Composite double-lsp material and preparation method and application thereof

Abstract

This invention relates to the field of nanomaterials technology, and more particularly to a composite dual LSPR material, its preparation method, and its applications. The present invention provides a method for preparing a composite dual LSPR material, comprising: using nano-sized W... 18 O 49 The material is used as the substrate. Bi is sputtered onto the substrate using magnetron sputtering to obtain a composite dual LSPR material. During the magnetron sputtering process, the operating current is controlled at 0.01–0.03 A, and the operating voltage at 150–360 V. The Bi content in the composite dual LSPR material is controlled at 2–13 wt%. This preparation method allows Bi to directly react with W containing oxygen vacancies in elemental form. 18 O 49 By combining these materials, a composite dual LSPR material with superior bonding properties can be obtained. At the same time, the dual LSPR material is tightly bonded and has advantages such as nanoscale structure, good dispersibility, and high photocatalytic activity.

Description

Technical Field

[0001] This invention relates to the field of nanomaterials technology, and in particular to a composite dual LSPR material, its preparation method, and its applications. Background Technology

[0002] As an n-type semiconductor, tungsten trioxide (WO3) has attracted widespread attention due to its narrow bandgap structure and excellent light absorption properties. Compared with traditional photocatalysts (such as TiO2), the narrow bandgap structure exhibits broadened spectral response, even extending into the visible-infrared region. Since most sunlight is visible light, with ultraviolet light accounting for only 5%, WO3 can utilize the properties of visible light, demonstrating significant application potential in photocatalysis. However, the narrow bandgap structure may also lead to an increased recombination rate of photogenerated electrons and holes during photocatalysis, hindering redox reactions and ultimately affecting the photocatalytic effect.

[0003] Currently known photocatalytic materials are primarily modified through structural morphology adjustment or doping and loading composite methods to improve their application performance. At present, some researchers have also proposed synthesizing non-stoichiometric defect-type WO3. 3-X Materials and methods for constructing heterojunction structures are used to reduce electron-hole pair recombination.

[0004] But defective WO 3-X Although the material has many advantages in application, such as stronger light absorption and faster electron transfer speed, there is still room for further improvement in its photocatalytic effect.

[0005] Regarding the construction of heterojunction structures, while existing technologies include combining noble metals such as Au, Ag, and Pt with target semiconductors to construct heterojunctions, all of these methods invariably employ wet chemical processes to achieve uniform bonding. However, this method requires further chemical reactions, and those skilled in the art currently find it difficult to control the reaction process, making it challenging to guarantee a stable bonding effect with the catalytic material. CN 114392741 A discloses an Ag nanoparticle-modified W... 18 O 49 The preparation method of nanowires, which is used to obtain W 18 O 49 After the nanowires are fabricated, AgNO3 solution is reduced and deposited onto the nanowire surface at high temperature. However, in practice, it is difficult to ensure the AgNO3 solution is properly deposited. + All Ag is generated, but even if Ag can be obtained, its size and W cannot be controlled. 18 O 49 The nanowires showed good matching. CN 111589460 A disclosed the combination of the tertiary halide bismuth oxide compound BiOX and W... 18 O 49The construction of heterostructures using nanowires still involves a wet chemical method of reacting bismuth nitrate alcohol solution, metal halide solution, and W... 18 O 49 W was obtained by chemical deposition after mixing nanowires. 18 O 49 / BiOX composite photocatalysts also have the same problem.

[0006] In view of this, the present invention is proposed. Summary of the Invention

[0007] This invention provides a composite dual LSPR material, its preparation method, and its application to address the aforementioned deficiencies. On the one hand, it improves the light absorption performance of the photocatalyst, and on the other hand, it can also improve the separation efficiency of the photoexcitation support and promote redox reactions in the photocatalytic application process.

