Preparation method of oxygen-enriched semiconductor titanium dioxide material
By preparing oxygen-rich titanium dioxide materials, the problem of instability of existing SERS substrate materials in acid and alkali environments is solved, and SERS performance is optimized by regulating the energy band structure, and high sensitivity detection effect in extreme environments is achieved.
Patent Information
- Application Number
- CN202411715244.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-11-27
- Publication Date
- 2025-02-28
AI Technical Summary
The existing semiconductor SERS substrate materials are unstable in acid-base environments, and the wide band gap of titanium dioxide materials limits its application in SERS.
By treating the tetrabutyl titanate hydrolysate with an oxidant, an oxygen-rich titanium dioxide material was prepared, and its energy band structure was regulated through different temperature treatments to optimize SERS performance.
The oxygen-rich titanium dioxide material maintains high sensitivity SERS performance and excellent material stability in extreme acid and alkali environments, and is suitable for detection applications in extreme environments.
Smart Images
Figure CN119528214A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to the field of semiconductor SERS preparation technology, and in particular to a method for preparing an oxygen-rich semiconductor titanium dioxide material and stabilizing SERS detection in an extreme environment. Background Art
[0002] Ultrasensitive molecular sensing is of great significance in homeland security, biomedicine, catalytic monitoring and environmental monitoring. Compared with fluorescence, electrochemistry and mass spectrometry, surface enhanced Raman scattering (SERS) is a sensitive, label-free and non-destructive analytical technique that can even achieve single molecule detection. As the core of SERS technology, the research on ultrasensitive substrate materials has always attracted much attention. At present, the most common SERS substrates are mainly divided into 0D substrates such as nano-precious metal sols, 1D substrates such as precious metal nanowires, 2D substrates such as silver (gold)-loaded silicon wafers, and 3D substrates such as silver (gold)-loaded aerogels. Although these substrate materials often have excellent SERS performance, there are still significant shortcomings, such as nano-silver (gold) is easily corroded in some corrosive acid-base solutions, and nano-silver has been oxidized after being placed in the natural environment for a long time.
[0003] In recent years, charge transfer-derived semiconductor materials have been considered as effective candidate materials to replace precious metal substrates due to their excellent stability, adjustable physical and chemical properties, and easy manufacturing. Among them, titanium dioxide is a commercial semiconductor with the advantages of low price, non-toxicity, and environmental protection, and is widely used in catalysis and sensing. However, its wide band gap energy (Eg = 3.2 eV) limits its further application in SERS. In this context, strategies such as element doping, defect engineering, and crystalline state regulation have been proposed to adjust the band gap of titanium dioxide, and research has made remarkable progress. Summary of the invention
[0004] The purpose of the present invention is to solve the above problems and propose a method for preparing an oxygen-rich semiconductor titanium dioxide material, which optimizes the surface enhanced Raman scattering (SERS) performance and still has high-sensitivity SERS performance in extreme environments such as superacid (fuming nitric acid) and alkaline.
[0005] The present invention achieves the above-mentioned purpose through the following technical solutions:
[0006] The present invention provides a method for preparing an oxygen-rich semiconductor titanium dioxide material and a SERS detection method thereof in an extreme environment, comprising the following steps:
[0007] Step S1, weighing tetrabutyl titanate and adding it to deionized water, stirring it in an ice bath for a period of time, and collecting the hydrolyzate by washing and centrifugation. Adding an oxidant to dissolve the hydrolyzate to form a peroxide titanate complex. Heating the solution to gel it, and heating it in an air drying oven to obtain a solid. Finally, calcining it in a muffle furnace to form an oxygen-rich titanium dioxide material;
[0008] Step S2, immersing the oxygen-rich titanium dioxide material in an ethanol solution of 4-mercaptobenzoic acid (4-MBA) analyte. Then, the substrate is removed from the solvent and dried under ambient conditions. A Renishaw inVia Raman microspectrometer is used to collect Raman signals, with a laser emission wavelength of 532 nm;
[0009] Step S3, immersing the oxygen-rich titanium dioxide material in an acidic or alkaline solution, centrifugally cleaning, and then performing a SERS test to characterize the acid and alkali resistance of the sample;
[0010] Step S4, immersing the oxygen-rich titanium dioxide material in a stock solution of nitric acid nitrating 1,2,4-triazole-5-one (TO) to generate 3-nitro-1,2,4-triazole-5-one (NTO). A Renishaw inVia Raman microspectrometer is used to collect Raman signals, and the laser emission wavelength is 532nm.
