Papers by Keyword: Cataluminescence

Abstract: A sensitive cataluminescence-based detecting technology using nanosized Mo₄V₆Ti₁₀O₄₇ as a probe was proposed for determination of formaldehyde in air. Trace formaldehyde was firstly absorbed on active carbon at room temperature to concentrate, then desorbed at 75°C to determine. The method showed high selectivity to formaldehyde at wavelength of 575nm, satisfying activity at temperature of 260°C and good stability at carrier flow rate of 145 ml/min. The linear range of CTL intensity versus concentration of formaldehyde was 0.04~78 mg/m³, and the detection limit (3σ) was 0.02 mg/m³. The recovery of artificial sample was 96.8%-103.4% by this method. There was no response to CO, CO₂, SO₂, NH₃, methanol, ethanol, benzene, toluene and xylenes.

Abstract: A rapid and sensitive cataluminescence-based gas sensor utilizing nanosized Y₂MnO₅ as the sensing materials for determining dimethyl ether in air was proposed. The luminescence characteristics and the optimal conditions were investigated in detail. The gas sensor showed high selectivity for dimethyl ether at 620 nm and satisfying activity at 210°C under the optimized conditions. The linear range of cataluminescence intensity versus concentration of dimethyl ether was 5~120 mg/m³, and the detection limit (3σ) was 3 mg/m³. No or weak interference was observed while the foreign substances, such as formaldehyde, ammonia, ethanol, benzene, carbon monoxide and sulfur dioxide, were passing through the sensor under selected conditions. The gas sensor displayed good stability for continuously introducing dimethyl ether over 100 h, and allowed real-time monitoring of dimethyl ether in air.

Abstract: Instrumentation was constructed for the detection of automobile exhaust utilizing cataluminescence method on nanosized Fe3O4/SiO2.The microspheres with a diameter of about 450 nm, were synthesized by the hydrolyzation of tetraethyl orthosilicate (TEOS). The scanning electronic microscopy (SEM), transmission electronmicroscopy (TEM) and energy dispersive spectroscopy (EDS) were employed to characterize the microspheres. Automobile exhaust, a harmful gas, was selected as a model to investigate the cataluminescence sensing properties of the SiO2/Fe3O4 microspheres in the current work. Results indicated that the microspheres exhibited outstanding cataluminescence properties. The performance of the SiO2/Fe3O4 microspheres based sensor instrument suggested the promising application of the SiO2/Fe3O4 nanomaterials for the detection of automobile exhaust.

Abstract: A novel cataluminescence(CTL)-based sensor array consisting of 9 types of catalytic nanomaterials was developed for the determination and identification of harmful gas. The sensing nanomaterials, including nano-sized metal oxides, carbonates and decorated nanoparticles, have been selected carefully. A 3 x 3 array was integrated by depositing these nanosized catalysts onto the ceramic chip. Dynamic and static analysis methods were utilized to characterize the performance of the sensor array to 4 kinds of harmful gas. Each compound gives its unique CTL pattern after interact with the sensor array, which can be employed to recognize ether, acetone, chloroform, and toluene. PCA was conducted to classify the harmful gas and the plots showed that the groups were well classified. In addition, the patterns obtained at different working temperature and the analytical characteristics of array were investigated. The CTL-based sensor array shows promising perspective for the recognition and discrimination of harmful gas.

Abstract: A new gas sensor was designed based on cataluminescence (CTL) by using catalytic reduction of benzene, toluene and xylene (BTEX) on the surface of nanosized catalyst Al₂O₃/Pt with hydrogen as the carrier gas. The result indicated that the sensor showed strong CTL response, high selectivity and excellent durability under optimal conditions: Al₂O₃/Pt (1%), the temperature of 395oC, the wavelength of 425 nm and the flow rate of 270 mL/min. The detection limit (3σ) is 0.2 ppm for benzene, 0.3 ppm for toluene and xylene. Other corresponding substances such as methanol, ethanol, formaldehyde, acetaldehyde, ethylacetate, ammonia and trichloromethane had no or less interference. It is a simple and convenient sensor with good selectivity and sensitivity for detecting BTEX.

