scholarly journals Preparation and NH3 Gas-Sensing Properties of Double-Shelled Hollow ZnTiO3 Microrods

Sensors ◽  
2019 ◽  
Vol 20 (1) ◽  
pp. 46 ◽  
Author(s):  
Pi-Guey Su ◽  
Xiang-Hong Liu
Keyword(s):  
Electron Microscopy ◽  
Room Temperature ◽  
Gas Sensing ◽  
Strong Response ◽  
X Ray ◽  
Sensing Properties ◽  
Diallyldimethylammonium Chloride ◽  
Transmission Electron ◽  
Low Concentrations ◽  
Gas Sensing Properties

A novel double-shelled hollow (DSH) structure of ZnTiO3 microrods was prepared by self-templating route with the assistance of poly(diallyldimethylammonium chloride) (PDDA) in an ethylene glycol (EG) solution, which was followed by calcining. Moreover, the NH3 gas-sensing properties of the DSH ZnTiO3 microrods were studied at room temperature. The morphology and composition of DSH ZnTiO3 microrods films were analyzed using scanning electron microscopy (SEM), transmission electron microscopy (TEM) and X-ray diffractometry (XRD). The formation process of double-shelled hollow microrods was discussed in detail. The comparative gas-sensing results revealed that the DSH ZnTiO3 microrods had a higher response to NH3 gas at room temperature than those of the TiO2 solid microrods and DSH ZnTiO3 microrods did in the dark. More importantly, the DSH ZnTiO3 microrods exhibited a strong response to low concentrations of NH3 gas at room temperature.

Synthesis of Al Doped ZnO with a Novel Rice Microstructure by Hydrothermal Process and Analysis of their Gas Sensing Properties

2014 ◽  
Vol 809-810 ◽  
pp. 724-730
Author(s):  
Zan Li ◽  
Wei Qin ◽  
Xiao Hong Wu
Keyword(s):  
Electron Microscopy ◽  
Gas Sensing ◽  
Hydrothermal Process ◽  
Hexagonal Wurtzite Structure ◽  
X Ray ◽  
Sensing Properties ◽  
Transmission Electron ◽  
Gas Sensing Properties ◽  
Doped Zno ◽  
Hydrothermal Approach

Al-doped ZnO (AZO) powers with a novel rice-like morphology have been successfully synthesized through a simple and efficient hydrothermal approach, the products have been characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) with an energy-dispersive X-ray analyzer and transmission electron microscopy (TEM). It showed that all the samples presented an hexagonal wurtzite structure of high crystallinity, and the microstructure was composed of numerous dumbbells. Furthermore, the heater gas sensors were fabricated and an investigation of gas sensing properties has been conducted. The sensors showed good selectivity to ethanol comparing with NH3, SO2, CO and HCHO and possible mechanism was discussed. The Sensors based AZO powers exhibited high response values, reproducible response-recovery to ethanol 50-1800 ppm at 332°C.

The Characterization and Gas Sensing Properties of Polythiophene Coated V2O5 Nanotubes

2010 ◽  
Vol 654-656 ◽  
pp. 1154-1157 ◽  
Author(s):  
Yu Lu ◽  
Wei Jin ◽  
Wen Chen
Keyword(s):  
Electron Microscopy ◽  
Gas Sensing ◽  
In Situ Polymerization ◽  
X Ray Diffraction ◽  
X Ray ◽  
Sensing Properties ◽  
Transmission Electron ◽  
Gas Sensing Properties ◽  
Higher Sensitivity

Polythiophene (PTP) coated V2O5 nanotubes were prepared by an in-situ polymerization of thiophene monomers in the presence of prepared V2O5 nanotubes. The nanotubes were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM), which proved the polymerization of thiophene monomer and the strong interaction between polythiophene and V2O5 nanotubes (VONTs). The gas sensing properties of PTP coated V2O5 nanotubes were studied at room temperature, which was found that PTP coated V2O5 nanotubes could detect ethanol with much higher sensitivity than pure VONTs. The sensing mechanism of PTP coated V2O5 nanotubes to ethanol is presumed to be the synergetic interaction between polythiophene (PTP) and V2O5 nanotubes.

scholarly journals Gas Sensing Properties of Perovskite Decorated Graphene at Room Temperature

Sensors ◽  
2019 ◽  
Vol 19 (20) ◽  
pp. 4563 ◽  
Author(s):  
Juan Casanova-Cháfer ◽  
Rocío García-Aboal ◽  
Pedro Atienzar ◽  
Eduard Llobet
Keyword(s):  
Electron Microscopy ◽  
Photoelectron Spectroscopy ◽  
Room Temperature ◽  
Gas Sensing ◽  
Semiconductor Film ◽  
Promising Alternative ◽  
Sensing Properties ◽  
Enhanced Sensitivity ◽  
Transmission Electron ◽  
Gas Sensing Properties

