A low-temperature sensitive material for detecting trace amounts of ethanol in the air

Abstract

This invention relates to a low-temperature sensitive material for detecting trace amounts of ethanol in the air, characterized by a Pt-doped composite powder material composed of Ga₂O₃, CuO, and RuO₂. The preparation process includes: converting gallium and copper salts into a mixed powder of gallium oxide and copper oxide via a hydrothermal method; converting ruthenium salt into ruthenium oxide via high-temperature calcination; thoroughly grinding each component; attaching chloroplatinic acid to the surfaces of gallium oxide, copper oxide, and ruthenium oxide via impregnation; and then decomposing the mixture at high temperature to obtain platinum atoms, thereby obtaining the Pt-doped composite powder material composed of Ga₂O₃, CuO, and RuO₂. An ethanol gas sensor made using this sensitive material can operate at temperatures not exceeding 100°C and can detect trace amounts of ethanol in the air with high sensitivity on-site without interference from other common coexisting molecules.

Description

Technical Field

[0001] This invention relates to a low-temperature sensitive material for detecting trace amounts of ethanol in the air, particularly a Pt-doped composite powder material composed of Ga2O3, CuO, and RuO2, belonging to the field of sensing technology. Background Technology

[0002] Trace amounts of ethanol in the air typically require enrichment and elution using an atmospheric sampler before accurate measurement using large analytical instruments such as gas chromatographs, liquid chromatographs, or spectrophotometers. This process is time-consuming and difficult to perform on-site. Currently, the breathalyzers used by traffic management departments primarily employ electrochemical and colorimetric methods, both of which have significant errors and can only serve as semi-quantitative analytical methods. Invention patent ZL201811448348.1 discloses a catalytic luminescent sensitive material for ethanol. The operating temperature of this sensitive material has been reduced from 350℃ to 150-200℃, and its detection limit and linear range meet routine monitoring requirements. However, two problems were discovered when designing a sensor using this sensitive material: firstly, the interference signals from acetaldehyde and acetone molecules cannot be ignored; secondly, the thermal radiation signal generated at operating temperatures above 150℃ still significantly affects the sensor's sensitivity. Summary of the Invention

[0003] The purpose of this invention is to overcome the shortcomings of previous technologies and provide a sensitive material that exhibits high catalytic luminescence activity and selectivity for ethanol at temperatures not exceeding 100°C. An ethanol gas sensor made from this sensitive material can be used at lower operating temperatures, and common coexisting molecules in the air, such as formaldehyde, acetaldehyde, benzene, toluene, xylene, ammonia, methanol, propanol, methane, ethylene, acetone, butanone, carbon monoxide, carbon dioxide, sulfur dioxide, and hydrogen sulfide, do not interfere with the determination of ethanol.

[0004] The sensitive material described in this invention is a Pt-doped composite powder material composed of Ga2O3, CuO, and RuO2. Its preparation method is as follows: Gallium salt and copper salt are dispersed in a 30-35% (w / w) isopropanol aqueous solution and stirred continuously for 1-2 hours. The mixture is then transferred to a stainless steel high-pressure reactor lined with polytetrafluoroethylene (PTFE). The reactor is placed in an oven at 150-180°C and maintained at that temperature for 15-20 hours. After cooling and depressurization, the solid product is separated. This solid product is washed sequentially with anhydrous ethanol and deionized water, dried, and thoroughly ground to obtain A. Ruthenium salt is placed in a crucible and subjected to a box-type resistance thermometer at 600-700°C. Calcination in a furnace for 4-6 hours, followed by natural cooling to room temperature, and thorough grinding to obtain B; under continuous stirring, chloroplatinic acid is added to an ethanol aqueous solution with a mass fraction of 20-25%, and stirred at a constant temperature of 30-35℃ until clear, then A is added, the temperature is raised to 50℃, and stirred at a constant temperature for 3-4 hours, then B is added, and stirred at a constant temperature for 4-5 hours, followed by natural cooling to room temperature and standing for 12 hours, then filtered, and the filter cake is placed in a box-type resistance furnace and heated to 400-450℃ in an air atmosphere for 3-4 hours, followed by natural cooling to obtain a Pt atom-doped composite powder material composed of Ga2O3, CuO and RuO2.

[0005] Among them, gallium salt is one or a mixture of several anhydrous or hydrated forms of gallium nitrate, gallium acetate, gallium sulfate, gallium perchlorate, and gallium chloride; copper salt is one or a mixture of several anhydrous or hydrated forms of copper chloride, copper sulfate, copper phosphate, and copper nitrate; and ruthenium salt is one or a mixture of several anhydrous or hydrated forms of ruthenium chloride, ruthenium nitrate, ruthenium sulfate, and ruthenium acetate.

