固体电能质SO2气体传感器特性研究

采用溶胶-凝胶法合成NASICON固体电解质及ZnSnO3复合金属氧化物材料,并以NASICON为基体材料,ZnSnO3为敏感电极制作管式SO2气体传感器.研究表明.在325～430℃时,SO2浓度在(5～50)×10-6体积分数范围内,器件的EMF值与SO2浓度的对数呈现较好的线性关系.器件在375℃时对SO2的灵敏度达到255mV/decade,并且器件在此温度下表现出较好的选择性和响应恢复特性.最后对其敏感机理进行了分析.     

固体电解质电位型CO气体传感器的研究

以NASICON(钠超离子导体)固体电解质为离子导电层,Y2O3为敏感电极研制了一种用于测定CO的电化学气体传感器.结果表明,器件对(5～50)×10-6范围内的CO具有较好的敏感特性.在400℃下,器件对CO的灵敏度为-45 mV/decade.并且器件对CO具有较高的选择性和良好的响应恢复特性.     

固体电解质SO2气体传感器的特性研究

采用溶胶-凝胶法合成NASICON固体电解质及ZnSnO3复合金属氧化物材料,并以NASICON为基体材料,ZnSnO3为敏感电极制作管式SO2气体传感器。研究表明,在325-430℃时,SO2浓度在（5～50）×10^-1体积分数范围内,器件的EMF值与SO2浓度的对数呈现较好的线性关系。器件在375℃时对SO2的灵敏度达到255mV／decade,并且器件在此温度下表现出较好的选择性和响应恢复特性。最后对其敏感机理进行了分析。     

CO-C7H8双功能一体化固体电解质气体传感器的研制

采用溶胶-凝胶法合成NASICON固体电解质,并以NASICON为基体材料,Y2O3及ZnTiO3为敏感电极制作管式CO-C7H8双功能一体化气体传感器。研究表明,在350~450℃时,CO及C7H8浓度在(5~50)×10-6体积分数范围内,器件的EMF值与CO和C7H8浓度的对数分别呈现较好的线性关系。器件在400℃时对CO和C7H8的灵敏度分别为-40和64mV/decade。并且器件在此温度下表现出较好的选择性和响应恢复特性。     

电化学CO2气体传感器的制备及评价

采用空心氧化铝陶瓷管作为衬底,制备了以NASICON材料为固体电解质,Li2CO3-BaCO3二元碳酸共晶混合物为辅助电极的固体电解质的管式CO2传感器,对传感器电极材料进行分析表征并对传感器性能进行了测试。结果表明元件均对CO2气体具有良好的线性响应。当工作电压为6V时,加热温度约为550℃左右时,元件表现出很好的灵敏度特性,其灵敏度值能与由能斯特方程得到的理论值较好的符合。     

NASICON固体电解质VOC气体传感器研究

采用溶胶-凝胶法制备NASICON（钠超离子导体）和NiCrxMn2-xO4材料,以NASICON为离子导电层,尖晶石结构材料NiCrxMn2-xO4（x=0.6-1.4）为敏感电极构建混成电位型VOC气体传感器。结果表明,以NiCr0.6Mn1.4O4为敏感材料制作的气体传感器对正己醇,苯,甲醛和甲醇具有较好的响应。在350℃时,对100×10-6正己醇、甲醛和甲醇的EMF变化分别为116、73和60 mV。对10×10-6~300×10-6正己醇的灵敏度可达到89 mV/decade。另外,传感器具有良好的可再现性,较快的响应恢复速率以及较宽的测试范围。     

立方锡酸镁/氧化锡复合氧化物的合成及其气敏性能

采用水热法制备MgSn(OH)6前驱体,经过高温煅烧得到了Mg2SnO4/SnO2复合氧化物立方纳米颗粒。采用XRD、SEM、EDS对煅烧前后样品的物相、形貌、组分进行了表征。在不同温度下测试了Mg2SnO4/SnO2复合氧化物气敏元件对甲醇气体的敏感性能。结果表明,该复合氧化物对甲醇气体具有良好的灵敏度和选择性。在最佳工作温度为300℃时对50×10-6~5 000×10-6浓度范围内的甲醇气体具有良好的线性关系,2 000×10-6时气敏元件的响应、恢复时间分别为12 s和8 s。     