This paper explores the gas sensing properties of graphene nanolayers decorated with lead halide perovskite (CH3NH3PbBr3) nanocrystals to detect toxic gases such as ammonia (NH3) and nitrogen dioxide (NO2). A chemical-sensitive semiconductor film based on graphene has been achieved, being decorated with CH3NH3PbBr3 perovskite (MAPbBr3) nanocrystals (NCs) synthesized, and characterized by several techniques, such as field emission scanning electron microscopy, transmission electron microscopy and X-ray photoelectron spectroscopy. Reversible responses were obtained towards NO2 and NH3 at room temperature, demonstrating an enhanced sensitivity when the graphene is decorated by MAPbBr3 NCs. Furthermore, the effect of ambient moisture was extensively studied, showing that the use of perovskite NCs in gas sensors can become a promising alternative to other gas sensitive materials, due to the protective character of graphene, resulting from its high hydrophobicity. Besides, a gas sensing mechanism is proposed to understand the effects of MAPbBr3 sensing properties.

scholarly journals Controlled Synthesis of Hierarchically Assembled Porous ZnO Microspheres with Enhanced Gas-Sensing Properties

2015 ◽  
Vol 2015 ◽  
pp. 1-9
Author(s):  
Shengsheng You ◽  
Haojie Song ◽  
Jing Qian ◽  
Ya-li Sun ◽  
Xiao-hua Jia
Keyword(s):  
Electron Microscopy ◽  
Gas Sensing ◽  
Hexagonal Phase ◽  
Trisodium Citrate ◽  
Zinc Hydroxide ◽  
Scanning Calorimetry ◽  
Sensing Properties ◽  
Transmission Electron ◽  
Porous Nanosheets ◽  
Gas Sensing Properties

The ZnO microspheres constructed by porous nanosheets were successfully synthesized by calcinating zinc hydroxide carbonate (ZHC) microspheres obtained by a sample hydrothermal method. The samples were characterized in detail with scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), and thermogravimetric and differential scanning calorimetry (TG-DSC). The results indicated that the prepared ZnO microspheres were well crystalline with wurtzite hexagonal phase. The effects of reaction time, temperature, the amount of trisodium citrate, and urea on the morphology of ZnO microspheres were studied. The formation mechanism of porous ZnO microspheres was discussed. Furthermore, the gas-sensing properties for detection of organic gas of the prepared porous ZnO microspheres were investigated. The results indicated that the prepared porous ZnO microspheres exhibited high gas-sensing properties for detection of ethanol gas.

A Metastable Ion (III) Oxide Phase (ε-Fe2O3): Preparation and Gas Sensing Properties

2016 ◽  
Vol 697 ◽  
pp. 737-740 ◽  
Author(s):  
Ming Jing Wang ◽  
Hui Ming Ji ◽  
Ya Lu Chen ◽  
Qian Qian Jia
Keyword(s):  
Electron Microscopy ◽  
Gas Sensing ◽  
Sol Gel ◽  
Oxide Phase ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Gas Sensing Properties ◽  
Addition Amount ◽  
Scanning Electron

ε-Fe2O3 is a rare and metastable iron (III) oxide phase. ε-Fe2O3/SiO2 composites were prepared by combining the reverse-micelle and sol-gel methods. An appropriate amount of Ba2+ was needed in this system to promote the formation of ε-Fe2O3 nanorods in SiO2. The size of nanorods varied with different Ba2+ addition amount and sintering procedure. Then pure ε-Fe2O3 nanorods were obtained after stripping SiO2 by etching due to NaOH aqueous solution. The as-synthesized ε-Fe2O3 nanorods were discussed using X-ray diffraction (XRD), scanning electron microscope (SEM) and transmission electron microscopy (TEM). Interestingly, metastable ε-Fe2O3 nanorods showed a promising performance for the response for ethanol, compared with the stable phases of α-Fe2O3 and γ-Fe2O3. It indicates that nanostructure ε-Fe2O3 (including ε-Fe2O3 nanorods) could be a valuable material for the fabrication of advanced sensing devices.

Synthesis and Gas Sensing Properties of SnO2-CuO Nanocomposites

2013 ◽  
Vol 645 ◽  
pp. 129-132 ◽  
Author(s):  
Jantasom Khanidtha ◽  
Suttinart Noothongkaew ◽  
Supakorn Pukird
Keyword(s):  
Room Temperature ◽  
Gas Sensing ◽  
Precipitation Method ◽  
Monoclinic Structure ◽  
X Ray Diffraction ◽  
Sem Images ◽  
X Ray ◽  
Sensing Properties ◽  
Gas Sensing Properties ◽  
Co Precipitation

SnO2-CuO nanocomposites have been synthesized with the simple co-precipitation method for gas sensing properties. Sn and CuO powder were the starting materials. The synthesized products were investigated by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The results show that SnO2-CuO nanocomposites have a tetragonal and monoclinic structure, respectively. SEM images verify that the some microballs are up to 10 µm and nanorods have a diameter range from 10-100 nm, while length ranges a few micrometers. The nanocomposite products were highly sensitivity to CO2gas at room temperature.