[0008] This invention first provides a composite dual LSPR material, comprising: nano-W 18 O 49 The material is a substrate material, and Bi is sputtered onto the substrate material by magnetron sputtering to obtain a composite dual LSPR material;

[0009] During the magnetron sputtering process, the operating current is controlled at 0.01–0.03 A and the operating voltage at 150–360 V; the Bi content in the composite double LSPR material is controlled at 2–13 wt%.

[0010] This invention discovers that the non-noble metal bismuth (Bi) exhibits excellent LSPR effect. Using the above-described preparation method, when the current and voltage are simultaneously controlled within the aforementioned ranges, Bi can directly react with W containing oxygen vacancies in its elemental form. 18 O 49 By combining these components, a composite dual LSPR material with superior bonding properties can be obtained. Furthermore, by controlling the Bi content in the composite dual LSPR material within the aforementioned range, the dual LSPR effect can be ensured to be higher than that of W. 18 O 49 The single LSPR effect of the material improves the catalytic degradation effect.

[0011] Meanwhile, this invention further discovers that the composite dual LSPR material obtained by the preparation method within the above parameter range significantly improves the bonding stability of the two materials compared with the catalytic material obtained by the mainstream wet chemical method. This not only effectively avoids the subsequent delamination problem, but most importantly, it can solve the problem of unstable effect of wet chemical method and significantly improve the success rate of preparation.

[0012] Preferably, the Bi content in the composite double LSPR material is controlled to be 4–8 wt%.

[0013] This invention has discovered that Bi and W in the composite material18 O 49 Both exhibit the LSPR effect, but when constructing heterojunctions using magnetron sputtering, the LSPR effect is mutually masked, leading to a weakening of the effect. Subsequent studies have found that by further controlling the thickness of Bi in the composite dual LSPR material within the aforementioned range, the dual LSPR effect can be ensured to remain unmasked, resulting in a stronger LSPR effect and further enhancing the catalytic degradation effect.

[0014] Preferably, during magnetron sputtering, the inert gas flow rate is controlled at 15–30 sccm, and the chamber pressure is below 0.3 Pa.

[0015] Preferably, the inert gas is argon.

[0016] Preferably, the sputtering time during magnetron sputtering is 0.5 to 5 minutes.

[0017] Preferably, the nano W 18 O 49 The material was prepared through the following steps:

[0018] (1) Mix the tungsten source with the solvent to obtain a mixed solution;

[0019] (2) The mixed solution is subjected to a high-temperature reaction, and after the reaction is completed, it is cooled to room temperature to obtain the reaction product;

[0020] (3) The reaction product is washed and dried to obtain nano W. 18 O 49 Material;

[0021] The high temperature is 150–250°C.

[0022] In this invention, the high-temperature reaction is carried out in a sealed reaction vessel.

[0023] Preferably, the tungsten source includes at least one of tungsten hexachloride, sodium tungstate, and ammonium tungstate, and more preferably tungsten hexachloride.

[0024] Preferably, the solvent is an alcohol or an alkane, more preferably at least one of methanol, ethanol and n-heptane.

[0025] Preferably, the concentration of the tungsten source in the mixed solution is 0.5–20 g / ml.

[0026] As a preferred technical solution of the present invention, it specifically includes the following steps:

[0027] (1) Disperse the tungsten source in an organic solvent and stir thoroughly to obtain a mixed solution in a fully dissolved state;

[0028] (2) The mixed solution is transferred to a reaction vessel for high-temperature reaction. After the reaction is completed, it is cooled to room temperature to obtain the reaction product.

[0029] (3) After washing and drying, the reaction product is used to obtain nano-W 18 O 49 ;

[0030] (4) With the nano W 18 O 49 The material is a substrate, and Bi is sputtered onto it using magnetron sputtering to obtain a composite double LSPR material.

[0031] In this invention, the stirring conditions described in step (1) can be magnetic stirring at room temperature or manual stirring, as long as the solute is completely dissolved and the solution is homogeneous; at the same time, those skilled in the art can make reasonable selections of the specifications of the reaction vessel as needed.

[0032] In practice, the cooling method described in step (2) can be air cooling, furnace cooling, or water cooling, as long as it does not affect the structure of the final product.

