CN-116953034-B - Sequential logic gas sensor

Abstract

The invention provides a sequential logic type gas sensor, and relates to the technical field of sensors. The time sequence logic type gas sensor comprises a substrate electrode and a sensitive material layer coated on the surface of the substrate electrode, wherein the specific surface area of the sensitive material is more than or equal to 20m 2 /g, the sensitive material comprises semiconductor metal oxide, and the absolute value of theoretical adsorption energy between at least one semiconductor metal oxide in the sensitive material and gas molecules to be detected is more than or equal to 2.0eV. The sequential logic type gas sensor formed by the sequential logic type gas sensor has the functions of gas response and response signal memory, and can realize effective monitoring of intermittent low-concentration polluted gas.

Inventors

• LI XIAOWEI
• LIU YU
• JIANG XINGYUAN
• SHAO CHANGLU
• LI XINGHUA
• LIU YICHUN

Assignees

• 东北师范大学

Dates

Publication Date

20260505

Application Date

20230726

Claims (8)

1. 1. A time sequence logic type gas sensor comprises a substrate electrode and a sensitive material layer coated on the surface of the substrate electrode, wherein the specific surface area of the sensitive material is more than or equal to 20m 2 /g, the sensitive material comprises a composite semiconductor metal oxide, and the absolute value of theoretical adsorption energy between at least one semiconductor metal oxide in the sensitive material and gas molecules to be detected is more than or equal to 2.0 eV; the sensitive material comprises a semiconductor metal oxide nanofiber heterojunction material; the semiconductor metal oxide nanofiber heterojunction material comprises a nanofiber trunk and nanowire branches loaded on the surface of the nanofiber trunk, wherein the nanofiber trunk is made of a first semiconductor metal oxide, and the nanowire branches are made of a second semiconductor metal oxide containing oxygen vacancies.
2. 2. The time series logic gas sensor of claim 1, wherein the first semiconductor metal oxide comprises ZnO, WO 3 , or SnO 2 .
3. 3. The time series logic gas sensor of claim 1, wherein the second semiconductor metal oxide containing oxygen vacancies comprises MoO 3-x 、BiO 2-x or WO 3-x .
4. 4. A time-sequential logic gas sensor according to any one of claims 1 to 3, wherein the diameter of the nanofiber trunk is 50 to 200nm and the diameter of the nanowire branch is 5 to 10 nm.
5. 5. The time series logic type gas sensor according to claim 1, wherein the thickness of the sensitive material layer is 0.3-0.8 mm.
6. 6. The time series logic gas sensor of claim 1, wherein the substrate electrode comprises noble metal or copper.
7. 7. The time sequential logic gas sensor of claim 6, wherein the noble metal comprises gold or silver palladium.
8. 8. The time sequential logic gas sensor of claim 6 or 7, wherein the base electrode is an interdigitated electrode.

Description

Sequential logic gas sensor Technical Field The invention relates to the technical field of sensors, in particular to a sequential logic type gas sensor. Background The Semiconductor Metal Oxide (SMO) gas sensor has the advantages of low cost, small size, easy integration and the like, and is widely applied to the field of polluted gas monitoring. The conventional SMO-based gas sensor is intended to realize a gas real-time monitoring function, and thus, the SMO-based gas sensor has a fast response/recovery speed, when gas adsorption/desorption of the SMO surface is fast reversible. In this case, the SMO gas sensor will quickly return to the original state once the contaminant gas in the environment has disappeared briefly. Therefore, the conventional gas sensor can only realize instant detection on single high-concentration pollution, and can not sense the potential hazard of the intermittently-occurring polluted gas according to the occurrence frequency and concentration of the polluted gas. In general, low concentrations of contaminant gases are less damaging and often ignored. However, if these low concentrations of contaminant gases are frequently exposed for extended periods of time, the environment and organisms are irreversibly damaged. In order to be able to early warn of such hazards, it is of great importance to evaluate the potential hazard of the contaminated gas by long-term monitoring of the frequency and concentration of occurrence of the contaminated gas. Disclosure of Invention The invention aims to provide a time sequence logic type gas sensor which can effectively monitor intermittent low-concentration polluted gas. In order to achieve the above object, the present invention provides the following technical solutions: The invention provides a time sequence logic type gas sensor which comprises a substrate electrode and a sensitive material layer coated on the surface of the substrate electrode, wherein the specific surface area of the sensitive material is more than or equal to 20m 2/g, the sensitive material comprises a composite semiconductor metal oxide, and the absolute value of theoretical adsorption energy between at least one semiconductor metal oxide in the sensitive material and gas molecules to be detected is more than or equal to 2.0eV. Preferably, the sensitive material comprises a semiconductor metal oxide nanofiber heterojunction material. Preferably, the semiconductor metal oxide nanofiber heterojunction material comprises a nanofiber trunk and nanowire branches loaded on the surface of the nanofiber trunk, wherein the nanofiber trunk is a first semiconductor metal oxide, and the nanowire branches are second semiconductor metal oxides containing oxygen vacancies. Preferably, the first semiconducting metal oxide comprises ZnO, WO 3 or SnO 2. Preferably, the second semiconductor metal oxide containing oxygen vacancies comprises MoO 3-x、BiO2-x or WO 3-x. The invention provides the time sequence logic type gas sensor, wherein the diameter of the nanofiber trunk is 50-200 nm, and the diameter of the nanowire branch is 5-10 nm. Preferably, the thickness of the sensitive material layer is 0.3-0.8 mm. Preferably, the material of the base electrode includes noble metal or copper. Preferably, the noble metal comprises gold or silver palladium. Preferably, the base electrode is an interdigital electrode. The invention provides a time sequence logic type gas sensor which comprises a substrate electrode and a sensitive material layer coated on the surface of the substrate electrode, wherein the specific surface area of the sensitive material is more than or equal to 20m 2/g, the sensitive material comprises a composite semiconductor metal oxide, and the absolute value of theoretical adsorption energy between at least one semiconductor metal oxide in the sensitive material and gas molecules to be detected is more than or equal to 2.0eV. The invention selects the semiconductor metal oxide with larger adsorption energy to the gas molecules to be detected as the sensitive material, and controls the specific surface area of the sensitive material, so that when the gas molecules to be detected appear, the gas molecules are ensured to be strongly adsorbed on the surface of the sensitive material, the strong adsorption can enable the gas molecules to keep an adsorption state for a long time, the response signal of the sensor cannot disappear immediately after the gas to be detected disappears (under the condition that the concentration of the gas to be detected at room temperature is 1ppm, the response recovery time of the sensor is more than or equal to 500s after the gas to be detected disappears), and the sensor shows a certain memory function to the response signal. The gas sensor provided by the invention has the functions of gas response and response signal memory, and the response signal output at a certain moment not only depends on the real-time gas concentration, but also depends on t