[0006] When the mass fractions of each component of the prepared composite powder material meet the requirements of Pt (0.5-1.2%), Ga2O3 (23-28%), CuO (38-43%), and RuO2 (30-35%), and the particle size does not exceed 50 nanometers, it can be used as a catalytic luminescence sensitive material for detecting ethanol in the air. It has high catalytic luminescence activity and selectivity for ethanol at temperatures below 100℃. Detailed Implementation

[0007] Example 1

[0008] Gallium nitrate nonahydrate and copper chloride dihydrate were dispersed in a 30% (w / w) isopropanol aqueous solution and stirred continuously for 2 hours. The mixture was then transferred to a stainless steel high-pressure reactor lined with polytetrafluoroethylene (PTFE). The reactor was placed in an oven at 175°C and maintained at that temperature for 16 hours. After cooling and depressurization, the solid product was separated. This solid product was washed sequentially with anhydrous ethanol and deionized water, dried, and thoroughly ground to obtain A. Ruthenium chloride was placed in a crucible and calcined in a box-type resistance furnace at 650°C for 5 hours. After natural cooling to room temperature, it was thoroughly ground to obtain... B; Under continuous stirring, chloroplatinic acid was added to a 20% (w / w) aqueous solution of ethanol and stirred at 35°C until clear. Then, A was added, the temperature was raised to 50°C, and the mixture was stirred at a constant temperature for 3 hours. Then, B was added, and the mixture was stirred at a constant temperature for 5 hours. The mixture was then allowed to cool naturally to room temperature and stand for 12 hours. After filtration, the filter cake was placed in a box-type resistance furnace and heated to 430°C in an air atmosphere for 3 hours. After natural cooling, a Pt atom-doped composite powder material composed of Ga2O3, CuO, and RuO2 was obtained.

[0009] Analysis: The composite powder material was analyzed and found to contain 0.6% Pt, 25.1% Ga2O3, 39.7% CuO and 34.6% RuO2 by mass percentage; the particle size was found to be no more than 40 nm by transmission electron microscopy.

[0010] Application: This powder material was used as a catalytic luminescent sensing material for detecting ethanol in the air, with an operating temperature of 87.2℃ and a linear range of 0.9-300 mg / m³. 3 The detection limit is 0.5 mg / m³. 3 Common coexisting molecules do not interfere.

[0011] Example 2

[0012] Gallium acetate and copper sulfate pentahydrate were dispersed in a 35% isopropanol aqueous solution and stirred continuously for 1 hour. The mixture was then transferred to a stainless steel high-pressure reactor lined with polytetrafluoroethylene. The reactor was placed in an oven at 155°C and maintained at that temperature for 20 hours. After cooling and depressurization, the solid product was separated. The solid product was washed sequentially with anhydrous ethanol and deionized water, dried, and thoroughly ground to obtain A. Ruthenium nitrate was placed in a crucible and calcined in a box-type resistance furnace at 680°C for 4 hours. After naturally cooling to room temperature, it was thoroughly ground to obtain B. Chloroplatinic acid was added to a 25% (w / w) aqueous ethanol solution under continuous stirring. The mixture was stirred at 30°C until clear. Then, A was added to the solution, the temperature was raised to 50°C, and the mixture was stirred at a constant temperature for 4 hours. B was then added to the solution, and the mixture was stirred at a constant temperature for 4 hours. The mixture was then allowed to cool naturally to room temperature and stand for 12 hours. After filtration, the filter cake was placed in a box-type resistance furnace and heated to 420°C in an air atmosphere for 4 hours. After natural cooling, a Pt atom-doped composite powder material composed of Ga2O3, CuO, and RuO2 was obtained.

[0013] Analysis: The composite powder material was analyzed and found to contain 1.0% Pt, 26.5% Ga2O3, 41.1% CuO and 31.4% RuO2 by mass; the particle size was found to be no more than 45 nm by transmission electron microscopy.

[0014] Application: This powder material was used as a catalytic luminescent sensing material for detecting ethanol in the air, with an operating temperature of 91.5℃ and a linear range of 0.7-280 mg / m³. 3 The detection limit was 0.4 mg / m³. 3 Common coexisting molecules do not interfere.

