Prussian blue analogue-based composite nanomaterials, methods for preparing the same, and applications thereof

Abstract

The application discloses a kind of composite nanomaterials based on prussian blue analogue and its preparation method and application.The composite nanomaterial includes cubic structure and needle structure;The needle structure is distributed on the surface of cubic structure, and forms heterojunction with cubic structure;The cubic structure and needle structure are all composed of prussian blue analogue.The composite nanomaterial provided by the application has excellent photo-thermal conversion performance and good catalytic activity, high stability, can be used repeatedly for a long time, and its preparation is simple and easy to implement, low in cost, has universality, and is conducive to large-scale production.

Description

Technical Field

[0001] This invention relates to a nanomaterial, and more particularly to a composite nanomaterial based on a Prussian blue analogue, its preparation method and application, belonging to the field of materials science. Background Technology

[0002] Prussian blue and its analogues belong to the organic framework compound family and possess excellent biocompatibility, superior electron mobility, large specific surface area, high photothermal conversion efficiency, and excellent catalytic performance. Prussian blue and its analogues have broad application prospects in energy, chemical engineering, biological detection, and disease diagnosis. However, the inherently singular structure and function of single Prussian blue or its analogues greatly limit their applications. For example, while Prussian blue exhibits high photothermal performance, its catalytic activity is not ideal due to its structure containing only iron ion catalytic sites. Similarly, Prussian blue analogues with multiple metal sites, although possessing good catalytic performance, suffer from low near-infrared and ultraviolet absorption and low photothermal conversion efficiency due to the influence of multiple metal elements. These factors restrict their wider application. Summary of the Invention

[0003] The main objective of this invention is to provide a composite nanomaterial based on Prussian blue analogues, its preparation method, and its application. The composite nanomaterial possesses both excellent photothermal conversion and catalytic properties, thereby overcoming the shortcomings of the prior art.

[0004] To achieve the above-mentioned objectives, the present invention provides the following technical solution:

[0005] One aspect of the present invention provides a composite nanomaterial based on a Prussian blue analogue, comprising a cubic structure and a needle-like structure; the needle-like structure is distributed on the surface of the cubic structure and forms a heterojunction with the cubic structure; both the cubic structure and the needle-like structure are composed of a Prussian blue analogue.

[0006] In one embodiment, the diameter of the cubic structure is 50-300 nm, and the length of the needle-like structure is 5 nm-100 nm, and the diameter is 2 nm-20 nm.

[0007] In one embodiment, the structural formula of the Prussian blue analogue is Na. x M[Fe(CN)6].zH2O, where M is selected from transition metal elements such as copper, manganese, nickel, and zinc, x = 3–4, z = 14–16.

[0008] Furthermore, the needle-like structure is formed in situ on the surface of the cubic structure.

[0009] Another aspect of the present invention provides a method for preparing composite nanomaterials based on Prussian blue analogues, comprising:

[0010] S1. Provide a solution A containing a transition metal nitrate and trisodium citrate, a solution B containing potassium ferricyanide, and a solution C containing ferrous sulfate, wherein the solvents of solutions A, B, and C all include deionized water.

[0011] S2. Mix solution A and solution B thoroughly at room temperature, then let stand at room temperature, and then separate the cubic structure from the obtained reaction mixture;

[0012] S3. The cubic structure is added to solution C and reacted at a temperature of 60-110°C to form a needle-like structure on the surface of the cubic structure, thereby obtaining the composite nanomaterial.

[0013] The cubic structure and the needle-like structure are both composed of Prussian blue analogues, and the needle-like structure and the cubic structure form a heterojunction.

[0014] In one embodiment, the molar ratio of the transition metal nitrate, trisodium citrate, and potassium ferricyanide is 2:2 to 3:1.5 to 3, for example, 2:2.25:2.

[0015] In one embodiment, the mass ratio of the ferrous sulfate to the cubic structure is 2–3.5:1.5–2.5, for example, 3:2.

[0016] In one embodiment, the transition metal nitrate salt comprises, but is not limited to, any one or a combination of copper, manganese, nickel, and zinc. For example, the transition metal nitrate salt may be selected from any one or a combination of copper nitrate, manganese nitrate, nickel nitrate, and zinc nitrate.

