Fabrication Of Gas Sensors Research Articles

Carbon nanowall-based gas sensors for carbon dioxide gas detection

Carbon nanowalls (CNWs) have attracted significant attention for gas sensing applications due to their exceptional material properties such as large specific surface area, electric conductivity, nano- and/or micro-porous structure, and high charge carrier mobility. In this work, CNW films were synthesized and used to fabricate gas sensors for carbon dioxide (CO2) gas sensing. The CNW films were synthesized using an inductively-coupled plasma (ICP) plasma-enhanced chemical vapor deposition (PECVD) method and their structural and morphological properties were characterized using Raman spectroscopy and electron microscopy. The obtained CNW films were used to fabricate gas sensors employing interdigitated gold (Au) microelectrodes. The gas sensors were fabricated using both direct synthesis of CNW films on interdigitated Au microelectrodes on quartz and also transferring presynthesized CNW films onto interdigitated Au microelectrodes on glass. The CO2 gas-sensing properties of fabricated devices were investigated for different concentrations of CO2 gas and temperature-ranges. The sensitivities of fabricated devices were found to have a linear dependence on the concentration of CO2 gas and increase with temperature. It was revealed that devices, in which CNW films have a maze-like structure, perform better compared to the ones that have a petal-like structure. A sensitivity value of 1.18% was obtained at 500 ppm CO2 concentration and 100 °C device temperature. The CNW-based gas sensors have the potential for the development of easy-to-manufacture and efficient gas sensors for toxic gas monitoring.

Layer-Dependent Sensing Performance of WS2-Based Gas Sensors.

Two-dimensional (2D) materials, such as tungsten disulfide (WS2), have attracted considerable attention for their potential in gas sensing applications, primarily due to their distinctive electrical properties and layer-dependent characteristics. This research explores the impact of the number of WS2 layers on the ability to detect gases by examining the layer-dependent sensing performance of WS2-based gas sensors. We fabricated gas sensors based on WS2 in both monolayer and multilayer configurations and methodically evaluated their response to various gases, including NO2, CO, NH3, and CH4 at room temperature and 50 degrees Celsius. In contrast to the monolayer counterpart, the multilayer WS2 sensor exhibits enhanced gas sensing performance at higher temperatures. Furthermore, a comprehensive gas monitoring system was constructed employing these WS2-based sensors, integrated with additional electronic components. To facilitate user access to data and receive alerts, sensor data were transmitted to a cloud-based platform for processing and storage. This investigation not only advances our understanding of 2D WS2-based gas sensors but also underscores the importance of layer engineering in tailoring their sensing capabilities for diverse applications. Additionally, the development of a gas monitoring system employing 2D WS2 within this study holds significant promise for future implementation in intelligent, efficient, and cost-effective sensor technologies.

Room-temperature NH3 gas sensing of S-hyperdoped silicon: Optimization through substrate resistivity

Sulfur-hyperdoped black silicon (S-BSi) prepared by femtosecond laser-assisted etching in SF6 atmosphere has dual characteristics of large specific surface area and super-doped impurities, and its physics and applications have attracted extensive attention. The room-temperature NH3 gas sensing capability of the samples is studied in the conductance mode. The S-BSi-based sensors exhibit a response to NH3 gas. Interestingly, their responsivity varies with the substrate resistance, and the sensor based on an appropriate substrate resistance shows the optimal responsivity. Additionally, the device demonstrates fast response and recovery speed, as well as good selectivity. The evolution of the responsivity and response/recovery time is recorded with natural aging for two months, showing acceptable long-term durability. The mechanism by which the responsivity of S-BSi-based sensors varies with resistivity is discussed. Based on this mechanism, there is an optimal substrate resistivity that maximizes the responsivity. The results show that S-BSi is a potential material for the fabrication of conductivity gas sensor with good NH3 detection performance.

Proposals for gas-detection improvement of the FeMPc monolayer towards ethylene and formaldehyde by using bimetallic synergy.

