Ethanol Gas Sensor Research Articles

A novel peony shaped ZnO and its excellent ethanol gas-sensing performance

In order to improve the gas-sensing performance of ZnO, a novel peony shaped ZnO stacked with nanosheets were prepared using hydrothermal method, and the obtained ZnO was characterized and tested for gas sensitivity. The results showed that the particle distribution of the peony shaped ZnO was uniform, with a particle size of about 0.8μm. The gas-sensing response test results show that the peony shaped ZnO has excellent selectivity to ethanol gas. When the concentration of ethanol gas is 100ppm, the gas-sensing response of the peony shaped ZnO to ethanol gas reaches 17.4, and the response time and recovery time are 8 seconds and 12 seconds, respectively. Even at an ethanol gas concentration of 2ppm, the gas-sensing response of the peony shaped ZnO to ethanol gas can reach 2.1. Compared to existing literature reports, the peony shaped ZnO prepared in this paper has better gas-sensing performance. This study will provide data support and theoretical reference for the development of high-performance gas sensors.

Development of High-Performance Ethanol Gas Sensors Based on La2O3 Nanoparticles-Embedded Porous SnO2 Nanofibers

Porous pure SnO2 nanofibers (NFs) and La2O3 nanoparticles (NPs)-embedded porous SnO2 NFs were successfully synthesized via electrospinning followed by calcination. These materials were systematically evaluated as gas-sensing elements in metal-oxide-semiconductor (MOS) sensors. The La2O3 NPs embedded in porous SnO2 NFs demonstrated superior gas-sensing performance compared to pure SnO2 NFs. Specifically, the incorporation of La2O3 resulted in a 12-fold enhancement in gas-sensing response towards ethanol, significantly improving both sensitivity and selectivity by tuning the carrier concentration and modifying oxygen deficiencies and chemisorbed oxygen levels. Thus, La2O3 NPs embedded in SnO2 NFs present a promising strategy for the development of high-performance ethanol gas sensors.

Correlation Between Structural, Electrical, and Optical Properties of ZnO:In for Ethanol Gas Sensing Application

Correlation Between Structural, Electrical, and Optical Properties of ZnO:In for Ethanol Gas Sensing Application

ZnSnO3 micro-polyhedrons with oxygen defects derived from rubidium incorporation for enhanced ethanol detection

Detecting ethanol in ambient air is of great significance in protection of ecological environment, human health and social economy. Herein, a strategy is adopted to substantially improve the gas sensing performance of the ZnSnO3 micro-polyhedrons through rubidium (Rb) doping. In this study, a series of ZnSnO3 micro-polyhedrons with different amounts of Rb doping were successfully synthesized through a typical hydrothermal procedure and air sintering. The sensor based on 2 mol% Rb-doped ZnSnO3 exhibits high response value (108) and rapid response/recover speed (20/8 s) to 100 ppm ethanol at 260 °C, as well as outstanding repeatability and stability. Combining theoretical calculations and various characterization techniques, the improved sensing property of the 2 mol% Rb-doped ZnSnO3 to ethanol gas can be ascribed to the large specific surface area and the abundant surface defects induced by Rb incorporation. We believe that this study opens up a new perspective for developing efficient and high-performance ethanol gas sensor.

Highly selective ethanol vapour sensing materials for a new generation of gas sensors based on molecularly imprinted polymers

A simple gas sensor consisting of a molecularly imprinted polymer-carbon nanotube composite cast onto a screen-printed electrode has been developed with extremely high selectivity for ethanol vapour over methanol vapour. Ethanol gas sensors typically display selectivity for ethanol over methanol in the range 2–4 times, while the mean ratio of ethanol to methanol response observed with the described device was 672. This selectivity was achieved under ambient conditions. Additionally, the molecularly imprinted polymer was produced using reagents previously applied in the development of a device selective for methanol, with only the template being changed. This demonstrates the versatility of molecular imprinting and provides a foundation for their greater integration into future gas sensors.

