Wide-range temperature sensor and preparation method thereof

Abstract

The invention belongs to the technical field of temperature sensors, and particularly relates to a wide-range temperature sensor and a preparation method thereof. The method comprises the following specific steps: S1, transferring 1-50 ml of a SnO2 nanoparticle colloidal solution into a reaction container; dissolving 1, 4-benzene dithiol in ethanol to obtain a mixed solution, adding 100 [mu] l of the mixed solution into the reaction container to be mixed with the nanoparticle colloidal solution, and incubating in a water bath environment to form a modified compound; s2, sequentially centrifuging and washing the formed modified compound, and then dispersing the modified compound in 1mL of ethanol to obtain a modified SnO2 nanoparticle modification solution; and S3, dispensing the SnO2 nano-particle modification solution on a substrate with two electrodes to form a SnO2 nano-particle modification layer, and connecting the SnO2 nano-particle modification layer to a signal acquisition circuit through the electrodes to prepare the temperature sensor. The temperature sensor based on the SnO2 nano material modified by 1, 4-benzene dithiol can be suitable for monitoring in a wide temperature range.

Description

Technical Field

[0001] The present invention belongs to the field of temperature sensors, and in particular relates to a wide-range temperature sensor and a preparation method thereof. Background Art

[0002] Temperature, one of the most common physical quantities, characterizes the degree of heat or cold in an object. Temperature measurement is a widespread requirement in fields such as medicine, industry, and agriculture. Currently, temperature sensors often suffer from issues such as slow response speed, limited temperature monitoring range, and poor long-term stability in practical applications. Semiconductor materials typically possess excellent temperature-dependent electrical conductivity, but temperature sensors based on these materials have a narrow temperature sensing range. For example, the article Materials Science & Engineering, 1:M16–M31, 2009, shows that the temperature sensing range of copper oxide is only 20°C to 80°C, making this type of temperature sensor only suitable for conventional applications. However, many fields have higher requirements for sensor temperature response ranges, such as specialty gas storage, healthcare, aerospace, and superconductor or semiconductor material testing, all of which require temperature response in low-temperature environments. Clearly, existing semiconductor-based sensors cannot meet these requirements.

[0003] Therefore, the present invention provides a wide-range temperature sensor and a preparation method thereof to solve the above problems. Summary of the Invention

[0004] To overcome the above-mentioned shortcomings of the prior art, the present invention provides a wide-range temperature sensor and a method for preparing the same. The temperature sensor, based on 1,4-benzenedithiol-modified SnO2 nanomaterial, is suitable for monitoring a wide temperature range and exhibits high sensitivity and stability.

[0005] To achieve one of the above purposes, the present invention adopts the following technical solutions:

[0006] A method for preparing a wide-range temperature sensor comprises the following steps:

[0007] S1. Transfer 1-50 ml of SnO2 nanoparticle colloidal solution to a reaction vessel; dissolve 1,4-benzenedithiol in ethanol to obtain a mixed solution, take 100 μl of the mixed solution and add it to the reaction vessel to mix with the nanoparticle colloidal solution, and incubate in a water bath to form a modified complex;

[0008] S2, centrifuging and washing the formed modified complex in sequence, and then dispersing it in 1 mL of ethanol to obtain a modified SnO2 nanoparticle modification solution;

[0009] S3. Drop-coat the SnO2 nanoparticle modified solution on a substrate having two electrodes to form a SnO2 nanoparticle modified layer, and connect the electrodes to a signal acquisition circuit to obtain a temperature sensor.

[0010] Preferably, in step S3, the thickness of the SnO2 nanoparticle modification layer is 200 nm-10 μm.

[0011] Preferably, the mass fraction of the SnO2 nanoparticle colloidal solution is 0.1-5%.

[0012] Preferably, the concentration in the mixed solution is 10 mM-1 M.

[0013] Preferably, in step S1, the water bath temperature is 20-80°C, preferably 40°C.

[0014] Preferably, in step S2, the incubation time is 2-24 hours, preferably 24 hours.

[0015] Preferably, in step S2, the modified complex is centrifuged and washed with ethanol to remove excess 1,4-benzenedithiol at a speed of 5000-10000 rpm for 5-15 minutes.

[0016] To achieve the second of the above objectives, the present invention provides a wide-range temperature sensor, which includes a substrate on which a SnO2 nanoparticle modification layer is deposited, and two electrodes are provided on the substrate, and the two electrodes are connected on both sides of the SnO2 nanoparticle modification layer.

[0017] Preferably, the substrate is one of ceramic or glass.

[0018] The advantages of the present invention are:

[0019] (1) The temperature sensor based on 1,4-benzenedithiol-modified SnO2 nanomaterials of the present invention greatly broadens the temperature response range. The preparation process is simple and convenient for large-scale production.

[0020] (2) The present invention introduces a 1,4-benzenedithiol modification layer on the surface of SnO2 nanoparticles, so that the resistance of SnO2 nanoparticles modified with 1,4-benzenedithiol changes at different temperatures, significantly improving the temperature response sensitivity and response speed. By optimizing the interface modification, the temperature response sensitivity is improved, meeting the needs of multiple fields such as industry, environmental monitoring and scientific research.

[0021] (3) The present invention also has the following advantages:

[0022] 1. Interface modification enhancement effect: Through the chemical bonding between 1,4-benzenedithiol molecules and the surface of SnO2 nanoparticles, the electron transport properties are improved and the temperature response sensitivity is increased.

[0023] 2. Expand the temperature monitoring range: Optimize the modified layer structure to enable the sensor to exhibit excellent temperature response characteristics in the range of extremely low to high temperatures.

