Air quality prediction by using semiconducting gas sensor with newly fabricated SmFeO3 film

doi:10.1016/j.snb.2003.08.013

Sensors and Actuators B: Chemical

Volume 97, Issues 2–3, 1 February 2004, Pages 190-197

https://doi.org/10.1016/j.snb.2003.08.013 Get rights and content

Abstract

The conductance changes of SmFeO₃-based p-type gas sensor and n-type SnO₂ gas sensor (TGS2600), with volatile organic compounds (VOCs) and NO₂ in air were examined. Prediction of the contaminated levels with VOCs became difficult when NO₂ levels were changed and also vice versa. The use of one sensor was poor to detect a level of contaminated air’s quality. By using at least two SmFeO₃ sensor operating at a different temperature, prediction of each contaminated level with VOCs and NO₂ became possible. Furthermore, by the combination with both sensor sub-ppm levels contamination with VOCs and NO₂ was interpretable due to a higher sensitivity of TGS2600 for NO₂ and of SmFeO₃ for VOCs.

Introduction

The perovskite-type LnMO₃ oxides having lanthanoids (Ln) and tri-valent cations (M) are one of the most applicable materials for catalysis [1], electrodes and solid electrolytes of fuel cells [2], [3], and gas sensors [4], [5], [6], [7], [8], [9], [10], [11], etc. Although the solid-state reaction of Ln₂O₃ and M₂O₃ single oxides is the most conventional method for the preparation of these heterometallic oxides, this method is very difficult to control the powder quality and particle size. The synthesis using chemical processing methods such as co-precipitation method, sol–gel method, and glycothermal method is performed at considerably lower temperatures than that through solid-state reaction methods, and finer perovskite-type products are obtainable [12]. As a new chemical method, we have been investigating the preparation of the perovskite-type oxides having homogeneous and finer particles in size by the thermal decomposition of the appropriate heteronuclear complexes containing Ln:M=1:1 ratio such as hexacyano and organic complexes [13], [14], [15], [16], [17], [18]. The perovskite-type materials have been applied for NO₂ gas sensor, because a number of perovskite-type oxides prepared in air show p-type semiconducting properties, and their conductivity increases with the adsorption of oxidizing gases [19], [20], [21], [22]. In our previous studies, we reported that the SmFeO₃ thick films prepared by the thermal decomposition of Sm[Fe(CN)₆]·nH₂O showed higher NO₂ sensing property compared with that of the solid-state reaction method [23]. It was observed that SmFeO₃ had the high gas sensitivity in LnFeO₃ (Ln=La∼Yb) and similar tendencies were also reported by Sugiyama et al. [21]. The highest sensitivity for NO₂ observed for SmFeO₃ was mainly attributed to the divalency of Sm³⁺ in SmFeO₃ and a higher surface coverage of Sm ion [24]. For a practical use, it should be examined the cross sensitivity of some volatile organic compounds (VOCs).

The contamination with oxidative gases and VOCs in air becomes serious problem for human life. Commercially available gas sensor basing SnO₂ sensing materials with n-type semiconducting behavior is sensitive to NO₂ and also VOCs. In this case, the conductance is increased with VOCs and decreased with NO₂. Under the mixture of VOC and NO₂, it suggests that the output signal shows the same levels of pure air quality, although the contaminated levels were different in the respect to the NO₂ and VOC levels. Use of plural gas sensors, electronic nose sensor is useful to predict an air quality [25], [26], [27].

In this study, we examined the gas sensing characteristics of the developed SmFeO₃-based gas sensor for an application to air quality interpretations.

