Pt-Pd-based high-entropy alloy porous nano-enzyme as well as preparation method and application thereof

Abstract

The invention discloses a Pt-Pd-based high-entropy alloy porous nano-enzyme as well as a preparation method and application of the Pt-Pd-based high-entropy alloy porous nano-enzyme. According to the method, an F127 polymer is used as a template, and the Pt-Pd-Cu-Rh-Ru nano-enzyme or the Pt-Pd-Cu-Rh-Ag nano-enzyme is synthesized through a hydrothermal reduction method. The nano-enzyme is a porous spherical nano-particle, has abundant active sites on the surface, has excellent POD catalytic performance and good stability, can maintain catalytic activity in high-temperature and acid-base environments, and has wide application prospects in the fields of catalysis, biosensing, environmental governance and the like.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of nanozymes, and relates to a Pt-Pd-based high-entropy alloy porous nanozyme and a preparation method and application thereof. BACKGROUND

[0002] Nanozymes are a kind of nanomaterials with catalytic activity similar to natural enzymes, which can simulate the functions of natural enzymes such as peroxidase, oxidase and catalase, and have broad application prospects in the fields of biosensing, environmental governance and medical diagnosis. Compared with traditional natural enzymes, nanozymes have higher stability, longer service life and lower cost, and therefore have become a research hotspot in recent years.

[0003] At present, common nanozymes are mainly made of metal oxides (such as Fe3O4, MnO2 and Co3O4), carbon-based materials (such as graphene and carbon nanotubes) or composite materials. These materials still have certain limitations in catalytic efficiency, selectivity, stability and controllability, for example, the catalytic efficiency of most nanozymes is lower than that of natural enzymes, which is difficult to meet the needs of high-sensitivity detection or high-efficiency degradation; they are easy to lose activity in high-temperature, acidic or alkaline or organic solvent environments; and there is a lack of effective means to control the morphology, size and composition of nanozymes, which affects their practical application.

[0004] In the modern catalytic field, traditional metal catalysts such as platinum (Pt), palladium (Pd) and gold (Au) are widely used in oxidation-reduction reactions, organic synthesis, environmental remediation and other fields due to their excellent catalytic activity. However, these noble metal catalyst nanoparticles are easy to aggregate during use, resulting in a decrease in specific surface area and a decrease in catalytic activity; they have insufficient selectivity and poor selectivity for specific reactions, which can easily cause side reactions.

[0005] With the development of nanomaterial science, researchers have begun to explore the introduction of high-entropy alloys (HEAs) into the field of nanozymes. High-entropy alloys are composed of multiple elements in near-equal molar ratios, with high mixing entropy, low thermodynamic stability, and excellent physical and chemical properties. Their unique composition not only improves the thermal stability and corrosion resistance of materials but also endows them with rich electronic structures, making it possible to precisely control catalytic performance. However, current research on high-entropy alloy nanozymes is still in its early stages, especially in terms of preparation methods, morphology control, and performance optimization, which have not yet formed a systematic result. Literature 1 (Ai Y, He M Q, Sun H, et al. Ultra-Small High-Entropy Alloy Nanoparticles: Efficient Nanozyme for Enhancing Tumor Photothermal Therapy [J]. Adv Mater, 2023, 35(23): e2302335.) reports a kind of ultra-small high-entropy alloy nanoparticles (Ultra-Small High-Entropy Alloy Nanoparticles), which is composed of Pt-Pd-Ru-Rh-Ir and has excellent peroxidase-like activity and photothermal conversion performance. However, the material needs high-temperature sintering in the preparation process, which increases energy consumption. Literature 2 (Yang X, Feng J, Li Y, et al. PdMoPtCoNi High Entropy Nanoalloy with Electron Self-Complementation-Induced Multisite Synergistic Effect for Efficient Nanozyme Catalysis [J]. Adv Sci (Weinh), 2024, 11(38): e2406149.) explores the preparation and application of PdMoPtCoNi high-entropy nanoalloy. This method does not require high-temperature sintering, but the use of non-noble metal systems makes its catalytic efficiency lower, and the material morphology control is not fine enough to meet the needs of different application scenarios. Therefore, there is an urgent need for a high-entropy alloy nanozyme material that is easy to prepare and has excellent catalytic performance to promote its widespread application in fields such as biological catalysis, environmental remediation, and medical diagnosis. SUMMARY

[0006] The application aims to provide a Pt-Pd-based high-entropy alloy porous nanoscale enzyme, a preparation method thereof and an application thereof.

[0007] The technical solution for achieving the application is as follows:

[0008] The preparation method of the Pt-Pd-based high-entropy alloy porous nanoscale enzyme has the following specific steps:

[0009] (1) Preparation of a precursor solution: F127 polymer is dissolved in N,N-dimethylformamide (DMF), and an acidic solution is added to fully dissolve the polymer, then under stirring, equimolar ratios of Pt, Pd, Cu, Rh, Ru or Ag five kinds of metal salts are sequentially added, and L-ascorbic acid (LAA) is added as a reducing agent after uniform mixing;

[0010] (2) Hydrothermal reaction: the mixed solution formed in step (1) is transferred to a high-pressure reaction kettle, and a reduction reaction is carried out at 100±20℃, after the reaction is completed, washing and freeze-drying are performed to obtain the final Pt-Pd-based high-entropy alloy porous nanoscale enzyme.

