Ammonia Gas Detection Research Articles

Fabrication of a Fully Printed Ammonia Gas Sensor Based on ZnO/rGO Using Ultraviolet-Ozone Treatment.

In this study, a room-temperature ammonia gas sensor using a ZnO and reduced graphene oxide (rGO) composite is developed. The sensor fabrication involved the innovative application of reverse offset and electrostatic spray deposition (ESD) techniques to create a ZnO/rGO sensing platform. The structural and chemical characteristics of the resulting material were comprehensively analyzed using XRD, FT-IR, FESEM, EDS, and XPS, and rGO reduction was achieved via UV-ozone treatment. Electrical properties were assessed through I-V curves, demonstrating enhanced conductivity due to UV-ozone treatment and improved charge mobility from the formation of a ZnO-rGO heterojunction. Exposure to ammonia gas resulted in increased sensor responsiveness, with longer UV-ozone treatment durations yielding superior sensitivity. Furthermore, response and recovery times were measured, with the 10 min UV-ozone-treated sensor displaying optimal responsiveness. Performance evaluation revealed linear responsiveness to ammonia concentration with a high R2 value. The sensor also exhibited exceptional selectivity for ammonia compared to acetone and CO gases, making it a promising candidate for ammonia gas detection. This study shows the outstanding performance and potential applications of the ZnO/rGO-based ammonia gas sensor, promising significant contributions to the field of gas detection.

Bimetallic MOF-Based Sensor for Highly Sensitive Detection of Ammonia Gases.

The demand for the detection of ultralow concentrations of ammonia gas is growing. A bimetallic metal-organic framework (MOF) comprising Prussian blue analogs (PBAs) was used to achieve highly sensitive and stable detection of ammonia gas at room temperature in this study. First, PB was enriched by using ammonia for improved gas sensing properties. Second, a sensitive membrane with more vacancies was formed by partially replacing Fe3+ with Cu2+ through a cation-exchange strategy. Finally, a capacitive sensor was developed for ultralow-concentration ammonia detection using a Cu-Fe PBA sensitive membrane and interdigitated electrodes (IDEs). To investigate the adsorption efficiency of the designed composite sensitive film for ammonia, PBAs nanoparticles were deposited on a quartz microcrystal balance (QCM) via cyclic voltammetry and a hydrothermal method. Approximately 10 ppm of ammonia was adsorbed under 1 atm by the Cu-Fe PBA film prepared using a reaction time of 36 h, and the adsorption efficiency was measured to be 2.2 mmol g-1 using the QCM frequency response. The Cu-Fe PBAs were also tested using scanning electron microscopy, transmission electron microscopy, X-ray diffraction, and Brunauer-Emmett-Teller theory. The introduction of Cu2+ ions significantly increased the specific surface area of Cu-Fe PBAs MOF, and the number of adsorption sites for ammonia also increased; however, its skeleton structure remained similar to that of PB. Then, the capacitive sensor based on Cu-Fe PBA sensitive membrane and IDE was fabricated and the gas sensing detection device was established for ammonia detection. Overall, the developed capacitive sensor exhibits a linear response of 75-1000 ppb and a detection limit of 3.8 ppb for ultralow ammonia concentrations, which makes it superior to traditional detection methods and thus allows excellent application prospects.

High-performance ammonia gas sensor based on spray pyrolysis developed In2O3:La films

La doped indium oxide (In2O3:La) thin films were deposited on glass substrate by nebulizer spray pyrolysis by different La doping concentrations. The crystalline structure, morphology, optical and gas sensing properties of thin films were investigated. XRD diffractograms present cubic crystal structure of In2O3 films, with decreased crystallite size with the incorporation of La dopants. SEM analysis of thin film samples exhibits approximately cube-shaped morphology without any cracks of microstructures. The optical band gap magnitude shows shift in energy values in the range of 3.12–3.29 eV with increasing La concentrations. For all films, the photoluminescence spectra showed violet-blue emission peaks at around 420–480 nm. All of the developed films were tested for ammonia (NH3) gas detection at ambient temperature. In2O3:La 5% sensor had the highest gas response value of 1720%, a quicker response and recovery times of 48/12 s, respectively, suggesting the sample could be better suited for the application of NH3 gas sensor.

