TWI816337B - Ozone sensing component - Google Patents

Abstract

An ozone sensing component includes a substrate and a reaction layer. The reaction layer is disposed on the substrate and includes an inorganic metal oxide. The inorganic metal oxide includes titanium dioxide and indium oxide, wherein the weight ratio of the titanium dioxide to the indium oxide ranges from 1:3 to 1:6. With such configuration, the user is able to efficiently and accurately obtain the ozone concentration in the environment at room temperature.

Description

Ozone sensing element

The invention relates to a gas sensing related device, in particular to an ozone sensing element.

Generally, ozone sensors are divided into semiconductor type, electrochemical type and thermal conductivity type. Among them, semiconductor type sensors are more suitable for civil gas detection due to their small size and low cost. The sensing principle of the semiconductor sensor is: after heating the metal oxide semiconductor, the defects on the surface of the material are used to allow the gas in the environment to adsorb to the surface of the material, causing the surface resistance of the material to change, and the ratio of the change is converted Obtain the concentration of the gas to be measured.

However, the sensitivity of existing semiconductor ozone sensors is extremely poor, and the signal response and recovery time is long. The time required for sensing is as long as tens of minutes, because ozone gas in the environment is always present. Due to changes in the environment, the ozone concentration sensed by existing semiconductor ozone sensors is difficult to be representative and cannot provide immediate early warning of harmful gases.

In addition, semiconductor ozone sensors need to heat the sensing element during the sensing process, and the sensing temperature is usually higher than 250°C or even as high as 400°C. In addition to the operational risks of long-term high-temperature detection, The packaging process of this kind of sensing element also has high heat resistance requirements for the outer packaging material, which invisibly increases the packaging cost.

The main purpose of the present invention is to provide an ozone sensing element that can quickly obtain highly accurate ozone concentration detection results at room temperature.

To achieve the above object, one embodiment of the present invention provides an ozone sensing element, which includes: a substrate and a reaction layer; the reaction layer is provided on the substrate, the reaction layer includes an inorganic metal oxide, and the inorganic metal oxide includes titanium dioxide. and indium oxide, wherein the weight ratio of the titanium dioxide to the indium oxide is 1:3 to 1:6.

In another embodiment of the present invention, the weight ratio of the titanium dioxide and the indium oxide of the inorganic metal oxide is 1:4.5 to 1:5.5.

In another embodiment of the present invention, the reaction layer further includes a coating agent.

In another embodiment of the present invention, the coating agent is polyphthalamide, tetrabutyl titanate, polyvinyl alcohol, stannous octoate, ethyl cellulose, Triton X-100, titanium tetraisopropoxide , ethanol, deionized water, isopropyl alcohol, tin chloride, stannous chloride or one or a combination thereof.

In another embodiment of the present invention, the thickness of the reaction layer is 25 ± 5µm, and the thickness of the substrate is 0.1cm.

In another embodiment of the present invention, the material of the substrate is alumina, ITO glass or FTO glass.

In another embodiment of the present invention, there is an electrode layer provided on the substrate. The electrode layer includes a first electrode and a second electrode. The first electrode and the second electrode respectively have a detection part and a connection part. .

In another embodiment of the present invention, the detection portions of the first electrode and the second electrode are generally comb-shaped and interlaced with each other.

In another embodiment of the present invention, the material of the detection portion of the first electrode and the second electrode is gold.

In another embodiment of the present invention, the material of the connecting portion of the first electrode and the second electrode is platinum.

In this way, the ozone sensing element of the present invention allows users to detect ozone without the need to heat the detection chip. In addition to saving the cost of chip packaging that requires high heat resistance, it has extremely high detection sensitivity for ozone. It can quickly and accurately obtain the ozone concentration in the environment.

In order to facilitate the explanation of the central idea of the present invention expressed in the above summary column, specific embodiments are hereby expressed. Various objects in the embodiments are drawn according to proportions, sizes, deformations or displacements suitable for illustration, rather than according to the proportions of actual components, and are explained first.

Please refer to Figures 1 to 9b. The present invention provides an ozone sensing element 100. Figure 1 is a schematic diagram of the appearance of the ozone sensing element 100 of the present invention; Figure 2 is a structural exploded schematic diagram of the ozone sensing element 100; Figures 3a to Figures 9b is a schematic diagram of the resistance signal of the ozone sensing element 100 of the present invention using different weight ratios of titanium dioxide and indium oxide for ozone detection, and a comparison diagram between the ozone sensing element 100 and a commercially available semiconductor ozone sensor.