Development and fabrication of a novel gas sensor with superb performance are crucial for enabling real-time monitoring of ethylene (C2H4) and formaldehyde (H2CO) emissions from industrial manufacture. Herein, first-principles calculations and AIMD simulations were carried out to investigate the effect of the Fe-M dimer on the adsorption of C2H4 and H2CO on metal dimer phthalocyanine (FeMPc, M = Ti-Zn) monolayers, and the electronic structures and sensing properties of the above adsorption systems were systematically discussed. The results show that the FeMPc (M = Ti, V, Cr, Mn) monolayers interact with C2H4 and H2CO by chemisorption except for the FeMnPc/H2CO system, while the other adsorption systems are all characterized by physisorption. Interestingly, the adsorption strength of C2H4 and H2CO can be effectively regulated by the bimetallic synergy of the Fe-M dimer. Moreover, the FeCrPc and FeMnPc monolayers exhibit excellent sensitivity towards C2H4 and H2CO, and have short recovery time (4.69 ms-2.31 s) for these gases at room temperature due to the effective surface diffusion at 300 K. Consequently, the FeCrPc and FeMnPc materials can be utilized as high-performance, reusable gas sensors for detecting C2H4 and H2CO, and have promising applications in monitoring the release of ethylene and formaldehyde from industrial processes.

Dielectrophoretically Assembled SWCNTs Networks on SU-8 Substrate for PEG/SWCNTs Composite Gas Sensor.

This study proposed a SU-8 based gas sensor, integrated with heater and sensing electrodes, to develop a multi-channel gas sensor with PEG/SWCNTs composite films. The impedance of single-walled carbon nanotubes (SWCNTs) on each sensing electrode was well controlled via dielectrophoresis technology. To investigate dielectrophoretic mobility characteristics, the concentric circular sensing electrode has three different spacing between the inner and outer electrodes, including 10 μm, 15 μm, and 20 μm. The electrodes were applied with a 5 MHz AC source with a voltage ranging from 1 Vpp to 5 Vpp. Polyethylene glycol (PEG) was deposited on the gas sensor via drop casting. The fabricated gas sensor was operated at different working temperatures, including 25 °C, 40 °C, 50 °C and 60 °C, to examine the sensing response. The response results revealed that the PEG/SWCNTs composites gas sensor with 60 °C working temperature exhibited the ability to detect 80 ppm ethanol vapor.

Trace carbon nitride-decorated SnO2 lamella boosting ultra-high response and fast recovery of NO2 gas at low temperature

The low-temperature NO2 gas sensors with ultra-high response are more helpful for their real-time and accurate monitoring in complex environment, however, the relevant reports are very less. Herein, we firstly prepared graphitic carbon nitride (g-C3N4) by pyrolysis of inexpensive melamine, which was used as template and directly soaked into SnCl4 ethanol/water solution. Afterwards, the immersed precursors were calcined to generate different SnO2-based materials. Among, the morphology of g-C3N4/SnO2-5 calcined at 500 °C is lamella structure composed of trace g-C3N4 and small-size SnO2 nanoparticles, which possesses narrow mesopores, large specific surface area, rich oxygen vacancy defects, as well as high concentration of surface O2-(ad) species. Under the synergy of multiple favorable factors, g-C3N4/SnO2-5 sensor exhibits ultra-high response (S = 12171) for 10 ppm NO2 gas at 92 °C, which is 1.93 times than that of SnO2-6 sensor. It is also the highest response value among reported g-C3N4/metal oxide composites. In addition, this sensor has fast recovery time (5 s), low detection limit, good moisture resistance and stability. Thus, the simple g-C3N4 template method provides a new strategy for the fabrication of gas sensors with highly efficient sensing ability.