In-doped ZnO films deposited by modified SILAR method for enhanced ethanol gas sensor application

The rapid and skillful detection of toxic gases is a crucial requirement for the advancement of gas sensors. In this study, we fabricated undoped and In-doped (1 %, 3 %, and 5 % by weight) ZnO films using a two-step modified SILAR deposition technique. The ethanol gas sensing properties of both undoped and In-doped ZnO films were examined across a range of operating temperatures (from room temperature, 27 °C–200 °C) and concentrations (1 ppm–50 ppm). Of all the films, those doped with 5 % Indium exhibited the most stable, reproducible, and highest response, achieving 86.27 % at 50 ppm ethanol at an operating temperature of 100 °C. Compared to the undoped ZnO films, all Indium-doped ZnO films demonstrated significantly shorter response times (17 s) and recovery times (19 s). The response of all the deposited films to various gases such as acetone, methanol, toluene, xylene, and formaldehyde was lower than their response to ethanol. The mechanism behind the enhanced sensing characteristics of the Indium-doped ZnO films is explored. Additionally, the impact of humidity on sensor performance was investigated. This study reveals that 5 % In-doped ZnO films hold great potential as materials for ethanol gas sensing applications.

Fast Responsive and Highly Sensitive Ethanol Gas Sensors Designed by Agar‐Laponite Hybrid Hydrogels

AbstractLaponite, a synthetic nanosilicate clay and agar, a natural polysaccharide, both imbibe large amount of water and form into hydrogels. Various physical and chemical stimuli elicit the hydrogel response, which has been applied in designing diverse sensors and biomedical systems. In this work, we exploit the change in hydrogel's ionic conductivity due to volatile organic compounds (VOCs) (e. g. ethanol) interaction with the surfaces of Laponite‐Agar hybrid hydrogel films. Gas sensing studies are carried out on silicon (Si) and flexible polyethylene terephthalate (PET) substrates by monitoring the resistance changes. Pristine Laponite hydrogel has shown increase in resistance as it interacted with the ethanol, whereas pure agar and Laponite‐Agar have shown decrease in resistance. Moreover, Laponite‐Agar gel films have exhibited high sensitivity, fast response (4 s) and recovery time (15 s) with lowest detection limit of 6 ppm. Selectivity test carried shows high ethanol sensing response and exhibited very good reproducibility. Observed responses and sensing mechanism are discussed based on changes in ionic conduction resulted due to interacting ethanol with the gel surface network structure. Present study paves the way for understanding and designing low cost, soft and flexible hydrogel gas sensors.

Vertically aligned 2D tin sulfide (SnS) nanoplates for selective detection of ethanol gas at room temperature

Abstract Detection of ethanol gas quickly and efficiently at room temperature is crucial for ensuring environmental, human as well as industrial safety. In this work, we have demonstrated a chemiresistive room temperature ethanol gas sensor based on vertically aligned tin sulfide (SnS) nanoplates. X-ray diffraction (XRD), field-emission scanning electron microscopy (FESEM), and Brunauer–Emmett–Teller (BET) analysis have revealed the formation of orthorhombic, vertically aligned SnS nanoplates with high specific surface area. The sensor has been fabricated by depositing the SnS powder sample on ITO sheets using electrophoretic deposition (EPD), followed by the deposition of silver (Ag) electrodes using the thermal evaporation technique. The sensor obtained has exhibited a response value (R g/R a) of 17.4–400 ppm ethanol gas concentration, a quick response, and a recovery time of 12.4 s and 20.2 s at room temperature. The sensor has demonstrated long-term stability of 15 min, impressive selectivity, and remarkable repeatability across three successive test cycles of ethanol gas at 400 ppm. Based on the experimental sensing results, a plausible mechanism has been proposed for the sensor. The sensing response of SnS-based sensor at room temperature expands its potential for innovative applications across industries, marking a significant advancement in sensing technology.

SnO2/ZnO/Ti3C2Tx MXene nanocomposites for highly sensitive and stable ethanol sensing at low temperature

Ethanol, a commonly used volatile organic compound (VOC), necessitates the creation of a high-performance ethanol gas sensor due to its widespread application. The hydrothermal technique was used to generate SnO2/ZnO/Ti3C2Tx MXene composites with varying ratios of Ti3C2Tx in this investigation. The study examined the impact of the quantity of MXene on the gas sensitivity of SnO2/ZnO/Ti3C2Tx MXene composites. The results shows, the SnO2/ZnO/Ti3C2Tx MXene composite sensor with 3 wt% Ti3C2Tx content exhibited higher response (121.1), faster response time (3 s) and good selectivity as compared to pure Ti3C2Tx or SnO2/ZnO nanomaterials. These results suggest that SnO2/ZnO/Ti3C2Tx MXene composites have the potential to be used as a material for sensing ethanol gas. Finally, the gas-sensitive mechanism of SnO2/ZnO/Ti3C2Tx MXene was proposed.

