Facile Synthesis of Hierarchical CuO Microspheres and their Gas Sensing Properties for NOx at Room Temperature

2015 ◽  
Vol 68 (10) ◽  
pp. 1569 ◽  
Author(s):  
Wanzhen Song ◽  
Hongyuan Wu ◽  
Jingchao Wang ◽  
Yufei Lin ◽  
Jiabao Song ◽  
...  

In this research, hierarchical CuO microspheres have been successfully synthesised by a facile reflux method. Scanning electron microscopy results clearly revealed that the hierarchical CuO microspheres were composed of two-dimensional nanosheets. The morphology of the prepared products could be tailored by changing the precursor concentration. The CuO-2 sample shows a higher NOx gas sensing performance with a low detection limit of 0.97 ppm, high gas response of 64.93 %, and short response time of 5.33 s to 97.0 ppm NOx at room temperature. The CuO-2 sensor also presents good selectivity and stability. The significantly improved gas response was concluded to be related to the well aligned microstructures and the improved conductivity of the CuO-2 sample. The unique hierarchical structure allows effective and rapid gas diffusion towards the sensing surfaces. In addition, the sensing mechanism based on the hierarchical CuO microspheres is discussed.

2017 ◽  
Vol 19 (29) ◽  
pp. 19043-19049 ◽  
Author(s):  
Shuai Wang ◽  
Da Huang ◽  
Shusheng Xu ◽  
Wenkai Jiang ◽  
Tao Wang ◽  
...  

Defects caused by Al3+doping significantly affect the gas-sensing properties of NiO nanosheets.


2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Hassan Ahmadvand ◽  
Azam Iraji zad ◽  
Raheleh Mohammadpour ◽  
Seyed Hossein Hosseini-Shokouh ◽  
Elham Asadian

Abstract Here in this research, room temperature ethanol and humidity sensors were prepared based on two dimensional (2D) hybrid nanostructures of tungsten di-sulfide (WS2) nanosheets and graphene oxide nanoribbons (GONRs) as GOWS. The characterization results based on scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (ESD), Raman spectroscopy and X-ray diffraction (XRD) analysis confirmed the hybrid formations. Ethanol sensing of drop-casted GOWS films on SiO2 substrate indicated increasing in gas response up to 5 and 55 times higher compared to pristine GONRs and WS2 films respectively. The sensing performance of GOWS hybrid nanostructures was investigated in different concentrations of WS2, and the highest response was about 126.5 at 1 ppm of ethanol in 40% relative humidity (R.H.) for WS2/GONRs molar ratio of 10. Flexibility of GOWS was studied on Kapton substrate with bending radius of 1 cm, and the gas response decreased less than 10% after 30th bending cycles. The high response and flexibility of the sensors inspired that GOWS are promising materials for fabrication of wearable gas sensing devices.


2017 ◽  
Vol 41 (24) ◽  
pp. 15042-15048 ◽  
Author(s):  
Qi Zhao ◽  
Guangsi Ma ◽  
Chengbo Zhai ◽  
Xiaodong Yang ◽  
Mingzhe Zhang

Hierarchical CuO microspheres assembled with monocrystalline nanosheets based sensors exhibit favorable ethanol gas sensing properties, particularly rapid response/recovery speed.


2020 ◽  
Vol 15 (7) ◽  
pp. 859-863
Author(s):  
Huaiqiu Zhu ◽  
Kaifang Wang ◽  
Fan Zhang ◽  
Wenbin Chen ◽  
Ze Wang ◽  
...  

As an indoor air toxic gas, formaldehyde is the main pollutant in interior decoration. In current work, we reported a novel formaldehyde gas sensing material and its gas sensing properties were investigated. We found that such novel two dimensional structure show excellent gas sensing performance towards formaldehyde and holding the potential of apply in detection of indoor air. Higher sensor response and faster response and recovery speed are primarily responsible for the unique morphology, leading to sufficient sensing reaction on the surface as well as abundant gas diffusion.


2019 ◽  
Vol 30 (18) ◽  
pp. 17094-17105
Author(s):  
Akshay Krishnakumar ◽  
Parthasarathy Srinivasan ◽  
Arockia Jayalatha Kulandaisamy ◽  
K. Jayanth Babu ◽  
John Bosco Balaguru Rayappan

2021 ◽  
Vol 16 (3) ◽  
pp. 363-367
Author(s):  
Gaoqi Zhang ◽  
Fan Zhang ◽  
Kaifang Wang ◽  
Tao Tian ◽  
Shanyu Liu ◽  
...  

Accurate and real-time detection of formaldehyde (HCHO) in indoor air is urgently needed for human health. In this work, a ceramic material (WO3·H2O) with unique structure was successfully prepared using an efficient hydrothermal method. The crystallinity, morphology and microstructure of the as-prepared sensing material were analyzed by X-ray diffraction (XRD), field emission scanning electron microscope (FESEM) as well as transmission electron microscope (TEM). The characterization results suggest that the as-prepared sample is composed of square-like nanoplates with uneven surface. Formaldehyde vapor is utilized as the target gas to investigate gas sensing properties of the synthesized novel nanoplates. The testing results indicate that the as-fabricated gas sensor exhibit high gas response and excellent repeatability to HCHO gas. The response value (Ra/Rg) is 24.5 towards 70 ppm HCHO gas at 350 °C. Besides, the gas sensing mechanism was described.


2020 ◽  
Vol 323 ◽  
pp. 128663
Author(s):  
Yingqiang Zhao ◽  
Xiaoxiao Yuan ◽  
Yimin Sun ◽  
Qian Wang ◽  
Xin-Yuan Xia ◽  
...  

2007 ◽  
Vol 1035 ◽  
Author(s):  
Amandeep Saluja ◽  
Jie Pan ◽  
Lei Kerr ◽  
Eunjung Cho ◽  
Seth Hubbard

AbstractIn this work, various ZnO nanostructures were synthesized and a detailed study on the effect of different process parameters such as temperature, carrier gas flow, inter-electrode spacing, gas concentration and material properties on gas sensitivity was conducted. Initial ZnO nanoparticles were prepared by a simple solution chemical process and characterized by Secondary Electron Microscopy (SEM) and Brunauer, Emmet and Teller (BET) Sorptometer to demonstrate the morphology and surface area respectively. Sensitivity of nano-platelets and porous films was measured for different concentrations of the analytes (H2, CO). High response was observed at room temperature for H2 gas with sensitivities in excess 80% for 60ppm and about 55% for 80ppm of H2 gas at room temperature were observed for the nano-platelets and the porous films respectively with short response and recovery times of about 200 seconds. The sensitivity of the nano-platelets to CO gas was also measured and found to be about near 90% for 80 ppm CO at operating temperatures of 200 °C.


Sign in / Sign up

Export Citation Format

Share Document