Ammonia Gas Detection Research Articles

Impact of SiGe pocket on different shape TFET structures for gas sensing application

Gas sensing requires highly sensitive and selective sensor technologies for environmental monitoring, industrial safety, and public health objectives. Although conventional MOSFET-based gas sensors are widely utilized, their detection of low quantities of gases, such as ammonia, is hindered by a number of severe constraints. TFET is emerged as the better device than MOSFET, particularly for the sensing applications. In this work we discussed the source engineered and shape engineered techniques to improve the performance of TFETs, specifically for ammonia gas detection. Comprehensive simulations on SILVACO TCAD and compared the four TFET structures SiGe-pocket DGTFET, SiGe-pocket vertical TFET SiGe-pocket Z-shape TFET, and SiGe-pocket U-shape TFET structure on the basis of various electrical characterization parameters. Significant improvements in efficiency and sensitivity are obtained by adjusting the work function of the molybdenum (4.40–4.60 eV) catalytic gate metal to find the optimal values. The findings reveal that the SiGe-pocket U-shape TFET structure exhibits superior performance, demonstrating an ION of 8.01 × 10−4 A/μm, an ION/IOFF ratio of 1.25×1013, and an OFF current sensitivity (SOFF) of 1.262. These results highlight the enhanced sensitivity and efficacy of the proposed SiGe-pocket U-shape tunnel FET in ammonia gas sensing applications, making it a promising candidate for practical uses in environmental monitoring and industrial safety.

IoT Based Poultry Cage Quality Monitoring System

This research aims to create a better cage quality monitoring system in poultry farms, the parameters observed in particular are ammonia gas, where this gas greatly affects the health and productivity of laying hens, the data taken is processed in percentage terms and a comparison of several conditions in the location where the equipment is placed. The system is made using ESP32 microcontroller as the main board, DHT22 as a temperature and humidity sensor, MQ135 as a sensor to detect ammonia gas levels, GY302/BH1750 as a light sensor, light sensor or light meter sensor is used to optimize the circadian cycle of laying hens, the monitor system uses data sent by the main board to the database and taken as output by the mobile application. At the implementation stage, the system is able to function properly where the monitor system can send and receive data with the database as an intermediary between hardware and software. The DHT22 sensor can detect temperature and humidity changes with minimal error, the error rate obtained for DHT22 sensor reaches 2.26%, the MQ135 sensor can detect ammonia gas levels according to set program, the GY302/BH1750 sensor can detect changes in light with quite optimal accuracy, all sensor activities can be monitored through the software that has been created, when the system is used for a long period of time periodically the main board will stop sending data to the database, This can last 30 to 40 minutes, with a reboot solution.

Biocompatible sensors for ammonia gas detection

In this work, three different dyes have been tested for the determination of gaseous ammonia. This gas is one of the products of microbial degradation and therefore its presence is an indicator of deterioration and could be used as a food freshness indicator.Three different sensors have been prepared and tested, two of them using the natural pigments curcumin and anthocyanin and the other one using bromothymol blue. All of them are biocompatible and therefore allowed to use in contact with food.Different compositions, materials for deposition, stability and reversibility for ammonia gas detection have been studied under high humidity conditions simulating real packaged food conditions. Colorimetry is the technique used to obtain the analytical parameter, the H coordinate of the HSV colour space, simply using a camera, avoiding the use of complex instrumentation.Sensibility, toxicity grade and stability found show that the sensor could be implemented in packaged food and form the basis of a freshness indicator for the food industry.