[0015] Example 3

[0016] Gallium nitrate nonahydrate, gallium sulfate hydrate, and copper phosphate were dispersed in a 32% (w / w) isopropanol aqueous solution and stirred continuously for 1.5 hours. The mixture was then transferred to a stainless steel high-pressure reactor lined with polytetrafluoroethylene (PTFE). The reactor was placed in an oven at 170°C and maintained at that temperature for 18 hours. After cooling and depressurization, the solid product was separated and washed sequentially with anhydrous ethanol and deionized water. The product was then dried and thoroughly ground to obtain A. Ruthenium sulfate was placed in a crucible and calcined in a box-type resistance furnace at 620°C for 6 hours. After natural cooling to room temperature, the product was thoroughly ground. B was obtained by grinding. Under continuous stirring, chloroplatinic acid was added to a 21% ethanol aqueous solution and stirred at 34°C until clear. Then A was added, the temperature was raised to 50°C, and the mixture was stirred at a constant temperature for 3 hours. B was added, and the mixture was stirred at a constant temperature for 5 hours. The mixture was then allowed to cool naturally to room temperature and stand for 12 hours. After filtration, the filter cake was placed in a box-type resistance furnace and heated to 440°C in air atmosphere for 3 hours. After natural cooling, a Pt atom-doped composite powder material composed of Ga2O3, CuO, and RuO2 was obtained.

[0017] Analysis: The composite powder material was analyzed and found to contain 0.8% Pt, 24.9% Ga2O3, 42.3% CuO and 32.0% RuO2 by mass percentage; the particle size was found to be no more than 40 nm by transmission electron microscopy.

[0018] Application: This powder material was used as a catalytic luminescent sensing material for detecting ethanol in the air, with an operating temperature of 88.7℃ and a linear range of 0.8-300 mg / m³. 3 The detection limit is 0.5 mg / m³. 3 Common coexisting molecules do not interfere.

[0019] Example 4

[0020] Gallium perchlorate hydrate and copper nitrate trihydrate were dispersed in a 34% (w / w) isopropanol aqueous solution and stirred continuously for 2 hours. The mixture was then transferred to a stainless steel high-pressure reactor lined with polytetrafluoroethylene (PTFE). The reactor was placed in an oven at 160°C and maintained at that temperature for 17 hours. After cooling and depressurization, the solid product was separated and washed sequentially with anhydrous ethanol and deionized water. The product was then dried and thoroughly ground to obtain A. Ruthenium nitrate and ruthenium acetate were placed in a crucible and calcined in a box-type resistance furnace at 650°C for 5 hours. After naturally cooling to room temperature, the mixture was thoroughly ground. B was obtained; under continuous stirring, chloroplatinic acid was added to a 22% (w / w) aqueous solution of ethanol, and stirred at 33°C until clear. Then A was added, the temperature was raised to 50°C, and stirred at a constant temperature for 4 hours. B was added, and stirred at a constant temperature for 4 hours. The mixture was then allowed to cool naturally to room temperature and stand for 12 hours. After filtration, the filter cake was placed in a box-type resistance furnace and calcined at 410°C in an air atmosphere for 4 hours. After natural cooling, Pt-doped composite powder material composed of Ga2O3, CuO, and RuO2 was obtained.

[0021] Analysis: The composite powder material was analyzed and found to contain 1.1% Pt, 23.8% Ga2O3, 42.4% CuO and 32.7% RuO2 by mass percentage; the particle size was found to be no more than 46 nm by transmission electron microscopy.

[0022] Application: This powder material was used as a catalytic luminescent sensing material for detecting ethanol in the air, with an operating temperature of 92.3℃ and a linear range of 1.0-310 mg / m³. 3 The detection limit was 0.6 mg / m³. 3 Common coexisting molecules do not interfere.

[0023] Example 5

[0024] Gallium chloride, copper chloride dihydrate, and copper sulfate pentahydrate were dispersed in a 31% (w / w) isopropanol aqueous solution and stirred continuously for 1 hour. The mixture was then transferred to a stainless steel high-pressure reactor lined with polytetrafluoroethylene (PTFE). The reactor was placed in an oven at 180°C and maintained at that temperature for 15 hours. After cooling and depressurization, the solid product was separated and washed sequentially with anhydrous ethanol and deionized water. The product was then dried and thoroughly ground to obtain A. Ruthenium acetate was placed in a crucible and calcined in a box-type resistance furnace at 700°C for 4 hours. After naturally cooling to room temperature, the product was thoroughly ground. B was obtained; under continuous stirring, chloroplatinic acid was added to a 23% (w / w) aqueous solution of ethanol and stirred at 32°C until clear. Then A was added, the temperature was raised to 50°C, and the mixture was stirred at a constant temperature for 3 hours. B was added, and the mixture was stirred at a constant temperature for 5 hours. The mixture was then allowed to cool naturally to room temperature and stand for 12 hours. After filtration, the filter cake was placed in a box-type resistance furnace and calcined at 450°C in an air atmosphere for 3 hours. After natural cooling, a Pt atom-doped composite powder material composed of Ga2O3, CuO, and RuO2 was obtained.

