纳米结构CuO为敏感电极的阻抗谱型NO2传感器

以浸渍技术制备的纳米CuO颗粒作敏感电极,以YSZ作为固体电解质制备了阻抗谱型NO2传感器。采用XRD、SEM对NO2传感器敏感材料的相组成和微观形貌进行了表征,应用电化学工作站测试了传感器的敏感性能。结果表明:浸渍法制得的CuO颗粒均匀分布在电解质的多孔层内,粒径在200 nm左右。在450～550℃,传感器对NO2有良好的敏感性,在0.1 Hz总阻抗|Z|=(Z′2+Z″2)～(1/2)姨与NO2浓度(0～200 mL.m-3)呈良好的线性关系。传感器的固有响应时间为50 s,共存的O2和CO2气体对传感器敏感性能几乎没有影响。     

基于La1-xSrxMnO3敏感材料的电流型NOx传感器研究

采用喷雾热分解技术制备了NO x传感器敏感材料La1-x Sr x MnO3,以多孔的氧化钇稳定的氧化锆(YSZ)为固体电解质,设计了一种新型的电流型NO x传感器。采用X射线衍射仪、扫描电子显微镜、程序升温脱附仪和X-射线光电子能谱(XPS)仪,表征了La1-x Sr x MnO3粉体的相组成和微观形貌,分析了敏感材料La1-x Sr x MnO3对NO x吸附强度与Mn氧化价态变化机理。在NO x传感器气敏性能测试装置上,利用DJS-292型恒电位仪测试了传感器敏感特性、温度特性、动态响应、抗干扰和稳定性。结果表明,以La0.5Sr0.5MnO3为敏感材料的NO x传感器,在极化电压为#300 mV,NO x浓度为0~1000μL/L时,NO x传感器线性度和灵敏度最大值分别为96.6%和97.1%,承受的温度上限为1200℃。在650℃,浓度从200μL/L转换到500μL/L时,NO x传感器动态响应和恢复时间分别为25 s和15 s。此传感器对CO、SO2、甲醛、乙醛、菲、丙酮和丙烯醛等气体具有良好的抗干扰性能。在汽车上连续使用12个月后,响应电流衰减了8.6%,响应电流正常时间为5个月。     

基于SnO2-In2O3复合纳米纤维的薄膜型甲醛传感器研究

采用双喷嘴静电纺丝技术制备了SnO2/In2O3复合纳米纤维,涂敷于带有金电极的氧化铝陶瓷管表面形成敏感薄膜,设计了一种新型薄膜型甲醛传感器。采用X射线衍射仪、热场发射扫描电子显微镜、O2-程序升温脱附仪和X-射线光电子能谱(XPS)仪,表征了SnO2/In2O3纳米纤维的相组成和微观形貌,分析了敏感薄膜成分配比对甲醛吸附强度与电化学的影响机理。在气体传感器静态测试系统上,采用XEDWS-60A型气敏元件分析仪测试了甲醛传感器敏感特性、温度特性、湿度特性、动态响应、抗干扰和稳定性。结果表明,以S50纳米纤维为敏感薄膜(膜厚为240 nm)的甲醛传感器,在温度为500℃,甲醛浓度为0.5~50 mg/L时,传感器线性度和灵敏度最大值分别为96.8%和97.5%,承受的温度上限为1000℃,动态响应和恢复时间分别为23和12 s。此传感器对CO、NO x、甲苯、菲、丙酮和甲醇等气体具有良好的抗干扰性能。在汽车上连续使用12个月后,响应衰减了5.5%,响应正常时间为6.4个月。     

基于CuO敏感电极的阻抗型NO_2传感器的多响应信号比较

采用Al掺杂的硅酸镧La_(10)Si_(5.5)Al_(0.5)O_(27)(LSAO)为固体电解质,CuO为敏感材料,构成了阻抗型NO_2传感器。通过X射线衍射和扫描电子显微镜对传感器的结构和形貌进行了表征。采用电化学工作站对分别以模值(|Z|)、相角(Θ)、实部(Z~')和虚部(Z~″)为响应信号的传感器的敏感性能进行了研究。结果表明:以模值(|Z|)、相角(Θ)、实部(Z~')和虚部(Z~″)作为传感器响应信号时,响应值与NO_2浓度均呈现良好的线性关系。在高频下,以相角和虚部作为响应信号的传感器在灵敏度,响应-恢复时间以及稳定性等方面具有更加出色的表现。     

