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.

Synthesis of flower-like Al doped ZnO microstructures by hydrothermal process and analysis of their gas sensing properties

2014 ◽  
Vol 07 (04) ◽  
pp. 1450037 ◽  
Author(s):  
Zan Li ◽  
Wei Qin ◽  
Wenjie Zhao ◽  
Xiaohong Wu
Keyword(s):  
Gas Sensing ◽  
Hydrothermal Process ◽  
Hexagonal Wurtzite Structure ◽  
Underlying Mechanism ◽  
Diffraction Spectrum ◽  
X Ray Diffraction ◽  
Sensing Properties ◽  
Gas Sensing Properties ◽  
Doped Zno ◽  
Hydrothermal Approach

Al -doped ZnO (AZO) powders with flower-like microstructures were successfully synthesized through a simple and efficient hydrothermal approach, and were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), and energy diffraction spectrum (EDS). All the samples presented high crystallinity with a hexagonal wurtzite structure. The heater gas sensors based on AZO were fabricated and investigation of gas sensing properties was conducted. The sensors showed high response values and reproducible response-recovery for 50–1800 ppm ethanol at 332°C, comparing with NH 3, SO 2, CO , and HCHO . The underlying mechanism was discussed.

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 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.

Characteristic of Al-Doped ZnO Nanorods by a Hydrothermal Process

2010 ◽  
Vol 434-435 ◽  
pp. 646-648 ◽  
Author(s):  
Jenn Kai Tsai ◽  
Ju Yu Wei ◽  
Yi Chi Chen ◽  
You Cheng Jheng ◽  
Teen Hang Meen
Keyword(s):  
Electron Microscopy ◽  
Zno Nanorods ◽  
Hydrothermal Process ◽  
Zinc Nitrate ◽  
Diffraction Field ◽  
Si Substrate ◽  
X Ray ◽  
Transmission Electron ◽  
Dilute Aqueous Solution ◽  
Doped Zno

In this study, well-aligned single-crystalline zinc oxide (ZnO) nanorods arrays were synthesized on Si substrate by simple hydrothermal process in dilute aqueous solution which consisting of zinc nitrate tetrahydrate (Zn(NO3)2•4H2O) and hexamethyltetramine (C6H12N4, HMT) at 90 °C, in the autoclave. ZnO thin film was pre-deposited on Si substrate by the sputter deposition to serve as the seed layer. Aluminum nitrite (Al(NO3)3) also has been mixed into reaction solution. Al doped ZnO nanorod arrays were fabricated successfully. ZnO nanorods were characterized by high resolution X-ray diffraction, field emission scanning electron microscopy, transmission electron microscopy, energy dispersive x-ray spectroscopy, and photoluminescence measurement.

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.

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.

Oxygen vacancies-contained SnO2 nanotubes with enhanced ethanol gas sensing properties

2019 ◽  
Vol 34 (01n03) ◽  
pp. 2040003 ◽  
Author(s):  
Yifan Chen ◽  
Xiuling Ma ◽  
Chen Li ◽  
Qiuyu Wu ◽  
Yongbo Wang ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
High Performance ◽  
Oxygen Vacancies ◽  
Gas Sensing ◽  
Original Sample ◽  
X Ray Diffraction ◽  
Sensing Properties ◽  
Transmission Electron ◽  
Gas Sensing Properties ◽  
Ethanol Sensing

[Formula: see text] porous nanotubes containing oxygen vacancies were prepared by electron spinning and H plasma treatment. The morphology and crystal structure of the samples were analyzed by scanning electron microscopy (SEM), transmission electron microscopy (TEM) and X-ray diffraction (XRD). The ethanol-sensing properties of the [Formula: see text] sensor were tested. The results show that the samples treated with H plasma for 20 min have the best performance. Its working temperature is [Formula: see text]C lower than [Formula: see text]C of the original sample, with a sensitivity of 17 at 100 ppm, which is seven times higher than the original sample. It also shows good selectivity to some common interfering gases. This enhancement can be ascribed to the introduced oxygen vacancy. This work provides an efficient way to design high-performance gas sensor materials.

Sign in / Sign up

Export Citation Format

Share Document