Fabrication of high-performance RT-NH3 gas sensor based on Cu and La co-doped ZnO films through a facile drop-casting method

In this work, undoped ZnO, 2 % Cu-doped ZnO, 2 % La-doped ZnO and 2 % (Cu:La) co-doped ZnO thin films are deposited on glass substrates using the facile drop-casting method, and their physical characteristics were investigated for the gas sensing application. The X-ray diffraction (XRD) patterns confirmed the hexagonal wurtzite structure and increase in crystallinity for the doped samples. Field Emission Scanning Electron Microscopy (FESEM) images revealed a significant change in morphology from the granular particles to densely packed nanoplates-like morphology for (Cu:La) co-doped ZnO. The doped samples exhibited a red shift in absorption edge and shrinkage of the optical bandgap. Multiple emission peaks in photoluminescence (PL) spectra indicated the presence of defect level in the material. It was discovered that Cu-doped and La-doped ZnO thin films had a considerable NH3 sensing response at ambient temperature. The gas response was remarkably enhanced to 341 % for (Cu:La) co-doped ZnO film and a quicker response/recovery time of 80/10 s for 250 ppm NH3. The (Cu:La) co-doped ZnO can serve as a feasible alternative for pure ZnO gas sensors.

Electrostatic Spray Deposition of Al-Doped ZnO Thin Films for Acetone Gas Detection

In this study, pure ZnO and Al-doped ZnO(AZO) thin films were coated onto a SiO2 wafer using the electrostatic spray deposition (ESD) process for acetone gas detection under laboratory conditions. Voltage levels were varied to determine the optimal conditions for producing thin films with the highest uniformity. The results indicate that the optimal coating voltage for achieving the highest uniformity of the coated films is 2.9 kV for ZnO and 2.6 kV for AZO. The thin films were produced under these optimal ESD conditions by adjusting the coating time, and gas sensors were fabricated by printing electrodes using a reverse offset process on top of the thin films. Analysis of the sensing response revealed that the AZO-coated gas sensor with a 200 s deposition exhibited the best acetone-sensing ability at 300 °C, with a maximum response of 13.41 at 10 ppm. Furthermore, the fabricated gas sensors effectively detected acetone gas even at a low concentration of 2 ppm, demonstrating high selectivity in comparison to other gases.

Dopant Enhanced Conjugated Polymer Thin Film for Low-Power, Flexible and Wearable DMMP Sensor.

Conjugated polymer has the potential to be applied on flexible devices as an active layer, but further investigation is still hindered by poor conductivity and mechanical stability. Here, this work demonstrates a dopant-enhanced conductive polymer thin film and its application in dimethyl methylphosphonate (DMMP) sensor. Among five comparable polymers this work employs, poly(bisdodecylthioquaterthiophene) (PQTS12) achieves the highest doping efficiency after doped by FeCl3, with the conductivity increasing by about five orders of magnitude. The changes in Young's modulus are also considered to optimize the conductivity and flexibility of this thin film, and finally the decay of conductivity is only 9.2% after 3000 times of mechanical bending. This work applies this thin film as the active layer of the DMMP gas sensor, which could be operated under 1mV driving voltage and 28 nW power consumption, with a sustainable durability against bending and compression. In addition, this sensor is provided with alarm capability while exposed to the DMMP atmospheres at different hazard levels. This work expects that this general approach could offer solutions for the fabrication of low-power and flexible gas sensors, and provide guidance for next-generation wearable devices with broader applications.

Highly sensitive and stable yolk-shell Bi2MoO6 gas sensor for ppb-level isopropanol detection

Metal oxide semiconductor used for the fabrication of volatile organic gas sensors has gained significant popularity in recent years. This paper discusses the synthesis of yolk-shell-structure Bi2MoO6 (YS-BMO) for isopropanol detection through quasi-molecular imprinting-based solvent-thermal methods. Various qualitative characterization techniques, gas sensing performance tests, and theoretical calculations collectively indicate that YS-BMO with molecular imprinting is a potential material for isopropanol sensing. YS-BMO with an average diameter of approximately 1.5 µm (15 h of solvothermal), demonstrates impressive isopropanol detection capabilities, a practical detection limit of 100 ppb, along with suitable response and recovery times. Density functional theory (DFT) calculations provide a deeper understanding and analysis of the response mechanism of Bi2MoO6 to isopropanol, considering aspects such as band structure, electron transfer, and adsorption energy.