Impact of reduced-graphene-oxide functionalization of flower-like zinc-oxide nanostructures on sensing performance of resistive ethanol gas sensor

This research presents a sensitive resistive ethanol gas sensor based on reduced graphene oxide (rGO)-functionalized Zinc oxide nanoflowers (ZnO NFs). Upon completion of synthesis, the resulting nanostructures were cast onto the photolithographed silver interdigitated electrodes positioned on an Al2O3 substrate. The graphene oxide (GO) with a low oxidation degree was synthesized using a Hummer's method. In the pursuit of optimizing sensing performance, rGO-functionalized ZnO NFs were synthesized through a one-pot hydrothermal process, utilizing different initial quantities of GO (0 mg, 2 mg, 8 mg, and 12 mg). According to the gas sensing measurements, the fabricated sensor with 8 mg initial GO showed the highest response to ethanol at 250 °C. The results show that the GO addition reduced the optimal working temperature of the pure ZnO NFs from 350 °C to 250 °C. The sensor exhibited a good selectivity, repeatability, and high long-term stability. Enhanced ethanol sensing response of the optimized gas sensor was related to the formation of p-n heterojunction between p-type rGO (formed during hydrothermal process at 200 °C) and n-type ZnO and the presence of the optimal amount of rGO on the surface of NFs. The results obtained in this investigation stress the significance of pinpointing the optimal quantity of GO for producing rGO-ZnO nanoflowers with the highest possible sensitivity to ethanol gas.

Highly selective sustainable ethanol gas sensor based on p-p heterojunction of SnS/MoSe2 nanocomposite at room temperature

Herein, a high-performance chemiresistive ethanol gas sensor operating at room temperature (RT) is demonstrated based on SnS/MoSe2 nanocomposite. The ethanol-sensing capabilities of the pristine-SnS and SnS/MoSe2 nanocomposite sensor are examined by exposing it to various ethanol concentrations ranging from 50 to 400 ppm at room temperature (RT). The sensing device based on the nanocomposite exhibits a high gas sensing response (Rg/Ra) of 26.8 to 400 ppm for ethanol gas. This results in improved response and recovery times of 9.1 s and 15.7 s respectively, along with high stability, selectivity, and reproducibility. Employing heterojunction in gas-sensing is an effective method for boosting the gas-sensing capabilities of 2D semiconductors. However, selecting semiconductors with compatible energy bands is equally crucial for optimizing gas sensing performance. The synergy arising from the p-p type heterojunction of SnS nanoplates and MoSe2 nanosheets is observed to enhance the sensor's response to ethanol gas. The sensing mechanism of the SnS/MoSe2 nanocomposite sensor is attributed to the formation of p-p heterojunction, modulation of the potential barrier, and charge carrier transfer. The findings suggest that the SnS/MoSe2-based nanocomposite stands out as a potential candidate for fabricating high-performance ethanol gas sensors for electronic applications in environmental monitoring.

An ethanol gas sensor based on floating gate carbon-based FETs with humidity resistance

An ethanol gas sensor based on floating gate carbon-based FETs with humidity resistance

Nebulized spray pyrolysis deposited CdO thin films for liquefied petroleum gas and ethanol gas sensor

High quality cadmium oxide (CdO) thin films were prepared through an inexpensive and simple nebulized Spray Pyrolysis (neb-SP) technique. The transparent conducting CdO thin films deposited at different substrate temperatures (TS) for the ethanol and liquefied petroleum gas (LPG) sensor application. XRD, SEM, UV–vis Spectroscopy and Hall Effect were done to study the structural, morphological, optical and electrical properties respectively. Polycrystalline nature thin films shows (1 1 1) cubic structure as the prominent peak. Surface morphology studies reveal that the grain size and roughness of the films are increased with increase in the substrate temperature. The average transmittance of the yellowish transparent CdO thin films is about 57%, thus the films are transparent in the visible region. The optical band gap (Eg) value of the CdO films increased from 2.16 to 2.28 eV with increase in the TS from 225 °C to 300 °C. The minimum value of electrical resistivity of the films is 1.40 × 10−3 Ωcm obtained at 275 °C. The neb-SP deposited CdO thin film (275 °C) shows maximum response to the ethanol and LPG gas sensitivity of 31.87% and 16.4% respectively at operating temperature of 573 K. Thus the results authenticate that the CdO thin films deposited low substrate temperature with high quality can be achieved via neb-SP technique compared to other wet chemical or physical method.