Investigation of sensing properties of Sn-doped NiO thin films for the detection of ammonia gas

In this study, we detail the fabrication of Sn-doped nickel oxide thin films using the spin-coating technique, elucidating the impact of Sn doping on structural, optical, and gas sensing properties. Systematic analysis via XRD, SEM, AFM, and UV–Visible spectroscopy delves into the structural and optical characteristics of the films. Notably, gas sensing capabilities, specifically towards NH3, are investigated. XRD analysis reveals the polycrystalline nature of NiO thin films, with crystallinity diminishing as Sn concentration increases. SEM and AFM analyses highlight a uniform film surface with spherical-shaped particles, and increased surface roughness with higher Sn content, a crucial factor for gas sensing applications. Raman analysis showcases first-order phonon modes of vibrations of Ni-O, while optical studies affirm the films' transparency in the visible wavelength. Notably, in ammonia gas sensing tests at room temperature, the 8 mol% Sn-doped NiO thin film exhibits an exceptional response of 3200 %, with a rapid 40-second response time and a 25-second recovery time at a 150 ppm concentration of ammonia gas. These findings suggest that Sn-doped NiO thin films hold promise as effective gas sensors for NH3 detection.

Integration of ZnO nanowires with coupled resonators for ammonia gas detection

Integration of ZnO nanowires with coupled resonators for ammonia gas detection

Facile synthesis of nitrogen-doped reduced graphene oxide/zinc oxide nanocomposites for enhanced room-temperature ammonia gas detection

Facile synthesis of nitrogen-doped reduced graphene oxide/zinc oxide nanocomposites for enhanced room-temperature ammonia gas detection

Unraveling the Ammonia Sensing Behavior and Degradation Pathways of Novel Lead-Free MA2CuBr4 based Ammonia Sensor

We report a lead-free copper-based halide perovskite gas sensor to detect ammonia gas at ambient temperature. The sensor uses methylammonium copper bromide as the active material and can trace ammonia...

Development of highly sensitive SnO2@ZnO based chemiresistor for Ammonia sensing

A room temperature (28°C) functional SnO2 supported ZnO (SnO2@ZnO) heterostructure based chemiresistor has been fabricated for sensing low-trace of ammonia (5–35 ppm). The decoration of SnO2 nanospheres on ZnO has been done via low-cost hydrothermal technique. The surface morphological examination done by FE-SEM reiterate the decoration of SnO2 nanospheres on the surface of ZnO. The Rietveld refinement for structural analysis of SnO2@ZnO heterostructure confirmed that both ZnO and SnO2 phases structures are present in prepared SnO2@ZnO. At lowermost concentration of 5 ppm, the sensor response of SnO2@ZnO heterostructure was 25.48 and for the maximum concentration of 35 ppm it was 159.16. The quick response and recovery time at 5 ppm were observed to be 4.05 s and 6.74 s, respectively. The response heightening supported the efficient fabrication of n-n heterojunction between the surface of ZnO and SnO2 spheres, resulting in the improved sensing performance. Also, the SnO2@ZnO chemiresistor verified high long-term stability and selectivity to ammonia as compared to other interfering gases such as methanol, ethanol, aniline, and toluene. This work opens a novel window for the development of devices that are room temperature operatable, highly sensitive and selective for quick detection of ammonia gas for its commercialization.

Performance of Pt/Ga2O3/GaN Schottky-diode ammonia sensor covered with thermally evaporated Pt nanoparticles

A Schottky-diode ammonia sensor utilizes a platinum (Pt)/Ga2O3/GaN structure coated with thermally evaporated Pt nanoparticles. Inserting a Ga2O3 sensing metal oxide with wide energy gap between the Pt catalytic metal and GaN layer can substantially reduce the metal-semiconductor Schottky barrier height upon detecting ammonia gas. Additionally, the thermally evaporated Pt nanoparticles on the Pt metal layer enhance surface roughness and the ratio of sensing surface area to volume, thereby improving ammonia adsorption efficiency. In experimental tests, the device achieves a high sensing response ratio (SR) of 733 at room temperature when exposed to 1000 ppm NH3/air while maintaining a forward voltage of 0.7 V. As the ammonia concentration decreases from 1000 ppm to 100 ppb NH3/air at 300 K, the SR decreases from 337 to 10.52 with a bias of 0.4 V. Due to its simple structure, ease of fabrication, excellent sensing performance, and durability at room temperature, this device stands as a strong candidate for application on ammonia sensing circuits.