The Microwave-Assisted Synthesis and Gas Sensing Properties for Ethanol of SnO2 Nanomaterials

2013 ◽  
Vol 721 ◽  
pp. 237-240 ◽  
Author(s):  
Yong Ju Liu ◽  
Qiu Ping Jiang ◽  
Yue Huan Li ◽  
He Yun Zhao
Keyword(s):  
Electron Microscopy ◽  
Gas Sensing ◽  
Microwave Assisted Synthesis ◽  
X Ray Diffraction ◽  
Sensing Properties ◽  
Microwave Assisted ◽  
Transmission Electron ◽  
Good Crystalline Quality ◽  
Gas Sensing Properties ◽  
Microwave Assisted Method

With the advantages of the microwave-assisted method, good crystalline quality SnO2nanomaterials were successfully synthesized. The morphology and microstructure of SnO2were characterized by X-ray diffraction (XRD), scanning electron microscopy, transmission electron microscopy and high-resolution (HRTEM) used to examine SnO2nanomaterials. Indirect-heating sensors based on nanorods were fabricated and investigated for the gas sensing properties to ethanol. The investigation demonstrates that the sensor based on prepared SnO2nanomaterials has good sensitivity, low detection limit and short response and reversion time to ethanol at 275 °C.

Growth, Characterization and Gas Sensing Properties of Nanotetrapod ZnO

2008 ◽  
Vol 8 (8) ◽  
pp. 4106-4110 ◽  
Author(s):  
Manmeet Kaur ◽  
Shovit Bhattacharya ◽  
Vibha Saxena ◽  
D. K. Aswal ◽  
Mainak Roy ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Photoelectron Spectroscopy ◽  
Gas Sensing ◽  
Green Emission ◽  
Near Band Edge ◽  
X Ray ◽  
Sensing Properties ◽  
Selected Area Electron Diffraction ◽  
Growth Characterization ◽  
Gas Sensing Properties

ZnO nanotetrapods have been obtained in large quantities by carbothermal reduction of ZnO powder. These were characterized by X-ray diffraction, X-ray photoelectron spectroscopy, scanning electron microscopy, transmission electron microscopy, selected area electron diffraction, UV-visible spectroscopy and photoluminescence. Electron microscopy revealed that the overall size of the tetrapods is 1.5–2 μm and legs are 30–50 nm in diameter. The size of tetrapods as well as diameter of the legs was found to increase with deposition temperature. Photoluminescence spectra revealed that green emission originating from oxygen vacancies overwhelmed that of the near-band-edge ultraviolet peak. A band gap of 3.27 eV was calculated from optical absorption spectra which agreed well with that estimated from PL spectra. Gas sensing properties of tetrapods were investigated and these were found to be 5 times more sensitive to H2S gas at room temperature in comparison to ZnO bulk polycrystalline material.

Simple Synthesis of Mesoporous SnO2 Microspheres and their Gas Sensing Properties

2014 ◽  
Vol 1044-1045 ◽  
pp. 96-99
Author(s):  
Zhi Peng Sun ◽  
Yi Lu
Keyword(s):  
Electron Microscope ◽  
Gas Sensing ◽  
Resorcinol Formaldehyde ◽  
X Ray ◽  
Sensing Properties ◽  
Transmission Electron ◽  
Gas Sensing Properties ◽  
Sensitivity And Selectivity ◽  
20 Nm ◽  
Tin Tetrachloride

In this work, uniform mesoporous SnO2microspheres have been prepared via a facile and scalable method using tin tetrachloride pentahydrate (SnCl4·5H2O) and resorcinol-formaldehyde gel (RF gel) as starting materials. Furthermore, the structure and morphology of the as-prepared product were characterized by scanning electron microscope (SEM), Transmission electron microscope (TEM) and X-ray diffractometer (XRD). The results revealed that as-synthesized microspheres were around 500 nm in size and composed of large amount of SnO2nanoparticles with diameters of 10-20 nm. Gas sensors based on mesoporous SnO2microspheres were fabricated, and their gas sensing properties were tested for response to methane, butane, H2and CO gas. The sensor exhibited better sensitivity and selectivity to H2vapors at 300 °C than that of the conventional SnO2materials. The enhancement in gas sensing properties was attributed to their unique nanostructures.

Fabrication, structural and humidity sensing properties of BaTiO3 nanofibers via electrospinning

2015 ◽  
Vol 29 (12) ◽  
pp. 1550066 ◽  
Author(s):  
Chen-Hao Sheng ◽  
Hong-Di Zhang ◽  
Shuai Chen ◽  
Jun-Cheng Zhang ◽  
Wen-Peng Han ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Recovery Time ◽  
Room Temperature ◽  
Electrospinning Technique ◽  
Humidity Sensing ◽  
X Ray ◽  
Sensing Properties ◽  
Transmission Electron ◽  
Humidity Sensitivity ◽  
Humidity Sensing Properties

Barium titanate (BTO) nanofibers were synthesized by electrospinning and followed calcination. The morphologies and microstructures of the nanofibers were characterized by X-ray diffractometer (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Calcinating temperature and process greatly influenced the surface morphology of the nanofibers. In addition, parallel BTO nanofibers were also successfully produced by a centrifugal electrospinning technique. And the humidity sensing properties of the nanofibers were measured. The results showed an ultrafast response time (~0.5 s) and a recovery time (~0.4 s) to humidity at room temperature, which revealed excellent humidity sensitivity performance.

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