Abstract: A rapid and sensitive cataluminescence (CTL)-based gas sensor using nanosized Y₂Zr_1.5O₆ as a probe was proposed for direct determination of ether in air. Trace ether was firstly absorbed on active carbon at room temperature to concentrate, then desorbed at 65°C to determine. The sensor showed high selectivity to ether at wavelength of 510nm, satisfying activity at temperature of 310°C and good stability at carrier flow rate of 110 ml/min. The linear range of CTL intensity versus concentration of ether was 2~100 mg/m³, and the detection limit (3σ) was 1.1 mg/m³. The recovery of artificial sample was 95.4%—106.7% by this method. The response to formaldehyde, benzene, NH₃ and ethanol was insignificant, and there was no response to SO₂, CO and acetone. The technique is a convenient and fast way of determining ether in air.

Abstract: A highly sensitive, simple and selective gas sensor was developed for the determination of trace acetaldehyde in air based on cataluminescence (CTL) on nano-sized Al₂Ti₂O₇. The gas sensor showed high selectivity for acetaldehyde at 515 nm and satisfying activity at 295°C. The linear range of the CTL intensity versus concentration of acetaldehyde was 1~65 mg/m³, and the detection limit (3σ) was 0.5 mg/m³. No interference was observed while the foreign substances, such as ammonia, ethanol, formaldehyde, benzene, carbon monoxide and sulfur dioxide, were passing through the sensor. The gas sensor displayed good stability for continuously introducing 10 mg/m³ acetaldehyde over 60 h, and allowed real-time monitoring of acetaldehyde in air.

Abstract: A cataluminescence (CTL)-based gas sensor utilizing nano-sized Mn_1.5Zr₂O₇ as the sensing material for the determination of hydrogen sulfide in air was proposed. The gas sensor showed high selectivity for hydrogen sulfide at 450 nm and satisfying activity at 320°C. The linear range of the CTL intensity versus concentration of hydrogen sulfide was 2~95 mg/m³, and the detection limit (3σ) was 1.5 mg/m³. No interference was observed while the foreign substances, such as formaldehyde, ammonia, ethanol, benzene, carbon monoxide and sulfur dioxide, were passing through the sensor. The gas sensor displayed good stability for continuously introducing hydrogen sulfide over 60 h, and allowed real-time monitoring of hydrogen sulfide in air.

Abstract: A sensitive cataluminescence (CTL)-based gas sensor using nano-sized Y₂Ti₃O₉ as a probe was proposed for the determination of trimethylamine (TMA) in air. The gas sensor showed high selectivity for TMA at 490 nm and satisfying activity at 320°C. The linear range of the CTL intensity versus concentration of TMA was 1~70 mg/m³ (γ = 0.995), and the detection limit (3σ) was 0.6 mg/m³. No interference was observed while the foreign substances, such as ammonia, ethanol, benzene, carbon monoxide and sulfur dioxide, were passing through the sensor. The gas sensor displayed good stability for continuously introducing TMA over 100 h, and allowed on-line monitoring of TMA in air.

Abstract: A rapid and sensitive cataluminescence (CTL)-based gas sensor using nanosized Cr₄TiO₈ as a probe was proposed for direct determination of acetone in air. Trace acetone was firstly absorbed on active carbon at room temperature to concentrate, then desorbed at 84°C to determine. The sensor showed high selectivity to acetone at wavelength of 430nm, satisfying activity at temperature of 366°C and good stability at carrier flow rate of 115 ml/min. The linear range of CTL intensity versus concentration of acetone was 2.5~150 mg/m³, and the detection limit (3σ) was 1.2 mg/m³. The recovery of artificial sample was 94.1%—106.2% by this method. The response to formaldehyde and ethanol was insignificant, and there was no response to SO₂, CO and benzene.