Section snippets

Preparation of SmFeO₃ sensor

The Sm[Fe(CN)₆]·nH₂O heteronuclear complexes were synthesized by mixing aqueous solutions of equimolar amounts of Sm(NO₃)₃·6H₂O and K₃Fe(CN)₆ with continuous stirring. The resulting precipitate was washed with water, ethanol and diethyl ether, before drying in air at 323 K. The SmFeO₃ oxide powders were prepared by the thermal decomposition of the complex at 1173 K for 1 h. An X-ray diffraction (XRD, Model Rint 2000, Rigaku Corporation, using a Cu Kα radiation) analysis was used to confirm the

Characterizations of SmFeO₃ film with XRD and XPS

Powders prepared by the thermal decomposition of heteronuclear complexes at various temperatures in air were examined by XRD as shown in Fig. 1. A single phase of perovskite-type oxide was obtained by the heating at 973 K. Particle size of the products was increased with the heat treatment temperature, since the full-width-at-half-maximum (FWHM) of XRD peak decreases with an increase in the temperature. The gas sensing characteristics were examined at 573 and 623 K. To prevent the growth of the

Conclusions

The contamination with oxidative gases and VOCs in air becomes serious problem for human life. The conductance changes of SmFeO₃-based sensor and TGS2600 with VOCs and NO₂ in air were examined. The use of one semiconducting gas sensor at a certain working temperature is poor to detect a level of contaminated air’s quality. For TGS2600, distinction of the contaminated levels with VOCs becomes difficult when NO₂ levels were changed and also vice versa. The sensitivity for VOCs of TGS2600 is

Munenobu Tomoda received his ME in Department of Materials Science and Engineering from Ehime University in 2003.

References (29)

J.G. McCarty et al.
Catal. Today
(1990)
K. Kuroda et al.
Solid State Ionics
(2000)
T. Arakawa et al.
Sens. Actuators
(1988)
E. Traversa et al.
Sens. Actuators B
(1995)
M.C. Carotta et al.
Sens. Actuators B
(1997)
G. Martinelli et al.
Sens. Actuators B
(1999)
M.C. Carotta et al.
Sens. Actuators B
(1998)
Y. Sadaoka et al.
J. Alloys Compd.
(1996)
M. Sakamoto et al.
J. Alloys Compd.
(1997)
Y. Sadaoka et al.
J. Alloys Compd.
(1998)

E. Hasegawa et al.

J. Alloys Compd.

(1999)

E. Traversa et al.

Sens. Actuators B

(1995)

M.C. Carotta et al.

Sens. Actuators B

(1997)

H. Aono et al.

Sens. Actuators B

(2003)

Cited by (54)

