阅读说明：本技术 一种色彩与电导的双模气体传感装置及其制备和使用方法 (Color and conductance dual-mode gas sensing device and preparation and use methods thereof ) 是由 鲍皓明 张洪文 崔锡荣 蔡伟平 于 2021-08-11 设计创作，主要内容包括：本发明属于气体检测领域,具体涉及一种色彩与电导的双模气体传感装置及其制备和使用方法。该传感装置由陶瓷加热片以及附着在陶瓷加热片上的金属氧化物薄膜组成,陶瓷加热片的两端均设置有金电极和导线,电导检测装置连接所述导线用于采集金属氧化物薄膜的电导率变化；金属氧化物薄膜上还设置有颜色探测器,光谱检测装置连接颜色探测器,用于分析和采集金属氧化物薄膜的光学吸收谱。本发明通过电导检测结果结合颜色变化的检测判断,使本发明提供的传感装置及检测方法既具有较高的检测能力,同时还具有可视化监测的效果,可以在不同气体环境检测中广泛应用。(The invention belongs to the field of gas detection, and particularly relates to a color and conductance dual-mode gas sensing device and a preparation and use method thereof. The sensing device consists of a ceramic heating sheet and a metal oxide film attached to the ceramic heating sheet, wherein both ends of the ceramic heating sheet are provided with a gold electrode and a lead, and a conductivity detection device is connected with the lead and is used for collecting the conductivity change of the metal oxide film; the metal oxide film is also provided with a color detector, and the spectrum detection device is connected with the color detector and used for analyzing and collecting the optical absorption spectrum of the metal oxide film. According to the invention, the conductivity detection result is combined with the detection and judgment of the color change, so that the sensing device and the detection method provided by the invention have high detection capability and a visual monitoring effect, and can be widely applied to detection of different gas environments.)

1. A color and conductance dual-mode gas sensing device is characterized by comprising a ceramic heating sheet (10) and a metal oxide film (11) attached to the ceramic heating sheet (10), wherein both ends of the ceramic heating sheet (10) are provided with electrodes (20) and leads (21), and a conductance detection device (22) is connected with the leads (21) and is used for collecting the conductivity change of the metal oxide film (11); the metal oxide thin film (11) is further provided with a color detector (30), and a spectrum detection device (31) is connected with the color detector (30) and used for analyzing and collecting the optical absorption spectrum of the metal oxide thin film (11).

2. A color and conductance dual mode gas sensor device according to claim 1, wherein said metal oxide in said metal oxide film (11) is any one of titanium dioxide, tin dioxide, zinc oxide, cerium oxide or ferric oxide.

3. The dual-mode gas sensing device of color and conductance according to claim 2, wherein the thickness of said metal oxide film (11) is 100-5000 nm.

4. A method of manufacturing a sensing device according to claim 1, comprising the steps of:

s1, mixing metal oxide nano powder with deionized water according to a mass ratio of (1: 10) - (1: 100), and fully performing ultrasonic treatment in an ultrasonic pool until a uniform colloidal solution is formed;

s2, 0.1-1mL of colloidal solution is dropwise added on a clean ceramic heating sheet (10), and the colloidal solution is uniformly coated on the ceramic heating sheet (10);

s3, after drying the spin-coated colloidal solution, repeating the step S2 for 2-5 times to obtain the ceramic heating sheet (10) with the metal oxide film (11);

s4, physically sputtering and depositing electrodes (20) at two ends of the ceramic heating sheet (10) prepared in the step S3, connecting a lead (21) on the electrodes (20), and arranging a color detector (30) on the metal oxide film (11);

and S5, connecting a lead (21) with a conductivity detection device (22), and connecting a spectrum detection device (31) with the color detector (30) to form the color and conductivity dual-mode gas sensing device.

5. The method according to claim 4, wherein the metal oxide nanopowder has a particle diameter of 5-200 nm.

6. The method according to claim 4, wherein in S2, a spin coater is used for coating, and the spin speed of the spin coater is 10-200 r/min.

7. The method of claim 4, wherein the conductivity detector (22) is a gas sensitive detector, the color detector (30) is for collecting light from the metal oxide film (11), and the spectral detector (31) is a spectrometer.

8. A method for gas detection using the sensing device of claim 1, wherein the dual mode monitoring is accomplished by placing the ceramic heating plate (10) with the metal oxide thin film (11) attached thereto in the target gas environment to be detected, adjusting the operating temperature of the ceramic heating plate (10) to a set temperature within the range of 50-400 ℃, turning on the conductance detecting device (22), the color detector (30) and the spectrum detecting device (31) and recording the optical absorption spectrum and the conductivity change of the metal oxide thin film (11).

9. The method for gas detection according to claim 8, wherein the target gas for detection is a reducing gas.

10. The method for gas detection according to claim 9, wherein the gas is any one of an alcohol gas, an aldehyde gas, a hydrocarbon gas, a thiol gas, hydrogen sulfide, or hydrogen gas.

Technical Field

The invention belongs to the field of gas detection, and particularly relates to a color and conductance dual-mode gas sensing device and a preparation and use method thereof.