TiO2-SnO2纳米晶膜紫外光照下对臭氧气敏性能的研究

以低温水热法制备了TiO2-SnO2复合纳米晶粒,采用提拉法涂敷于带有金电极的氧化铝陶瓷管表面形成敏感薄膜,设计了一种新型薄膜式臭氧传感器。采用X射线衍射仪、热场发射扫描电子显微镜、能量色散X射线谱仪和紫外-可见光谱能谱仪,表征了TiO2-SnO2纳米晶粒的晶体结构和微观形貌。采用紫外-可见吸收光谱法和电化学方法,讨论了TiO2-SnO2纳米晶粒对臭氧敏感机理与光电化学特性。在气体传感器静态测试系统上,采用XEDWS-60A型气敏元件分析仪测试了紫外光下臭氧传感器敏感特性、动态响应、抗干扰和稳定性。结果表明,以Ti与Sn摩尔比为6的TiO2-SnO2纳米晶粒为敏感薄膜的臭氧传感器,在相对湿度为40%和温度为25℃条件下,臭氧浓度为0.1~1.8μg/L时,有、无紫外光照射的臭氧传感器线性度分别为97.5%和78.5%,动态响应分别为2和9 s,恢复时间分别为5.5和15 s。此传感器对CO、NOx、甲醛、丙酮、丁醇和甲醇等气体具有良好的抗干扰性能。在汽车上连续使用12个月后,响应衰减了4.7%,响应正常时间为8.5个月。     

基于SnO2-CuO纳米纤维的薄膜型H2-S传感器研究

采用同轴静电纺丝技术制备了SnO2-CuO复合纳米纤维,采用提拉法将SnO2-CuO纳米纤维涂覆于印有梳状Au电极的氧化铝陶瓷管表面形成敏感薄膜,设计了一种新型薄膜式H2 S传感器。采用 X 射线衍射、扫描电子显微镜和X-射线光电子能谱( XPS)表征SnO2-CuO纳米纤维的相组成和微观形貌,分析了敏感薄膜成分配比和厚度对硫化氢敏感机理和电化学特性。采用WS-30A型气敏元件分析仪测试了H2 S传感器敏感特性、温度特性、湿度特性、动态响应、抗干扰特性和稳定性。结果表明,以C50纳米纤维为敏感薄膜(膜厚为70 nm)的H2 S传感器,在温度为25℃, H2 S气体浓度为10~60 mg/L时,传感器线性度和灵敏度分别为92.3％和98.2％,响应最大值为1080,承受的最大相对湿度为95％,动态响应和恢复时间分别为4和12 s。此传感器对CO, NO2, SO2, NH3, CO2, CH4和H2等有害气体具有较好的抗干扰性。在矿井中连续使用12月后,响应衰减了9.2％,响应正常时间为10.9月。     

基于氧化锌/聚苯胺复合材料的薄膜型甲醇传感器研究

采用低温水热法制备了纳米氧化锌(ZnO),并利用原位聚合法制备了ZnO/聚苯铵复合材料。将制备的ZnO/PANI纳米晶粒均匀涂覆于刻有叉指Pt电极玻璃基底表面形成敏感薄膜,设计了一种薄膜型甲醇传感器。采用X射线衍射仪、扫描电子显微镜和X-射线光电子能谱(XPS)仪表征了ZnO/PANI纳米晶粒的相组成和微观形貌,分析了敏感薄膜成分配比对甲醇气敏机理和电化学特性,测试了甲醇传感器敏感特性、温度特性、湿度特性、动态响应和选择稳定性。结果表明,以PZ50纳米晶粒为敏感薄膜的甲醇传感器,在温度为30℃、甲醇气体浓度为25 mg/m~3时,传感器响应最大值为1795.6,相对湿度限值为90%,动态响应和恢复时间分别为6.9和19.6 s。此传感器对N_2O、甲醛、乙醇、丙酮和1,3-丁二烯等气体无明显响应,在汽车上连续使用12周后,响应衰减了2.3%。     

空心纳米金在甲醛气体传感器中的应用研究

通过牺牲模板法合成了具有空心结构的纳米金催化剂,并进行了TEM、 SEM和XRD等物理表征.把该催化剂作为工作电极的活性物质,以1 mol/L KOH为电解质,组装了电流型甲醛气体传感器.在甲醛气体浓度为0～2.23×10-6 mol/L范围内对传感器进行了性能测试,传感器响应信号y(A)与气体浓度x(mol/L)线性回归方程为y=16.63x+4.063×10-7, r=0.9989.该传感器灵敏度高于同载量实心金纳米催化剂组装的传感器70%左右,达到了降低贵金属用量的目的.因其具有较快的响应时间、 良好的重现性和良好的线性关系等优点,可用于适当浓度范围内的甲醛气体检测.     