Interface engineering of a 3D carbon nanofiber/iron oxide scaffold for room-temperature ethanol sensing

Ethanol is one of the most widely consumed chemicals and has high volatility. Long-term exposure to ethanol can cause irritation and damage to human organs and even lead to cancer. Therefore, reliable, low-cost and low-power ethanol gas sensors are urgently needed. However, due to the high barrier associated with the reaction between adsorbed oxygen and ethanol gas, current commonly used chemiresistive sensors are difficult to detect low concentration of ethanol gas at room temperature. Herein, we developed a 3D composite scaffold sensor, i.e. iron oxide nanoparticles decorated carbon nanofiber scaffolds (CNFs) from both the inside and outside (named Fe2O3@FCNFs) through interface engineering. The Fe2O3@FCNFs composite scaffold exhibited a 6-fold increase in specific surface area as compared to that of the FCNFs, and its carrier concentration of was one order higher than that of its counterpart. Therefore, the typical Fe2O3@FCNFs sensor exhibited an unanticipated good response to ethanol gas at room temperature, including high sensitivity (-6.268 % toward 100 ppm) and low limit of detection (10 ppm). This study provides an effective solution for preparing room-temperature chemiresistive ethanol gas sensors, which can be extended to other gas detection by tuning the semiconductor sensitive materials.

Enhanced Ethanol Gas Sensor Performance through Adsorption Energy Analysis of Gd-Doped LaFeO3 with rGO Coating: A Density Functional Theory Study

LaFeO3 (LFO) is commonly used as a material for gas sensor applications. However, the LFO material in ethanol gas sensor applications can still improve sensitivity and selectivity parameters. Gadolinium (Gd) doping is widely used in gas sensor applications to increase the sensitivity of gas sensors. In addition, reduced graphene oxide (rGO) materials are commonly used in gas sensor applications to increase gas sensors' selectivity, sensitivity, and working temperature. This study analyzed the effect of Gd doping (LGFO) and the addition of an rGO single layer on LFO material (LGFO@rGO) on sensitivity and selectivity based on the adsorption energy of the system with ethanol gas molecules. Density Functional Theory studies were conducted to yield insight into the LGFO or LGFO@rGO – ethanol gas interactions and the sensitivity and selectivity improvement by changing adsorption energy. Based on the analysis, the presence of Gd doping and single-layer rGO could increase the adsorption energy. The addition of the rGO layer showed an escalation of the adsorption energy of about 9.45%, 2.49 eV in the LGFO to -2.75 eV LGFO@rGO. This improved adsorption capacity translates to a higher sensitivity for detecting lower concentrations of ethanol gas. This result shows the potential of LGFO and LGFO@rGO as ethanol gas sensor materials.

The room temperature ethanol gas sensors based on MoS2-CuGaO2 composite prepared by hydrothermal method

In this paper, MoS2-CuGaO2 composites were successfully synthesized by hydrothermal method. The composites were characterized by X-ray diffraction (XRD), Scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier transform infrared (FTIR), X-ray photoelectron spectroscopy (XPS), respectively. The specific surface area and pore size distribution were obtained by N2 adsorption-desorption isotherms. The gas sensing property measurements were conducted. The sensitivity of pure CuGaO2 based gas sensor to 100 ppm acetic acid and benzene vapor was 1.4 at 25oC. The sensitivity of MoS2-CuGaO2 composite (M − 5) was 6.0 towards 100 ppm ethanol vapor at 25oC. And the detection limit of MoS2-CuGaO2 (M − 5) based sensor was 0.1 ppm. The results demonstrated that MoS2 had effect on the selectivity and sensitivity of the MoS2-CuGaO2 composites. M − 5 composite is considered to be promising for ethanol sensing application in room temperature.