[0011] As a preferred embodiment of the present invention, the volume ratio of tetrabutyl titanate: deionized water: oxidant is 1: (20-30): (10-20).
[0012] As a preferred embodiment of the present invention, the oxidant is any one of sulfuric acid and hydrogen peroxide.
[0013] As a preferred embodiment of the present invention, the ice bath temperature is 1 to 5° C., and the stirring time is 0.5 to 3 h.
[0014] As a preferred embodiment of the present invention, the solvent is heated to gelation temperature of 40-80°C for 1-5 hours, and the air drying oven is heated to 80-150°C for 4-12 hours.
[0015] As a preferred embodiment of the present invention, the calcination temperature of the muffle furnace is 300-600° C., and the insulation time is 1-4 hours.
[0016] As a preferred embodiment of the present invention, the acidic or alkaline solution is any one of HCl, HNO3 or NaOH.
[0017] As a preferred embodiment of the present invention, the concentration of the acidic or alkaline solution is 1 to 10 M, and the soaking time is 1 to 12 hours.
[0018] As a preferred embodiment of the present invention, the nitric acid concentration is 60-90%, the reaction temperature is 30-60° C., the amount of nitric acid used is 1-10 mL, and the amount of TO used is 1-5 g.
[0019] The specific operation method is:
[0020] For the preparation method of oxygen-rich semiconductor titanium dioxide material. Weigh 5.5mL of tetrabutyl titanate and add it to (110-165mL) of deionized water, and ice bath at 1-5°C. After stirring for 0.5-3h, collect the hydrolyzate by washing and centrifugation. Add (55-110mL) of hydrogen peroxide to dissolve the hydrolyzate to form a peroxide titanate complex. Heat the solution (40-80°C) (1-5h) to gel it, and heat it in an air drying oven (80-150°C) (4-12h) to obtain a yellow solid product. Finally, calcine (1-4h) in a muffle furnace (300-600°C) to form an oxygen-rich titanium dioxide material.
[0021] For the detection of the probe molecule 4-MBA. The heat-treated oxygen-rich titanium dioxide material was immersed in an ethanol solution (1 mL) of different concentrations of 4-MBA. Then, the substrate was removed from the solvent, dried under ambient conditions, and the Raman spectrum was collected on a RenishawinVia Raman microscope. The excitation wavelength was 532 nm, and a Leica objective with a magnification of 20 times was used to focus the laser beam. A grating of 1800 lines / mm was used, and the spectral resolution was 1 cm -1 The spectrum acquisition time was 10 s, and the laser power was kept between 0.3 and 15 mW in all acquisitions.
[0022] For the stability test in extreme environments such as acid and alkali. The heat-treated oxygen-rich titanium dioxide material was immersed in 1-10M HCl, HNO3 and NaOH solutions, left to stand for 1-12 hours, centrifuged and cleaned, and the Raman spectrum was collected on a Renishaw inVia Raman microscope. The excitation wavelength was 532nm, and a Leica objective with a magnification of 20 times was used to focus the laser beam. A grating of 1800 lines / mm was used, and the spectral resolution was 1cm -1 The spectrum acquisition time was 10 s, and the laser power was kept between 0.3 and 15 mW in all acquisitions.
[0023] For the detection of the nitration synthesis process of NTO. First, TO was dissolved in nitric acid under ice bath conditions, heated to the set temperature, and the experiment was started. The heat-treated oxygen-rich titanium dioxide material was immersed in the nitration reaction stock solution (0.1mL) sampled at different times. The substrate was then taken out, dried under ambient conditions, and the Raman spectrum was collected on a Renishaw inVia Raman microscope. The excitation wavelength was 532nm, and a Leica objective with a magnification of 50 times was used to focus the laser beam. A grating of 1800 lines / mm was used, and the spectral resolution was 1cm-1. The spectral acquisition time was 20s, and the laser power in all acquisitions was maintained at 0.3-15mW.