Fabrication of Graphene-based Ammonia Sensors: A Review

Abstract: Graphene gas sensors have gained much scientific interest due to their high sensitivity, selectivity, and fast detection of various gases. This article summarizes the research progress of graphene gas sensors for detecting ammonia gas at room temperature. Firstly, the performance and development trends of the graphene/semiconductor Schottky diode sensor are discussed. Secondly, manufacturing methods and the latest developments in graphene field-effect transistor sensors are reviewed. Finally, the basic challenges and latest efforts of functional ammonia gas sensors are studied. The discussion delves into each sensor type's detection principles and performance indicators, including selectivity, stability, measurement range, response time, recovery time, and relative humidity. A comparative analysis is conducted to highlight the progress achieved in research, elucidating the advantages, disadvantages, and potential solutions associated with various sensors. As a result, the paper concludes by exploring the future development prospects of graphene-based ammonia sensors.

Improved ammonia gas adsorption of surface engineered WS2 nanoflakes

Recent investigations into nanostructured WS2 have shown promising results in the detection of reducing gases, such as ammonia. However, this material faces limitations with respect to the vital parameters such as sensitivity, recovery, and repeatability over an extended period in its purest form. To address these challenges, a low-energy (5 keV) argon ion beam was used to irradiate nanostructured WS2 nanoflakes at various fluences, leading to observable morphological and structural changes. The irradiation of WS2 resulted in a significant enhancement in its ability to detect ammonia gas. The sensing response saw a threefold increase, and both the response and recovery times were reduced significantly compared to pristine samples. Ion beam irradiation changes the overall morphology of nanoflakes and induces a certain degree of defects as apparent from electron microscopy, X-ray diffraction, Raman spectroscopy, and X-ray photoelectron spectroscopy studies. The ion-solid interaction simulation predicts a larger amount of sulfur vacancy than tungsten due to irradiation, which is also supported by experimental results. Density functional theory predicts that sulfur vacancy leads a decisive role in better adsorption of ammonia than the pristine surface. The NH3 molecule orients towards the defective surface leading to a higher charge transfer from the NH3 molecule to the surface than the pristine surface along with a smaller adsorption height.

Ultrasensitive and selective detection of ammonia gas at room temperature of La-doped ZnO thin films

Ultrasensitive and selective detection of ammonia gas at room temperature of La-doped ZnO thin films

Studying of the structural and optical properties of lead halide perovskite and useing in detecting ammonia gas

Studying of the structural and optical properties of lead halide perovskite and useing in detecting ammonia gas

Effect of Ce doping on MoO3 thin films for room temperature ammonia sensing application

In this work, we report the fabrication and gas sensing application of undoped, and Ce doped (1, 2, 3, 4, 5 wt%) MoO3 thin films via simple, effective, and low-cost nebulizer spray pyrolysis method. The crystal structure of the prepared thin films was found to be monoclinic by the prominent peaks observed at (001), (002) planes and the primary peak intensities increases from undoped to 3% Ce doped MoO3 thin film. The morphology of the samples was studied by FESEM, and the films have nanofibrous network embedded with nanorods spread over the surface of the nanofibers. The optical properties were characterised by the UV–vis spectroscopy and observed that the film’s energy band gap declines from 3.28 to 3.04 eV due to the Ce dopant which alters the energy levels of the conduction and valence bands of the host by oxygen defects. The defects were analysed by the PL spectroscopy, and it proved that the PL emission peaks arose due to the oxygen deficiencies. The 3% Ce doped MoO3 produced higher PL emission intensity indicated that the higher oxygen defects sites are the cause. The gas sensing responses were measured for the pristine and 1, 2, 3, 4 and 5 wt% Ce doped MoO3 gas sensors increase from 6.48 × 102 to 1.67 × 104 and found to be higher for the 3% Ce doped sensor to detect ammonia gas. The significant gas sensing property such as rise time and fall time were observed to be least for the 3% Ce doped MoO3 thin film was 54 and 5 s. This study revealed that 3% Ce doped MoO3 thin film could be an efficient prominent ammonia gas sensor at room temperature in future.