Natural honey (Mellifera) assisted combustion synthesis of ZnO, Ag-ZnO and Fe-ZnO nanoparticles for ethanol gas sensor applications

Biogenic combustion with Mellifera (Honey) capping produced ZnO, Ag-doped ZnO, and Fe-doped ZnO nanoparticles. The phase and crystal structure of metal oxide nanoparticles (MONPs) have been recorded through XRD spectrum. It confirms that the prepared metal oxides are within the nanoscale range. The average crystallite size of Fe-doped ZnO is 8.8 nm, smaller than ZnO and Ag-doped nanoparticles. The vibrational spectra of ZnO, Ag-doped ZnO, and Fe-doped ZnO nanoparticles confirm functional group stretching vibrational modes. The exterior surface morphology of all metal oxide nanoparticles was captured by FESEM. Metal oxide nanoparticle compositional analysis shows elemental presence, atomic, and weight %. The optical properties of metal oxide nanoparticles have been examined using UV–vis spectroscopy. The band gap energy of ZnO nanoparticles reduced from 2.68 eV to 1.74 eV under Fe doing and increased to 2.9 eV under Ag doing. Metal oxide thermal stability is also being investigated to determine how it affects ZnO nanoparticles. Fe-doped ZnO nanoparticles have greater sensor properties than other metal oxides due to their tiny size, band gap, and stability. Gas sensor behaviour of three metal oxide nanoparticles was examined in various accepts. It proves Fe-doped ZnO is a promising gas sensor material.

Study of Ethanol Gas Sensing Characteristics of An Al-Doped SnO₂ Thin Film Decorated With Gold Nanoparticles

Study of Ethanol Gas Sensing Characteristics of An Al-Doped SnO₂ Thin Film Decorated With Gold Nanoparticles

Mechanism of Interfacial Molecular Interactions Reveals the Intrinsic Factors for the Highly Enhanced Sensing Performance of Ag-Loaded Co3O4.

The noble metal-loaded strategy can effectively improve the gas-sensing performances of metal oxide sensors. However, the gas-solid interfacial interactions between noble metal-loaded sensing materials and gaseous species remain unclear, posing a significant challenge in correlating the physical and chemical processes during gas sensing. In this study, in situ diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) and in situ Raman spectroscopy were conducted to collaboratively investigate the interfacial interactions involved in the ethanol gas-sensing processes over Co3O4 and Ag-loaded Co3O4 sensors. In situ DRIFTS revealed differences in the compositions and quantities of sensing reaction products, as well as in the adsorption-desorption interactions of surface species, among Co3O4 and Ag-loaded Co3O4 materials. In parallel, in situ Raman spectroscopy demonstrated that the ethanol atmosphere can modulate the electron scattering of Ag-loaded Co3O4 materials but not of raw Co3O4. In situ experimental results revealed the intrinsic reason for the highly enhanced sensing performances of the Ag-loaded Co3O4 sensors toward ethanol gas, including a decreased optimal working temperature (from 250 to 150 °C), an improved gas response level (from 24 to 257), and accelerated gas recovery dynamics. This work provides an effective platform to investigate the interfacial interactions of sensing processes at the molecular level and further advances the development of high-performance gas sensors.

Ultra-sensitive optical fiber ethanol gas sensor based on Vernier effect in cascaded Mach-Zehnder interferometer and Sagnac interferometer

Optical fiber-based sensors, which show the merits of high sensitivity, real-time, and rapid detection, have important research value in the detection of volatile organic compounds (VOCs). In this paper, a novel ethanol gas sensor was experimentally investigated based on the cascaded optical fiber-based Sagnac interferometer and Mach-Zehnder interferometer. The Sagnac interferometer was constructed with an anisotropic nematic liquid crystal (NLC) film which acted as the reactor with ethanol gas. A tapered single-mode fiber (SMF) was used to build the Mach-Zehnder interferometer (MZI). The two interferometers were parallelly and tandemly cascaded respectively to achieve the magnification of measurement sensitivity. Experimental results showed that the sensitivities were 8.561 pm/ppm with a magnification factor of 3.76 for the parallel cascaded structure and 7.924 pm/ppm with a magnification factor of 3.48 for the tandemly cascaded structure. The designed optical fiber-based ethanol gas sensor, showing the advantages of compact structure, high sensitivity, small size, and low cost, could be a competitive candidate for the detection of ethanol gas leakage.