[0024] The beneficial effects of the present invention are: the hydrolysis product of tetrabutyl titanate is treated with an oxidant (sulfuric acid, hydrogen peroxide) to obtain an oxygen-rich titanium dioxide precursor. By treating the oxygen-rich titanium dioxide at different temperatures, its band structure is regulated to obtain an oxygen-rich titanium dioxide material with optimized SERS performance. By detecting the molecules to be tested in extreme acid and alkaline environments such as fuming nitric acid and sodium hydroxide, it is shown that the SERS substrate material has a highly sensitive detection effect and excellent material stability. By detecting the synthesis process of explosives under acidic conditions, the application potential of the SERS substrate for process detection in extreme environments is demonstrated. BRIEF DESCRIPTION OF THE DRAWINGS
[0025] Figure 1 This is the XRD diagram of oxygen-rich titanium dioxide material;
[0026] Figure 2 This is the SEM image of oxygen-rich titanium dioxide material;
[0027] Figure 3 The oxygen-rich titanium dioxide materials with different heat treatment temperatures are 10 -4 M 4-MBA Raman response;
[0028] Figure 4 Heat treatment temperature of 400℃ for oxygen-rich titanium dioxide material -3 ~10 -8 M 4-MBA Raman response;
[0029] Figure 5 This is the XRD diagram of oxygen-rich titanium dioxide material after being immersed in an extreme acid-base environment;
[0030] Figure 6 The oxygen-rich titanium dioxide material was immersed in an acid-base extreme environment for 10 -4 Raman response of M 4-MBA.
[0031] Figure 7 This is the Raman response of oxygen-rich titanium dioxide material to substances at different stages of nitration reaction. DETAILED DESCRIPTION
[0032] In order to make the objectives, technical solutions and advantages of the present invention clearer, the implementation method of the present invention will be described in detail below in conjunction with the accompanying drawings and embodiments, so that the implementation process of how the present invention applies technical means to solve technical problems and achieve technical effects can be fully understood and implemented accordingly.
[0033] In the following description, many specific details are set forth to facilitate a full understanding of the present invention. However, the present invention may also be implemented in other ways different from those described herein. Therefore, the protection scope of the present invention is not limited to the specific embodiments disclosed below.
[0034] Example 1
[0035] Preparation method of oxygen-rich titanium dioxide material:
[0036] Add 5.5 mL of tetrabutyl titanate to 150 mL of deionized water, and a white precipitate of hydrolysis is immediately produced. After stirring for 60 minutes, the hydrolyzate is collected by washing and centrifugation. Then 80 mL of hydrogen peroxide (30%) is added to dissolve the hydrolyzate to form a peroxy titanate complex. The solution is heated at 50°C for 3 hours to gel, and then dried in an air drying oven at 100°C for 6 hours to obtain a yellow solid substance, which is finally calcined at 400°C in a muffle furnace for 2 hours to form a nanocrystalline oxygen-rich titanium dioxide material. Figure 1 , 2 are the XRD characterization and SEM characterization of oxygen-rich titanium dioxide materials respectively.
[0037] Example 2
[0038] Using 4-MBA as the probe molecule, the SERS detection effect of oxygen-rich titanium dioxide material:
[0039] 4-MBA dissolved in ethanol solution was used as a probe molecule, and oxygen-rich titanium dioxide materials with different heat treatments were immersed in 4-MBA ethanol solution (1 mL) for a period of time. Then, the substrate was removed from the solvent, dried under ambient conditions, and SERS analysis was performed. Raman spectra were collected on a Renishaw inVia Raman microscope. The excitation wavelength was 532nm, and the laser beam was focused using a Leica objective with a magnification of 20 times. A grating of 1800 lines / mm was used, and the spectral resolution was 1cm -1 The spectrum acquisition time was 10 s, and the laser power was kept at 15 mW in all acquisitions. Figure 3 The difference in SERS performance of oxygen-rich titanium dioxide materials with different heat treatments under the same concentration of probe molecules is shown. Figure 4 Showing 10 -3 ~10 -8SERS performance of oxygen-rich titanium dioxide material heat-treated at 400℃ under the probe molecule concentration of M.
[0040] Example 3
[0041] Using 4-MBA as the probe molecule, the SERS detection effect of oxygen-rich titanium dioxide material in extreme environments:
[0042] The oxygen-rich titanium dioxide material sample heat-treated at 400°C was immersed in 5M HCl, HNO3 and NaOH solutions, left to stand for 6 hours, centrifuged and cleaned, and then subjected to SERS testing to characterize the acid and alkali resistance of the sample. Figure 5 The XRD characterization of the samples before and after acid and alkali immersion shows that the structure has not changed. Finally, a Renishaw inVia Raman microscope was used to obtain 10 -4 SERS signal of 4-MBA molecules at M concentration on oxygen-rich titanium dioxide material after acid and alkali immersion ( Figure 6 ), which is not much different from the SERS signal of the freshly prepared sample, indicating the excellent stability of the prepared material under extreme environments.