In this embodiment, the ozone sensing element 100 can cooperate with a detection device to measure the resistance change on the surface of the ozone sensing element 100 by illuminating light to detect the concentration of ozone (O ₃ ) in the environment; in this embodiment , the detection device is the PR10 data acquisition system.

The ozone sensing element 100 includes a substrate 10 and a reaction layer 20 . The reaction layer 20 is disposed on the substrate 10 .

In this embodiment, the material of the substrate 10 is aluminum oxide (Al ₂ O ₃ ), ITO glass or FTO glass; in this embodiment, the substrate 10 is generally rectangular, with a length of 1 cm and a width of 0.5 cm. The thickness of the substrate 10 is 0.1 cm.

The reaction layer 20 includes an inorganic metal oxide 21 and a coating agent 22. The reaction layer 20 is generally square, the length and width of the reaction layer 20 are 0.5cm, and the thickness of the reaction layer 20 is 25 ± 5µm.

In this embodiment, when detecting ozone, a UV-Visible LED with a spectral range of 385 to 425 nanometers is used to illuminate the reaction layer 20 to give the inorganic metal oxide 21 material energy, so that the electrons of the inorganic metal oxide 21 material Separate from the electric holes and apply a working voltage of 2V to the reaction layer 20 with a detection device, the surface resistance change of the reaction layer 20 can be measured at room temperature without heating the reaction layer 20, and further The resistance signal undergoes differential processing to obtain changes in the concentrated part of ozone.

The inorganic metal oxide 21 includes titanium dioxide (TiO ₂ ) and indium oxide (In ₂ O ₃ ); in this embodiment, the weight ratio of titanium dioxide to indium oxide is between 1:3 and 1:6, in which titanium dioxide and indium oxide are The optimal ratio of indium oxide is 1:5.

The coating agent 22 is used to tightly bond titanium dioxide and indium oxide; in this embodiment, the coating agent 22 is polyphthalamide (PPA, Polyphthalamide), tetrabutyl titanate (C ₁₆ H ₃₆ O ₄ Ti), polyvinyl alcohol ((C ₂ H ₄ O)x), stannous octoate (C ₁₆ H ₃₀ O ₄ Sn), ethyl cellulose ((C ₁₂ H ₂₂ O ₅ )n), Triton X-100 (C14H ₂₂ O(C ₂ H ₄ O) _n ( _n = _9-10 )), titanium tetraisopropoxide (Ti{OCH(CH₃)₂}₄), ethanol (C ₂ H ₅ OH), deionized water (Deionized Water), isopropyl alcohol (C ₃ H ₈ O), tin chloride (SnCl ₄ ), stannous chloride (SnCl ₂ ), or one or a combination thereof.

As shown in FIGS. 1 to 2 , in this embodiment, the ozone sensing element 100 further includes an electrode layer 30 , wherein the electrode layer 30 is disposed on the substrate 10 and between the substrate 10 and the reaction layer 20 . The reaction layer 20 is provided on the electrode layer 30; the substrate 10 can be inserted into the slot of the detection device to electrically connect the ozone sensing element 100 with the detection device. The electrode layer 30 is formed on the substrate 10 through screen printing to connect the reaction. Layer 20 and the internal detection circuit of the detection device.

The electrode layer 30 includes a first electrode 31 and a second electrode 32, wherein the first electrode 31 and the second electrode 32 respectively have a detection part T and a connection part C, wherein the first electrode 31 and the second electrode 32 The detection parts T are generally comb-shaped and interlaced (as shown in Figure 2). One end of the detection part T is connected to the reaction layer 20, and the other end is connected to the connection part C. When the substrate 10 is inserted into the slot of the detection device , the ozone sensing element 100 can be connected to the internal detection circuit of the detection device through the connection portion C to form a detection loop; in this embodiment, the reaction layer 20 is provided at the detection portion T of the first electrode 31 and the second electrode 32 .

In this embodiment, the material of the detection portion T of the first electrode 31 and the second electrode 32 is gold (Au); the material of the connecting portion C of the first electrode 31 and the second electrode 32 is platinum (Pt); where, In this embodiment, gold is used as the material of the detection part T, which can effectively improve the conductivity of the ozone sensing element 100 to enhance detection signal transmission.