A synergistic approach to enhance sensitivity and selectivity of room temperature operable ammonia gas sensor with humidity assistance using RGO/WO3 nanocomposite

In this study, the fabrication of an ultrahigh selective NH3 gas sensor based on RGO/WO3 nanocomposite has been proposed. The hydrothermal method was employed to synthesize the RGO/WO3 nanocomposite. The formation of RGO/WO3 nanocomposite and the elemental composition, structure and morphology of the as-synthesized materials were confirmed through an array of analytical techniques, including XRD, Raman, FT-IR, XPS and TEM. For gas sensing applications, pure RGO and RGO/WO3 have effectively spin-coated onto the interdigitated electrodes (IDE’s) based on fluorine doped tin oxide (FTO) respectively, and their sensitivity towards NH3 was tested. Gas sensing characteristics of prepared materials were analyzed at room temperature (25 °C) under different relative humidity (RH) levels. The developed RGO/WO3 sensor was subjected to different NH3 concentrations, demonstrating a high sensing response of 89% towards 500 ppm NH3 under 11%–97%–11% RH conditions. Notably, the sensor exhibited rapid response and recovery times with an average response time of 92 s and recovery time of 26 s when exposed to 500 ppm NH3 under the specified RH conditions. To gauge the material selectivity, the prepared nanocomposite was exposed to a range of volatile organic compounds and the results showcased the sensor’s remarkable selectivity and sensitivity specifically toward NH3 vapor. This superior performance can be attributed to the abundant active sites and the excellent electron transport properties inherent to the RGO component. Importantly, the RGO/WO3 sensor displayed high reproducibility and consistent responses, with minimal degradation (1.98% degradation) over 30 d at 11%–97%–11% RH. Furthermore, we examined the sensor’s response with varying levels of relative humidity to assess its potential for real-world applications. The sensor exhibited extremely low power consumption, outperforming a commercially available metal oxide sensor while operating at ambient temperature. The robust performance of RGO/WO3 coupled with low power requirements and ambient temperature operation, positions it as a promising candidate for next-generation gas sensing technologies.

Extended-gate structure for carbon-based field effect transistor type formaldehyde gas sensor

Field effect transistor (FET) type gas sensor plays a crucial role in real-time environmental monitoring, medical pre-diagnosis, and industrial control because of its trace hazardous gases detection capability, which can be attributed to the unique amplification of the electrical signal on its gate by FET. Limited by the nano-micro level manufacturing process, the controllable deposition of the tiny sensing gate composed of gas sensing materials and material selection limitations considering semiconductor process compatibility have become bottlenecks in developing FET-type gas sensors. Herein, based on a high-performance FET with semiconducting single-walled carbon nanotubes as the channel, a universal strategy of constructing an extended-gate structure by inkjet printing technology is proposed to realize the detection of trace gases. CuO widely used for HCHO detection is applied to this strategy, and the as-prepared EG-FET sensor has a limit of detection of 20 ppb for HCHO, good repeatability, long-term stability, and selectivity, which greatly improves the ability of conventional chemiresistive gas sensor to detect HCHO. The development of the EG structure makes the controlled deposition of gas sensing materials more accessible, and the introduction of inkjet printing expands the choices of sensing materials. In particular, it solves the issue of poor reproducibility in the fabrication of gas sensors from gas sensing materials and provides a feasible scheme for the reported excellent gas sensing materials from laboratory to application. We expect this work can provide a meaningful theoretical and experimental basis for the realization of high-performance trace gas sensors with the potential for on-chip integration.

Design of high-sensitivity La-doped ZnO sensors for CO2 gas detection at room temperature