超支化敏感聚合物基于QCM检测痕量TNT爆炸物

为对TNT类爆炸物进行痕量检测,以石英晶体微天平(QCM)传感器为平台,用具有氢键酸性的氟化醇为敏感端基的超支化敏感聚合物材料构造了化学传感器。制备的QCM传感器可以在室温下对2.2×10~(-10)mol/L浓度以上的TNT气体进行响应;连续循环检测3次TNT气体未见信号衰减;对H_2O、乙醇、H_2、H_2S、SO_2、甲烷和NO_2等气体有良好的抗干扰能力;QCM传感器可以用于对TNT类爆炸物的痕量检测。     

刚果红交联聚乙烯醇薄膜／K^＋交换玻璃光波导检测氯化氢气体

用环氧氯丙烷为交联剂合成了刚果红(CR)交联聚乙烯醇(PVA)CR-PVA敏感试剂.用匀胶机将其做成薄膜固定在钾离子交换玻璃光波导表面,研制出一种光波导氯化氢气体传感器.CR-PVA薄膜碱式结构的最大吸收波长在600 nm以下,对波长为632.8 nm的激光吸收很弱;薄膜与酸性气体发生反应后强烈吸收波长在632.8 nm附近的导波或消失波;检测输出光强度的变化,即能够测出酸性气体浓度.测试结果表明,本传感器对低浓度HCl气体有快速响应,且对1.6～192 mg/m3范围内有良好的线性响应;SO2、NO2气体的浓度大于18000 mg/m3时才有响应,而对于高、低浓度H2S气体均无响应.     

The porous CuO electrode fabricated by hydrogen bubble evolution and its application to highly sensitive non-enzymatic glucose detection

The porous Cu film was deposited on a Pt/Ti/Si substrate by electrochemical deposition accompanied by hydrogen evolution at very high current densities. CuO films with similar morphologies were obtained by subsequent annealing of the porous copper films. The morphology, composition and structure of the porous Cu and porous CuO were investigated by FE-SEM, EDS and XRD methods. The complete transformation of Cu to CuO after annealing was indicated. The sensing performances of the porous CuO film were evaluated in alkaline solution with the porous CuO film showing a wide linearity range from 1 μM to 2.5 mM with sensitivity of 2.9 mA cm⁻² mM⁻¹, and detection limit of 0.14 μM. The sensor showed good selectivity to conventional intermediates such as AA and UA and long term stability.     

基于叶片状氧化铜纳米材料的无酶葡萄糖传感电极

将Nafion交联剂与纳米材料修饰至玻碳电极基底制备一种无酶葡萄糖传感器,通过循环伏安曲线、时间-电流曲线检测该电极电化学特性. 氧化铜纳米复合膜具有高比表面积和多活性点位的优点. 实验结果表明,氧化铜纳米电极对葡萄糖的检测线性响应范围0.01 ~ 0.3 mmol·L^-1,灵敏度1783.58 μA·L·mmol^-1·cm^-2,检测限0.80 μmol·L^-1 (S/N=3),稳定性较好,能抵抗抗坏血酸、多巴胺和尿酸干扰.     

Simple self-assembly of 3D laminated CuO/SnO2 hybrid for the detection of triethylamine

Tin dioxide is important gas sensor material and has wide applications in the detection of toxic gases and volatile organic compounds. Here, we synthesized a 3D laminated structural CuO/SnO₂ material possessing p-n heterostructures. The morphology and structure were characterized by XRD, SEM, TEM and XPS techniques and the sensing properties were investigated for the detection of triethylamine (TEA). The results indicate that 3D laminated CuO/SnO₂ material, assembled by lamellae consisting of ordered nanoparticles, exhibit an enhanced sensing performance compared with SnO₂, and notably, CuO/SnO₂ with size less than 1 μm has obvious high selectivity in the detection of 100 ppm TEA. Particularly, it has a high response and stability to 1 and 5 ppm TEA (S is 8 and 33), and that is higher than SnO₂ material, suggesting 3D laminated CuO/SnO₂ is an effective candidate material served as sensor platform to detect low-concentration amines.     

Effects of Carrier on CuO／TiO2 and CuO／Ti0.5Zr0.5O2 Catalysts in the NO＋CO Reaction

Using TiO2 and Ti0.5Zr0.5O2 as carriers, the CuO/TiO2 and CuO/Ti0.5Zr0.5O2 catalysts were prepared by the impregnation method with Cu(NO3)2 as active component. The catalytic activities in NO CO reaction were investigated using a microreactor-GC system, and structure and reducibility of catalysts were characterized by means of physical adsorption, TPR, XRD, NO-TPD technologies. It was found that the activity of CuO/Ti0.5Zr0.5O2 catalyst was higher than that of CuO/TiO2, probably due to the large specific surface area of Ti0.5Zr0.5O2 that played an important role in NO CO reaction.     