Optimizing Gas Sensing Properties of Fe-Loaded Indium Zinc Oxide Nanocomposite for Efficient Detection of Ammonia Gas

The current study delineates the role of gas sensing properties of Fe-IZO (Iron loaded Indium Zinc oxide) a mixed metal oxide nanocomposite. The heterostructured Fe-IZO nanocomposite (NC) was synthesized via the facile co-precipitation method. The Fe-IZO NC was characterized by various experimental techniques and the results attained allowed us to suggest the mechanism for considering the connection between morphological variations and gas-sensing characteristics of Fe-IZO NC. One of the cutting-edge circumstances now-a-days is the prime use of gas sensors for environmental applications. The NC has a good selectivity for NH3 gas that has shown good stability up to 80 d. The response time (ℸres) is 64 s, recovery time (ℸrec) is 72 s for 50 ppm (parts per million) and obtained a highest response of 87% at room temperature. The Fe-IZO NC heterostructure with efficient charge transfer can enable the subsequent reaction mechanism with NH3 gas and the adsorbed oxygen ions leading to an increased response. Consequently, the results attained in this work has shown that the synthesized heterostructured NC sensor is suitable for room temperature NH3 sensing with high performance.

Colorimetric detection of ammonia using an adhesive, stretchable hydrogel patch

Currently, because of the harmful effects of ammonia on human health, ecosystems, and overall air quality, the development of easily usable, portable, cost-effective, and field-deployable ammonia sensors is urgently necessary. This study focused on the development of an ammonia-sensing patch composed of a fibrous sensing component and hydrogel-like support substrate. This sensor was capable of colorimetric ammonia sensing with a limit of detection of 0.2454 ppm. The fibrous sensing region was prepared by electrospinning a mixture of poly(acrylic acid) (PAA) and poly(vinyl alcohol) (PVA), followed by the partial crosslinking and adsorption of transition metal ions such as copper. A support substrate was prepared by combining PVA and borate compounds, resulting in a stretchable, adhesive, and self-healing hydrogel. The ammonia-sensing patch demonstrated enough adhesion to various substrates and could be used as a sticky plaster-type sensor that also function as a sealant. The patch exhibited a distinct color change from blue–green to blue upon exposure to ammonia gas, which was attributed to the formation of a complex between the copper ions and ammonia. The color change was analyzed by monitoring the average RGB intensities using a charge-coupled device (CCD) camera and a MATLAB program. Additionally, we assessed the patch's capability of detecting and sealing ammonia leakage through experiments conducted in a simulated gas leakage setup. Overall, the developed ammonia-sensing patch shows promise for the real-time colorimetric detection of ammonia gas and has potential applications in gas leakage detection and prevention.

Electrochemically Functionalized Single-Walled Carbon Nanotubes With Polypyrrole for the Detection of Sub-Part-per-Million Concentrations of Ammonia

Here we report a facile method of functionalization of single-walled carbon nanotubes (SWNTs) with polypyrrole and making a chemiresistive sensor using the functionalized nanomaterial for sub-part-per-million detection of ammonia gas at room temperature. The sensor fabrication involves three steps: (i) immobilization of SWNTs by dip coating method on a silane-treated silicon/silicon dioxide substrate, (ii) printing of two parallel lines of conducting silver paste 5 mm apart as source and drain to define the source and the drain electrode, and (iii) in-situ electrochemical polymerization to functionalize the SWNTs with polypyrrole. The functionalization of SWNT was confirmed using electrochemical current-voltage measurements. The functionalized SWNTs exhibited several folds higher sensitivity to ammonia gas than the pristine SWNTs. A charge density of 0.85 C.cm−2 was optimum for electrochemical functionalization, providing maximum sensing response toward ammonia. The functionalized SWNTs showed a large measurable response starting from 50 to 750 part-per-billion (ppb) of ammonia with a sensitivity of ∼1.55% per ppb, and a limit of detection of 5 ppb of ammonia. Almost complete recovery of the sensor and an average response time of ∼9 min was also observed.

Synthesis and Application of Polypyrrole/DBSA/Boron Nitride Ternary Composite as a Potential Chemical Sensor for Ammonia Gas Detection