[0017] In one embodiment, the ferrous sulfate salt includes, but is not limited to, ferrous ammonium sulfate.

[0018] In one embodiment, solution A contains 0.04–0.11 mmol / mL of a transition metal nitrate.

[0019] In one embodiment, solution B contains 0.08–0.15 mmol / mL potassium ferricyanide.

[0020] In one embodiment, solution C contains 0.001 to 0.002 mmol / mL ferrous sulfate.

[0021] In one embodiment, step S2 specifically includes: mixing solution A and solution B at room temperature and stirring continuously for more than 10 minutes, then letting it stand at room temperature for more than 12 hours, preferably 12 to 24 hours, and then separating the cubic structure from the obtained reaction mixture.

[0022] In one embodiment, the reaction time in step S3 is 3h-12h.

[0023] In one embodiment, see Figure 1 As shown, the method specifically includes:

[0024] (1) At room temperature, a transition metal nitrate and trisodium citrate are dissolved in deionized water and stirred until clear to obtain solution A. Potassium ferricyanide is dissolved in deionized water to obtain solution B. Solution A and solution B are mixed and stirred continuously with a magnetic stirrer for ten minutes. After being left at room temperature for a certain period of time, the mixture is centrifuged and washed with deionized water to obtain a cubic structure composed of Prussian blue analogues (abbreviated as PBA).

[0025] (2) At room temperature, ferrous ammonium sulfate is dissolved in deionized water and stirred until clear. The cubic structure is then added to the obtained solution C. The mixture is stirred continuously in an oil bath, centrifuged to obtain a precipitate, and washed to obtain the composite nanomaterial, which can also be named Prussian blue analog@Prussian blue heterojunction composite nanomaterial (abbreviated as PBA@PB).

[0026] For example, the method specifically includes the following steps:

[0027] a) Dissolve copper nitrate and trisodium citrate in 50 mL of deionized water at room temperature and stir until clear to obtain solution A; separately dissolve potassium ferricyanide in 50 mL of deionized water to obtain solution B. Mix solution A and solution B, stir continuously with a magnetic stirrer for ten minutes, let stand at room temperature for a certain period of time, then centrifuge and wash with deionized water to obtain cubic structures.

[0028] b) Dissolve ferrous ammonium sulfate in 20 mL of deionized water at room temperature, stir until clear, then add the above cubic structure, heat in an oil bath (60-110℃) and stir continuously for 3-12 h, then centrifuge to separate the precipitate and wash to obtain the composite nanomaterial.

[0029] Another aspect of the invention provides the use of the aforementioned Prussian blue analogue-based composite nanomaterials in the preparation of photothermal conversion materials or oxidase mimics.

[0030] Another aspect of the present invention provides a photothermal conversion material comprising the aforementioned Prussian blue analogue-based composite nanomaterial.

[0031] Another aspect of the present invention provides a photothermal conversion method comprising: irradiating the Prussian blue analogue-based composite nanomaterial with near-infrared light to achieve photothermal conversion.

[0032] In some cases, near-infrared cameras and other devices can be used to record the photothermal conversion process in real time.

[0033] Another aspect of the invention provides an oxidase mimic comprising the aforementioned Prussian blue-based composite nanomaterial.

[0034] Furthermore, the oxidase includes peroxidase, such as catalase.

[0035] Compared with the prior art, the technical solution of the present invention has at least the following advantages:

[0036] (1) The provided composite nanomaterial has a unique and novel structure, which has both excellent photothermal conversion performance and good catalase catalytic activity. Compared with single Prussian blue and Prussian blue analogues, the heterojunction composite nanomaterial has multifunctionality, and its photothermal conversion performance and enzyme activity are significantly improved. It also has the characteristics of high stability and can be used repeatedly for a long time.