固体电解质电位型甲烷传感器的气敏性能研究

研究了甲烷浓度和工作温度对氧化锆基混合电位型传感器响应值的影响.以氧化钇稳定的氧化锆(YSZ)为固体电解质,氧化锡(SnO2)为工作电极的传感器对(200~1000)×10 -6浓度的甲烷具有良好的传感性能,传感器响应值与甲烷浓度的对数值呈良好的线性关系,传感器在650℃时具有良好的传感性能,其中响应时间和恢复时间均低至5 s.     

CO2传感器的制作及特性

采用高温固相反应法制备了Na超离子导体（NASICON）的固体电解质材料，用IR技术分析了不同合成温度下制备的NASICON材料的基本性质。用所制得的NASICON材料制作了具有较高灵敏度和选择性的CO2气体传感器。     

Ce_(0.95)Ca_(0.05)F_(3-x)固体电解质氧传感器的研究

本文研究了Ce_(0.95)Ca_(0.05)F_(3-x)固体电解质及其氧传感器的制备和性质。在150℃时,Po_2在10~(-2)～10~(-1)MPa范围内传感器件的电位变化正比于Po_2的对数值。同时研究了不同参比电极和敏感电极对传感性能的影响。以Bi+BiF_3为参比电极时,EMF值稳定较快;当Pd作为敏感电极时,传感元件的响应较快;以RuO_2作敏感电极时,传感器件较灵敏。文章还讨论了敏感机理。     

采用BaCO_3—Li_2CO_3作电极的固体电解质CO_2传感器

采用NASICON(Na离子导体)与BaCO_3-Li_2CO_3电极相结合的方式,使新型CO_2传感器得到发展。据观察,其响应时间以及抗水湿性能都有了提高。对于CO_2浓度在1×10~(-4)～0.5这样宽的范围内,500℃时测得的电动势与能斯特方程符合的很好。该元件几乎不受共存的H_2S(10~(-4)),NO_2(10~(-4)),CO(10~(-4)),SO_2(10~(-4)),C_2H_5OH(10~(-4))、CH_4(5×10~(-3))以及NH_3(2×10~(-3))的影响。     

NASICON-based solid-electrolyte cell as transducer for enzyme sensors

Enzyme sensors for glucose and uric acid have been developed based on a solid-electrolyte cell using NASICON (Na₃Zr₂Si₂PO₁₂). These potentiometric devices respond reversibly to glucose and uric acid over a concentration range of two orders of magnitude with sensitivities of −54 and −52 mV/decade, respectively. The sensors can be used for a batch-type as well as a flow-through-type measuring system. Primarily the sensors respond to the H₂O₂ that is produced by the enzymatic reactions. The role of the three-phase region, electrolyte solution, sensing electrode metal and NASICON has been investigated. The liquid electrolyte/sensing electrode metal interface is found to work as a potential-determining as well as a rate-determining interface for the enzyme sensor.     

Solid-state potentiometric SO2 sensor combining NASICON with V2O5-doped TiO2 electrode

A compact tubular sensor based on NASICON (sodium super ionic conductor) and V₂O₅-doped TiO₂ sensing electrode was designed for the detection of SO₂. In order to reduce the size of the sensor, a thick-film of NASICON was formed on the outer surface of a small Al₂O₃ tube; furthermore, a thin layer of V₂O₅-doped TiO₂ with nanometer size was attached on the NASICON as a sensing electrode. This paper investigated the influence of V₂O₅ doping and sintering temperature on the characteristics of the sensor. The sensor attached with 5 wt% V₂O₅-doped TiO₂ sintered at 600 °C exhibited excellent sensing properties to 1–50 ppm SO₂ in air at 200–400 °C. The EMF value of the sensor was almost proportional to the logarithm of SO₂ concentration and the sensitivity (slope) was −78 mV/decade at 300 °C. It was also seen that the sensor showed a good selectivity to SO₂ against NO, NO₂, CH₄, CO, NH₃ and CO₂. Moreover, the sensor had speedy response kinetics to SO₂ too, the 90% response time to 50 ppm SO₂ was 10 s, and the recovery time was 35 s. On the basis of XPS analysis for the SO₂-adsorbed sensing electrode, a sensing mechanism involving the mixed potential at the sensing electrode was proposed.     

