/TiO2 heterostructure with improved visible-light photocatalytic activity for the degradation of methyl orange and sterilization of E.coli.Materials Technology 34(4):192-203.
Disclosure of Invention
The invention aims to provide a bifunctional composite nano material (silver bromide and silver molybdate composite) and a preparation method and application thereof.
In order to achieve the purpose, the invention adopts the technical scheme that:
a preparation method of a bifunctional composite nano material is characterized in that the bifunctional composite nano material is obtained by a one-step precipitation method through silver salt, molybdenum salt and CTAB.
Further, the following steps are carried out:
mixing silver salt, molybdenum salt and CTAB powder, adding deionized water to obtain a mixed solution, magnetically stirring the mixed solution in a dark environment for 1-2 hours, cleaning and centrifuging the obtained material, and drying the obtained composite material at 60-80 ℃ for 6-8 hours in vacuum after centrifugation to finally obtain the silver and molybdenum containing nano composite material; wherein the molar ratio of the molybdenum salt to CTAB is 1: 1.
Adding silver salt into distilled water for magnetic stirring to obtain a silver-containing solution, sequentially adding molybdenum salt and CTAB into distilled water for magnetic stirring to obtain a molybdenum-containing mixed solution, slowly dropwise adding the molybdenum-containing mixed solution into the silver-containing solution, and carrying out magnetic stirring for 1-2 hours in a dark environment after dropwise adding to react.
And after the magnetic stirring reaction in the dark environment, sequentially washing the reaction product by absolute ethyl alcohol and distilled water for 2 to 3 times respectively, washing the reaction product, centrifuging the reaction product, collecting yellow precipitates, drying the yellow precipitates in vacuum at 60 to 80 ℃ for 6 to 8 hours, and grinding the dried powder to obtain the bifunctional composite nanomaterial.
The silver salt is silver nitrate; the molybdenum salt is ammonium molybdate.
The difunctional nano composite material of the silver and molybdenum-containing irregular nano spherical particles is prepared by the method, wherein the particle size of the composite nano material reaches 100-250nm, and silver bromide is loaded on the surface of 100-250nm silver molybdate irregular nano spherical particles in a regular nano spherical shape of 9-20 nm.
The silver-molybdenum containing bifunctional composite nanomaterial is applied to degradation of dyes under visible light conditions as a mimic enzyme or a photocatalyst.
The silver-molybdenum containing bifunctional composite nano material is used as a mimic enzyme material and is applied to catalytic oxidation-reduction reaction of a substrate under an acidic condition.
The substrates are TMB and H2O2。
The dye is rhodamine B and/or tetracycline hydrochloride (TC).
Compared with the prior art, the invention has the following advantages and prominent effects:
the silver-molybdenum-containing composite nano material is obtained by a simple and feasible solvent precipitation method, and has the double functions of simulating enzyme and photocatalytic activity. Compared with some existing materials, the material obtained by the invention has higher photocatalytic activity, can degrade rhodamine B and TC simultaneously, and has oxidase activity and peroxidase activity; the cost is low, the preparation method is simple, the repeatability is high, and the preservation is easy; the material can be used as a novel material, has potential application value in the fields of engineering antifouling practice, immunoassay, biological detection, clinical diagnosis and the like, and has wide application prospect in novel catalytic oxidation analysis.
Description of the drawings:
FIG. 1 is a TEM image of a nanomaterial provided by an embodiment of the present invention;
FIG. 2 is an X-ray diffraction pattern of a qualitatively analyzed material composition provided by an embodiment of the present invention;
fig. 3 is a test chart of the catalysis of the nanomaterial simulation enzyme provided by the embodiment of the invention.
Fig. 4 is a nano-material photocatalytic degradation image provided by an embodiment of the present invention, where a is a photocatalytic degradation image for degrading rhodamine B, and B is a photocatalytic degradation image for degrading TC.
Detailed Description
The present invention is further illustrated by the following specific examples, which are intended to provide a more complete understanding of the invention by one of ordinary skill in the art, and are not intended to be limiting in any way.
Example 1:
1mmol of AgNO3Putting into a beaker, adding 20mL of distilled water, and magnetically stirring for 20min to dissolve the mixture in the distilled water to obtain a silver-containing solution; 0.036mmol (NH)4)6Mo7O24·4H2Placing O and 0.25mmol CTAB into a beaker, adding 20mL of distilled water, and magnetically stirring for 20min to dissolve the CTAB in the distilled water to obtain a molybdenum-containing mixed solution; slowly dripping the obtained molybdenum-containing mixed solution into the AgNO3The solution was stirred for 1h in the dark to obtain the product. Washing the obtained product with distilled water and anhydrous ethanol for 3 times, centrifuging at 6000r/min, collecting yellow precipitate, and drying at 60 deg.C for 6 hr in vacuum drying oven to obtain 1: 1AgBr/Ag2MoO4The nanomaterial was compounded (see fig. 1), and the resulting material was subjected to XRD testing (see fig. 2).