[0033] Preferably, the washing in step (3) includes washing with pure water and alcohol 2 to 3 times respectively to remove residual impurities on the product.

[0034] Preferably, the drying in step (3) is carried out in a drying oven or drying box, with a drying temperature of 50-70°C and a drying time of 10-13 hours.

[0035] In this invention, the substrate material includes powder samples and immobilized samples. The difference lies in whether an immobilized sheet is used in the product preparation stage. Those skilled in the art can select the immobilized sample according to the application conditions, and no limitation is made here.

[0036] The present invention also provides a composite dual LSPR material, which is prepared by the above preparation method.

[0037] Preferably, the particle size of Bi in the composite dual LSPR material is less than 10 nm.

[0038] In this invention, by controlling the condition parameters using the above method, the Bi sputtered on the substrate material has a smaller particle size and better product bonding.

[0039] The present invention further provides the application of the composite dual LSPR material in the field of photocatalysis.

[0040] Based on the above technical solution, the beneficial effects of the present invention are as follows:

[0041] The method for preparing the composite dual LSPR material provided by this invention enables Bi to directly react with W containing oxygen vacancies in elemental form.18 O 49 By combining these methods, a composite dual-LSPR material with superior bonding properties can be obtained. This method has the advantages of being simple, environmentally friendly, stable, reliable, and highly controllable; at the same time, the prepared composite product can completely retain the original product's nano-W 18 O 49 The structural morphology of the double LSPR material is characterized by its tight bonding and advantages such as nanoscale structure, good dispersibility, and high photocatalytic activity.

[0042] Furthermore, a Bi / W composite material with a double LSPR effect prepared based on this method was also obtained. 18 O 49 Compared with existing photocatalytic materials, it has excellent application effects in recalcitrant organic pollutants (PPCPs, pharmaceuticals and personal care products), further demonstrating the feasibility of this method as a new material preparation method, and also showing the great potential of the dual LSPR material prepared based on this method in the field of photocatalytic applications. Attached Figure Description

[0043] To more clearly illustrate the technical solutions in this invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0044] Figure 1 These are SEM images of the product obtained in Example 1 of this invention;

[0045] Figure 2 These are XRD images of the product obtained in Example 1 of this invention;

[0046] Figure 3 This is the Bi target material after melting in Comparative Example 1 of the present invention;

[0047] Figure 4 Here is a SEM image of the product obtained in Comparative Example 2 of this invention;

[0048] Figure 5 Here is a SEM image of the product obtained in Comparative Example 3 of this invention;

[0049] Figure 6 The image shows the XRD pattern of the product obtained in Comparative Example 3 of this invention.

[0050] Figure 7 The diagram shows the catalytic degradation of the products in the embodiments and comparative examples of this invention.

[0051] Figure 8The diagrams show the catalytic degradation of composite products with different Bi contents in Examples 1 and 2 of this invention.

[0052] Figure 9 This is an absorbance diagram of the products of the embodiments and comparative examples of the present invention. Detailed Implementation

[0053] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0054] Magnetron sputtering equipment: Magnetron sputtering machine (JCP-350M2, BEIJING TECHNOL CO.,LTD).

[0055] Example 1

[0056] This embodiment provides a composite dual LSPR material—nano-Bi / W 18 O 49 The material, and its preparation method includes the following steps:

[0057] 1.5 g of WCl6 was weighed and dispersed in 150 ml of methanol solution, and magnetically stirred for 2 h to obtain a homogeneous mixture. The mixture was then transferred to a 200 ml reactor, sealed, and solvothermal reacted at 180 °C for 9 h. After the reaction, the mixture was allowed to cool naturally to room temperature, then washed with pure water and alcohol, and centrifuged (3000 r / min) 2–3 times to remove unreacted residues. The washed product was placed in a drying oven and dried at 60 °C under atmospheric pressure for 12 h to obtain the solvothermal product, nano-WCl6. 18 O 49 .