Photo-thermal synergistic excitation: Feasible strategy to detect ethanol for wide bandgap ZIF-8 at low work temperature
2024, Journal of Environmental Sciences (China)
Zeolitic Imidazolate Framework-8 (ZIF-8) material was prepared by chemical precipitation method. The microstructure and physical properties of the as-prepared samples were characterized by XRD, BET, FESEM and UV spectrophotometer. The self-made four-channel measurement device was used to test the gas sensitivity of ZIF-8 material toward ethanol gas under photo-thermal synergistic excitation. The results showed that the sample was typical ZIF-8 (E_g = 4.96 eV) with a regular dodecahedron shape and the specific surface is up to 1793 m²/g. The as-prepared ZIF-8 has a gas response value of 55.04 to 100 ppm ethanol at 75°C and it shows good gas sensing selectivity and repeated stability. The excellent gas sensitivity can be attributed to the increase of free electron concentration in the ZIF-8 conduction band by photo-thermal synergistic excitation, and the large specific surface area of ZIF-8 material provides more active sites for gas-solid surface reaction. The reaction mechanism of ZIF-8 material under multi-field excitation was also discussed.
Rough surface Sn-doped SmFeO<inf>3</inf> nanofibers gas sensor
2023, Vacuum
Sn doped SmFeO₃ nanofibers were successfully prepared using high-pressure electrospinning technology combined with high-temperature calcination process. Meanwhile, in order to compare and study the role of metal Sn doping in optimizing gas sensing performance, pure SmFeO₃ nanofibers were prepared using the same method. The crystal structure, microstructure, and elemental composition of SmFeO₃ nanofibers were systematically analyzed using characterization techniques such as XRD, SEM, TEM, and XPS. The test results show that compared with pure SmFeO₃ nanofibers, Sn doped SmFeO₃ nanofibers have a rougher surface, higher porosity, and more vacancy oxygen, providing a foundation for promoting the diffusion, adsorption, and desorption of gas molecules.
A portable acetone detector based on SmFeO<inf>3</inf> can pre-diagnose diabetes through breath analysis
2022, Journal of Alloys and Compounds
Breath analysis using gas sensors is becoming one of the important supplementing ways for an early diagnosis of diseases. The feasibility of detecting acetone concentration in exhaled breath using a SmFeO₃-based sensor has been studied herein. The detection limits of acetone using a SmFeO₃-based sensor are extremely low (1.56–0.01 ppm; 1.87–0.02 ppm; 2.39–0.05 ppm; 3.22–0.1 ppm; 4.1–0.2 ppm; 4.79–0.5 ppm; 5.92–1 ppm). To remove the effects of carbon dioxide and relative humidity (RH), a mathematical model between the response and acetone concentration, carbon dioxide concentration and RH in a person’s exhaled breath is established via machine learning. Volunteer studies have proved the accuracy of this mathematical model. Compare with the acetone concentration obtained by GC-MS method, the accuracy of the proposed method exceeded 85 %. Finally, a portable acetone detector based on the SmFeO₃ sensor is designed and realized to monitor the dynamic change in acetone concentration in the exhaled breath of volunteers before and after meals, and the experimental results have proved that the method based on the gas sensor and Machine learning (ML) is feasible and effective in accurately detecting acetone concentration in persons’ exhaled breath.
EMF response of the YSZ based potentiometric sensors in VOC contaminated air
2018, Current Opinion in Electrochemistry
Recent works on potentiometric volatile organic compound (VOC) detection based on oxygen sensor with yttria-stabilized zirconia (YSZ) and modified Pt electrodes is reviewed. Sub-ppm or lower level of VOC contamination in air is now detectable using YSZ based oxygen concentration cell. The VOC contamination fluctuates the concentration of adsorbed oxygen on the Pt sensing electrode, leading to a substantial deviation from the electromotive force (EMF) value predicted by the Nernst equation, E = (RT/4F)ln{P₁(O₂)/P₂(O₂)}. Sensitivity of the Pt electrode is tunable by the coating of the Pt electrode with some ceramic layers tunes, which may vary the concentration of the adsorbed oxygen and even the reaction electron number of oxygen.
NO<inf>2</inf> sensing properties of SmFeO<inf>3</inf> porous hollow microspheres
2018, Sensors and Actuators, B: Chemical
Citation Excerpt :
Research has also been carried out on perovskite-type oxides as gas sensor materials [12–17], due to the high thermal stability, catalytic activity and semiconducting behavior of the perovskite structure. Detection of NO2 using perovskite-type oxides has also been reported [18–23]. In particular, SmFeO3 has shown the highest NO2 sensing response among perovskite-structured LnFeO3 (Ln = La- Yb) compounds [24].
Porous hollow microspheres of SmFeO₃ were prepared from a simple process involving a metal organic framework (MOF) compound as the templating precursor. With a diameter of about 2 μm, these hollow-centered microspheres are formed by nanoporous thin walls of SmFeO₃. Chemoresistive gas sensors based on these microspheres exhibits excellent sensing performance on NO₂ at 200 °C, including high sensitivity (response of 10.2 under 200 ppb) with detection limit as low as 50 ppb, high selectivity, and reasonably short time for response and recovery (369 s/478 s). The superior sensing response over other SmFeO₃-based NO₂ sensors can be ascribed to the electron-accepting reactions during NO₂ adsorption, which is facilitated by the special morphological features of the microsphere.
Enhanced mixed potential NO<inf>x</inf> gas response performance of surface modified and NiO nanoparticles infiltrated solid-state electrochemical-based NiO-YSZ composite sensing electrodes
2018, Sensors and Actuators, B: Chemical
We have designed the solid-state electrochemical mixed potential type NiO and yttrium-stabilized zirconia (YSZ) composite based sensing electrode for selective detection of NO_x at elevated temperatures. The planner NiO-YSZ composite sensing electrode could detect NO_x even at 400 °C, with acceptable response/recovery rates. The change in emf values of the sensor varied linearly with NO_x concentrations on a logarithmic scale in the range of 5–100 ppm. The response characteristic of the sensor was improved by modifying the surface with different vol% of pore former. As a result, obtained porous electrodes showed better response characteristics concerning speed and response owing to higher porosity. To improve response kinetics of porous NiO-YSZ electrode, NiO nanoparticles are infiltrated into an optimized NiO-YSZ sensing electrode surface by controlled urea/cation infiltration method. The experimental results demonstrated that NiO nanoparticles infiltrated NiO-YSZ sensor electrode reveal remarkably high emf response to NO_x compared that of planar electrode, suggesting that NiO nanoparticles introduction can significantly enhance catalytic activity and electrochemical performance of NiO-YSZ electrode. Finally, the porosity effect of electrode subtracts (YSZ) with NO_x gases response and recovery kinetics was examined under the optimum operating temperature at 400 °C. The sensing mechanism based on the mixed potential for the surface modified NiO-YSZ composite sensing electrode was discussed based on the obtained result of sensing characterizations.

