Gold-titanium dioxide / zirconium dioxide ternary composite nanomaterials, preparation method thereof and application thereof in surface enhanced Raman spectroscopy

Abstract

The present invention belongs to the technical field of composite material preparation, and specifically relates to a gold-titanium dioxide / zirconium dioxide ternary composite nanomaterial, a preparation method thereof, and an application thereof in surface-enhanced Raman spectroscopy. By combining gold nanomaterials with titanium dioxide / zirconium dioxide composite materials, the obtained ternary composite nanomaterial is composed of gold nanoparticles with a larger diameter (20-50 nanometers) and titanium dioxide and zirconium dioxide nanoparticles with a smaller size (5-20 nanometers). The gold-titanium dioxide / zirconium dioxide ternary composite nanomaterial prepared by the present invention has excellent detection capabilities for methylene blue, crystal violet, and coomassie brilliant blue in surface Raman enhancement spectroscopy tests, and can achieve a lower detection limit. Therefore, the present invention can be used for the rapid analysis and detection of trace organic substances.

Description

Technical Field

[0001] The present invention belongs to the technical field of composite material preparation, and particularly relates to a gold-titanium dioxide / zirconium dioxide ternary composite nanomaterial, a preparation method thereof, and an application thereof in surface-enhanced Raman spectroscopy. Background Art

[0002] Gold plays an important role in SERS detection research and has made remarkable progress. Current research mainly focuses on the design of gold nanostructures, surface modification and functionalization, the study of surface-enhanced effect mechanisms, and the exploration of new gold-semiconductor composite nanomaterial SERS materials. By controlling the shape, size, and structure of gold nanomaterials, as well as the modification and functionalization of the gold surface, a higher SERS enhancement effect can be achieved. Composite with semiconductor materials can enhance the plasmon resonance effect on the material surface, enhance the light absorption ability, and improve the separation and migration efficiency of photo-generated carriers, becoming materials with good SERS performance and photocatalytic performance.

[0003] Titanium dioxide (TiO2) is a common wide-bandgap semiconductor with advantages such as stable chemical properties and low price. TiO2 has special optoelectronic properties and has been widely used in many fields such as information storage, sensors, and optics. TiO2 has been widely studied in the field of photocatalysis. Existing research has shown that it will generate hole-electron pairs under light irradiation and has good photocatalytic activity. There have also been many studies on the Raman enhancement effect of TiO2. It has Raman enhancement performance itself, and its surface is easy to modify. It can be modified by doping noble metals or composite with other materials to adjust its bandgap, thereby improving its Raman enhancement performance.

[0004] Zirconium dioxide (ZrO2) has high chemical stability in high-temperature and light environments, and it is an N-type semiconductor with a bandgap of about 5.0 eV. It has ultraviolet light absorption function and good photocatalytic performance in the ultraviolet light region, but this also limits its utilization efficiency in visible light. ZrO2 also has a high refractive index, which can enhance the local electric field of incident light, thereby increasing the Raman signal, but the enhancement effect is limited. Therefore, coupling the two semiconductors to form a heterojunction to achieve the directional migration of carriers between the two, reduce the recombination of photo-generated electron-hole pairs, prolong the carrier lifetime, improve its photocatalytic activity, and then use Au nanoparticles for surface modification to enhance the local surface plasmon resonance effect and improve its Raman enhancement performance.

[0005] Surface-Enhanced Raman Spectroscopy (SERS) has developed into a powerful spectroscopic analysis technique due to its non-destructive, high-sensitivity, and rapid detection characteristics. As an advanced spectroscopic analysis technique, SERS has been widely applied in many fields such as pesticide residue detection, surface science analysis, biochemical analysis, and environmental monitoring. Due to its unique fingerprint analysis, it has developed into an important technical means for in-situ analysis on the surface or interface, and plays an important role in micro-detection and trace detection due to its outstanding detection sensitivity.