[0011] Preferably, in step (1), the acid radical ion in the acidic solution is the same as the Pt salt anion, and the acidic solution is selected from hydrochloric acid, sulfuric acid or phosphoric acid, etc.

[0012] Preferably, in step (1), the Pt, Pd, Cu, Rh, Ru or Ag metal salt is a chloride salt, which is potassium platinous chloride, potassium platinous chloride, rhodium trichloride trihydrate, ruthenium chloride, copper chloride and silver nitrate, respectively.

[0013] Preferably, in step (2), the reduction reaction time is 4-8h.

[0014] Preferably, in step (2), the washing method is centrifugal washing with a mixture of acetone and water for more than 3 times, the centrifugal speed is 10000rpm, and each time is 10min.

[0015] Preferably, in step (2), the Pt-Pd-based high-entropy alloy porous nanoscale enzyme is a porous spherical nanoparticle, which is a nanoscale enzyme A composed of Pt-Pd-Cu-Rh-Ru or a nanoscale enzyme B composed of Pt-Pd-Cu-Rh-Ag.

[0016] The application also provides the Pt-Pd-based high-entropy alloy porous nanoscale enzyme prepared by the above preparation method.

[0017] Further, the application provides the application of the above Pt-Pd-based high-entropy alloy porous nanoscale enzyme in catalyzing H2O2 decomposition.

[0018] Compared with the prior art, the present application has the following advantages:

[0019] (1) The preparation method is simple, and high-temperature sintering is not required: the nanometer enzyme is prepared by a hydrothermal method, without relying on high-temperature sintering or a complex vacuum environment, so that the preparation process is greatly simplified, the energy consumption and equipment requirements are reduced, and large-scale production and practical application are facilitated.

[0020] (2) Composition diversity: the nanometer enzyme of the present application is composed of five metal elements, and by flexibly adjusting the element types, the composition and electronic structure of the material can be accurately designed, so that the catalytic performance is optimized, and the applicability in different application scenarios is expanded.

[0021] (3) Excellent catalytic performance and stability: compared with traditional single-metal nanometer enzymes, the high-entropy alloy nanometer enzyme of the present application has higher catalytic efficiency and wider reaction applicability, and exhibits high-efficiency catalytic capacity in hydrogen peroxide decomposition, organic pollutant degradation, and biomolecule detection reactions; and the high-entropy alloy structure endows the nanometer enzyme with good thermal stability and chemical stability, so that the catalytic performance can be maintained stable in high temperature, acid and alkali, and complex environment, thereby effectively prolonging the service life, reducing the use cost, and having wide application prospects. BRIEF DESCRIPTION OF DRAWINGS

[0022] Figure 1 is a transmission electron microscope (TEM) image of nanometer enzyme A (Pt-Pd-Cu-Rh-Ru).

[0023] Figure 2 is a TEM image of nanometer enzyme B (Pt-Pd-Cu-Rh-Ag).

[0024] Figure 3 is an element distribution map of the TEM of nanometer enzyme A (Pt-Pd-Cu-Rh-Ru).

[0025] Figure 4 is an element distribution map of the TEM of nanometer enzyme B (Pt-Pd-Cu-Rh-Ag).

[0026] Figure 5 is an element proportion map of nanometer enzyme A (Pt-Pd-Cu-Rh-Ru) under a scanning electron microscope.

[0027] Figure 6 is an element proportion map of nanometer enzyme B (Pt-Pd-Cu-Rh-Ag) under a scanning electron microscope.

[0028] Figure 7 is an XRD map of nanometer enzyme A and nanometer enzyme B.

[0029] Figure 8Figure of catalytic performance of POD of nanoenzyme A (a) and nanoenzyme B (b). DETAILED DESCRIPTION

[0030] The application will be further described in connection with the specific embodiments and the accompanying drawings.

[0031] In the following examples, Pluronic F-127 was purchased from Sigma-Aldrich, item P2443-250G.

[0032] Example 1

[0033] (1) 30 mg of F127 polymer was dissolved in 4 ml of DMF, and 2 ml of 6 mmol / L hydrochloric acid solution was added to completely dissolve it, and then 40 μmol / L potassium chloropalladite solution, 40 μmol / L potassium chloroplatinite solution, 40 μmol / L rhodium trichloride trihydrate solution, 40 μmol / L ruthenium chloride solution and 40 μmol / L copper chloride solution were added in turn, and stirred at 30°C for 10 min, and then 10 ml of 1 mmol / L LAA solution was added;

[0034] (2) The mixed solution formed in step (1) was transferred to a high-pressure reaction kettle, and incubated at 100°C for 4 h, and the obtained product was washed with a mixture of acetone and water at 10000 rpm for 10 min each time to remove the residual polymer template, and the washed product was freeze-dried for 72 h to obtain a Pt-Pd-Cu-Rh-Ru spherical porous high-entropy alloy nanoenzyme, named nanoenzyme A.