A large-dynamic range conductivity-modulated PANI online analysis and sensing platform for ammonia gas detection using coupled optical probing mode

Due to the large-dynamic range and reversible conductivity modulation capability, polyaniline (PANI) shows promising prospects for diverse applications, such as supercapacitors, rechargeable batteries, and electrochromic materials. However, online characterization of the optical properties of the conductive polymer in the infrared band throughout the synthesis and redox state changing processes poses a challenge. Here, we propose and demonstrate an analysis and sensing platform for real-time evaluation of both thickness and the complex refractive index of PANI nanofilm, and employed for ammonia gas concentration sensing. The coupled optical probing mode of tilted fiber Bragg grating (TFBG) as a robust and portable permittivity perception tool is utilized for online perceiving the large-dynamic-range conductivity change of PANI nanofilm. By reproducing the spectral evolution of the probing cladding mode resonance, we introduce a simulation method for analyzing the optical properties of polymer nanofilms within the infrared band. For ammonia gas detection, the sensing platform exhibited continuous and reliable detection within a concentration range of 25–500 ppm, with an optimal film thickness of 156 nm. A good linear response was observed with a sensitivity of up to 5.2 × 10−3 dB/ppm, and a linearity (R2 = 0.9876) with a detection limit of 10 ppm. Our proposed low-cost and large dynamic range conductivity-modulated PANI-TFBG platform for optical properties online analysis and sensing shows potential in environmental monitoring, healthcare, and the biochemical field.

An Ammonia Gas Sensor Based on Reduced Graphene Oxide Nanocomposite Hydrogels

AbstractA flexible gas sensor based on nanocomposite has been developed and characterized for detecting ammonia gas (NH3) in the atmosphere. This sensor utilizes nanocomposite hydrogels composed of Arabic gum (AG), acrylic acid (AAc), reduced graphene oxide (RGO), and silver nanoparticles (AgNPs). Various techniques, including FTIR (Fourier Transform Infrared Spectroscopy), AFM (Atomic Force Microscopy), XRD (X‐ray Diffraction), SEM (Scanning Electron Microscopy), XRF (X‐ray Fluorescence), TGA (Thermo‐gravimetric Analysis), DSC (Differential Scanning Calorimetry), were used to evaluate the sensor‘s properties. The nanocomposite hydrogels showed exceptional swelling ability (597 %), advantageous for accommodating gas molecules like NH3. The Polymerization and network formation percentages of 31 % and 56 %, respectively, suggest a robust hydrogel matrix structure. When tested for NH3 gas sensing at room temperature, the RGO/AgNPs/AGPAAc‐hydrogel exhibited high sensitivity and stability compared to other variants across gas concentrations ranging from 0 to 100 ppm. The improved performance of the physiochemical properties of the nanocomposite hydrogels might be attributed to the combined effect of AgNPs and RGO, which likely enhance sensitivity and stability. Selectivity tests conducted for three gases at room temperature revealed that the sensor response was highly selective to NH3 at a concentration of 50 ppm. Furthermore, the sensor demonstrated consistent performance over time. These findings suggest potential applications in environmental monitoring and industrial safety, with the possibility of contributing to advancements in gas sensing technology and addressing environmental and safety concerns.

Room temperature NH3 gas sensor based on In(OH)3/Ti3C2Tx nanocomposites.

Industrialization and agricultural demand have both improved human life and led to environmental contamination. Especially thedischarge of a lot of poisonous and harmful gases, including ammonia, ammonia pollution has become a pressing problem. High concentrations of ammonia can pose significant threats to both the environment and human health. Therefore, accurate monitoring and detection of ammonia gas are crucial. To address this challenge, we have developed an ammonia gas sensor using In(OH)3/Ti3C2Tx nanocomposites through an in-situ electrostatic self-assembly process. This sensor was thoroughly characterized using advanced techniques like XRD, XPS, BET, and TEM. In our tests, the I/M-2 sensor exhibited remarkable performance, achieving a 16.8% response to 100ppm NH3 at room temperature, which is a 3.5-fold improvement over the pure Ti3C2Tx MXene sensor. Moreover, it providesswift response time (20s), high response to low NH3concentrations (≤ 10ppm), and excellent long-term stability (30days). These exceptional characteristics indicate the immense potential of our In(OH)3/Ti3C2Tx gas sensor in ammonia detection.