[0006] Currently, a large number of gold-semiconductor composite nanomaterials are used as SERS substrates. Liu Yang et al. designed and prepared ternary Au@Cu2O-Ag NCs by electroplating substitution method, achieving high-sensitivity SERS detection of malachite green (MG) with a detection limit as low as 10 −9 M. Sun Dawen et al. prepared molybdenum disulfide-coated titanium dioxide modified with gold nanoparticles (MoS2@TiO2@Au) as a recyclable SERS substrate for repeatable and sensitive SERS analysis and in-situ monitoring of the photodegradation process of three fungicides (methylene blue, malachite green, and crystal violet). Due to the unique comprehensive advantages of the MoS2@TiO2@Au heterojunction, this substrate can be reused five times. At the same time, in the experiment of determining methylene blue in shrimp protein solution, the detection limit reached 1.509 μg / L.

[0007] Since SERS substrates have strong selectivity, different substrate materials have different detection effects on different substances. At present, a large number of SERS substrate materials have not been prepared yet, and the insufficient SERS detection sensitivity of the substrate will also affect the practical application of SERS.

[0008] In addition, although gold nanomaterials have excellent SERS performance, they have disadvantages such as poor stability and high price; semiconductor nanomaterials have advantages such as good stability, a variety of types, and low price, and also have a certain Raman enhancement effect. At present, there are no research reports on gold-titanium dioxide / zirconium dioxide ternary composite nanomaterials, nor are there research reports on the application of related composite systems in surface-enhanced Raman spectroscopy. Summary of the Invention

[0009] In view of this, the present invention discloses a gold-titanium dioxide / zirconium dioxide ternary composite nanomaterial, a preparation method thereof, and its application in surface-enhanced Raman spectroscopy.

[0010] It should be noted that the gold-titanium dioxide / zirconium dioxide ternary composite nanomaterial disclosed in the present invention combines the excellent SERS enhancement effect of gold nanoparticles and the excellent optoelectronic properties due to the formation of a heterojunction by coupling two semiconductors, titanium dioxide and zirconium dioxide. Moreover, this ternary composite nanomaterial also has a high specific surface area and excellent chemical stability.

[0011] To achieve the above object, the present invention adopts the following technical solutions:

[0012] The first object of the present invention is to provide a gold-titanium dioxide / zirconium dioxide ternary composite nanomaterial, which is composed of gold nanoparticles and titanium dioxide / zirconium dioxide composite nanoparticles. The molar ratio of the gold nanoparticles to titanium dioxide and zirconium dioxide is 1:4:2.5. Moreover, the particle size of the gold nanoparticles is 20-50 nanometers, and the particle size of the titanium dioxide / zirconium dioxide composite nanoparticles is 5-20 nanometers.

[0013] The second object of the present invention is to provide a preparation method of the gold-titanium dioxide / zirconium dioxide ternary composite nanomaterial as described above. The method specifically includes the following steps:

[0014] (1) Preparation of titanium dioxide / zirconium dioxide composite nanoparticles:

[0015] Dissolve titanium tetrachloride (TiCl4) and zirconium nitrate pentahydrate (Zr(NO3)4·5H2O) in deionized water, stir vigorously, adjust the pH value of the suspension with ammonia water to obtain a milky white suspension, and then carry out a hydrothermal reaction. After cooling to room temperature, centrifuge, wash, dry, and then calcine to obtain a white powdery sample, which is the titanium dioxide / zirconium dioxide composite nanoparticles.

[0016] (2) Loading of gold nanoparticles:

[0017] Add polyvinylpyrrolidone (PVP) and L-ascorbic acid to distilled water. After fully dissolving, add the titanium dioxide / zirconium dioxide composite nanoparticles prepared in step (1) thereto, heat and stir. Take chloroauric acid HAuCl4 and add it to distilled water to prepare a chloroauric acid solution, pour the solution into the mixture for reaction, centrifuge, wash, and then dry to finally obtain the gold-titanium dioxide / zirconium dioxide (Au-TiO2 / ZrO2) ternary composite nanomaterial.