The present study demonstrates the self-assembly method of chemical oxidative polymerization of polypyrrole (PPy), polypyrrole/boron nitride (PPy/BN), and polypyrrole/dodecylbenzene sulfonic acid/boron nitride (PPy/DBSA/BN) thin films for ammonia (NH3) gas detection. The PPy, PPy/BN, and PPy/DBSA/BN thin films were comprehensively characterized using Attenuated Total Reflectance Fourier-Transform Infrared Spectroscopy (ATR-FTIR), Scanning Electron Microscopy (SEM), X-ray diffractometry (XRD) and conductivity measurement. ATR-FTIR revealed all the pertinent peaks of PPy, BN, and DBSA present in the PPy/DBSA/BN. SEM images of PPy/DBSA/BN depict well-organized morphology. PPy/DBSA/BN recorded the highest conductivity of 4.771 x 10-6 S cm-1 among the prepared polymer thin films. The obtained characterization results are in good agreement with the NH3 gas sensor measurements conducted on the PPy/DBSA/BN composite. The linear correlation coefficient between the two was found to be R2 = 0.9916, indicating a strong relationship. Furthermore, the PPy/DBSA/BN thin film demonstrated a low limit of detection (LOD) of 5.8 ppm, surpassing the OSHA threshold value for NH3 gas. This suggests that the sensor is highly sensitive to trace amounts of NH3 gas. Moreover, the PPy/DBSA/BN thin film exhibited exceptional reusability, with the ability to be used for up to 10 cycles without a significant decrease in performance. The sensor also demonstrated selectivity towards NH3 gas in the presence of common interfering species. Additionally, it exhibited long-term stability, maintaining its performance over a period of 7 days. The proposed self-assembled gas sensor has showcased remarkable performance in detecting NH3 gas at room temperature, making it a promising candidate for industrial applications.

A Polymer‐Based Chemiresistive Gas Sensor for Selective Detection of Ammonia Gas

AbstractBreath analysis is a non‐invasive tool used in medical diagnosis. However, the current generation of breath analyzers is expensive, time‐consuming, and requires sample gas separation. In this work, a simple, yet effective, low‐cost ammonia gas sensor based on poly(2‐acrylamido‐2‐methyl‐1‐propanesulfonic acid) is presented for non‐invasive medical diagnosis. The designed sensor has a broad detection range to ammonia gas up to 1000 ppm with a limit of detection of 30 ppb. This is a robust sensor, which functions at high relative humidity (RH) (>90%) and exhibits consistent electrical responses under different test conditions. The result of a blind test validates the sensor's selective response to ammonia in the presence of other gases such as carbon dioxide. Furthermore, it is viable to integrate this sensor into a mask for real‐time ammonia gas detection accurately. Overall, this study demonstrates the feasibility of developing a simple, non‐invasive, and cost‐effective sensor for real‐time monitoring of ammonia gas with high potential in applications such as medical diagnostics, food safety, and environmental conditions.

Optimizing Gas Sensing Performance of CuO Nanoparticles via Sol-Gel Synthesis Approach for Efficient Detection of Ammonia Gas

In this study, we present a plastic optical fiber for volatile organic compound (VOC) gas sensing, where a small portion of the cladding was replaced by CuO sensing material. The structural characterization of the CuO was assessed via powder diffraction X-ray analysis (XRD) and morphological analysis done by SEM imaging. For a variety of VOC gas concentrations, such as ammonia, ethanol, and methanol (0-500 parts per million), as well as for various lengths (1.5 cm and 3 cm) of sensing materials coated on the optical fiber, the spectrum properties of the CuO-coated fiber optic gas sensor were investigated. The 3cm coated CuO over the clad modified region of the plastic optical fiber showed highest intensity of fluctuation towards ammonia gas at wavelengths of 682, 753, and 926 nm, indicating that it is more sensitive to the gas and has a faster response and recovery rate at room temperature than the other two gases.

Highly efficient and cost-effective polyaniline-based ammonia sensor on the biodegradable paper substrate at room temperature

A highly efficient, flexible and cost-effective ammonia (NH3) gas sensor is developed on a biodegradable paper substrate. The polyaniline (PANI) film as an active sensing material was deposited by a simple in-situ polymerization method and optimized for NH3 detection. The PANI film was investigated using X-ray diffraction (XRD) and field emission scanning electron microscopy (FESEM) for structural and morphological properties. The sensor was tested for its efficiency to detect the NH3 gas over the concentration range of 12–1000 ppm at room temperature. The sensor showed excellent repeatability, stability and selectivity towards NH3 detection. At concentrations of 12 ppm (lower level), 200 ppm (intermediate level), and 1000 ppm (higher level), the sensor exhibited effective response values of 3.60, 6.85, and 9.33, respectively. The sensor exhibited a quick response time of 30–9 s when subjected to 12–1000 ppm of NH3. The sensor can detect ammonia gas in real-time, which makes it useful for identifying rapid changes in NH3 concentration. The sensor response was reduced by 5.5% towards 200 ppm NH3 despite a significant variation in relative humidity from 20% to 80%. Based on these results, our flexible PANI sensor is a viable option for efficient and cost-effective on-site NH3 detection.

