The influence of working temperature on the accuracy of the PdNi alloy thin film hydrogen sensor was investigated. The PdNi hydrogen sensor was fabricated on a silicon chip together with a Pt temperature sensor by DC sputtering. The PdNi hydrogen sensor shows excellent response to H-2 with concentration from 0.02% to 40% at room temperature. Results show that the response of PdNi hydrogen sensor is nonlinearly related to the hydrogen concentration and working temperature. And correction method only based on considering the baseline temperature correction cannot obtain high measurement accuracy in the whole range area. Therefore, in order to improve the full range detection accuracy of PdNi hydrogen sensor, a modified algorithm which takes baseline and sievert constant temperature compensation into account is presented in this work. After applying the algorithm, the PdNi hydrogen sensor exhibits enhanced H-2 sensing accuracy and stability even in violent temperature fluctuate situations.

Pt particles with different nanosizes were loaded on reduced graphene oxides by a hydrothermal synthesis method.The morphology and composite of the products were examined by SEM and XPS.The hydrogen sensing properties of Pt-rGO based gas sensor were measured.The results indicate that the sample with smaller Pt particles has better hydrogen sensing property than that of the larger Pt particles sample in the operating temperature range of 50-150 ℃.The hydrogen sensing property of the Pt-doped reduced graphene oxides with smaller Pt particles (20-40 nm) gas sensor was also investigated at 80 ℃.The results demonstrate that the gas sensor exhibits excellent sensing performances and shows linear response to hydrogen in the range of 0.5％-2％ (volume fraction).All the response time is less than 180 s.The Pt-rGO based gas sensor also exhibits good reproducibility and high recovery ability,which has certain application prospects.

The color change phenomenon of 1,3,5-triamino-2,4,6-trinitrobenzene (TATB) has puzzled the energetic researchers for decades. Many efforts have been dedicated to identifying the “colored TATB”, however, hardly any of well-established evidences have been ascertained. After detailed reviewing the literatures, we herein propose a new insight to survey the coloration of TATB. And a 3D photonic crystal model has been proposed to elucidate the color change phenomenon of TATB. Coloration behavior of the TATB is confirmed by home-made TATB thin film. It is proved that the coloration of TATB is a physical appearance, structural color.

Design and fabrication of organic-inorganic hybrid sensing materials is a promising strategy to combine the advantages of good stability of inorganic species and high sensitivity, selectivity and low operating temperature of organic ones. In this work, CuPcTS(Copper (II) Phthalocyanine Tetrasulfonic Acid Tetrasodium Salt)/SnO2 organic-inorganic hybrid film was prepared through a simple soak-assembling process. The p-type CuPcTS molecules were homogenously adsorbed on the surfaces of n-type SnO2 film to form p-n heterojunctions. Due to the low adsorption energy of NO2 on CuPcTS at low temperature, the CuPcTS/SnO2 hybrid film exhibits significantly improved sensing performance towards ppb-level NO2 with high sensitivity (Rg/Ra = 2400 up to 1 ppm NO2), ultra-low theoretical detection limit (similar to 40 ppb when signal-to-noise ratio is 3) and excellent selectivity. The ultrahigh sensitivity and selectivity upon ppblevel NO2 indicate the promising capability of CuPcTS/SnO2 hybrid film for environmental monitoring of NO2 concentrations. (C) 2017 Elsevier B.V. All rights reserved.

Chemiresistive gas sensors employing p-n heterostructures offer a compelling combination of high sensitivity and specific selectivity due to the synergic effects at interface. In this study, the p-Co3O4/n-SnO2 composites with different molar ratio of Co/Sn have been prepared using a simple soak-calcination method and their sensing properties are systematically investigated. The sensors demonstrate exclusive H-2 sensing properties with p-type sensing response, and n-type sensing response to the typical reducing gases such as CO, H2S and NH3. We propose that the abnormal sensing behaviors might be associated with the modulation of potential barrier heights formed in p-Co3O4/n-SnO2 heterojunctions, namely the modulation from the asymmetric gas sensing reactivity of SnO2 and Co3O4 to the reducing gases. This work may open up a general approach for tailoring the sensing selectivity of gas sensors via the modulation of potential barrier heights in p-n heterojunctions. (C) 2017 Elsevier B.V. All rights reserved.