[0018] Optionally, the molar ratio of titanium tetrachloride (TiCl4) to zirconium nitrate pentahydrate (Zr(NO3)4·5H2O) is 1:1, the pH value of the suspension is 7-8, the temperature of the hydrothermal reaction is 100 °C, and the reaction time is 12 hours.

[0019] Further, in step (1), the drying temperature is 150 °C and the drying time is 12 hours; the calcination temperature is 550 °C and the calcination time is 6 hours.

[0020] Optionally, the mass ratio of polyvinylpyrrolidone (PVP), L-ascorbic acid to titanium dioxide / zirconium dioxide composite nanoparticles is 0.30 - 0.40 g: 0.55 - 0.65 g: 0.04 - 0.06 g, and the mass ratio of chloroauric acid to titanium dioxide / zirconium dioxide composite nanoparticles is 0.2:1.

[0021] Further, in step (2), the reaction temperature is 90 °C and the reaction time is 3 h; the drying temperature is 60 °C and the drying time is 6 h.

[0022] The third object of the present invention is to provide an application of the gold-titanium dioxide / zirconium dioxide ternary composite nanomaterial prepared by the above method in the rapid analysis and detection of trace organic compounds.

[0023] Further, the application of the gold-titanium dioxide / zirconium dioxide ternary composite nanomaterial in surface Raman enhanced spectroscopy can be used as a surface Raman enhanced spectroscopy substrate. Using a Raman spectrometer (in the example, the model of the handheld Raman spectrometer is RMS1000 of Shanghai Ruhai Optoelectronic Technology Co., Ltd.), rapid analysis and detection of organic compounds can be carried out.

[0024] Specifically, the detection application of the gold-titanium dioxide / zirconium dioxide ternary composite nanomaterial in surface Raman enhanced spectroscopy for methylene blue, crystal violet and chrysoidine.

[0025] It should be noted that the present invention innovatively combines gold nanomaterials and titanium dioxide / zirconium dioxide composite materials. The preparation scheme of the gold-titanium dioxide / zirconium dioxide ternary composite nanomaterial is involved, and the related preparation process includes the preparation method of titanium dioxide / zirconium dioxide composite nanomaterials and the gold nanoparticle loading method. According to characterization means such as TEM, XPS, XRD, etc., it is proved that the obtained ternary composite nanomaterial is composed of gold nanoparticles with larger diameters (20 - 50 nm) and titanium dioxide and zirconium dioxide nanoparticles with smaller sizes (5 - 20 nm), and according to the BET results, it is proved that the ternary composite nanomaterial has a high specific surface area.

[0026] The gold-titanium dioxide / zirconium dioxide ternary composite nanomaterial prepared by the present invention has excellent detection ability for methylene blue, crystal violet and chrysoidine in surface Raman enhanced spectroscopy tests, and can reach a lower detection limit. Therefore, the present invention can be used for the rapid analysis and detection of trace organic compounds.

[0027] Compared with the prior art, the beneficial effects of the present invention are:

[0028] 1) Since gold nanomaterials can generate a strong local surface plasmon resonance effect under visible light irradiation and play a major role in the mechanism of Raman scattering electromagnetic field enhancement (EM), gold nanomaterials have excellent SERS performance as SERS substrates. Titanium dioxide and zirconium dioxide, as semiconductors, have special optoelectronic properties and high stability. When the two materials are compounded to form a heterojunction, the directional migration of carriers between them can be achieved, the recombination of photo-generated electron-hole pairs can be reduced, and the carrier lifetime can be prolonged, which will improve the charge transfer efficiency between the composite material and the probe molecule, thereby causing chemical enhancement (CM). The composite nanostructure can combine the two Raman enhancement mechanisms and has more excellent Raman performance. Therefore, the present invention creatively combines gold nanoparticles with titanium dioxide / zirconium dioxide composite nanomaterials. The gold-titanium dioxide / zirconium dioxide composite nanomaterial combines the electromagnetic enhancement mechanism of gold nanoparticles and the chemical enhancement mechanism of titanium dioxide / zirconium dioxide composite nanomaterials, and acts on the Raman signal together to produce a better Raman signal. In addition, the ternary composite nanomaterial has a high specific surface area, and as a Raman substrate, it is more conducive to the adsorption of probe molecules on its surface, further enhancing its Raman performance.