Pt/Ni—氧化石墨烯修饰电极用于莱克多巴胺测定

将石墨烯作为基底材料修饰到玻碳电极上,并在其表面沉积Pt/Ni二元金属制得定量检测莱克多巴胺的电化学传感器。探讨了石墨烯表面金属合金沉积时间和样品富集时间等条件对传感器性能的影响。在最优条件下,测定莱克多巴胺的浓度线性范围为1.98×10-7～2.67×10-4mol/L,其检测限为6.66×10-8mol/L。实验结果表明:该传感器灵敏度高、稳定性好。     

Electrical properties of nickel oxide thin films for flow sensor application

In this work, Ni oxide thin films, with thermal sensitivity superior to Pt and Ni thin films, were formed through annealing of Ni films deposited by a r.f. magnetron sputtering. The annealing was carried out in the temperature range of 300–500 °C under atmospheric conditions. Resistivity of the resulting Ni oxide films were in the range of 10.5 μΩ cm/°C to 2.84 × 10⁴ μΩ cm/°C, depending on the extent of Ni oxidation. The temperature coefficient of resistance (TCR) of the Ni oxide films also depended on the extent of Ni oxidation; the average TCR of Ni oxide resistors, measured between 0 and 150 °C, were 5630 ppm/°C for the 300 °C and 2188 ppm/°C for 500 °C films. Because of their high resistivity and very linear TCR, Ni oxide thin films are superior to pure Ni and Pt thin films for flow and temperature sensor applications.     

H2 sensing properties of diode-type gas sensors fabricated with Ti- and/or Nb-based materials

A thermally oxidized TiO₂ or Nb₂O₅ film equipped with a top Pd film electrode and a bottom Ti or Nb plate electrode (Pd/MO(n)/M, MO: oxide film, M: metal plate, n: annealing temperature (°C)) has been investigated as a diode-type H₂ sensor under air or N₂ atmosphere. Pd/TiO₂(n)/Ti sensors showed relatively poor H₂ sensing properties in air, in comparison with Pd/anodic-TiO₂(n)/Ti sensors constructed with an anodized TiO₂ film equipped with a top Pd film electrode and a bottom Ti plate electrode, which were reported in our previous studies. On the other hand, Pd/Nb₂O₅(n)/Nb sensors showed relatively larger H₂ response with fast response and recovery speeds than Pd/TiO₂(n)/Ti sensors in air under high forward bias conditions. A Pd/Nb₂O₅(450)/Ti sensor, which was fabricated by radio-frequency magnetron sputtering of Nb metal on a Ti substrate followed by thermal oxidation at 450 °C, showed the largest H₂ response and relatively fast response and recovery speeds in air, among the sensors tested. In addition, H₂ response of the Pd/Nb₂O₅(450)/Ti sensor in air was much lower than that in N₂, but the logarithm of H₂ response was almost proportional to the logarithm of H₂ concentration in a wide range of H₂ concentration (10–8000 ppm) in air, and the H₂ sensitivity in air was much higher than that in N₂.     

表面碳化的硅纳米孔柱阵列的H2S室温电容传感特性

通过将硅纳米孔柱阵列(Si-NPA)进行高温碳化处理,制备出一种SiC/Si-NPA复合纳米体系。对SiC/Si-NPA的表面形貌和结构表征揭示,生长于Si-NPA上的SiC薄膜由具有立方结构的SiC纳米颗粒组成,厚度为～200 nm。SiC/Si-NPA整体上保持了Si-NPA原有的柱状阵列结构特征。对浓度介于0～1 200×10-6的H2S气体的室温传感性能测试表明,SiC/Si-NPA对H2S气体的电容响应灵敏度可高达790%,而其对400×10-6浓度H2S气体的响应和恢复时间则分别为170 s和200 s,元件具有较好的测量重复性和稳定性。SiC/Si-NPA可能是一种室温条件下较为理想的H2S气体传感材料。