Hafnium oxide nanoparticles synthesized via sol-gel route for an efficient detection of volatile organic compounds at room temperature

Author(s):  
Anamitra Chattopadhyay ◽  
Jhasaketan Nayak
Materials ◽  
2020 ◽  
Vol 13 (3) ◽  
pp. 523 ◽  
Author(s):  
Simonas Ramanavičius ◽  
Milda Petrulevičienė ◽  
Jurga Juodkazytė ◽  
Asta Grigucevičienė ◽  
Arūnas Ramanavičius

In this research, the investigation of sensing properties of non-stoichiometric WO3 (WO3−x) film towards some volatile organic compounds (VOC) (namely: Methanol, ethanol, isopropanol, acetone) and ammonia gas are reported. Sensors were tested at several temperatures within the interval ranging from a relatively low temperature of 60 up to 270 °C. Significant variation of selectivity, which depended on the operational temperature of sensor, was observed. Here, the reported WO3/WO3–x-based sensing material opens an avenue for the design of sensors with temperature-dependent sensitivity, which can be applied in the design of new gas- and/or VOC-sensing systems that are dedicated for the determination of particular gas- and/or VOC-based analyte concentration in the mixture of different gases and/or VOCs, using multivariate analysis of variance (MANOVA).


Sensors ◽  
2021 ◽  
Vol 21 (2) ◽  
pp. 440
Author(s):  
Daniel Garcia-Osorio ◽  
Pilar Hidalgo-Falla ◽  
Henrique E. M. Peres ◽  
Josue M. Gonçalves ◽  
Koiti Araki ◽  
...  

Gas sensors are fundamental for continuous online monitoring of volatile organic compounds. Gas sensors based on semiconductor materials have demonstrated to be highly competitive, but are generally made of expensive materials and operate at high temperatures, which are drawbacks of these technologies. Herein is described a novel ethanol sensor for room temperature (25 °C) measurements based on hematite (α‑Fe2O3)/silver nanoparticles. The AgNPs were shown to increase the oxide semiconductor charge carrier density, but especially to enhance the ethanol adsorption rate boosting the selectivity and sensitivity, thus allowing quantification of ethanol vapor in 2–35 mg L−1 range with an excellent linear relationship. In addition, the α-Fe2O3/Ag 3.0 wt% nanocomposite is cheap, and easy to make and process, imparting high perspectives for real applications in breath analyzers and/or sensors in food and beverage industries. This work contributes to the advance of gas sensing at ambient temperature as a competitive alternative for quantification of conventional volatile organic compounds.


2021 ◽  
Vol 10 (4) ◽  
pp. 97-102
Author(s):  
Nhung Nguyen Hong ◽  
Hung Khong Manh ◽  
Thang Le Minh ◽  
Phuong Pham Thi Mai ◽  
Nam Chu Thi Hai

Toluene is a component of volatile organic compounds which need to be converted into non-poisonous one. Thus, we study the spinel-typed catalyst as NiCo2O4 for total oxidation of toluene because the advantage of spinel catalyst is multi- defective. Based on the sol-gel method, the catalysts NiCo2O4 were successfully prepared with different ratios of Ni/Co. The characteristic properties of catalysts were evaluated by XRD, BET, H2-TPR and EPR experiments. Amongst these ratios, the catalyst with ratio Ni/Co as 0.5 had the best activity in the total oxidation of toluene, as 100% conversion reached at 250 oC.


2020 ◽  
Vol 289 ◽  
pp. 121494
Author(s):  
Jiraporn Buasakun ◽  
Phakinee Srilaoong ◽  
Gun Chaloeipote ◽  
Ramida Rattanakram ◽  
Chatchawal Wongchoosuk ◽  
...  

RSC Advances ◽  
2016 ◽  
Vol 6 (99) ◽  
pp. 97048-97054 ◽  
Author(s):  
Junhui Wang ◽  
Wan-Qiu Wang ◽  
Zhengping Hao ◽  
Gang Wang ◽  
Yang Li ◽  
...  

The hyper-cross-linked polymers CLBE-xwere prepared at room temperature and exhibit a large surface area, super-hydrophobicity and high adsorption for benzene.


2018 ◽  
Vol 36 (3) ◽  
pp. 452-459
Author(s):  
Raad S. Sabry ◽  
Roonak Abdul Salam A. Alkareem

AbstractZnO-CuO flower-like hetero-nanostructures were successfully prepared by combining hydrothermal and dip coating methods. Flower-like hetero-nanostructures of ZnO-CuO were examined by X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), and UV-Vis. The sensing properties of ZnO-CuO flower-like hetero-nanostructures to volatile organic compounds (VOCs) were evaluated in a chamber containing acetone or isopropanol gas at room temperature. The sensitivity of ZnO-CuO flower-like hetero-nanostructures to VOCs was enhanced compared to that of pure leafage-like ZnO nanostructures. Response and recovery times were about 5 s and 6 s to 50 ppm acetone, and 10 s and 8 s to 50 ppm isopropanol, respectively. The sensing performance of ZnO-CuO flower-like hetero-nanostructures was attributed to the addition of CuO that led to formation of p-n junctions at the interface between the CuO and ZnO. In addition, the sensing mechanism was briefly discussed.


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