[0029] 2) Using methylene blue, crystal violet, and chrysoidine as probe molecules, the rapid Raman detection effect of the gold-titanium dioxide / zirconium dioxide composite nanomaterial as a Raman substrate was tested. The results prove that the composite nanoparticle material prepared by the present invention can be used as a Raman substrate, and the detection limit for methylene blue reaches 10 -9 M, the detection limit for crystal violet reaches 10 -9 M, and the detection limit for chrysoidine reaches 10 -6 M, having excellent rapid Raman detection performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are only the embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained according to the provided drawings.

[0031] Figure 1 is a schematic structural diagram of the gold-titanium dioxide / zirconium dioxide (Au-TiO2 / ZrO2) ternary composite nanomaterial of the present invention.

[0032] Figure 2 is the HRTEM image of the gold-titanium dioxide / zirconium dioxide (Au-TiO2 / ZrO2) ternary composite nanomaterial of the present invention.

[0033] Figure 3It is the EDS mapping spectrum of the gold-titanium dioxide / zirconium dioxide (Au-TiO2 / ZrO2) ternary composite nanomaterial described in the present invention.

[0034] Figure 4 It is the XRD spectrum of the gold-titanium dioxide / zirconium dioxide (Au-TiO2 / ZrO2) ternary composite nanomaterial described in the present invention.

[0035] Figure 5 It is the XPS spectrum of the gold-titanium dioxide / zirconium dioxide (Au-TiO2 / ZrO2) ternary composite nanomaterial described in the present invention.

[0036] Figure 6 It is the MB and CV Raman spectra of the gold-titanium dioxide / zirconium dioxide (Au-TiO2 / ZrO2) ternary composite nanomaterial described in the present invention.

[0037] Figure 7 It is the Raman spectrum for detecting chrysoidine of the gold-titanium dioxide / zirconium dioxide (Au-TiO2 / ZrO2) ternary composite nanomaterial described in the present invention. Detailed implementation manners

[0038] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0039] The special term "embodiment" here, any embodiment described as "exemplary" does not have to be interpreted as superior to or better than other embodiments. For the performance index tests in the embodiments of this application, unless otherwise specified, the conventional test methods in the art are adopted. It should be understood that the terms described in this application are only used to describe specific embodiments and are not used to limit the content disclosed in this application.

[0040] Unless otherwise specified, the technical and scientific terms used herein have the same meanings as those generally understood by those of ordinary skill in the technical field to which this application belongs; the test methods and technical means not specifically noted in other parts of this application refer to the experimental methods and technical means commonly adopted by those of ordinary skill in the art.

[0041] To better illustrate the content of this application, numerous specific details are given in the following specific embodiments. Those skilled in the art should understand that this application can also be implemented without some specific details. In the embodiments, some methods, means, instruments, equipment, etc. well-known to those skilled in the art are not described in detail to highlight the gist of this application.

[0042] On the premise of no conflict, the technical features disclosed in the embodiments of the present application can be arbitrarily combined, and the obtained technical solutions belong to the content disclosed in the embodiments of the present application.

[0043] The present invention discloses a gold-titanium dioxide / zirconium dioxide ternary composite nanomaterial, a preparation method thereof, and an application thereof in surface-enhanced Raman spectroscopy.

[0044] To better understand the present invention, the following embodiments are used to further specifically elaborate on the present invention, but it should not be understood as a limitation of the present invention. For those skilled in the art, some non-essential improvements and adjustments made according to the above-mentioned invention content are also considered to fall within the protection scope of the present invention.

