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

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.

2014 ◽  
Vol 809-810 ◽  
pp. 724-730
Author(s):  
Zan Li ◽  
Wei Qin ◽  
Xiao Hong Wu

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.


2015 ◽  
Vol 14 (04) ◽  
pp. 1550011 ◽  
Author(s):  
A. Sharma ◽  
M. Tomar ◽  
V. Gupta ◽  
A. Badola ◽  
N. Goswami

In this paper gas sensing properties of 0.5–3% polyaniline (PAni) doped SnO 2 thin films sensors prepared by chemical route have been studied towards the trace level detection of NO 2 gas. The structural, optical and surface morphological properties of the PAni doped SnO 2 thin films were investigated by performing X-ray diffraction (XRD), Transmission electron microscopy (TEM) and Raman spectroscopy measurements. A good correlation has been identified between the microstructural and gas sensing properties of these prepared sensors. Out of these films, 1% PAni doped SnO 2 sensor showed high sensitivity towards NO 2 gas along with a sensitivity of 3.01 × 102 at 40°C for 10 ppm of gas. On exposure to NO 2 gas, resistance of all sensors increased to a large extent, even greater than three orders of magnitude. These changes in resistance upon removal of NO 2 gas are found to be reversible in nature and the prepared composite film sensors showed good sensitivity with relatively faster response/recovery speeds.


2014 ◽  
Vol 2 (39) ◽  
pp. 16697-16706 ◽  
Author(s):  
Shouli Bai ◽  
Song Chen ◽  
Yangbo Zhao ◽  
Teng Guo ◽  
Ruixian Luo ◽  
...  

The response of ZnO nanofibers is significantly enhanced via Cd doping, which can be attributed to the change of defects in ZnO and has been confirmed by PL and XPS analysis.


2013 ◽  
Vol 873 ◽  
pp. 304-310 ◽  
Author(s):  
Jin Zhang ◽  
Yu Min Zhang ◽  
Chang Yi Hu ◽  
Zhong Qi Zhu ◽  
Qing Ju Liu

The gas-sensing properties of zinc doped lanthanum ferrite (Zn-LaFeO3) compounds for formaldehyde were investigated in this paper. Zn-LaFeO3 powders were prepared using sol-gel method combined with microwave chemical synthesis. The powders were characterized by X-ray diffraction (XRD) and transmission electron microscopy (TEM), respectively. The formaldehyde gas-sensing characteristics for the sample were examined. The experimental results indicate that the sensor based on the sample Zn-LaFeO3 shows excellent gas-sensing properties to formaldehyde gas. At the optimal operating temperature of 250°C, the sensitivity of the sensor based on LaFe0.7Zn0.3O3 to 100ppm formaldehyde is 38, while to other test gases, the sensitivity is all lower than 20. The response and recovery times for the sample to formaldehyde gas are 100s and 100s, respectively.


RSC Advances ◽  
2016 ◽  
Vol 6 (31) ◽  
pp. 26227-26238 ◽  
Author(s):  
David E. Motaung ◽  
Ioannis Kortidis ◽  
Gugu H. Mhlongo ◽  
Mart-Mari Duvenhage ◽  
Hendrik. C. Swart ◽  
...  

Schematic diagram showing the 2D TOF SIMS overlays of Si+, Mn+and Zn+. The insert corresponds to the correlation between the sensing response and FMR signal as a function of Mn concentration when exposed to various gases.


2018 ◽  
Vol 212 ◽  
pp. 292-295 ◽  
Author(s):  
T. Çorlu ◽  
I. Karaduman ◽  
S. Galioglu ◽  
B. Akata ◽  
M.A. Yıldırım ◽  
...  

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