[0025] Analysis: The composite powder material was analyzed and found to contain 0.9% Pt, 25.8% Ga2O3, 40.2% CuO and 33.1% RuO2 by mass percentage; the particle size was found to be no more than 42 mm by transmission electron microscopy.

[0026] Application: This powder material was used as a catalytic luminescent sensing material for detecting ethanol in the air, with an operating temperature of 94.4℃ and a linear range of 0.8-280 mg / m³. 3 The detection limit is 0.5 mg / m³. 3 Common coexisting molecules do not interfere.

[0027] Example 6

[0028] Gallium sulfate hydrate, gallium chloride, and copper nitrate trihydrate were dispersed in a 33% (w / w) isopropanol aqueous solution and stirred continuously for 2 hours. The mixture was then transferred to a stainless steel high-pressure reactor lined with polytetrafluoroethylene (PTFE). The reactor was placed in an oven at 150°C and maintained at that temperature for 19 hours. After cooling and depressurization, the solid product was separated and washed sequentially with anhydrous ethanol and deionized water. The product was then dried and thoroughly ground to obtain A. Ruthenium chloride was placed in a crucible and calcined in a box-type resistance furnace at 600°C for 6 hours. After naturally cooling to room temperature, the product was thoroughly ground. B was obtained; under continuous stirring, chloroplatinic acid was added to a 24% (w / w) aqueous solution of ethanol and stirred at 31°C until clear. Then A was added, the temperature was raised to 50°C, and the mixture was stirred at a constant temperature for 4 hours. B was added, and the mixture was stirred at a constant temperature for 4 hours. The mixture was then allowed to cool naturally to room temperature and stand for 12 hours. After filtration, the filter cake was placed in a box-type resistance furnace and heated to 400°C in air atmosphere for 4 hours. After natural cooling, a Pt atom-doped composite powder material composed of Ga2O3, CuO, and RuO2 was obtained.

[0029] Analysis: The composite powder material was analyzed and found to contain 0.7% Pt, 27.6% Ga2O3, 38.8% CuO and 32.9% RuO2 by mass percentage; the particle size was found to be no more than 40 nm by transmission electron microscopy.

[0030] Application: This powder material was used as a catalytic luminescent sensing material for detecting ethanol in the air, with an operating temperature of 86.1℃ and a linear range of 0.7-270 mg / m³. 3 The detection limit was 0.4 mg / m³. 3 Common coexisting molecules do not interfere.

Claims

1. A low-temperature sensitive material for detecting trace amounts of ethanol in air, characterized in that: A Pt-doped composite powder material composed of Ga₂O₃, CuO, and RuO₂, wherein the mass percentages of each component range from 0.5-1.2% Pt, 23-28% Ga₂O₃, 38-43% CuO, and 30% RuO₂. - 35% RuO2; its preparation method is as follows: gallium salt and copper salt are dispersed in an isopropanol aqueous solution with a mass fraction of 30-35%, stirred continuously for 1-2 hours, transferred to a stainless steel high-pressure reactor lined with polytetrafluoroethylene, the reactor is placed in an oven at 150-180℃ and maintained at the temperature for 15-20 hours, cooled and depressurized to separate the solid product, washed with anhydrous ethanol and deionized water in sequence, dried and thoroughly ground to obtain A; ruthenium salt is placed in a crucible and calcined in a box-type resistance furnace at 600-700℃ for 4-6 hours, naturally cooled to room temperature, and then... B is obtained by grinding. Under continuous stirring, chloroplatinic acid is added to an aqueous ethanol solution with a mass fraction of 20-25%, and stirred at a constant temperature of 30-35℃ until clear. Then A is added, the temperature is raised to 50℃, and stirred at a constant temperature for 3-4 hours. B is added, and stirred at a constant temperature for 4-5 hours. The mixture is then naturally cooled to room temperature and allowed to stand for 12 hours. After filtration, the filter cake is placed in a box-type resistance furnace and heated to 400-450℃ in an air atmosphere for 3-4 hours. After natural cooling, a Pt atom-doped composite powder material composed of Ga2O3, CuO, and RuO2 is obtained.

2. The low-temperature sensitive material for detecting trace amounts of ethanol in air according to claim 1, characterized in that... The gallium salt is one or a mixture of several anhydrous or hydrated forms of gallium nitrate, gallium acetate, gallium sulfate, gallium perchlorate, and gallium chloride; the copper salt is one or a mixture of several anhydrous or hydrated forms of copper chloride, copper sulfate, copper phosphate, and copper nitrate; and the ruthenium salt is one or a mixture of several anhydrous or hydrated forms of ruthenium chloride, ruthenium nitrate, ruthenium sulfate, and ruthenium acetate.