[0045] As Figure 1 shown, the larger circles in the figure represent gold nanoparticles with a diameter of 20 - 50 nm, the smaller circles with dots inside represent TiO2 nanoparticles with a diameter of 5 - 20 nm, and the smaller circles with slashes inside represent ZrO2 nanoparticles with a diameter of 5 - 20 nm.

[0046] Example 1

[0047] (1) Dissolve 1.00 g of titanium tetrachloride (TiCl4) and 2.25 g of zirconium nitrate pentahydrate (Zr(NO3)4·5H2O) in 20 mL of deionized water (the molar ratio of TiCl4:Zr(NO3)4·5H2O is (1:1)). After vigorously stirring for 10 minutes, use ammonia water (NH3·H2O) to adjust the pH of the suspension to approximately 7 - 8 to obtain a milky white suspension; perform a hydrothermal reaction at 100 °C for 12 hours to form a good white precipitate. After cooling to room temperature, centrifuge, wash 3 times each with deionized water and ethanol, place in an oven and dry at 150 °C for 12 hours, and then place in a muffle furnace and calcine at 550 °C for 6 hours to obtain a white powdery sample, which is a titanium dioxide / zirconium dioxide composite nanoparticle.

[0048] (2) Weigh 0.35 g of polyvinylpyrrolidone (PVP) and 0.60 g of L-ascorbic acid and add them to 60 mL of distilled water. After fully dissolving, weigh 0.05 g of the prepared titanium dioxide / zirconium dioxide composite nanoparticles and add them to the solution. Heat the mixture to 90 °C and keep stirring for 10 minutes; take 0.20 mL of HAuCl4 (0.05 g / mL) and add it to 10 mL of distilled water, then introduce the solution into the mixture, react for 3 h, centrifuge, wash 3 times with distilled water and absolute ethanol, place in an oven and dry at 60 °C for 6 h to finally obtain a gold-titanium dioxide / zirconium dioxide (Au-TiO2 / ZrO2) ternary composite nanomaterial.

[0049] Example 2

[0050] (1) Dissolve 0.50 g of titanium tetrachloride (TiCl4) and 1.70 g of zirconium nitrate pentahydrate (Zr(NO3)4·5H2O) in 20 mL of deionized water (the molar ratio of TiCl4:Zr(NO3)4·5H2O is (2:3)). After vigorously stirring for 10 minutes, adjust the pH of the suspension to approximately 7 - 8 using ammonia water (NH3·H2O) to obtain a milky white suspension; carry out a hydrothermal reaction at 100 °C for 12 hours to form a good white precipitate. After cooling to room temperature, centrifuge, wash 3 times each with deionized water and ethanol, place in an oven and dry at 150 °C for 12 hours, then place in a muffle furnace and calcine at 550 °C for 6 hours to obtain a white powder sample, which is titanium dioxide / zirconium dioxide composite nanoparticles.

[0051] (2) Weigh 0.35 g of polyvinylpyrrolidone (PVP) and 0.60 g of L-ascorbic acid and add them to 60 mL of distilled water. After fully dissolving, weigh 0.05 g of the prepared titanium dioxide / zirconium dioxide composite nanoparticles and add them to the solution. Heat the mixture to 90 °C and keep stirring for 10 minutes; take 0.20 mL of HAuCl4 (0.05 g / mL) and add it to 10 mL of distilled water, then introduce the solution into the mixture and react for 3 h. Centrifuge, wash 3 times with distilled water and anhydrous ethanol, place in an oven and dry at 60 °C for 6 h to finally obtain gold-titanium dioxide / zirconium dioxide (Au-TiO2 / ZrO2) ternary composite nanomaterials.