[0037] (2) The general preparation method of the composite nanomaterials provided is simple and easy to implement, low in cost, conducive to large-scale production, and has universality. It can be extended to prepare more heterojunction composite materials, which is conducive to greatly expanding the application prospects of this material. Attached Figure Description

[0038] Figure 1 This is a schematic diagram illustrating the preparation process principle of a composite nanomaterial based on a Prussian blue analogue in one embodiment of the present invention:

[0039] Figure 2 This is a transmission electron microscope image of a cubic structure (CuFePBA) prepared in Example 1;

[0040] Figure 3 This is a transmission electron microscope image of a cubic structure (NiZnFePBA) prepared in Example 2;

[0041] Figure 4 This is a transmission electron microscope image of a cubic structure (NiCuZnFePBA) prepared in Example 3;

[0042] Figure 5 This is a transmission electron microscope image of a composite nanomaterial (CuFe@PB) prepared in Example 1;

[0043] Figure 6 This is a transmission electron microscope image of a composite nanomaterial (NiZnFe@PB) prepared in Example 2;

[0044] Figure 7 This is a transmission electron microscope image of a composite nanomaterial (NiCuZnFe@PB) prepared in Example 3;

[0045] Figure 8 This is the ultraviolet spectrum of a composite nanomaterial (CuFe@PB) prepared in Example 1;

[0046] Figure 9 This is the ultraviolet spectrum of a composite nanomaterial (NiZnFe@PB) prepared in Example 2;

[0047] Figure 10 This is the ultraviolet spectrum of a composite nanomaterial (NiCuZnFe@PB) prepared in Example 3;

[0048] Figure 11 These are the photoelectron spectra of CuFePBA and the corresponding CuFe@PB in Example 1;

[0049] Figure 12 This is a high-resolution XPS spectrum of Fe2p in CuFe@PB in Example 1;

[0050] Figure 13 This is a high-resolution XPS spectrum of Cu2p in CuFe@PB in Example 1;

[0051] Figure 14 This is a high-resolution XPS spectrum of Fe3p in CuFe@PB in Example 1;

[0052] Figure 15 These are the photothermal properties of CuFePBA, NiZnFePBA, and NiCuZnFePBA in Examples 1-3;

[0053] Figure 16 These are the photothermal performance diagrams of CuFe@PB, NiZnFe@PB, and NiCuZnFe@PB in Examples 1-3;

[0054] Figure 17 This is a diagram showing the enzyme-like activity of CuFePBA and the corresponding CuFe@PB catalyzing TMB in Example 1;

[0055] Figure 18 This is a diagram showing the enzyme-like activity of NiZnFePBA and the corresponding NiZnFe@PB catalyzing TMB in Example 2;

[0056] Figure 19 Here is a diagram showing the enzyme-like activity of NiCuZnFePBA and the corresponding NiCuZnFe@PB catalyzing TMB, as shown in Example 3:

[0057] Figure 20 This is the on / off cyclic irradiation test spectrum of CuFe@PB under near-infrared light in Example 1. Detailed Implementation

[0058] The present invention is further illustrated by the following embodiments: The present invention can be better understood from the following embodiments. However, those skilled in the art will readily understand that the specific material ratios, process conditions, and results described in the embodiments are for illustrative purposes only and should not, and will not, limit the present invention as described in detail in the claims.

[0059] Unless otherwise specified, the various raw materials, reaction equipment, testing equipment and testing methods used in the following embodiments are all known in the art.

[0060] Example 1: The principle of a method for preparing composite nanomaterials based on Prussian blue analogues can be found in [reference needed]. Figure 1 Specifically, it includes the following steps:

[0061] (1) Synthesis of cubic structures of Prussian blue analogues

[0062] Dissolve 2 mmol of copper nitrate and 2.5 mmol of trisodium citrate in deionized water and stir until clear to obtain solution A, in which the final concentration of copper nitrate is 0.04 mmol / mL and the final concentration of trisodium citrate is 0.05 mmol / mL.

[0063] Solution B was prepared by dissolving 2 mmol of potassium ferricyanide in deionized water, with a potassium ferricyanide concentration of 0.05 mmol / mL.

[0064] Solution A and solution B were mixed at a volume ratio of 1:1 at room temperature and stirred continuously with a magnetic stirrer for ten minutes. The mixture was then left at room temperature for 24 hours. After that, the solid phase in the reaction mixture was separated by centrifugation and washed three times with deionized water to obtain the cubic structure of the Prussian blue analogue, named CuFePBA.

[0065] (2) Synthesis of composite nanomaterials

[0066] 0.02 mmol of ferrous ammonium sulfate was dissolved in 20 mL of deionized water at room temperature and stirred until clear. Then, 1 mL of CuFePBA dispersion with a concentration of about 0.1 g / mL was added. The mixture was stirred continuously in an oil bath at 90 °C for 6 h. After that, the precipitate in the reaction mixture was separated by centrifugation and washed three times with deionized water to obtain the composite nanomaterial, named CuFe@PB.