Background

The high-efficiency monitoring of the gas has important significance for public safety and social production. An efficient gas sensor should have fast response, high sensitivity, high accuracy, etc. However, the current major technologies have difficulty in satisfying these requirements at the same time.

For example, a representative conductivity type gas sensing technology can achieve high sensitivity, quick response and the like, but the conductivity type sensing method depends on electrical measurement, cannot work once a circuit fails, and cannot guarantee safety for a monitoring and early warning system. In addition, some sensing methods that utilize color change, such as the gasochromic technique, while not relying on electrical measurements, facilitate visual monitoring. However, the single sensing method has low accuracy and reliability is still to be improved.

Disclosure of Invention

The invention provides a monitoring technology which can simultaneously realize the dual-mode response of color and conductance of gas on the same thin film device in order to overcome the defects in the prior art.

The invention adopts the following technical scheme:

the invention firstly provides a color and conductance dual-mode gas sensing device, which consists of a ceramic heating sheet and a metal oxide film attached to the ceramic heating sheet, wherein both ends of the ceramic heating sheet are provided with electrodes and leads, and a conductance detection device is connected with the leads and is used for collecting the conductivity change of the metal oxide film; the metal oxide film is also provided with a color detector, and the spectrum detection device is connected with the color detector and used for analyzing and collecting the optical absorption spectrum of the metal oxide film.

Preferably, the metal oxide in the metal oxide thin film is any one of titanium dioxide, tin dioxide, zinc oxide, cerium oxide or ferric oxide.

Preferably, the thickness of the metal oxide film is 100-5000 nm.

The ceramic heating plate is a commercial ceramic heating plate.

The invention further provides a method for preparing the color and conductance dual-mode gas sensing device, which comprises the following steps:

s1, mixing metal oxide nano powder with deionized water according to a mass ratio of (1: 10) - (1: 100), and fully performing ultrasonic treatment in an ultrasonic pool until a uniform colloidal solution is formed;

s2, 0.1-1mL of colloidal solution is dripped on a clean ceramic heating sheet, and the ceramic heating sheet is uniformly coated;

s3, after drying the spin-coated colloidal solution, repeating the step S2 for 2-5 times to obtain a ceramic heating sheet with a metal oxide film;

s4, physically sputtering and depositing electrodes at two ends of the ceramic heating sheet prepared in the step S3, connecting a lead to the electrodes, and arranging a color detector on the metal oxide film;

and S5, connecting the lead with a conductivity detection device, and connecting a spectrum detection device on the color detector to form the color and conductivity dual-mode gas sensing device.

Preferably, the particle diameter of the metal oxide nano powder is 5-200 nm.

Preferably, in S2, the spin coater is used for coating, and the spin speed of the spin coater is 10 to 200 r/min.

Preferably, the electrode is a gold electrode.

Preferably, the conductivity detection device is a gas-sensitive detector, and the spectrum detection device is a spectrometer.

The color detector can collect light from the metal oxide thin film and pass it to a spectrometer, which analyzes the light. The color detector can also be used together with a colorimeter or a spectrocolorimeter to directly obtain color information.

The invention finally provides a method for gas detection by using the color and conductance dual-mode gas sensor, which comprises the following steps: placing the ceramic heating sheet attached with the metal oxide film in a target gas environment to be detected, adjusting the working temperature of the ceramic heating sheet to be a certain set temperature within the range of 50-400 ℃ and keeping unchanged, starting a conductivity detection device, a color detector and a spectrum detection device, recording the optical absorption spectrum and the conductivity change of the metal oxide film, and completing the dual-mode monitoring.

Preferably, the target gas for detection is a reducing gas.

Preferably, the gas is an alcohol gas, an aldehyde gas, a hydrocarbon gas, a thiol gas, hydrogen sulfide or hydrogen gas.

The invention has the beneficial effects that:

the film detection device is formed by spin-coating the metal oxide on the ceramic heating plate, the preparation method is simple, and the preparation cost is low. The metal oxide acts with the target gas at a certain temperature, so that the characteristics of dual-mode monitoring of conductance change and color change can be realized simultaneously.

The films applied to the gasochromic technology in the prior art are often specialized and cannot be used for detecting color and conductivity simultaneously. The oxide film of the invention can simultaneously meet the two detection requirements.

The dual-mode monitoring method can improve the reliability of monitoring and reduce the false alarm rate. Meanwhile, the stability of the system is improved. For example, when the conductance monitoring device breaks down, the spectrum detection device still can provide the monitoring state in real time, even under the condition that the total circuit breaks down, also can observe the oxide film color change of this application through naked eyes, the supplementary judgement.

The detection method provided by the invention has high detection capability and also has a visual monitoring effect by combining the conductivity detection result with the detection judgment of color change. Compared with the prior art that a gas detection device singly performs electrical measurement on conductance change or singly applies the detection application of a gasochromic technology, the sensing device and the detection method provided by the invention can be widely applied to detection of different gas environments.