View all citing articles on Scopus

Munenobu Tomoda received his ME in Department of Materials Science and Engineering from Ehime University in 2003.

Satoshi Okano received his BE in Department of Materials Science and Engineering from Ehime University in 2003. He is an academic staff in Ehime University.

Yoshiteru Itagaki received his BE in Department of Applied Chemistry in 1993 and his ME in 1995 in Graduate School of Engineering, Hiroshima University. He obtained a Dr. Eng. from Hiroshima University in 1998. He was at Linköping University in Sweden as a post-doctor from 1998 to 2000. Then, he was assistant researcher in Hiroshima University from 2000 to 2002 and researcher in Kinki University in 2002. He is research associate in Ehime University since 2003. His main interests are functional materials and materials chemistry.

Hiromichi Aono received his BE in Industrial Chemistry from Ehime University in 1986. He was on the Faculty in the Department of Industrial Chemistry at Niihama National College of Technology from 1986 to 1996. He obtained a Dr. Eng. from Osaka University in 1994. He has been on the Faculty in Department of Materials Science and Engineering at Ehime University since 1996. He is associate professor since 2001. His main interests are the solid-state chemistry and its applications.

Yoshihiko Sadaoka received his ME in Industrial Chemistry from Ehime University in 1971. He has been on the Faculty of engineering at Ehime University since 1971. He obtained a Dr. Eng. from Kyusyu University in 1979. He is professor at Department of Materials Science and Engineering since 1996. His main interests are inorganic and organic functional materials for chemical sensor and green materials.

View full text

Air quality prediction by using semiconducting gas sensor with newly fabricated SmFeO3 film

Abstract

Introduction

Section snippets

Preparation of SmFeO3 sensor

Characterizations of SmFeO3 film with XRD and XPS

Conclusions

Catal. Today

Solid State Ionics

Sens. Actuators

Sens. Actuators B

Sens. Actuators B

Sens. Actuators B

Sens. Actuators B

J. Alloys Compd.

J. Alloys Compd.

J. Alloys Compd.

J. Alloys Compd.

Sens. Actuators B

Sens. Actuators B

Sens. Actuators B

Air quality prediction by using semiconducting gas sensor with newly fabricated SmFeO₃ film

Preparation of SmFeO₃ sensor

Characterizations of SmFeO₃ film with XRD and XPS