As can be seen from figure 1, the average particle size of the composite nano material reaches 189nm, silver bromide with the average particle size of 16nm is loaded on the surface of silver molybdate irregular nano spherical particles with the average particle size of 189nm in a regular nano spherical shape. FIG. 2 shows the composition of the composite material, which is obtained by mixing the components with AgBr Standard card (JCPDS No.79-0149) and Ag2MoO4Standard of meritThe card (JCPDS No.08-0473) is inosculated, namely the product in the composite nano material contains AgBr and Ag2MoO4。
Examples 2 to 4:
the preparation process comprises the following steps:
1mmol of AgNO3Putting into a beaker, adding 20mL of distilled water, and magnetically stirring for 20min to dissolve the mixture in the distilled water to obtain the silver-containing solution. The different ratios (NH) shown in Table 14)6Mo7O24·4H2O, CTAB placing into a beaker, adding 20mL distilled water, magnetically stirring for 20min to dissolve in distilled water to obtain molybdenum-containing mixed solution; slowly dripping the obtained molybdenum-containing mixed solution into the AgNO3The solution was stirred for 1h in the dark to obtain the product. Washing the product with distilled water and anhydrous ethanol for 3 times, respectively, centrifuging at 6000r/min after washing, collecting yellow precipitate, drying in a vacuum drying oven at 60 deg.C for 6h, and obtaining 1: 2AgBr/Ag2MoO4、2：1AgBr/Ag2MoO4And 3: 1AgBr/Ag2MoO4A composite nanomaterial.
TABLE 1
(NH4)6Mo7O24·4H2O/mmol
CTAB/mmol
Example 1
0.036
0.25
Example 2
0.047
0.16
Example 3
0.023
0.33
Example 4
0.018
0.375
The particle size of the composite nano-material obtained in the above examples 2-4 reaches 170-210nm, and silver bromide is loaded on the surface of the irregular nano-spherical silver molybdate particles at 170-210nm in a regular nano-sphere shape of 12-18 nm.
Application example 1
At 0.5mM H2O24mM TMB, 1 obtained in example 1 above: 1AgBr/Ag2MoO4The nano material is used as three substances of mimic enzyme, the three substances are added into a sodium acetate acetic acid buffer solution with the pH value of 4 under different conditions (TMB, hydrogen peroxide and mimic enzyme material, TMB and mimic enzyme material or hydrogen peroxide and TMB and mimic enzyme material), the mimic enzyme performance is tested in a total 1mL system, the substances are added, the solution color observation is carried out after 5min, and the absorbance test is carried out under the wavelength of 652 nm. When only hydrogen peroxide and TMB exist in the system, the solution is colorless and transparent; when only hydrogen peroxide and mimic enzyme material 1: 1AgBr/Ag2MoO4When no TMB is added, the solution is colorless and transparent; when adding the mimic enzyme material 1 to the TMB and hydrogen peroxide system: 1AgBr/Ag2MoO4And when only TMB and mimetic enzyme material 1: 1AgBr/Ag2MoO4At this point, the solution turned darker blue, demonstrating that the TMB had been oxidized to blue oxTMB; combining the absorbance data in fig. 3, it can be seen that the nanomaterial provided by the invention has higher activities of oxidase and peroxidase mimic enzymes.
Application example 2
Treatment 1: to 40mL of 10m40mg of 1mg/mL AgBr/Ag obtained in each example was added to g/L rhodamine B2MoO4And then adding the mixture into a quartz tube with a bottom optical filter to perform a visible light photocatalytic degradation experiment, firstly stirring the mixture for 30min at the speed of 250r/min under a dark state condition to achieve adsorption-desorption balance, then turning on a xenon lamp light source to take reaction solution every 30min, centrifuging 1mL of the reaction solution at the speed of 6000r/min, and then performing an absorbance test. The system color has no obvious change after the blank group reacts for 120min under visible light, the experimental group changes from purple red to colorless, and the degradation rate of rhodamine B can reach 100 percent (figure 4a) according to the result of figure 4.
And (3) treatment 2: 40mg of 1mg/mL AgBr/Ag obtained in each of the above examples was added to 40mL of 10mg/L TC2MoO4Adding the solution into a quartz tube with a bottom optical filter to perform a visible light photocatalytic degradation experiment, firstly stirring the solution for 30min at the speed of 250r/min under a dark state condition to achieve adsorption-desorption balance, then turning on a xenon lamp light source to take reaction solution every 30min, centrifuging 1mL of the reaction solution at the speed of 6000r/min, and then performing an absorbance test. The system color has no obvious change after the blank group reacts for 120min under visible light, the experimental group changes from light yellow to nearly colorless, and the degradation rate of TC within 120min reaches 73 percent (figure 4 b). The nano material provided by the invention has excellent photocatalytic activity, and can degrade dye rhodamine B and antibiotic TC; the catalyst is a novel high-efficiency bifunctional catalytic material due to the fact that the catalyst simultaneously has the mimic enzyme activity.