It is further explained that the weight ratio of titanium dioxide and indium oxide in the inorganic metal oxide 21 will have different effects on the detection of ozone. In this embodiment, the inorganic metal oxide 21 with different weight ratios of titanium dioxide and indium oxide is used to detect ozone and obtain the resistance. changes, and further compare the concentration detection results after signal processing with a commercially available semiconductor ozone sensor (2B Technologies, Model 202). The experimental data are shown in Figure 3a to Figure 9b:

As shown in Figures 3a to 3b, Figure 3a is a schematic diagram of the resistance signal of an inorganic metal oxide 21 with a weight ratio of titanium dioxide to indium oxide of 1:1; Figure 3b is a schematic diagram of an inorganic metal with a weight ratio of titanium dioxide to indium oxide of 1:1. Comparison diagram between oxide 21 and commercially available semiconductor ozone sensors; during the detection process, ozone is introduced into the detection environment every 500 seconds. Among them, a detection curve of the ozone sensing element 100 can be observed in Figure 3a S, the detection device samples the ozone sensing element 100 once every second to form the detection curve S, and then performs differential processing on the detection curve S to convert the detection curve S into the concentration curve S' of Figure 3b, and then Compare with the concentration signal P of a commercially available semiconductor ozone sensor.

It can be observed from the comparison results in Figure 3b that the concentration curve S' obtained by the inorganic metal oxide 21 with a weight ratio of titanium dioxide and indium oxide of 1:1 is noisy and has no response to the introduction of ozone. Compared with The concentration signal P of the commercially available semiconductor ozone sensors does not show a good detection effect.

As shown in Figures 4a to 4b, Figure 4a is a schematic diagram of the resistance signal of an inorganic metal oxide 21 with a weight ratio of titanium dioxide to indium oxide of 1:2; Figure 4b is a schematic diagram of an inorganic metal with a weight ratio of titanium dioxide to indium oxide of 1:2. Comparison diagram between oxide 21 and commercially available semiconductor ozone sensors; during the detection process, ozone is introduced into the detection environment every 500 seconds. Among them, a detection curve of the ozone sensing element 100 can be observed in Figure 4a S, the detection device samples the ozone sensing element 100 once every second to form the detection curve S, and then performs differential processing on the detection curve S to convert the detection curve S into the concentration curve S' of Figure 4b, and then Compare with the concentration signal P of a commercially available semiconductor ozone sensor.

It can be observed from the comparison results in Figure 4b that the concentration curve S' obtained for the inorganic metal oxide 21 with a weight ratio of titanium dioxide and indium oxide of 1:2 is also noisy. Although there is some slight response to the introduction of ozone, Compared with the concentration signal P of commercially available semiconductor ozone sensors, it does not show better detection results.

As shown in Figures 5a to 5b, Figure 5a is a schematic diagram of the resistance signal of an inorganic metal oxide 21 with a weight ratio of titanium dioxide to indium oxide of 1:3; Figure 5b is a schematic diagram of an inorganic metal with a weight ratio of titanium dioxide to indium oxide of 1:3. Comparison diagram between oxide 21 and commercially available semiconductor ozone sensors; during the detection process, ozone is introduced into the detection environment every 500 seconds. Among them, a detection curve of the ozone sensing element 100 can be observed in Figure 5a S, the detection device samples the ozone sensing element 100 once every second to form the detection curve S, and then performs differential processing on the detection curve S to convert the detection curve S into the concentration curve S' of Figure 5b, and then Compare with the concentration signal P of a commercially available semiconductor ozone sensor.

It can be observed from the comparison results in Figure 5b that the concentration curve S' obtained for the inorganic metal oxide 21 with a weight ratio of titanium dioxide and indium oxide of 1:3 is better for the introduction of ozone than a commercially available semiconductor ozone sensor. The concentration signal P of the detector shows a faster response.

As shown in Figures 6a to 6b, Figure 6a is a schematic diagram of the resistance signal of an inorganic metal oxide 21 with a weight ratio of titanium dioxide to indium oxide of 1:4; Figure 6b is a schematic diagram of an inorganic metal with a weight ratio of titanium dioxide to indium oxide of 1:4. Comparison diagram between oxide 21 and commercially available semiconductor ozone sensors; during the detection process, ozone is introduced into the detection environment every 500 seconds. Among them, a detection curve of the ozone sensing element 100 can be observed in Figure 6a S, the detection device samples the ozone sensing element 100 once every second to form the detection curve S, and then performs differential processing on the detection curve S to convert the detection curve S into the concentration curve S' of Figure 6b, and then Compare with the concentration signal P of a commercially available semiconductor ozone sensor.

It can be observed from the comparison results in Figure 6b that the concentration curve S' obtained for the inorganic metal oxide 21 with a weight ratio of titanium dioxide and indium oxide of 1:4 is better for the introduction of ozone than the commercially available semiconductor ozone sensor. The concentration signal P of the detector shows extremely fast response and detection sensitivity.