[0052] Example 3

[0053] (1) Dissolve 1.00 g of titanium tetrachloride (TiCl4) and 2.25 g of zirconium nitrate pentahydrate (Zr(NO3)4·5H2O) in 20 mL of deionized water (the molar ratio of TiCl4:Zr(NO3)4·5H2O is (1:1)). After vigorously stirring for 10 minutes, adjust the pH of the suspension to approximately 7 - 8 using ammonia water (NH3·H2O) to obtain a milky white suspension; carry out a hydrothermal reaction at 100 °C for 12 hours to form a good white precipitate. After cooling to room temperature, centrifuge, wash 3 times each with deionized water and ethanol, place in an oven and dry at 150 °C for 12 hours, then place in a muffle furnace and calcine at 550 °C for 6 hours to obtain a white powder sample, which is titanium dioxide / zirconium dioxide composite nanoparticles.

[0054] (2) Weigh 0.30 g of polyvinylpyrrolidone (PVP) and 0.55 g of L-ascorbic acid and add them to 60 mL of distilled water. After completely dissolving, weigh 0.05 g of the prepared titanium dioxide / zirconium dioxide composite nanoparticles and add them to the solution. Heat the mixture to 90 °C and keep stirring for 10 minutes; take 0.20 mL of HAuCl4 (0.05 g / mL) and add it to 10 mL of distilled water, then introduce the solution into the mixture. React for 3 h, centrifuge, wash with distilled water and absolute ethanol three times, and place in an oven at 60 °C for drying for 6 h to finally obtain the gold-titanium dioxide / zirconium dioxide (Au-TiO2 / ZrO2) ternary composite nanomaterial.

[0055] Comparative Example 1

[0056] (1) Dissolve 1.00 g of titanium tetrachloride (TiCl4) and 2.25 g of zirconium nitrate pentahydrate (Zr(NO3)4·5H2O) in 20 mL of deionized water (the molar ratio of TiCl4:Zr(NO3)4·5H2O is (1:1)). After vigorously stirring for 10 minutes, use 0.1 M sodium hydroxide solution (NaOH) to adjust the pH of the suspension to approximately 7 - 8 to obtain a milky white suspension; perform a hydrothermal reaction at 100 °C for 12 hours to form a good white precipitate. After cooling to room temperature, centrifuge, wash with deionized water and ethanol three times each, place in an oven at 150 °C for drying for 12 hours, and then place in a muffle furnace at 550 °C for calcination for 6 hours to obtain a white powdery sample, which is the titanium dioxide / zirconium dioxide composite nanoparticles.

[0057] (2) Weigh 0.35 g of polyvinylpyrrolidone (PVP) and 0.60 g of L-ascorbic acid and add them to 60 mL of distilled water. After completely dissolving, weigh 0.05 g of the prepared titanium dioxide / zirconium dioxide composite nanoparticles and add them to the solution. Heat the mixture to 90 °C and keep stirring for 10 minutes; take 0.20 mL of HAuCl4 (0.05 g / mL) and add it to 10 mL of distilled water, then introduce the solution into the mixture. React for 3 h, centrifuge, wash with distilled water and absolute ethanol three times, and place in an oven at 60 °C for drying for 6 h to finally obtain the gold-titanium dioxide / zirconium dioxide (Au-TiO2 / ZrO2) ternary composite nanomaterial.

[0058] In order to further prove the beneficial effects of the present invention and better understand the present invention, the technical features disclosed in the present invention are further clarified / verified through the following experiments.

[0059] 1. Use a high-resolution transmission electron microscope (HRTEM) and an energy-dispersive spectrometer (EDS) to analyze the surface morphology and composition of the samples

[0060] Analyze the surface morphology of the samples using a high-resolution transmission electron microscope (HRTEM), asFigure 2 . Figure 2 In a, and Figure 2 in b, it can be clearly seen that the sample is composed of a small amount of particles with larger diameters distributed dispersedly and a large amount of particles with smaller diameters distributed aggregately. Figure 2 In c and d, the interplanar spacings of the diffraction fringes of Au and TiO2, ZrO2 were calculated. The HRTEM results indicate that the gold-titanium dioxide / zirconium dioxide (Au-TiO2 / ZrO2) ternary composite nanomaterial was successfully prepared using the preparation method in Example 1.