For the sake of people's health and the safety of the environment, more efforts should be directed towards the fabrication of gas sensors that can operate effectively at room temperature (RT). In this context, increased attention has been paid to developing gas sensors based on rare-earth (RE)-doped transparent conducting oxides (TCO). In this report, lanthanum-doped zinc oxide (La-doped ZnO) films were fabricated by sol–gel and spin-coating techniques. XRD analysis revealed the hexagonal structure of the ZnO films, with preferred growth along the (002) direction. The crystallite size was decreased from 33.21 to 26.41 nm with increasing La content to 4.0 at.%. The UV–vis–NIR indicating that the films are highly transparent (˃ 80%), La-doping increased the UV blocking ability of the films and narrowed the optical band gap (Eg) from 3.275 to 3.125 eV. Additionally, La-doping has influenced the refractive index of the samples. Gas sensing measurements were performed at ambient temperature (30 °C) and a relative humidity (RH) of 30%, employing different flow rates of carbon dioxide (CO2) gas used synthetically with air. Among the evaluated sensors, the ZnO: 4.0 at.% La sensor exhibited the most significant gas response, with a value of 114.22%. This response was observed when the sensor was subjected to a flow rate of 200 SCCM of CO2 gas. Additionally, the sensor revealed a response time of 24.4 s and a recovery time of 44 s. The exceptional performance exhibited by the sensor makes it very appropriate for a wide range of industrial applications. Additionally, we assessed the effect of humidity, selectivity, reusability, repeatability, detection limit, and limit of quantification.

Synthesis and growth mechanism of ZnO nanocandles using thermal evaporation and their efficient CO sensing performance

We report on the single step grown ZnO nanocandles without adding any catalyst for efficient CO gas sensing application. A simple, scalable, and cost-effective thermal evaporation technique was employed for the growth of ZnO nanostructures on alumina substrate at 600 °C. It was observed that oxygen ambient (variation in oxygen flow rates from 20 to 40 sccm) strongly influences the shape and size of the ZnO nanostructures (i.e., the formation of nanocandles or nanorods). The as grown ZnO nanostructures were characterized using various techniques such as X-ray diffraction, Field emission scanning electron microscopy, photoluminescence, and X-ray photoelectron spectroscopy. Further, a comprehensive analysis of the CO gas sensing performance of each sample was recorded under various conditions, and the corresponding mechanism was reported. We have achieved the maximum sensor response (SR%) ∼ 78.3% along with a response/recovery time ∼ 59.5 s/109.4 s towards 91 ppm of CO gas at 400 °C for the sample synthesized at 40 sccm oxygen gas flow rate (i.e., for nanocandles). While, a relatively lower SR ∼ 70.1% and ∼ 64.1% and higher response/recovery time of ∼ 77.8 s/118.6 s and ∼ 84.6 s/122.1 s were obtained for the samples synthesized at 30 sccm and 20 sccm, respectively (i.e., for nanorods). Moreover, the calculated detection limit for ZnO nanocandles was 110 ppb. The selectivity test shows that the ZnO nanocandles are highly responsive to CO gas and exhibits long term stability (tested over 360 days). Thus, ZnO nanocandles can be used for the fabrication of robust CO gas sensors.

LPG sensing behavior and dielectric properties of lanthanum doped cobalt-iron oxide nano ferrite sensors towards room temperature detection at ppb level

Herein, we report for the first time cost-effective synthesis of lanthanum doped cobalt-iron ferrite composite sensors towards the detection of liquified petroleum gas (LPG) at room temperature. The synthesized ferrite composites were characterized by different analytical techniques such as scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and ultraviolet–visible (UV–Vis) spectroscopy methods to analyse the surface morphology, elemental composition, functional groups, structural and optical properties. The synthesized ferrite composite exhibit improved ac conductivity and dielectric attributes due to the doping of rare earth (RE) lanthanum NPs into the cobalt-iron ferrites. Doping of lanthanum nanoparticle (NPs) into cobalt-iron ferrites result into porous surface with interconnected network which support for easy transportation of charge carriers into neighbouring sites. The gas sensing response of the lanthanum doped cobalt-iron ferrites was carried out at room temperature. The gas sensing properties of the synthesized CoFe2-xLaxO4 samples were studied for LPG, ethane, propane, butane, methane, and petrol vapours of variable hydrocarbon gas species. The CoFe2-xLaxO4 composite shows superior gas response towards LPG gas at room temperature. The gas response of CoFe2-xLaxO4 (x -0.1) composite sample was measured to be nearly 98% for LPG with enhanced response and recovery times. Furthermore, the long-term stability of these gas sensor towards LPG indicates that, that among the synthesized samples x - 0.1 composite samples show stable performance even after 60 days of operation. Owing to improved electrical conductivity, gas sensing behaviour and quick response and recovery times at room temperature, these CoFe2-xLaxO4 composites could be employed as suitable candidate towards fabrication of room temperature gas sensors especially for the detection of LPG at low concentration (ppb level).