[0058] Then, based on the aforementioned W... 18 O 49 The substrate was Bi, and the sputtering target was Bi. The sputtering parameters were as follows: Ar as the protective gas, gas flow rate 20.2 sccm, DC sputtering, chamber pressure 0.25 Pa, operating voltage 260 V, operating current 0.01 A, and sputtering time 3.0 min. The final composite product was nano-Bi / W. 18 O 49 The Bi content in the material is 4.5 wt%.

[0059] SEM image of the final composite product is shown below. Figure 1 As shown, the XRD pattern is as follows Figure 2 As shown.

[0060] Figure 1 It can be clearly seen that the prepared product has a uniform size distribution and a one-dimensional nanorod cluster urchin-like structure, meaning that the sputtered sample has well preserved the morphological and structural advantages of the original sample. Figure 2 It can be seen that its phase peaks are similar to those of h-Bi and mW. 18 O 49 Correspondingly.

[0061] Example 2

[0062] This embodiment provides a composite dual LSPR material—nano-Bi / W 18 O 49 The material was prepared using the same method as in Example 1, except that it contained nano-Bi / W. 18 O 49 The Bi content in the material is 12.3 wt%.

[0063] Comparative Example 1

[0064] This comparative example provides a composite dual LSPR material, whose preparation method is the same as that of Example 1, except that the operating current is 0.1A. The final target material is melted, as... Figure 3 As shown. This indicates that when applying magnetron sputtering to the material, the operating current needs further optimization, and conventional magnetron sputtering parameters are not applicable.

[0065] Comparative Example 2

[0066] This comparative example provides a composite dual LSPR material—nano-Bi / W 18 O 49 Materials, of which the substrate material W 18 O 49 The preparation method of the material is the same as in Example 1, except that the composite product is prepared using a conventional wet chemical method (solvothermal method), specifically including the following steps:

[0067] Weigh 1.0 g of bismuth nitrate and dissolve it in 60 ml of ethylene glycol. Stir well at room temperature, then add 0.7 g of W. 18 O 49 The material was stirred until homogeneous and then transferred to a reactor. The reaction was carried out at 180°C for 9 hours, followed by cooling, washing, and drying to obtain Bi / W. 18 O 49 The material, named B / WO to distinguish it from magnetron sputtering products, is shown in the SEM image below. Figure 4 As shown.

[0068] Figure 4 and Figure 1 The comparison shows that although the product prepared by the wet chemical method does indeed contain some Bi / W...18 O 49 structure( Figure 4 However, only a very small portion of the total Bi formed can be well bonded to the substrate material; most of the Bi tends to bond with each other rather than composite with W. 18 O 49 The surface; and the formed Bi particles are relatively large (d≈50nm), unable to bond well with the substrate material, thus severely affecting the catalytic effect. Therefore, conventional wet chemical methods for obtaining this material have low efficiency and poor bonding effect. It is also noted that, due to the W... 18 O 49 After undergoing another process of high temperature, washing, and drying, its urchin-like structure disappeared, transforming into a one-dimensional structure of varying lengths. This is consistent with... Figure 1 The characteristics of the products before and after recombination are significantly different in that they retain their original morphology. Furthermore, the above method does not always achieve the desired effect during preparation, and the stability of the effect is relatively poor.

[0069] Comparative Example 3

[0070] This comparative example provides a commonly used photocatalytic material in this field—nano W. 18 O 49 The material, and its preparation method are the same as those used in Example 1 for preparing nano-W 18 O 49 The method for the materials is the same. Its SEM image is as follows: Figure 5 As shown, the XRD pattern is as follows Figure 6 As shown. Figure 5 The prepared product can be clearly seen to have a uniform size distribution and a sea urchin-like structure of one-dimensional nanorod clusters. Figure 6 It can be seen that its phase peaks are related to mW 18 O 49 Correspondingly.