As shown in Figures 7a to 7b, Figure 7a is a schematic diagram of the resistance signal of an inorganic metal oxide 21 with a weight ratio of titanium dioxide to indium oxide of 1:5; Figure 7b is a schematic diagram of an inorganic metal with a weight ratio of titanium dioxide to indium oxide of 1:5. Comparison diagram between oxide 21 and commercially available semiconductor ozone sensors; during the detection process, ozone is introduced into the detection environment every 500 seconds. Among them, a detection curve of the ozone sensing element 100 can be observed in Figure 7a S, the detection device samples the ozone sensing element 100 once every second to form the detection curve S, and then performs differential processing on the detection curve S to convert the detection curve S into the concentration curve S' of Figure 7b, and then Compare with the concentration signal P of a commercially available semiconductor ozone sensor.

It can be observed from the comparison results in Figure 7b that the concentration curve S' obtained for the inorganic metal oxide 21 with a weight ratio of titanium dioxide and indium oxide of 1:5 is better for the introduction of ozone than a commercially available semiconductor ozone sensor. The concentration signal P of the detector shows extremely fast response and has the best detection sensitivity.

As shown in Figures 8a to 8b, Figure 8a is a schematic diagram of the resistance signal of an inorganic metal oxide 21 with a weight ratio of titanium dioxide to indium oxide of 1:6; Figure 8b is a schematic diagram of an inorganic metal with a weight ratio of titanium dioxide to indium oxide of 1:6. Comparison diagram between oxide 21 and commercially available semiconductor ozone sensors; during the detection process, ozone is introduced into the detection environment every 500 seconds. Among them, a detection curve of the ozone sensing element 100 can be observed in Figure 8a S, the detection device samples the ozone sensing element 100 once every second to form the detection curve S, and then performs differential processing on the detection curve S to convert the detection curve S into the concentration curve S' of Figure 8b, and then Compare with the concentration signal P of a commercially available semiconductor ozone sensor.

It can be observed from the comparison results in Figure 8b that the concentration curve S' obtained for the inorganic metal oxide 21 with a weight ratio of titanium dioxide and indium oxide of 1:6 is better for the introduction of ozone than the commercially available semiconductor ozone sensor. The concentration signal P of the detector shows extremely fast response and detection sensitivity.

As shown in Figures 9a to 9b, Figure 9a is a schematic diagram of the resistance signal of an inorganic metal oxide 21 with a weight ratio of titanium dioxide to indium oxide of 2:1; Figure 9b is an inorganic metal with a weight ratio of titanium dioxide to indium oxide of 2:1. Comparison diagram between Oxide 21 and commercially available semiconductor ozone sensors; during the detection process, ozone is introduced into the detection environment every 500 seconds. Among them, a detection curve of the ozone sensing element 100 can be observed in Figure 9a S, the detection device samples the ozone sensing element 100 once every second to form the detection curve S, and then performs differential processing on the detection curve S to convert the detection curve S into the concentration curve S' of Figure 9b, and then Compare with the concentration signal P of a commercially available semiconductor ozone sensor.

It can be observed from the comparison results in Figure 9b that the concentration curve S' obtained for the inorganic metal oxide 21 with a weight ratio of titanium dioxide and indium oxide of 2:1 is also noisy. Although there is some slight response to the introduction of ozone, Compared with the concentration signal P of commercially available semiconductor ozone sensors, it does not show better detection results.

From the test results of Figure 3a to Figure 9b, it can be observed that the concentration curve S' obtained by the inorganic metal oxide 21 with a weight ratio of titanium dioxide and indium oxide of 1:3 to 1:6 is much better than that of commercially available semiconductor ozone The concentration signal P of the sensor has a faster detection response time and shows better sensitivity. Among them, the inorganic metal oxide 21 with a weight ratio of titanium dioxide and indium oxide of 1:5 has the best ozone detection. Effect.

In summary, the ozone sensing element 100 of the present invention allows users to detect ozone at room temperature without operating in a high temperature environment. In addition to reducing the packaging cost of materials for the ozone sensing element 100, it can also save money. Overall detection energy consumption. In addition, through the weight ratio of titanium dioxide and indium oxide, it can quickly respond to ozone in the environment and obtain accurate ozone concentration.

The above embodiments are only used to illustrate the present invention and are not intended to limit the scope of the present invention. All modifications or changes that do not violate the spirit of the present invention fall within the scope of the invention.