Comparison of printing techniques for the fabrication of flexible carbon nanotube-based ammonia chemiresistive gas sensors

Even though a plethora of printing technologies are currently available and their potential for the fabrication of low-cost and flexible sensors has been widely investigated, systematically based, and statistically sustained comparative studies are missing in the literature. In this work, we compare screen, inkjet, and dispense printing for the fabrication of carbon nanotube (CNT)-based ammonia (NH3) chemiresistive flexible gas sensors for the first time. Moreover, we report the first CNT-based gas sensor fabricated via Voltera printer. The devices were made of a thin layer of spray-coated CNTs and printed silver-based interdigitated electrodes. To draw a thoughtful comparison the same sensor layout, materials, and fabrication flow were used. The device morphological features were acquired through microscopic, atomic force microscope, and 3D images; additionally, the response to NH3 as well as the printing process characteristics for each technique was analyzed. From 300 µm nominal spacing between lines, we obtained a decrease of 25%, 13%, and 5% on the printed spacings with dispense, screen, and inkjet printing, respectively. At 100 ppm of NH3, a maximum response of 33%, 31%, and 27% with the dispense-, inkjet-, and screen-printed sensors were found, respectively. Statistical differences were observed between the mean values on the NH3 response of dispense- compared to the inkjet- and screen-printed sensors, which in effect showed the highest response in the Tukey test. This demonstrated that the fabrication technique employed can induce a different response mainly driven by the printed outcomes. Following a holistic approach that includes the sensor response, the application, the market perspective, and the process versatility, we suggest screen printing as the most suitable method for CNT-based NH3 gas sensor fabrication.

Flexible In2Se3 sensor for chemiresistive NO2 detection at room temperature

Piezoelectric semiconductors offer tremendous opportunity in nanosensors. In this work, we demonstrate the fabrication of a flexible gas sensor based on few-layer In2Se3 nanosheets synthesized by CVD, which exhibits high sensitivity to NO2 with fast response/recovery speed (3/40 s) at room temperature (RT) and a low detection limit of 71 ppb. We further investigated the piezoelectric effect by mechanical deformation on the sensor properties. When the deformation increased from 0.18% to 0.98%, the sensor response showed a remarkable increase and reached the maximum at 0.31%, then decreased. The improved sensing property can be ascribed to coupled effect of piezoelectricity and adsorption-induced charge transfer in the In2Se3 device. Our work opens up a way to develop new piezoelectric chemical sensors.

Fabrication and verification of a single aligned nanofibre gas sensor based on non‐contact direct writing method

AbstractIn this letter, the non‐contact direct writing method for producing single aligned fibre utilizing polyvinylpyrrolidone (PVP) polymer has been explored. It has been shown that with the help of this method, nanofibres can be created in a controlled manner with designed structures. This form of nanofibres is being studied with the goal of using it in carbon monoxide (CO) gas sensors. The temperature required for the annealing operation was 500°C, and finally the authors obtained nanofibres with diameter of 200 nm. In addition, a simulation technique built on the Monte Carlo method has also been introduced. It is shown that this simulation method is compatible with the experimental results with reasonable accuracy. The results showed that the authors have a correlation of about 0.934 between experimental results obtained in 30 ppb of CO gas and its simulation data.