[0067] Example 2: A method for preparing composite nanomaterials based on Prussian blue analogues includes:

[0068] (1) This is basically the same as step (1) in Example 1, except that copper nitrate is replaced with a mixture of zinc nitrate and nickel nitrate, in which the total molar amount of nitrate is 2 mmol and the molar ratio of nickel to zinc is 3:1. The resulting Prussian blue analog cubic structure is named NiZnFePBA.

[0069] (2) This step is basically the same as step (1) in Example 1, except that CuFePBA is replaced with NiZnFePBA. The resulting composite nanomaterial is named NiZnFe@PB.

[0070] Example 3: A method for preparing composite nanomaterials based on Prussian blue analogues includes:

[0071] (1) This is basically the same as step (1) in Example 1, except that copper nitrate is replaced with a mixture of zinc nitrate, copper nitrate and nickel nitrate, wherein the total molar amount of nitrate in the mixture is 2 mmol, and the molar ratio of nickel / copper / zinc is 2:1:1. The resulting Prussian blue analog cubic structure is named NiCuZnFePBA.

[0072] (2) This step is basically the same as step (1) in Example 1, except that CuFePBA is replaced with NiCuZnFePBA. The resulting composite nanomaterial is named NiCuZnFe@PB.

[0073] Figures 2-4 Transmission electron microscope (TEM) images of CuFePBA, NiZnFePBA, and NiCuZnFePBA obtained in Examples 1-3 are shown respectively. These images clearly show that these Prussian blue analogues have similar morphologies, are uniform in size, and all exhibit a clear cubic structure.

[0074] Figures 5-7 Transmission electron microscope (TEM) images of CuFe@PB, NiZnFe@PB, and NiCuZnFe@PB obtained in Examples 1-3 are shown. These images clearly show that after the introduction of ferrous ammonium sulfate, the Prussian blue analogs CuFePBA, NiZnFePBA, and NiCuZnFePBA were successfully transformed into Prussian blue analog @Prussian blue heterojunction composite nanomaterials CuFe@PB, NiZnFe@PB, and NiCuZnFe@PB, respectively. These materials exhibit relatively uniform size and structure, but their surfaces display needle-like structures, giving them an overall urchin-like structure.

[0075] Figures 8-10The ultraviolet (UV) spectra of CuFe@PB, NiZnFe@PB, and NiCuZnFe@PB obtained in Examples 1-3 are shown respectively. UV spectroscopy analysis indicates that, compared with Prussian blue analogues such as CuFePBA, NiZnFePBA, and NiCuZnFePBA, the composite nanomaterials CuFe@PB, NiZnFe@PB, and NiCuZnFe@PB exhibit a wider absorption range, with the absorption wavelength range expanding from 600 nm to 1100 nm. This suggests that these composite nanomaterials have the potential for application as photothermal agents.

[0076] Figures 11-14 The structures of CuFePBA and CuFe@PB surfaces analyzed by X-ray photoelectron spectroscopy (XPS) are shown. Figure 11 As can be seen, the same elements were found in the CuFePBA and CuFe@PB heterojunctions, including C1s, N1s, Cu2p, Fe2p, and Fe3p. Figures 12-14 The following are high-resolution XPS spectra of various elements in CuFe@PB. The four main Fe2p peaks are located at 708.6 eV (Fe2p). 2+ Fe 2p 3 / 2 ), 721.7eV (Fe 2+ Fe 2p 1 / 2 ), 710.0eV (Fe 3+ Fe 2p 3 / 2 ) and 723.8eV (Fe 3+ Fe 2p 1 / 2 Compared with CuFePBA, Fe 2+ The significantly increased proportion indicates that after the formation of CuFe@PB, the valence state of iron ions shifts to a lower valence state, which is beneficial to improving its catalytic performance. Similarly, a valence of 935.4 eV (Cu2p) was detected in the Cu2p XPS spectrum. 2+ Cu2p 3 / 2 ), 932.8eV (Cu + Cu2p 3 / 2 ), 955.5eV (Cu 2+ Cu2p 1 / 2 ) and 952.7eV (Cu + Cu2p 1 / 2 The four main peaks, compared with CuFePBA, indicate that the valence state of copper ions shifts to a lower valence state after the formation of CuFe@PB, which is also beneficial to its catalytic performance. Fe3p at 55.9 eV (Fe 2+ ) and 57.1 eV (Fe 3+ The two main peaks at () further prove that the formation of CuFe@PB leads to the existence of low valence states of metal ions.