[0043] Example 4
[0044] The detection effect of the nitric acid nitration synthesis NTO process based on oxygen-rich titanium dioxide material:
[0045] First, 1g of TO was dissolved in 5mL of nitric acid (concentration of 80%) in an ice bath and heated to 40°C for nitration. 0.1mL of the reaction stock solution was taken at different times of the nitration reaction and mixed with the oxygen-rich titanium dioxide material heat-treated at 400°C. The substrate was then removed and dried for SERS testing. Raman spectra were collected on a Renishaw inVia Raman microscope. Figure 7 The Raman response of oxygen-rich titanium dioxide material to substances in the sample solution is shown at different reaction stages (5, 14, 16, and 20 min). As the reaction progresses, TO is gradually converted into NTO, which is manifested in the gradual enhancement of the -NO2 characteristic peaks corresponding to NTO at 1331 cm-1 and 1359 cm-1 in the spectrum.
[0046] Although the present invention is described herein with reference to the illustrative embodiments of the present invention, the above embodiments are only preferred embodiments of the present invention, and the embodiments of the present invention are not limited to the above embodiments. It should be understood that those skilled in the art can design many other modifications and embodiments, which will fall within the scope and spirit of the principles disclosed in this application.
Claims
1. A method for preparing an oxygen-rich semiconductor titanium dioxide material, characterized in that: The steps include: Step S1, weighing tetrabutyl titanate and adding it to deionized water, stirring it in an ice bath for a period of time, collecting the hydrolysis product by washing and centrifugation; adding an oxidant to dissolve the hydrolysis product to form a peroxide titanate complex; heating the solution to gel it, and heating it in an air drying oven to obtain a solid; and finally calcining it in a muffle furnace to form an oxygen-rich titanium dioxide material; Step S2, immersing the oxygen-rich titanium dioxide material in an ethanol solution of a 4-mercaptobenzoic acid (4-MBA) analyte; then, removing the substrate from the solvent and drying it under ambient conditions; using a Renishaw inVia Raman microspectrometer to collect Raman signals, with a laser emission wavelength of 532 nm; Step S3, immersing the oxygen-rich titanium dioxide material in an acidic or alkaline solution, centrifugally cleaning, and then performing a SERS test to characterize the acid and alkali resistance of the sample; Step S4, immersing the oxygen-rich titanium dioxide material in a stock solution of nitric acid nitrating 1,2,4-triazole-5-one to generate 3-nitro-1,2,4-triazole-5-one, and collecting Raman signals using a Renishaw inVia Raman microspectrometer with a laser emission wavelength of 532 nm.
2. The method for preparing an oxygen-rich semiconductor titanium dioxide material according to claim 1, characterized in that: The volume ratio of tetrabutyl titanate: deionized water: oxidant is 1: (20-30): (10-20).
3. The method for preparing an oxygen-rich semiconductor titanium dioxide material according to claim 2, characterized in that: The oxidant is any one of sulfuric acid and hydrogen peroxide.
4. The method for preparing an oxygen-rich semiconductor titanium dioxide material according to claim 3, characterized in that: The ice bath temperature is 1-5°C, and the stirring time is 0.5-3h.
5. The method for preparing an oxygen-rich semiconductor titanium dioxide material according to claim 4, characterized in that: The solvent is heated to gelation temperature of 40-80°C for 1-5 hours; the air drying oven is heated to 80-150°C for 4-12 hours.
6. The method for preparing an oxygen-rich semiconductor titanium dioxide material according to claim 5, characterized in that: The muffle furnace calcination temperature is 300-600° C., and the insulation time is 1-4 hours.
7. The method for preparing an oxygen-rich semiconductor titanium dioxide material according to claim 6, characterized in that: The acidic or alkaline solution is any one of HCl, HNO3 or NaOH.
8. The method for preparing an oxygen-rich semiconductor titanium dioxide material according to claim 7, characterized in that: The concentration of the acidic or alkaline solution is 1 to 10 M, and the soaking time is 1 to 12 hours.
9. The method for preparing an oxygen-rich semiconductor titanium dioxide material according to claim 8, characterized in that: The nitric acid concentration is 60-90%, the reaction temperature is 30-60° C., the amount of nitric acid used is 1-10 mL, and the amount of 1,2,4-triazole-5-one used is 1-5 g.