Fast and green synthesis of iron oxide using low-power laser sintering on reduced graphene oxide sensor for ammonia gas detection

Oxide materials are important for gas sensing applications. Unfortunately, most of the synthesis methods use many toxic chemicals and need long calcination at high temperatures. Thus, developing simple and green synthesis processes, which can be performed fast and at low temperatures, is imperative for both industrial manufacturers and our environment. Here, our fast and green synthesis method based on low-power laser sintering for producing FeOx (with Fe2O3 as the main composition) is presented. Besides, FeOx particles were decorated on reduced graphene oxide (RGO) to form a resistive sensor. Notably, our FeOx material can reduce the response of RGO toward acidic gas (NO2) but it enhances the RGO response toward the basic NH3 gas. Particularly, our hybrid FeOx/RGO sensor can detect NH3 gas at above 2 ppm under dry and humidified conditions (<85 % RH). That effect of FeOx is found due to the formation of alpha-phase Fe2O3 which acts as a p-type semiconductor, which is explored and explained in the discussion section. Finally, our findings not only reveal the potential of our hybrid sensing materials for practical NH3 sensing applications but also confirm the usefulness of laser-sintering to produce catalytic oxide materials environmentally friendly and at low cost.

High-sensitivity ammonia gas sensor based on hollow microsphere MXene@SnS2@polyaniline composite material with humidity resistance

Conductive polymer-based gas sensors are frequently utilized because of their benefits, which include affordability, good gas selectivity, and room-temperature detection. However, they are still limited by low sensitivity, high detection limit, and slow response-recovery speed. In this study, a hollow flower-shaped composite gas-sensing material was designed. MXene microspheres formed by electrostatic adsorption using Polymethyl Methacrylate (PMMA) as a template were used as substrates, and SnS2 nanosheets were produced hydrothermally on the MXene microsphere surface to form flower-shaped gas-sensitive materials. After calcination to remove the template, polyaniline (PANI) was coated onto each SnS2 nanosheet via in situ polymerization. The synthesized MXene@SnS2@PANI nanoflowering composites exhibited an extremely high responsiveness to ammonia gas at 25 °C, extremely low detection limits, and unique selectivity towards ammonia gas. When exposed to 100 ppm NH3 at 25 °C and 45% relative humidity (RH), the MSP-100 gas sensor's reaction reached 119.76%, which was five times that of PANI. Notably, in the range of 0%–90% RH, the MSP-100 based gas sensor's reaction grew as humidity rose, reaching a peak response of 215.18% at 90% RH. In addition, the MXene@SnS2@PANI based gas sensor had an extremely low detection limit of 1.557 ppm and prominent selectivity, indicating the its promising application in ammonia gas detection.

Exploring the gas sensing potential of BiOBr0.9I0.1: A highly responsive sensor for ammonia detection at room temperature

Bismuth halide oxides (BiOX, where X = Cl, Br, I) are renowned in photocatalysis for their distinct layered structure, modifiable band gap, and affordability. However, their application in gas sensing has garnered comparatively less research attention. Notably, solid solutions of BiOX demonstrate superior attributes over pure BiOX compounds. BiOBrxI1-x solid solution was successfully synthesized using in situ precipitation method and used as a gas-sensitive material for ammonia (NH3) gas sensor. The structural and compositional integrity of the synthesized samples was meticulously confirmed by X-ray diffraction (XRD), which revealed the coexistence of different BiOBr and BiOI phases. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) provided insights into the morphology, revealing a flower-like nanostructure, which favors the surface reaction rate. The electronic and optical properties of the material were further elucidated by photoluminescence (PL) spectroscopy and ultraviolet–visible diffuse reflectance spectroscopy (UV-DRS), which revealed that the band gap is tailored to facilitate the sensitivity and selectivity of ammonia detection. Key properties including surface area and porosity were quantitatively evaluated by Bruner-Emmett-Taylor (BET) analysis and found BiOBr0.9I0.1 sensor to have a specific surface area of 13.08 m2/g. Specifically, the BiOBr0.9I0.1 sensor's response ratio (Ra/Rg) to 100 ppm of ammonia reaches 8, approximately fourfold higher than that of the pure BiOBr sensor. The flower-like morphology of BiOBr0.9I0.1 enhances surface activity and charge transfer efficiency, thereby facilitating greater gas adsorption and elevating sensor performance. The rapid response and recovery times (12/24 s at 30 ppm), low detection threshold (LOD, 0.75 ppm), along with its selectivity and reproducibility at room temperature, position the BiOBr0.9I0.1 material as a promising candidate for ammonia gas detection.