Carnation‐like CuO Hierarchical Nanostructures Assembled by Porous Nanosheets for Nonenzymatic Glucose Sensing

Carnation‐like CuO hierarchical nanostructures assembled by ultrathin porous nanosheets were successfully fabricated via a facile solvothermal route followed with heat treatment. As‐prepared CuO nanostructures exhibited excellent catalytic activity toward glucose oxidation in the absence of any enzymes. Under the optimized conditions, the CuO‐based enzymeless glucose sensor showed high sensitivity of 3.15 mA mM^?1 cm^?2, low limit of detection (98 nM, S/N=3), good reproducibility, excellent selectivity and long‐time stability. The superb nonenzymatic glucose sensing performance of the CuO hierarchical nanostructures was attributed to the highly catalytically active sites at the edges and basal planes of the CuO nanosheets, facile transportation of analytes through the abundant mesopores and macropores, robust and stable hierarchical structure. Moreover, the CuO‐based enzymeless glucose sensor showed high accuracy and reliability in comparison with clinical glucometer for quantitative determination of glucose in human blood serum samples.     

Hydrothermal Synthesis and Primary Gas Sensing Properties of CuO Nanosheets

Uniformity nanosheets of CuO were prepared by a mild hydrothermal synthesis method. Phase analysis was carried out using x-ray diffraction (XRD) and the result confirmed the CuO nanosheets as a single phase. The field-emission scanning electron microscopy (FE-SEM) was used to observe the morphology of CuO nanosheets while the gas sensing properties of these unique CuO nanosheets were tested at a static state system. The results show that the CuO has uniformity nanosheets, and the gas sensing property show that the CuO nanosheets gas sensor has a stable gas response and the same gas sensitivity trend to tested gases. This method may be suitable for larger-scale production of these CuO nanosheets for practical applications.     

溶胶-凝胶薄膜光纤传感器法测定空气中二氧化氮

以四乙氧基硅烷合成溶胶-凝胶薄膜,包埋偶氮试剂制备得到对二氧化氮具有灵敏响应的传感膜;与分支光纤等元件耦合成光纤传感器,通过累积吸收法能够现场测定空气中的低浓度二氧化氮．其检出限为每小时5ng／L;测定相对标准偏差为4．4％（n=6,C（NO2）=200ng／L,1h）。实验表明,CO2、NO、SO2、NO等共存气体在低浓度下对传感器测定NO2无明显干扰。     

焙烧温度对CuO/γ-Al2O3和CeO2-CuO/γ-Al2O3催化剂NO还原活性的影响

用浸渍法制备了CuO/γ-Al2O3催化剂和CeO2改性的CeO2-CuO/γ-Al2O3催化剂,考察了焙烧温度对CuO/γ-Al2O3和CeO2-CuO/γ-Al2O3催化剂C3H6还原NO反应活性的影响,以及CeO2的添加量对CeO2-CuO/γ-Al2O3催化剂C3H6还原NO反应活性的影响。结果表明,在200 ℃～500 ℃的焙烧温度范围内,焙烧温度对CuO/γ-Al2O3催化剂的活性影响很小；在500 ℃～800 ℃的焙烧温度范围内,随着焙烧温度的升高CuO/γ-Al2O3催化剂的活性急剧下降,由XRD物相测定结果可知,归因于对反应表现惰性的尖晶石CuAl2O4相的生成。当焙烧温度为500 ℃时,CeO2的添加对CuO/γ-Al2O3催化剂的活性影响很小；当焙烧温度为800 ℃时,CeO2的添加对CuO/γ-Al2O3催化剂有明显的助催化作用,当Ce和Cu的摩尔比为1∶10时,NO转化率较为理想。     

CuO/Al_2O_3催化剂中毒与氧吸附

燃煤烟气属于贫燃燃烧 (燃烧时通入过量空气 )尾气 ,其中除含 NOx、SO2 外还含有 O2 等 ,与非贫燃系统尾气中 NOx 的催化还原脱除相比有着很大的不同 .目前这一领域的研究工作虽然取得一些进展 ,但仍有许多问题尚待解决 [1] .无论是 NOx 的催化还原还是催化分解 ,气相中存在的SO2 对非贵金属及其氧化物催化剂构成了严重威胁 ,原因是非贵金属氧化物很容易吸收 SO2 生成稳定的硫酸盐而使催化剂中毒失活 .为脱除烟气中的 NOx,有报道先将气相中的 NO催化氧化为NO2 ,然后将 NO2 和 SO2 同时液相吸收 .研究表明 ,作为 NO催化氧化的非贵…