[0024] 3. Improve stability and repeatability: Through reasonable material design, the sensor's anti-aging ability is enhanced to achieve long-term reliable operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 This is an SEM image of thiol-modified tin oxide nanoparticles of the present invention.

[0026] Figure 2 It is a structural schematic diagram of the present invention.

[0027] Figure 3 Response curves of the temperature sensor of the present invention under different temperature conditions (-150°C to +150°C).

[0028] The meanings of the symbols in the figure are as follows:

[0029] 1-substrate, 2-electrode, 3-SnO2 nanoparticle modification layer. DETAILED DESCRIPTION

[0030] A wide-range temperature sensor includes a ceramic substrate 1 on which a 200nm-10μm SnO2 nanoparticle modification layer 3 is deposited. Two electrodes 2 are provided on the substrate 1, and two electrodes 2 are connected to each other on both sides of the SnO2 nanoparticle modification layer 3.

[0031] A method for preparing a wide-range temperature sensor, the specific steps are as follows:

[0032] The purchased 1-50ml SnO2 nanoparticle colloidal solution is reacted with a 1,4-benzenedithiol solution (concentration of 10mM-1M) pre-dissolved in ethanol at 20-80°C for 2-24 hours to allow the 1,4-benzenedithiol molecules to adsorb on the surface of the SnO2 nanoparticles to form a modified complex; subsequently, the excess 1,4-benzenedithiol is removed by centrifugation and multiple washings with ethanol, and then dispersed in an ethanol solution for later use. The scanning electron microscope photo of the modified SnO2 nanoparticles is shown below. Figure 1 As shown, it can be seen that the SnO2 nanoparticles are in the form of nanoparticles. Finally, the modified SnO2 nanoparticles are combined with the substrate 1 material and connected to the signal acquisition circuit through the electrode 2 to prepare a temperature sensor.

[0033] Example 1

[0034] 1. Transfer 1ml of the purchased SnO2 nanoparticle colloidal solution to the reaction vessel and add 100ul of pre-dissolved SnO2 nanoparticles in ethanol for 10 -4 M of 1,4-benzenedithiol solution to obtain a mixed solution;

[0035] 2. Place the mixture in a 40°C water bath to react for 24 hours to ensure that 1,4-benzenedithiol is fully adsorbed on the surface of SnO2 nanoparticles and forms a stable modification layer through SnO2 sulfur bonds;

[0036] 3. After the reaction is completed, centrifugation and multiple washing steps are used to remove unbound 1,4-benzenedithiol, and then dispersed in 1 ml of ethanol solution to obtain functionalized SnO2 nanoparticle modification solution.

[0037] 4. The modified SnO2 nanoparticle modified solution obtained in step S3 is evenly applied on the ceramic substrate 1 and connected to the signal acquisition circuit through the electrode 2 to prepare a temperature sensor.

[0038] 5. Using the resistance change test method, the resistance response of the temperature sensor in a wide temperature range (-150℃ to +150℃) is tested. The results are as follows: Figure 3 shown.

[0039] Depend on Figure 3 The test results show that the sensor can respond from -150℃ to +150℃ and is suitable for monitoring in a wide temperature range.

[0040] In addition, the present invention uses 1,4-benzenedithiol to modify the surface of SnO2 nanoparticles, which significantly improves the temperature response sensitivity and response speed; the preparation process is simple and easy to scale production; the prepared sensor shows excellent stability and repeatability in a wide temperature range.

[0041] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A method for preparing a wide-range temperature sensor, characterized in that: The steps include: S1. Transfer 1-50 ml of SnO2 nanoparticle colloidal solution to a reaction vessel; dissolve 1,4-benzenedithiol in ethanol to obtain a mixed solution, take 100 μl of the mixed solution and add it to the reaction vessel to mix with the SnO2 nanoparticle colloidal solution, and incubate in a water bath to form a modified complex; S2, centrifuging and washing the formed modified complex in sequence, and then dispersing it in 1 mL of ethanol to obtain a modified SnO2 nanoparticle modification solution; S3. Drop-coat the SnO2 nanoparticle modified solution on a substrate (1) having two electrodes (2) to form a SnO2 nanoparticle modified layer (3), and connect the signal acquisition circuit through the electrodes (2) to obtain a temperature sensor.

2. The method for preparing a wide-range temperature sensor according to claim 1, wherein: In step S3, the thickness of the SnO2 nanoparticle modification layer (3) is 200nm-10μm.

3. The method for preparing a wide-range temperature sensor according to claim 1, wherein: The mass fraction of the SnO2 nanoparticle colloidal solution is 0.1-5%.

4. The method for preparing a wide-range temperature sensor according to claim 1, wherein: The concentration of the mixed solution is 10mM-1M.

5. The method for preparing a wide-range temperature sensor according to claim 1, wherein: In step S1, the water bath temperature is 20-80°C.

6. The method for preparing a wide-range temperature sensor according to claim 1, wherein: In step S2, the incubation time is 2-24 hours.

7. The method for preparing a wide-range temperature sensor according to claim 1, wherein: In step S2, the modified complex is washed by centrifugation using ethanol at a speed of 5000-10000 rpm for 5-15 minutes.

8. A wide-range temperature sensor prepared using the preparation method according to claims 1-7, characterized in that: The sensor comprises a substrate (1), a SnO2 nanoparticle modified layer (3) is deposited on the substrate (1), two electrodes (2) are provided on the substrate (1), and the two electrodes (2) are connected to each other on both sides of the SnO2 nanoparticle modified layer (3).

9. The wide-range temperature sensor according to claim 8, characterized in that: The substrate (1) is made of ceramic or glass.

10. The wide-range temperature sensor according to claim 8, characterized in that: The electrode (2) is a gold electrode.

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