[0077] Figures 15-16 Near-infrared thermograms of CuFePBA, NiZnFePBA, NiCuZnFePBA, CuFe@PB, NiZnFe@PB, and NiCuZnFe@PB under near-infrared light irradiation (808 nm, 5 min) are shown. It can be seen that, compared to water, the Prussian blue analogues such as CuFePBA, NiZnFePBA, and NiCuZnFePBA do not show a significant temperature increase, while the temperatures of CuFe@PB, NiZnFe@PB, and NiCuZnFe@PB increase significantly, indicating that these composite nanomaterials possess excellent photothermal conversion capabilities.

[0078] Figures 17-19 The catalase-like activity curves of CuFePBA, NiZnFePBA, NiCuZnFePBA, CuFe@PB, NiZnFe@PB, and NiCuZnFe@PB are shown. The results indicate that CuFe@PB, NiZnFe@PB, and NiCuZnFe@PB possess excellent catalase activity, and their activities are significantly higher than those of Prussian blue analogues such as CuFePBA, NiZnFePBA, and NiCuZnFePBA.

[0079] Figure 20 The on / off cyclic irradiation test spectrum of CuFe@PB under near-infrared light (wavelength 808nm) is shown. It can be seen that the temperature fluctuation of CuFe@PB is negligible, indicating that this material has good chemical and light stability.

[0080] It should be understood that although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the claims. Any person skilled in the art can make several possible changes and modifications without departing from the concept of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope defined in the claims of the present invention.

Claims

1. A method for preparing composite nanomaterials based on Prussian blue analogues, characterized in that, include: S1. Provide a solution A containing a transition metal nitrate and trisodium citrate, a solution B containing potassium ferricyanide, and a solution C containing ferrous sulfate, wherein the solvents of solutions A, B, and C all include deionized water. S2. Mix solution A and solution B thoroughly at room temperature, then let stand at room temperature, and then separate the cubic structure from the obtained reaction mixture; S3. The cubic structure is added to solution C and reacted at a temperature of 60~110℃ to form a needle-like structure on the surface of the cubic structure, thereby obtaining the composite nanomaterial. The cubic structure and the needle-like structure are both composed of Prussian blue analogues, and the needle-like structure and the cubic structure form a heterojunction.

2. The preparation method according to claim 1, characterized in that: The molar ratio of the transition metal nitrate, trisodium citrate, and potassium ferricyanide is 2:2~3:1.5~3.

3. The preparation method according to claim 1, characterized in that: The mass ratio of the ferrous sulfate to the cubic structure is 2~3.5:1.5~2.

5.

4. The preparation method according to claim 1, characterized in that: The transition metal nitrate comprises any one or more combinations of copper, manganese, nickel, and zinc.

5. The preparation method according to claim 1, characterized in that: Solution A contains 0.04~0.11 mmol / mL of transition metal nitrates, solution B contains 0.08~0.15 mmol / mL of potassium ferricyanide, and solution C contains 0.001~0.002 mmol / mL of ferrous sulfate.

6. The preparation method according to claim 1, characterized in that: The ferrous sulfate salt includes ferrous ammonium sulfate.

7. The preparation method according to claim 1, characterized in that, Step S2 specifically includes: mixing solution A and solution B at room temperature and stirring continuously for more than 10 minutes, then letting it stand at room temperature for more than 12 hours, and then separating the cubic structure from the obtained reaction mixture.

8. The preparation method according to claim 1, characterized in that: The reaction time in step S3 is 3h-12h.

9. The preparation method according to claim 1, characterized in that: The diameter of the cubic structure is 50-300nm, and the length of the needle-like structure is 5nm-100nm, with a diameter of 2nm-20nm.

10. The preparation method according to claim 1, characterized in that: The structural formula of the Prussian blue analogue is Na. x M[Fe(CN)6].zH2O, where M is selected from transition metal elements, x=3~4, z=14~16.

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