100:Ozone sensing element 10:Substrate 20:Reaction layer 21:Inorganic metal oxides 22:Coating agent 30:Electrode layer 31: First electrode 32: Second electrode T:Testing Department C:Connection part S: detection curve S’: concentration curve P: concentration signal

Figure 1 is a schematic diagram of the appearance of the ozone sensing element of the present invention. Figure 2 is an exploded schematic diagram of the structure of the ozone sensing element of the present invention. Figure 3a is a schematic diagram (1) of a resistance signal according to an embodiment of the present invention, which is used to show the ozone detection results of an inorganic metal oxide with a weight ratio of titanium dioxide and indium oxide of 1:1. Figure 3b is a comparison diagram (1) between the embodiment of the present invention and a commercially available semiconductor ozone sensor. Figure 4a is a schematic diagram (2) of a resistance signal according to an embodiment of the present invention, which is used to show the ozone detection results of an inorganic metal oxide with a weight ratio of titanium dioxide and indium oxide of 1:2. Figure 4b is a comparison diagram (2) between the embodiment of the present invention and a commercially available semiconductor ozone sensor. Figure 5a is a schematic diagram (3) of a resistance signal according to an embodiment of the present invention, which is used to show the ozone detection results of an inorganic metal oxide with a weight ratio of titanium dioxide and indium oxide of 1:3. Figure 5b is a comparison diagram (3) between the embodiment of the present invention and a commercially available semiconductor ozone sensor. Figure 6a is a schematic diagram (4) of a resistance signal according to an embodiment of the present invention, which is used to show the ozone detection result of an inorganic metal oxide with a weight ratio of titanium dioxide and indium oxide of 1:4. Figure 6b is a comparison diagram (4) between the embodiment of the present invention and a commercially available semiconductor ozone sensor. Figure 7a is a schematic diagram (5) of a resistance signal according to an embodiment of the present invention, which is used to show the ozone detection results of an inorganic metal oxide with a weight ratio of titanium dioxide and indium oxide of 1:5. Figure 7b is a comparison diagram (5) between the embodiment of the present invention and a commercially available semiconductor ozone sensor. Figure 8a is a schematic diagram (6) of a resistance signal according to an embodiment of the present invention, which is used to show the ozone detection results of an inorganic metal oxide with a weight ratio of titanium dioxide and indium oxide of 1:6. Figure 8b is a comparison diagram (6) between the embodiment of the present invention and a commercially available semiconductor ozone sensor. Figure 9a is a schematic diagram (7) of a resistance signal according to an embodiment of the present invention, which is used to show the ozone detection result of an inorganic metal oxide with a weight ratio of titanium dioxide and indium oxide of 2:1. Figure 9b is a comparison diagram (7) between the embodiment of the present invention and a commercially available semiconductor ozone sensor.

100:Ozone sensing element

10:Substrate

20:Reaction layer

21:Inorganic metal oxides

22:Coating agent

30:Electrode layer

31: First electrode

32: Second electrode

T:Testing Department

C:Connection part

Claims (10)

An ozone sensing element including: a substrate; and A reaction layer is provided on the substrate. The reaction layer includes an inorganic metal oxide. The inorganic metal oxide includes titanium dioxide and indium oxide, wherein the weight ratio of the titanium dioxide to the indium oxide is 1:3 to 1 :6. The ozone sensing element according to claim 1, wherein the weight ratio of the titanium dioxide and the indium oxide of the inorganic metal oxide is 1:4.5 to 1:5.5. The ozone sensing element of claim 1, wherein the reaction layer further includes a coating agent. The ozone sensing element according to claim 3, wherein the coating agent is polyphthalamide, tetrabutyl titanate, polyvinyl alcohol, stannous octoate, ethyl cellulose, Triton X-100 , titanium tetraisopropoxide, ethanol, deionized water, isopropyl alcohol, tin chloride, stannous chloride or one or a combination thereof. The ozone sensing element as described in claim 1, wherein the thickness of the reaction layer is 25 ± 5µm, and the thickness of the substrate is 0.1cm. The ozone sensing element according to claim 1 or 5, wherein the material of the substrate is alumina, ITO glass or FTO glass. The ozone sensing element of claim 1 further has an electrode layer provided on the substrate. The electrode layer includes a first electrode and a second electrode, and the first electrode and the second electrode respectively have a detection part and a connection part. The ozone sensing element according to claim 7, wherein the detection portions of the first electrode and the second electrode are generally comb-shaped and interlaced with each other. The ozone sensing element according to claim 7, wherein the material of the detection portion of the first electrode and the second electrode is gold. The ozone sensing element according to claim 7, wherein the material of the connecting portion of the first electrode and the second electrode is platinum.