ZnO nanomaterials have been directly grown on Al2O3 ceramic tube by two step seeds-assisted solution method with different ammonia sources. The crystalline phase and morphology of the ZnO nanomaterials are characterized by XRD and SEM. The results of SEM reveal that the ZnO nanomaterials present different morphologies and hierarchical structures where rhombus-shaped nanoprisms, nanorods assembled nanoflowers and nanoleaves constructed nanourchins are obtained in NH4F, hexamethylenetetramine (HMT) and urea, respectively. All of the ZnO nanomaterials show the optimal working temperature at 320 °C and excellent repeatability. Gas sensing experiments demonstrate that the ZnO nanomateirals perform high responses and fast response-recovery to volatile organic compounds, especially for the nanorods assembled nanoflowers prepared in the HMT. It is believed that the enhancement of the gas sensing performances is mainly attributed to the hierarchical structures, exposed deficiencies and excellent ohm contact of the direct grown ZnO nanomaterials.

A new, highly sensitive and selective hydrogen gas (H-2) sensor based on birnessite-type manganese oxide (delta-MnO2) nanoflakes was prepared. The delta-MnO2 nanoflakes sensor selectively detected H-2 with detection limits in air of 150 ppb at 200 degrees C and 7.5 ppm at room temperature. In addition, the sensor also exhibited a considerable response to H-2 in an N-2 atmosphere. The sensor rapidly responded to trace levels of H-2 gas and displayed reversible recovery, while the detected H-2 concentrations could be accurately calculated using a modified Langmuir isotherm adsorption equation. The influence of the temperature and humidity on the sensing performance of the sensor was also investigated. The mechanism of the sensor is based on the oxidation of H2O and H-2 accompanied by the formation and oxidation of MnOOH. It is believed that the low detection limit, high selectivity and fast reversible response of the delta-MnO2 nanoflake sensor are important benefits that make this sensor a promising candidate for H-2 leak detection. (C) 2014 Elsevier B.V. All rights reserved.

The high capacity of Co3O4 nanoflowers (NFs) on Ni foam as anodes in Li ion batteries is reported in this paper. The NFs grown firmly on Ni foam is convenient for the construction of lithium ion batteries without any extra electrode preparation process. The NFs presents an initial discharge capacity of 811mAh g(-1) at a current of 1 C. Our facile solvothermal film growth technique offers an exciting opportunity for growth of metal oxide nanostructures on substrates with practical application in lithium ion batteries.

Instant detection of trace-level nitroaromatic explosives is highly desirable for national security and environmental protection. In this paper, a new strategy for the construction of nitroaromatic-indicator paper was proposed based on a mixture of red emitting cysteamine modified cadmium telluride quantum dots and green emitting thioglycollic acid capped cadmium telluride quantum dots which served as the nitroaromatic sensor and reference probes, respectively. Nitroaromatic-indicator paper showed excellent response to trinitrotoluene and picric acid with visual detection limits of 1.59 and 1.16 ng mm(-2). The screening process was accomplished within half a minute. The visualization of the nitroaromatic-indicating paper was significantly enhanced when the green reference probe was used as the background. Therefore, a rapid, simple, convenient, and high selectivity paper sensor was developed for nitroaromatics.

应用简单溶液法制备出多棱梭形和球形两种形貌的CuO微纳米材料,用XRD对产品进行表征,用SEM,TEM研究产物的形貌和大小。并研究了两种形貌的CuO微纳米材料对罗丹明B的光催化降解性能,发现这两种形貌CuO微纳米材料对罗丹明B都有良好的光催化降解性能。

A large-scale flowerlike ZnO nanostructure is prepared using a very simple solution method at near room temperature. The flowerlike ZnO nanostructure is self-assembled by thin and uniform nanosheets with a thickness of approximately 18nm. X-ray powder diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM) are used to characterize the structure and morphology. The possible growth mechanism is carefully discussed based on the reaction process. The as-prepared ZnO nanoflowers exhibit a good response and reversibility to some organic gases, such as ethanol and n-butanol. The responses to 100ppm ethanol and n-butanol are 25.4 and 24.1, respectively, at a working temperature of 320°C. In addition, the sensors exhibit a good response to acetone, 2-propanol, and methanol. The relationship between the gas-sensing properties and the microstructure of the as-prepared ZnO nanoflowers is also investigated.