Synthesis of lignin-based carbon/graphene oxide foam and its application as sensors for ammonia gas detection

The present study highlights the integration of lignin with graphene oxide (GO) and its reduced form (rGO) as a significant advancement within the bio-based products industry. Lignin-phenol-formaldehyde (LPF) resin is used as a carbon source in polyurethane foams, with the addition of 1 %, 2 %, and 4 % of GO and rGO to produce carbon structures thus producing carbon foams (CFs). Two conversion routes are assessed: (i) direct addition with rGO solution, and (ii) GO reduction by heat treatment. Carbon foams are characterized by thermal, structural, and morphological analysis, alongside an assessment of their electrochemical behavior. The thermal decomposition of samples with GO is like those having rGO, indicating the effective removal of oxygen groups in GO by carbonization. The addition of GO and rGO significantly improved the electrochemical properties of CF, with the GO2% sensors displaying 39 % and 62 % larger electroactive area than control and rGO2% sensors, respectively. Furthermore, there is a significant electron transfer improvement in GO sensors, demonstrating a promising potential for ammonia detection. Detailed structural and performance analysis highlights the significant enhancement in electrochemical properties, paving the way for the development of advanced sensors for gas detection, particularly ammonia, with the prospective market demands for durable, simple, cost-effective, and efficient devices.

Bibliometric analysis on conducting polymer sensors for ammonia gas detection using Scopus database

AbstractConducting polymers (CPs)‐based sensing materials have emerged as a prominent option for the sensitive detection of gaseous ammonia (NH3) due to their cost‐effectiveness, ease of production, and increased sensing performance. Although more than 1400 articles published in the past decades, no bibliometric analysis which can highlight the publication trend and research clusters within the scope of conducting polymer‐based sensors for ammonia detection (CPAD) is available in the literature. The aim of this bibliometric analysis is to document the research trends of CPAD during the last 27 years, since the inception of the first report on conducting polymer as potential NH3 gas sensor which has been published in 1994. The bibliometric analysis was carried out using VOSviewer and Publish or Perish software to analyze keywords trend, the impact of the scientific community, publishing trends among the authors, institutions, and countries. The review discovered that over 80% of the relevant papers produced after 1994, based on bibliographical examination of 1476 Scopus‐indexed articles. Citation analysis was used to identify key authors and articles that shaped the evolution of this literature. Overall, this bibliometric approach allows us to analyze the evolution of a CPAD field while also offering insights on the field's growing areas.

Ultrasensitive and selective Cr-doped ZnO thin films synthesized via spray pyrolysis technique for detection of ammonia gas

Ultrasensitive and selective Cr-doped ZnO thin films synthesized via spray pyrolysis technique for detection of ammonia gas

Synthesis and Properties of Eu and Ni Co-Doped ZnS Nanoparticles for the Detection of Ammonia Gas