Drawings

FIG. 1 is a schematic structural view of a gas sensor device according to the present invention;

FIG. 2 is a graph showing the change in the resistance of a titanium dioxide film in the present application in example 3;

FIG. 3 is a graph showing the change in the optical absorption spectrum of a titanium dioxide film in an environment according to example 3 of the present application, wherein the black curve is the optical absorption spectrum of a titanium dioxide film exposed to a target gas and the gray curve is the optical absorption spectrum of a titanium dioxide film not in contact with a target gas;

FIG. 4 is a graph showing the absorbance of a titanium dioxide film exposed to a target gas for light having a wavelength of 600nm as a function of time in example 3 of the present application.

The meanings of the reference symbols in the drawings are as follows:

10-ceramic heater chip 11-metal oxide thin film

20-electrode 21-lead 22-conductance detection device

30-color detector 31-spectral detection means.

Detailed Description

The technical scheme of the invention is more specifically explained by combining the following embodiments and comparative examples:

example 1:

as shown in fig. 1, a color and conductance dual mode gas sensing device includes a ceramic heater chip 10 and a metal oxide thin film 11 attached to the ceramic heater chip 10. The metal oxide film 11 is a titanium dioxide film, and both ends of the ceramic heating plate 10 are provided with an electrode 20 and a lead 21. The lead 21 is connected with a gas-sensitive detector, and a color detector 30 connected with a spectrometer is also arranged on the titanium dioxide film.

In this example, the thickness of the titanium dioxide film was 1 μm, the ceramic heating sheet 10 used in the commercial industry was 30 mm × 30 mm × 3 mm, and the electrode 20 was a gold electrode.

The gas-sensitive detector uses a commercial sensitive instrument such as a portable single-channel gas-sensitive tester (model ZWX-P1) of Nanjing intelligent microchip formula, and is used for collecting the conductance change of the titanium dioxide film; the color detector 30 is a spectrocolorimeter, and the color detector 30 may also transmit a portion of the light collected from the titanium dioxide film to a spectrometer, which collects an optical absorption spectrum of the titanium dioxide film using a UV-vis spectrometer.

Example 2

A method of making the sensing device of example 1, comprising the steps of:

s1, mixing 0.1g of anatase titanium dioxide nano-particle (p 25) powder with 5 mL of deionized water, and fully performing ultrasonic treatment in an ultrasonic pool until a uniform colloidal solution is formed;

s2, dripping 0.1mL of colloidal solution on a clean alumina ceramic heating plate 10, and carrying out spin coating at the working speed of a spin coater of 10-200 r/min;

s3, after drying the spin-coated colloidal solution, repeating the step S2 for 5 times to obtain the ceramic heating plate 10 with the titanium dioxide film, wherein the thickness of the prepared titanium dioxide film is 1 mu m;

s4, physically sputtering and depositing gold electrodes at two ends of the ceramic heating sheet 10 prepared in the step S3 by a covering method, respectively connecting conducting wires 21 on the gold electrodes, and arranging a color detector 30 on the titanium dioxide film;

and S5, connecting the leads 21 at two ends of the ceramic heating sheet 10 with the same gas-sensitive tester, and connecting the UV-vis spectrometer with the color detector 30 to form the color and conductivity dual-mode gas sensing device.

Example 3

The target gas was measured using the sensor of example 1, and the gas was ethanol vapor with a concentration of 100ppm, as follows:

s1, placing an alumina ceramic heating plate 10 attached with a titanium dioxide film in a target gas environment to be detected, setting the temperature of the ceramic heating plate 10 to be 200 ℃ through the heating function of the ceramic heating plate 10, and setting the working temperature of a sensing device to be 200 ℃;

and S2, starting the gas-sensitive tester, the color detector 30 and the UV-vis spectrometer, and recording the optical absorption spectrum and the conductivity change of the titanium dioxide film.

When the target gas appears in the environment, the color of the titanium dioxide film can be observed to change and gradually turn yellow.

In the embodiment, the change of the titanium dioxide film resistor in the monitoring process is shown in fig. 2, and the titanium dioxide film resistor can be seen to drop rapidly in about 200s, which indicates that target detection gas ethanol vapor appears in the environment; in the temperature of 200-650s, the resistance of the titanium dioxide film is slowly reduced, which indicates that the concentration of the target detection gas in the environment is kept constant or changes slightly; the resistance of the titania film gradually returns to a normal level around 650-750s, indicating that the target detection gas in the environment gradually dissipates.

The change of the optical absorption spectrum of the titanium dioxide film in the presence of ethanol gas in the environment is shown in FIG. 3, and it can be seen that when ethanol is present, the film exposed to ethanol gas has higher absorption in the visible light band (i.e. 400-800 nm) than the unexposed film, resulting in the change of color. Referring to the absorbance at a wavelength of 600nm, a time-dependent change in absorbance is obtained as shown in fig. 4, and it can be seen that the change in absorbance coincides with the time at which the change in resistance occurs.

The above embodiments are only used to illustrate the technical solutions of the present invention, and do not limit the present invention; although the present invention has been described in detail with reference to the foregoing embodiments, it will be understood by those skilled in the art that: any modification, equivalent replacement, and improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.