[0071] Test case

[0072] 1. Catalytic degradation effect

[0073] (1) In the following experiments, the raw materials used were the products of Example 1 and Comparative Examples 2-3, respectively, to verify the degradation effects of different materials. The specific steps included:

[0074] 10 mg of the material to be validated was dispersed in 100 ml of 10 mg / L TMP (trimethoprim, a typical PPCPs pollutant) solution and stirred for 30 min under light-protected conditions to reach adsorption equilibrium. Then, it was placed on an LED lamp device (610 nm red light irradiation, 1 A current) and the TMP degradation process under visible light was carried out with continuous stirring. Samples were taken at fixed time intervals, and the MB content in the solution was detected after centrifugation. The degradation efficiency of the product at a certain time was calculated.

[0075] The final degradation effects of different materials are as follows Figure 7 As shown, the composite product with dual LSPR effect exhibits the best degradation effect on TMP, reaching 93% at 120 min.

[0076] (2) Catalytic degradation effects of composite products with different Bi contents in Examples 1 and 2. See Figure 8 .

[0077] This application found that, compared to Example 1, when the Bi content in the product was 12.3%, its catalytic degradation effect was as high as 89%, and the Bi particles and W 18 O 49 Although the LSPR binding effect is weakened to some extent, it is still better than W. 18 O 49 The material achieves 85% better results and is more stable than materials prepared by wet chemical methods.

[0078] 2. Light absorption

[0079] The light absorption properties of the materials in the comparative examples and the comparative examples are shown in the figure. Figure 9 The comparison shows that Bi / W with dual LSPR properties 18 O 49 The product exhibits the best light absorption. Furthermore, compared to composite products prepared by wet chemical methods, it possesses advantages such as smaller size and better binding properties. (Bi / W) 18 O 49 The product exhibits a more pronounced LSPR peak shape in the visible light region, which means that its light absorption and LSPR effect are also stronger.

[0080] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for preparing a composite dual LSPR material, characterized in that, include: With nano W 18 O 49 The material is a substrate material, and Bi is sputtered onto the substrate material using magnetron sputtering to obtain a composite double LSPR material; wherein, during the magnetron sputtering process, the operating current is 0.01~0.03 A and the operating voltage is 150~360 V; The content of Bi in the composite double LSPR material is controlled to be 4~8wt%.

2. The method for preparing the composite dual LSPR material according to claim 1, characterized in that, During magnetron sputtering, the inert gas flow rate is controlled at 15.0~30.0 sccm, and the chamber pressure is below 0.3 Pa.

3. The method for preparing the composite dual LSPR material according to claim 1 or 2, characterized in that, The nano W 18 O 49 The material was prepared through the following steps: (1) Mix the tungsten source with the solvent to obtain a mixed solution; (2) The mixed solution is subjected to a high-temperature reaction, and after the reaction is completed, it is cooled to room temperature to obtain the reaction product; (3) The reaction product is washed and dried to obtain nano W. 18 O 49 Material; The high temperature is 150~250 ℃.

4. The method for preparing the composite dual LSPR material according to claim 3, characterized in that, The tungsten source includes at least one of tungsten hexachloride, sodium tungstate, and ammonium tungstate.

5. The method for preparing the composite dual LSPR material according to claim 4, characterized in that, The tungsten source is tungsten hexachloride.

6. The method for preparing the composite dual LSPR material according to claim 3, characterized in that, The solvent is an alcohol or an alkane.

7. The method for preparing the composite dual LSPR material according to claim 6, characterized in that, The solvent is at least one of methanol, ethanol and n-heptane.

8. The method for preparing the composite dual LSPR material according to claim 3, characterized in that, In the mixed solution, the concentration of the tungsten source is 0.5~20 g / l.

9. A composite dual LSPR material, characterized in that, It is prepared by the preparation method described in any one of claims 1 to 8.

10. The composite dual LSPR material according to claim 9, characterized in that, The particle size of Bi in the composite dual LSPR material is less than 10 nm.

11. The application of the composite dual LSPR material according to claim 9 or 10 in the field of photocatalysis.

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