Zinc sulfide nanoparticles were synthesized successfully via chemical co-precipitation, both in undoped form and co-doped with Europium (Eu) and Nickel (Ni). All prepared samples exhibited cubic zinc blende structure as confirmed by X-ray diffraction (XRD). The average particle size ranged from 3 to 6 nm for both pure and (Eu, Ni) co-doped ZnS, with no alteration in the crystal structure due to Eu and Ni co-doping. However, increasing the Ni dopant concentration (0, 2, 4, & 6 at%) while maintaining a constant Eu concentration (4 at%) led to an enhancement in the crystallite size. This was further validated by transmission electron microscopy (TEM), which showed particle sizes consistent with the XRD findings (3–5 nm). Microscopic analysis via scanning electron microscopy and TEM revealed spherical agglomerated morphology for the (Eu, Ni) co-doped nanoparticles. Energy-dispersive X-ray spectroscopy spectra confirmed the stoichiometric chemical composition of ZnS: Eu, Ni. Photoluminescence studies demonstrated an increased intensity of green luminescence at 6 at% Ni co-dopant concentration. Moreover, the synthesized samples exhibited promising gas sensing properties, particularly towards ammonia gas, with good selectivity. Notably, both pure and (Eu, Ni) co-doped ZnS nanoparticles showed rapid response and recovery times at room temperature, suggesting their potential applicability in gas sensing applications.

Novel cost-effective Hibiscus flower based colorimetric paper sensor containing anthocyanins to monitoring the quality and freshness of raw fish

This article described the low-cost hibiscus flower based colorimetric paper sensor to monitor the quality and freshness of raw fish. The extract of hibiscus flower was used to develop pH sensing paper strips for qualitative analysis. The sensitivity of paper sensor was checked by colorimetric detection of ammonia gas and then it was implemented to monitor the freshness of fish visually. The extract of hibiscus flower containing anthocyanin molecules are the key molecule for visual detection of spoiled food. The above molecule was spectroscopically analyzed with change in pH of the solution before and after the interaction of food products. We also studied the variation of both color and shade of paper sensor with change in pH at natural and artificial light conditions. The color information extracted from images and their relationship with pH was explored in red, green, blue (RGB) and hue, saturation, and value (HSV) color spaces by the image-J software for qualitative monitoring of food. Anthocyanin based paper sensor is used as a convenient and real time smart food sensor in packaging application.

Optimizing the structural, thermal, gas sensing and electrical properties of in-situ polymerized poly(thiophene-co-indole)/silicon carbide nanocomposites for energy storage applications

Conducting copolymer nanocomposites of thiophene and indole incorporated with silicon carbide nanoparticles [poly (thiophene-co-indole-SiC) (PPSiC)] has been developed by in-situ copolymerization and these nanocomposites were characterized by different analytical techniques. The FTIR peak at 865 cm−1 signifies the successful incorporation of SiC nanoparticles in the copolymer matrix. The intensity of the UV-Vis absorbance of the copolymer nanocomposites increased with the nanoparticle concentrations, and PPSiC7 showed the highest intensity. This was in correlation with its low optical bandgap energy (3.032 eV) and high refractive index (2.388) value. XRD revealed the consistent positioning of sharp and distinct crystalline peaks of SiC in the copolymer. SEM revealed the effective dispersion of nanoparticles throughout the matrix and uniform dispersion was obtained for PPSiC7 nanocomposite. HR-TEM images validated the presence of spherical-shaped particles in the nanocomposite with the nano-size distribution of SiC. The surface roughness of the copolymer nanocomposite was evident from AFM analysis. TGA and DSC revealed that PPSiC nanocomposites have better thermal properties than the copolymer. AC conductivity increased with frequency and temperature. The PPSiC7 exhibits a maximum conductivity of 1.5×10−2 S/cm at 106 Hz and an activation energy of 0.064 eV. PPSiC nanocomposites demonstrated excellent results in degrading dye and detecting ammonia gas at ambient temperature. All analyses showed that the PPSiC7 nanocomposite exhibited superior properties than the copolymer. These admirable properties can be exploited in developing optoelectronic devices, energy storage devices and gas sensors.