CN-122016948-A - Method for preparing high-sensitivity gas sensor based on undaria pinnatifida

Abstract

In recent years, undaria pinnatifida planting is rapidly developed in coastal areas, but the problem of discarding the expired undaria pinnatifida is gradually revealed. Conventional treatment methods such as incineration and composting each have drawbacks. Incineration, while removing residues, releases harmful fumes, affecting the environment. Composting is environment-friendly, but causes pathogenic bacteria problems due to improper treatment. In order to solve the problem, the invention provides a method for preparing a high-sensitivity gas sensor by using expired undaria pinnatifida, which comprises the steps of freeze drying, carbonization and the like. The sensor can detect 500ppm of hydrazine, formaldehyde, ammonia and trimethylamine target gases at room temperature. The innovation not only enriches the field of gas-sensitive materials, but also opens up new possibilities for the application of biomass materials. The preparation method is simple and convenient, and provides technical support for the undaria pinnatifida-based gas sensor. The technology is expected to be popularized nationally, and provides a new scheme for treating and reutilizing the abandoned marine plants.

Inventors

• SUN JUN
• FANG JIALU
• RAN BO
• HU PING

Assignees

• 新疆大学

Dates

Publication Date

20260512

Application Date

20241111

Claims (3)

1. 1. The preparation method of the gas-sensitive material comprises the following steps: a. fully cleaning the expired undaria pinnatifida produced in WiHai city of Shandong province provided by volunteers with deionized water, drying to constant weight at 70 ℃, closing a drying oven, and naturally cooling to room temperature; b. B, taking out the undaria pinnatifida obtained in the step a, and soaking in a beaker filled with deionized water; c. B, putting the undaria pinnatifida obtained in the step b into a refrigerator at the temperature of-7 ℃; d. c, putting the pre-frozen undaria pinnatifida in the step c into a freeze dryer for 16 hours of freeze drying; e. Taking out the undaria pinnatifida obtained in the step d, putting the undaria pinnatifida into a porcelain boat, putting the porcelain boat into a chemical vapor deposition furnace, introducing N 2 , carbonizing at 500 ℃ for 3h, and naturally cooling the undaria pinnatifida to room temperature in a tubular furnace to obtain a biomass carbon gas-sensitive material; f. taking out the sample obtained after the carbonization in the step e, fully grinding the sample with an agate mortar for 5min to obtain fine powder, mixing the fine powder with deionized water in a certain proportion, continuously grinding the mixture to obtain uniformly dispersed solution, uniformly dripping the uniformly dispersed solution on an interdigital electrode plate with a dropper, standing the solution at room temperature for 24-48: 48 h until the solution is dried, and thus obtaining the undaria pinnatifida-based gas sensor. The method for preparing a high-sensitivity gas sensor based on undaria pinnatifida according to claim 1, wherein in the step e, the heating rate of a tube furnace is 5 ℃ per minute and the nitrogen flow rate is 0.1-0.2L per minute in the carbonization treatment process.
2. 2. A high sensitivity gas sensor prepared based on undaria pinnatifida, characterized in that it is prepared according to the preparation method of any one of claims 1 to 2.
3. 3. The use of the undaria pinnatifida-based high-sensitivity gas sensor for preparing the same, which is disclosed in claim 3, for efficiently and rapidly detecting hydrazine gas.

Description

Method for preparing high-sensitivity gas sensor based on undaria pinnatifida Technical Field The invention relates to the field of biological material science and the field of gas-sensitive sensing, in particular to a method for preparing a high-sensitivity gas sensor based on undaria pinnatifida. Background Hydrazine is an important chemical substance and is widely used in the fields of aerospace, chemical industry, pharmacy and the like. However, hydrazine is extremely toxic and constitutes a serious threat to human health. Hydrazine has strong acute toxicity, and inhalation or skin contact can cause serious health problems, symptoms including headache, nausea, vomiting, dyspnea and confusion. At the same time, hydrazine is irritating to the skin and eyes, possibly leading to redness, pain and chemical burns. Long-term exposure may cause liver and kidney damage, affect nervous system function, and may trigger allergic reactions. It is notable that hydrazine is also a flammable liquid that can form explosive mixtures when mixed with air. Therefore, it is particularly important and urgent to develop a high-efficiency hydrazine gas sensor for explosion monitoring and human health protection, so as to ensure that measures can be timely taken when hydrazine leakage or exposure occurs, and ensure the safety and health of human beings. Currently, a common choice in the market is a semiconductor gas sensor, which is based on metal oxides. However, such sensors have problems of high energy consumption, high price, high working temperature, and the like, which limit the development and application thereof. Particularly in environments where accurate detection is required, the lower sensitivity and higher operating temperature of the metal oxide semiconductor gas sensitive material becomes a short plate thereof. They generally need to operate at high temperatures of 150-400 ℃, which not only increases power consumption, but also increases the risk of fire or explosion in the high temperature operating environment when detecting flammable and explosive gases such as hydrazine. In recent years, carbon materials have received attention because of their advantages of high conductivity, low cost, good stability, and ease of design. However, conventional carbon-based materials such as carbon nanotubes and graphene, depending on petrochemical products, have problems of non-reproducibility, non-environmental protection, complicated preparation process, and the like. Researchers have begun to find new carbon materials that are more environmentally friendly, low cost, and renewable. Biomass energy is taken as a renewable energy source, and has the advantages of good biocompatibility, biodegradability and permeability, sustainability, low cost and the like. The characteristics of degradability, environmental protection and the like are realized, and the defects of rigidity, nondegradability and the like of the traditional sensor substrate are overcome. Accordingly, biomass materials are considered ideal sensor substrate materials. Marine biological materials, particularly algal biochar, have attracted considerable attention due to their high regeneration rate and low price, can grow in natural fresh water and seawater without additional land and fertilizer, and have more biomass per unit volume than land plants. They are economical resources and worthy of development and utilization. The planting area and the yield of the undaria pinnatifida are steadily increased year by year. Taking 2023 as an example, the planting area of undaria pinnatifida exceeds 55 ten thousand mu, and the yield reaches 160 ten thousand tons. The undaria pinnatifida is used as an important marine plant in China and is mainly planted in coastal areas such as Fujian, zhejiang, shandong and the like. Under the condition that a large amount of undaria pinnatifida emerges, if the undaria pinnatifida cannot be consumed in time, the problem of expired undaria pinnatifida gradually appears. The traditional undaria pinnatifida treatment method mainly comprises incineration and composting. While incineration can quickly remove residues and release certain nutrients, it also presents serious environmental problems, such as emissions of carbon dioxide and hazardous fumes, which can affect air quality and pose a threat to people's health. Composting is an environmentally friendly treatment which helps to recycle nutrients, but if improperly treated, can lead to the development of off-flavors and pathogens. In view of this, the present invention proposes an innovative solution. We collect the waste and expired undaria pinnatifida, prepare the biomass porous carbon material through low temperature prefreezing, freeze drying and carbonization treatment, and test the gas-sensitive performance. The method not only solves the recycling problem of the waste and expired undaria pinnatifida, but also obtains the high-performance gas-sensitive material. This innovative techn