[0035] Table 1 Comparison of catalytic performance of different nanoenzymes

[0036]

[0037]

[0038] Example 2

[0039] This example is basically the same as example 1, except that the metal salts are potassium chloropalladite, potassium chloroplatinite, rhodium trichloride trihydrate, silver nitrate and copper chloride, to obtain a Pt-Pd-Cu-Rh-Ag spherical porous high-entropy alloy nanoenzyme, named nanoenzyme B.

[0040] As shown in Figures 1-6 , the atomic ratio of nanoenzyme A and nanoenzyme B under TEM is Pt:Pd:Cu:Rh:Ru = 24:17:25:25:7 and Pt:Pd:Cu:Rh:Ag = 32:17:10:16:23 respectively, and the content of each component is higher than 5%, which meets the definition of high-entropy alloy, and the particle size of the nanoenzyme is 100-200 nm, and the pore size of each porous nanoenzyme is about 10-20 nm. Figure 7The XRD results of the high-entropy alloy nanoszymes A and B confirmed that they had good composition uniformity and suitable crystal structures, which provided a structural basis for their excellent catalytic performance.

[0041] Example 3

[0042] POD catalytic performance detection of the nanoszyme:

[0043] The POD-like performance of the nanoszyme is to catalyze the oxidation of the substrate by consuming hydrogen peroxide or organic peroxide. The specific experimental method is to measure its catalytic performance by using the color development of tetramethylbenzidine (TMB) under acidic conditions. The nanoszyme catalyzes the decomposition of hydrogen peroxide to generate hydroxyl radicals to oxidize TMB to oxTMB, which makes the solution turn blue. The catalytic ability of the material can be detected by detecting the absorbance of the solution at 652 nm.

[0044] The POD catalytic performance of the nanoszyme A and nanoszyme B under different pH conditions was explored by changing the pH of the solution, and the results are shown in Figure 8 (a) and (b). It can be found that the nanoszyme A and nanoszyme B have the best catalytic effect at pH = 4. By changing the concentration of TMB, the absorbance of the solution was detected at the same time, and the curve obtained was fitted by the Michaelis equation, and the catalytic rate of the nanoszyme was obtained. The results are shown in Figure 8 (c) and (d). It can be found that the catalytic rate of the nanoszyme A and nanoszyme B is much higher than that of the ordinary ternary alloy nanoszyme, and has good application potential.

Claims

1. A method for preparing Pt-Pd-based high-entropy alloy porous nanozymes, characterized in that, The specific steps are as follows: (1) Preparation of precursor solution: F127 polymer was dissolved in DMF and acidic solution was added to fully dissolve the polymer. Then, under stirring, five metal salts, Pt, Pd, Cu, Rh, Ru or Ag, were added in equal molar ratios. After mixing evenly, LAA was added as a reducing agent. (2) Hydrothermal reaction: The mixed solution formed in step (1) is transferred to a high-pressure reactor and a reduction reaction is carried out at 100±20℃. After the reaction is completed, the solution is washed and freeze-dried to obtain the final Pt-Pd-based high-entropy alloy porous nanoenzyme.

2. The preparation method according to claim 1, characterized in that, In step (1), the acid radical ions in the acidic solution are the same as the Pt salt anions.

3. The preparation method according to claim 1, characterized in that, In step (1), the acidic solution is selected from hydrochloric acid, sulfuric acid or phosphoric acid.

4. The preparation method according to claim 1, characterized in that, In step (1), the metal salts Pt, Pd, Cu, Rh, Ru or Ag are chloride salts, namely potassium palladium chloride, potassium platinum chloride, rhodium trichloride trihydrate, ruthenium chloride, copper chloride and silver nitrate, respectively.

5. The preparation method according to claim 1, characterized in that, In step (2), the reduction reaction time is 4~8h.

6. The preparation method according to claim 1, characterized in that, In step (2), the washing method is to centrifuge with a mixture of acetone and water more than 3 times, with a centrifugation speed of 10000 rpm and 10 min each time.

7. The preparation method according to claim 1, characterized in that, In step (2), the Pt-Pd-based high-entropy alloy porous nanozyme is a porous spherical nanoparticle, which is either nanozyme A composed of Pt-Pd-Cu-Rh-Ru or nanozyme B composed of Pt-Pd-Cu-Rh-Ag.

8. Pt-Pd-based high-entropy alloy porous nanozymes prepared by any of the preparation methods described in claims 1 to 7.

9. The application of the Pt-Pd-based high-entropy alloy porous nanoenzyme according to claim 8 in the catalytic decomposition of H2O2.

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