NO2 Adsorption Sensitivity Adjustment of As/Sb Lateral Heterojunctions through Strain: First Principles Calculations

Strain engineering is an effective way to adjust the sensing properties of two-dimensional materials. In this paper, lateral heterojunctions (LHSs) based on arsenic and antimony have been designed along the armchair (AC) or zigzag (ZZ) edges. The adsorption and sensing characteristics of As/Sb LHSs to NO2 before and after applying different types of strain are calculated by first principles. The band gaps of all As/Sb heterostructures are contributed by As-p and Sb-p orbitals. In addition, the adsorption energy of As/Sb ZZ-LHS with −4% compression strain is the largest. Furthermore, its work function changes significantly before and after the adsorption of NO2. Meanwhile, strong orbital hybridizations near the Fermi level are observed and a new state is yielded after applying compressive strain. These results indicate that the As/Sb LHS with ZZ interface under −4% compression strain possesses the best sensing properties to NO2. This work lays the foundation for the fabrication of high-performance NO2 gas sensors. High-performance gas sensors can be used to track and regulate NO2 exposure and emission, as well as to track NO2 concentrations in the atmosphere and support the assessment of air quality.

ZnO Intercalated PVA-PEDOT:PSS Composite Nanofiber for Detection of Ammonia Gases

Keywords: Ammonia, Electrospinning, and Zinc OxideThe matter of air pollution has dramatically risen the worldwide concern on detecting of hazardous gases present in the atmosphere because they are highly detrimental to human health [4,5]. Additionally, the detection and monitoring of such harmful gases is necessary for process control in the industry as well as the general safety of the environment. Zinc oxide (ZnO) is an n-type semiconductor with a wide direct bandgap width (3.37 eV), high excitation binding energy (60meV), high electron mobility, thermal stability, and excellent electrical properties [1]. Other promising materials for gas-sensing applications encompass single elements, silicon and tellurium-based materials and organic semiconductors. The sensing materials that are of intense research interest are conducting polymers such as polyaniline (PANI), polypyrrole (PPy) and poly(3,4-thylenedioxythiophene) (PEDOT) used in the fabrication of polymer-based gas sensors [2]. Its capability to work at low operating temperatures while maintaining high sensitivity leads to the synergistic effect when in combination with metal oxides to produce high-performance gas sensors. They are very appealing in terms of energy saving as they do not need an additional source of heat, consequently reducing the operating cost, simplifying the fabrication process, and extending the lifespan of the device [3]. In this work, ZnO intercalated PVA-PEDOT:PSS composite nanofiber as a sensing layer was prepared by electrospinning method. This material was characterized both morphologically and structurally by X-ray diffraction analysis, scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier-transform infrared spectroscopy and thermogravimetric analysis. The results from TEM and SEM show well distribution of ZnO particles in the polymer matrix. The gas measurement results reveal that the fabricated ZnO loaded PVA-PEDOT:PSS composite sensor exhibits excellent gas response (63%) to ammonia gas in 100 ppm gas concentration at 120 °C. Acknowledgment This research was supported by the research grant 021220CRP0122 “Development of highly sensitive MOS based nano-film gas sensors” from Nazarbayev University. References S. Bhati, M. Hojamberdiev, and M. Kumar, “Enhanced sensing performance of ZnO nanostructures-based gas sensors: A Review,” Energy Reports, vol. 6, pp. 46–62, 2020.Yan, Y. et al. (2020) “Conducting polymer-inorganic nanocomposite-based Gas Sensors: A Review,” Science and Technology of Advanced Materials, 21(1), pp. 768–786.Zhang, J. et al. (2015) “Nanostructured materials for room-temperature gas sensors,” Advanced Materials, 28(5), pp. 795–831.C. Eze, E. Schaffner, E. Fischer, T. Schikowski, M. Adam, M. Imboden, M. Tsai, D. Carballo, A. von Eckardstein, N. Künzli, C. Schindler, and N. Probst-Hensch, “Long-term air pollution exposure and diabetes in a population-based Swiss cohort,” Environment International, vol. 70, pp. 95–105, 2014.C. Shim, J. Han, D. K. Henze, M. W. Shephard, L. Zhu, N. Moon, S. K. Kharol, E. Dammers, and K. Cady-Pereira, “Impact of NH3 emissions on particulate matter pollution in South Korea: A case study of the seoul metropolitan area,” Atmosphere, vol. 13, no. 8, p. 1227, 2022. Figure 1