[0061] Through EDS mapping scanning, the elemental spectrum of the gold-titanium dioxide / zirconium dioxide ternary composite nanomaterial can be obtained to determine the elemental composition, such as Figure 3 . Figure 3 In a, b, c, and d respectively correspond to the EDS spectra of the four elements O, Au, Ti, and Zr. Through the EDS result analysis, the sample is composed of three elements O, Au, Ti, and Zr, and is consistent with the electron microscopy results, proving that the sample is the gold-titanium dioxide / zirconium dioxide ternary composite nanomaterial.

[0062] 2. Analyze the structure of the sample using an X-ray diffractometer (XRD) and X-ray photoelectron spectroscopy (XPS)

[0063] The crystal structure of the gold-titanium dioxide / zirconium dioxide ternary composite nanomaterial can be analyzed by an X-ray diffractometer (XRD), and the results are as Figure 4 shown. In the lower part of the figure, the peaks corresponding to the Au standard card (JCPDS: 04-0784) are used respectively with black lines. It can be obtained from the figure that the peaks correspond one by one. The absence of the characteristic peaks of TiO2 and ZrO2 is due to the too small grain size and insufficient crystallinity of the two metal oxides. The absence of other diffraction peaks in the figure indicates that the sample is a pure gold-titanium dioxide / zirconium dioxide ternary composite nanomaterial.

[0064] The surface composition and elemental valence states of the gold-titanium dioxide / zirconium dioxide ternary composite nanomaterial can be analyzed by the XPS results, and the results are as Figure 5 shown. The results obtained from the XPS test are analyzed by peak fitting using the Advantage software, and the peak position of C1s at 284.8 eV is used for charge calibration. Figure 5 In a is the XPS full spectrum of the Au-TiO2 / ZrO2 composite nanomaterial, showing that the sample is mainly composed of the elements O, Ti, Zr, and Au. Figure 5 In b is the fine spectrum of Au 4f. Through peak fitting, the Au element has Au 0 , Au 1+ two valence states. The fine spectrum of Ti 2p is as Figure 5As shown in c, all the characteristic peaks of Ti correspond to Ti according to the fitting results. 4+ . Figure 5 Figure d is the fine spectrum of Zr 3d. All the characteristic peaks belong to Zr through peak fitting. 4+ .

[0065] 3. Using probe molecules methylene blue (MB) and crystal violet (CV), the analytical detection performance of the gold-titanium dioxide / zirconium dioxide (Au-TiO2 / ZrO2) ternary composite nanomaterial as a Raman detection substrate material for organic substances was tested.

[0066] Using common probe molecules: methylene blue (MB) and crystal violet (CV), the analytical detection performance of the gold-titanium dioxide / zirconium dioxide (Au-TiO2 / ZrO2) ternary composite nanomaterial as a Raman detection substrate material for organic substances was tested. The results are as Figure 6 . Figure 6 Figure a is the Raman spectrum for detecting MB. The detection limit of the gold-titanium dioxide / zirconium dioxide ternary composite nanomaterial for MB is 10 -9 M. Figure 6 Figure b is the Raman spectrum for detecting CV. The detection limit of CV is 10 -9 M. The above conclusions indicate that the gold-titanium dioxide / zirconium dioxide ternary composite nanomaterial has excellent surface-enhanced Raman performance as a Raman substrate.

[0067] 4. The analytical detection performance of the gold-titanium dioxide / zirconium dioxide (Au-TiO2 / ZrO2) ternary composite nanomaterial as a Raman detection substrate material for chrysoidine.

[0068] As Figure 7 shown, using chrysoidine as a probe molecule, when the concentration is 10 -5 M, the characteristic peaks are very obvious. However, when the concentration is 10 -7 M, the peak value is not obvious and the peak value cannot correspond to the standard characteristic peak. The above results prove that the detection limit of the gold-titanium dioxide / zirconium dioxide ternary composite nanomaterial as a Raman substrate for chrysoidine is 10 -6 M.