Porous flower-like tin oxide (SnO2) nanostructure is prepared by annealing of the flower-like tin sulfur (SnS2) nanostructures. The morphology and crystal structure of the flower-like SnO2 nanostructures are characterized by field emission scanning electron microscopy, transmission electron microscopy, and X-ray diffraction. The average SnO2 crystallite size is about 6.1nm. The as-prepared porous flower-like SnO2 nanostructures exhibit a good response and reversibility to some organic gases, such as ethanol and n-butanol. The sensor responses to 100ppm ethanol and n-butanol are 42.6 and 77.2, respectively, at a working temperature of 240°C. In addition, the sensors exhibit a good response to methanol, 2-propanol, and acetone. The relationship between the gas-sensing properties and the microstructure of the as-prepared flower-like SnO2 nanostructures is also investigated.

Sb-doped SnO2 whiskers were prepared by thermal evaporation of mixture of SnO and Sb2O3 powders Sb segregation to the surface of SnO2 whisker was demonstrated The humidity sensitive characteristics of single SnO2 whisker-based sensors have been investigated By monitoring the current through the SnO2 whisker at fixed voltage, relative humidity can be determined It is found that the current of the Sb-doped SnO2 whisker-based sensor increases by about five orders of magnitude with increasing relative humidity (RH) from 43.2 to 84 3% The response and recovery time of the sensor are approximate 12 and 8 s, respectively Compared to the pure SnO2 whisker, Sb-doped SnO2 whisker exhibits greatly improvement of sensitivity which could be explained by the surface-segregated Sb atoms This is the first step towards fundamental understanding of single-crystalline tin oxide whiskers for sensor applications, which could lead to integration in real devices.

Sb-doped SnO2 whiskers were prepared by thermal evaporation of mixture of SnO and Sb2O3 powders. And then the surface of the whisker was modified with the Au nanoparticles (Au NPs) by in situ reduction method. FE-SEM observations reveal that the synthesized products consist of a large number of whiskers. The Au NPs were homogeneously distributed on the surface of the whisker. The ethanol sensitive characteristics of single SnO2 whiskerbased sensors have been investigated. These sensors show good sensitivity, rapid response and recovery. The response and recovery time of the sensor is about 38-45 s and 125-150 s, respectively. It is found that the working temperature of the sensor decreases after the surface of Sb-doped whiskers modified with Au NPs. Compared to the unmodified Sbdoped SnO2 whisker, Au NPs modified Sb-doped SnO2 whisker exhibits greatly improvement of sensitivity which could be explained by the catalytic action of Au NPs. These results indicate that the Au NPs modifying the surface of SnO2 whiskers is important for improving its sensitivity and lowering the working temperature. This is the first step towards fundamental understanding of single-crystalline tin oxide whiskers for sensor applications, which could lead to integration in real devices.

Titanium and high concentration sodium hydroxide solution was used to synthesize titania nanotube via hydrothermal method.The nanotube was characterized by SEM,TEM,and XRD.The length of the nanotube is about 200~300nm,the diameter is about 20~25nm.The nanotube was screen-printed on the FTO glass,and then it was treated with heating.After being sintered the TiO2 electrode was immersed into a N719 dye solution,then assembled with another FTO glass coated with platonic.Photovoltaic measurement of DSC employed the simulated solar rays and its fill factor was 0.43,short current 0.48mA,open voltage 0.35V,solar to electric power conversion efficiency 0.07%.

A novel highly sensitive gas ionization sensor for ammonia detection in ambient air is introduced in this paper. Carbon nanotubes (CNTs) grown on silicon substrate were incorporated to fabricate a gas ionization sensor. Application of a positive bias to the CNTs generates electric fields sufficiently to field-ionize passing gas-phase molecular and initiate a prebreakdown current. When the CNTs film is configured as the cathode, secondary electrons repelled away from the CNTs tips into the gap spacing make more ionizing collisions and also initiate a prebreakdown current. By monitoring the prebreakdown current, the gas ionization sensor was demonstrated to be capable of ionizing and detecting the ammonia and with a linear response over the entire range from 1 to 160ppm ammonia in air. The sensitivity mechanism of the gas ionization sensor was also discussed in detail. The sensitivity and selectivity of the gas ionization sensor to the gases is not only dependent on its ionization energy but also its electric dipole moment. The novel CNTs-based gas ionization sensor described here exhibits high accuracy, repeatability and stability. The sensor is promising for use in various fields.