Design of Ammonia Gas Detection and Control Devices in Chicken Farms Based on Arduino Uno

Broiler chicken is a superior breed that has high productivity. Ammonia odor that pollutes the area around the cage is a problem in broiler management. Due to the activity of microorganisms in feces, unabsorbed protein amino acids, and other non-protein nitrogen (NPN) compounds break down into ammonia gas. In addition to damaging the environment, NH3 gas can interfere with animal performance, making them susceptible to disease. This research aims to solve the problem that comes from ammonia by measuring and designing an automatic ammonia gas controller based on Arduino using an MQ-135 sensor. If ammonia levels in the cage are greater than 5 ppm, ammonia levels are controlled by spraying liquid smoke to limit ammonia gas emissions. The results of this study show that the tool is able to reduce ammonia gas levels to 8 ppm.
 Ayam broiler adalah jenis ras unggulan yang memiliki daya produktivitas tinggi. Bau amoniak yang mencemari area sekitar kandang menjadi masalah dalam pengelolaan ayam broiler. Karena aktivitas mikroorganisme dalam feses, protein yang tidak diserap asam amino, dan senyawa nitrogen non-protein (NPN) lainnya terurai menjadi gas amoniak. Selain merusak lingkungan, gas NH3 dapat mengganggu performa hewan, sehingga rentan terkena penyakit. Penelitian ini bertujuan untuk mengatasi masalah yang berasal dari amonia dengan metode pengukuran dan perancangan alat pengontrol gas amoniak otomatis berbasis arduino menggunakan sensor MQ-135. Jika kadar amoniak di dalam kandang lebih besar dari 5 ppm, kadar amoniak dikendalikan dengan penyemprotan asap cair untuk membatasi emisi gas amoniak. Hasil dari penelitian ini alat tersebut mampu menurunkan kadar gas ammonia hingga 8 ppm.

A tough and stretchable colorimetric sensor based on a curcumin-loaded polyurethane electrospun fiber mat for hazardous ammonia gas detection

In this study, a flexible colorimetric sensor is developed to detect harmful ammonia gases using curcumin, a natural pH indicator. By applying an electrospinning method, the flexibility of polyurethane (PU) and the colorimetric characteristics of curcumin were simultaneously expressed in each nanofiber constituting the mat sensor. The physical properties of the mat according to the loaded curcumin concentration were investigated. And, the gas detection behavior was confirmed by the color change response of the mat to ammonia gas. Through the above process, the optimal conditions for fabricating a flexible colorimetric gas sensor with excellent tensile strength and elastic strain were established. The sensor fabricated with the curcumin loading of 30 wt% demonstrated approximately 3.5 times higher tensile strength and strain at break than the pure PU fiber mat. In addition, the color of the mat sensor changed from orange to red in proportion to the concentration of ammonia gases. Finally, the newly developed curcumin-PU mat could effectively withstand repeated external physical stress and was suitable for warning of dangerous toxic gas situations through immediate visual detection, even when repeatedly exposed to harmful gas.

Photoluminescent Lanthanide Coordination Polymers for Ammonia Gas Detection at Ambient Temperature and Humidity

Photoluminescent Lanthanide Coordination Polymers for Ammonia Gas Detection at Ambient Temperature and Humidity

E-Nose-Driven Advancements in Ammonia Gas Detection: A Comprehensive Review from Traditional to Cutting-Edge Systems in Indoor to Outdoor Agriculture

Ammonia (NH3) represents a perilous gas that poses a substantial hazard to both human well-being and the environment, particularly within agricultural regions. Agricultural activities constitute a primary source of ammonia emissions. Thus, effective monitoring and measurement of ammonia sources in agriculture are imperative for mitigating its adverse impact. However, not all existing ammonia detection methods are suitable for discerning the low concentrations typically encountered in agricultural ammonia volatilizing (ranging from 0.01 to 5 parts per million). Consequently, curtailing ammonia volatilization from farmland assumes paramount importance, with real-time monitoring serving as a crucial mechanism for assessing environmental contamination and minimizing agricultural ammonia losses. Deploying appropriate detection methodologies ensures that requisite measures are taken to safeguard human health and the environment from the deleterious repercussions of ammonia exposure. The present paper introduces a comprehensive approach to detecting and analyzing ammonia in agricultural settings. It elucidates the merits and demerits of conventional indoor and outdoor ammonia detection methods, juxtaposing them with the innovative technology of Electronic nose (E-nose). Within the paper, seven widely employed ammonia detection methods in farmland are scrutinized and compared against traditional techniques. Additionally, the constructional aspects and distinct components of E-nose are meticulously delineated and appraised. Ultimately, the paper culminates in a comprehensive comparative analysis encompassing all the aforementioned methodologies, elucidating the potential and limitations of E-nose in facilitating ammonia detection endeavors within agricultural contexts.