[0069] The above description of the disclosed embodiments enables those skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to those skilled in the art. The general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to these embodiments shown herein, but rather will be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A preparation method of a gold-titanium dioxide / zirconium dioxide ternary composite nanomaterial, characterized in that The method specifically includes the following steps: (1) Prepare titanium dioxide / zirconium dioxide composite nanoparticles: Dissolve titanium tetrachloride (TiCl4) and zirconium nitrate pentahydrate (Zr(NO3)4·5H2O) in deionized water, stir vigorously, adjust the pH value of the suspension with ammonia water to obtain a milky white suspension, then carry out hydrothermal reaction. After cooling to room temperature, centrifuge, wash, dry and then calcine to obtain a white powder sample, which is the titanium dioxide / zirconium dioxide composite nanoparticles; (2) Load gold nanoparticles: Add polyvinylpyrrolidone (PVP) and L-ascorbic acid to distilled water. After fully dissolving, add the titanium dioxide / zirconium dioxide composite nanoparticles prepared in step (1) into it, heat and stir. Take chloroauric acid HAuCl4 and add it to distilled water to prepare a chloroauric acid solution, pour the solution into the mixture to react, centrifuge, wash and then dry to finally obtain the gold-titanium dioxide / zirconium dioxide (Au-TiO2 / ZrO2) ternary composite nanomaterial.

2. The preparation method of the gold-titanium dioxide / zirconium dioxide ternary composite nanomaterial according to claim 1, characterized in that, The molar ratio of titanium tetrachloride (TiCl4) to zirconium nitrate pentahydrate (Zr(NO3)4·5H2O) is 1:

1. The pH value of the suspension is 7-8, the temperature of the hydrothermal reaction is 100 °C, and the reaction time is 12 hours.

3. The preparation method of the gold-titanium dioxide / zirconium dioxide ternary composite nanomaterial according to claim 1 or 2, characterized in that, In step (1), the drying temperature is 150 °C and the drying time is 12 hours; the calcination temperature is 550 °C and the calcination time is 6 hours.

4. The preparation method of the gold-titanium dioxide / zirconium dioxide ternary composite nanomaterial according to claim 1, characterized in that, The mass ratio of the polyvinylpyrrolidone (PVP), L-ascorbic acid to the titanium dioxide / zirconium dioxide composite nanoparticles is 0.30-0.40:0.55-0.65:0.04-0.06, and the mass ratio of the chloroauric acid to the titanium dioxide / zirconium dioxide composite nanoparticles is 0.2:

1.

5. The preparation method of the gold-titanium dioxide / zirconium dioxide ternary composite nanomaterial according to claim 1 or 4, characterized in that, In step (2), the reaction temperature is 90 °C and the reaction time is 3 h; the drying temperature is 60 °C and the drying time is 6 h.

6. A gold-titanium dioxide / zirconium dioxide ternary composite nanomaterial prepared by the method according to claim 1, characterized in that, The ternary composite nanomaterial is composed of gold nanoparticles and titanium dioxide / zirconium dioxide composite nanoparticles. The molar ratio of the gold nanoparticles to titanium dioxide and zirconium dioxide is 1:4:2.5; and the particle size of the gold nanoparticles is 20-50 nanometers, and the particle size of the titanium dioxide / zirconium dioxide composite nanoparticles is 5-20 nanometers.

7. Application of the gold-titanium dioxide / zirconium dioxide ternary composite nanomaterial prepared by the method as described in claim 1 in the rapid analysis and detection of trace organic substances.

8. The application according to claim 7, wherein Application of the gold-titanium dioxide / zirconium dioxide ternary composite nanomaterial in surface Raman enhanced spectroscopy, which can be used as a surface Raman enhanced spectroscopy substrate.

9. The application according to claim 8, wherein Detection application of the gold-titanium dioxide / zirconium dioxide ternary composite nanomaterial to methylene blue, crystal violet and chrysoidine in surface Raman enhanced spectroscopy testing.

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