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1.
Sci Rep ; 14(1): 15708, 2024 Jul 08.
Article in English | MEDLINE | ID: mdl-38977755

ABSTRACT

This study investigates the potential of platinum (Pt) decorated single-layer WSe2 (Pt-WSe2) monolayers as high-performance gas sensors for NO2, CO2, SO2, and H2 using first-principles calculations. We quantify the impact of Pt placement (basal plane vs. vertical edge) on WSe2's electronic properties, focusing on changes in bandgap (ΔEg). Pt decoration significantly alters the bandgap, with vertical edge sites (TV-WSe2) exhibiting a drastic reduction (0.062 eV) compared to pristine WSe2 and basal plane decorated structures (TBH: 0.720 eV, TBM: 1.237 eV). This substantial ΔEg reduction in TV-WSe2 suggests a potential enhancement in sensor response. Furthermore, TV-WSe2 displays the strongest binding capacity for all target gases due to a Pt-induced "spillover effect" that elongates adsorbed molecules. Specifically, TV-WSe2 exhibits adsorption energies of - 0.5243 eV (NO2), - 0.5777 eV (CO2), - 0.8391 eV (SO2), and - 0.1261 eV (H2), indicating its enhanced sensitivity. Notably, H2 adsorption on TV-WSe2 shows the highest conductivity modulation, suggesting exceptional H2 sensing capabilities. These findings demonstrate that Pt decoration, particularly along WSe2 vertical edges, significantly enhances gas sensing performance. This paves the way for Pt-WSe2 monolayers as highly selective and sensitive gas sensors for various applications, including environmental monitoring, leak detection, and breath analysis.

2.
Article in English | MEDLINE | ID: mdl-38946100

ABSTRACT

Solution-based processing of van der Waals (vdW) one- (1D) and two-dimensional (2D) materials is an effective strategy to obtain high-quality molecular chains or atomic sheets in a large area with scalability. In this work, quasi-1D vdW Ta2Pt3Se8 was exfoliated via liquid phase exfoliation (LPE) to produce a stably dispersed Ta2Pt3Se8 nanowire solution. In order to screen the optimal exfoliation solvent, nine different solvents were employed with different total surface tensions and polar/dispersive (P/D) component (P/D) ratios. The LPE behavior of Ta2Pt3Se8 was elucidated by matching the P/D ratios between Ta2Pt3Se8 and the applied solvent, resulting in N-methyl-2-pyrrolidone (NMP) as an optimal solvent owing to the well-matched total surface tension and P/D ratio. Subsequently, Ta2Pt3Se8 nanowire thin films are manufactured via vacuum filtration using a Ta2Pt3Se8/NMP dispersion. Then, gas sensing devices are fabricated onto the Ta2Pt3Se8 nanowire thin films, and gas sensing property toward NO2 is evaluated at various thin-film thicknesses. A 50 nm thick Ta2Pt3Se8 thin-film device exhibited a percent response of 25.9% at room temperature and 32.4% at 100 °C, respectively. In addition, the device showed complete recovery within 14.1 min at room temperature and 3.5 min at 100 °C, respectively.

3.
ACS Sens ; 2024 Jul 05.
Article in English | MEDLINE | ID: mdl-38967239

ABSTRACT

Limited by insufficient active sites and restricted mechanical strength, designing reliable and wearable gas sensors with high activity and ductility remains a challenge for detecting hazardous gases. In this work, a thermally induced and solvent-assisted oxyanion etching strategy was implemented for selective pore opening in a rigid microporous Cu-based metal-organic framework (referred to as CuM). A conductive CuM/MXene aerogel was then self-assembled through cooperative hydrogen bonding interactions between the carbonyl oxygen atom in PVP grafted on the surface of defect-rich Cu-BTC and the surface functional hydroxyl group on MXene. A flexible NO2 sensing performance using the CuM/MXene aerogel hybridized sodium alginate hydrogel is finally achieved, demonstrating extraordinary sensitivity (S = 52.47 toward 50 ppm of NO2), good selectivity, and rapid response/recovery time (0.9/4.5 s) at room temperature. Compared with commercial sensors, the relative error is less than 7.7%, thereby exhibiting significant potential for application in monitoring toxic and harmful gases. This work not only provides insights for guiding rational synthesis of ideal structure models from MOF composites but also inspires the development of high-performance flexible gas sensors for potential multiscenario applications.

4.
J Mol Model ; 30(8): 249, 2024 Jul 05.
Article in English | MEDLINE | ID: mdl-38967854

ABSTRACT

CONTEXT: Various toxic gasses are being released into the environment with the increasing industrialization. However, detecting these gasses at low concentrations has become one of the main challenges in environmental monitoring and protection. Thus, developing sensors with high performance to detect toxic gasses is of utmost significance. For this purpose, researchers have introduced 2D materials thanks to their unique electronic qualities and large specific surface area. Within this piece of research, a hexagonal boron phosphide monolayer (h-BPML) is employed as the substrate material. The adhesion behavior of ambient nitrogen-containing toxic gasses, i.e., N2O, NH3, NO2, and NO, onto the h-BPML is investigated through DFT computations. The adhesion energy values for gasses NO and NO2 were calculated to be - 0.509 and - 0.694 eV on the h-BPML, respectively. Meanwhile, the absorbed energy values for gasses NH3 and N2O were found to be - 0.326 and - 0.119 eV, respectively. The recovery time, DOS, workfunction, and Bader charges were computed based on four optimal adhesion structures. After the absorption of NO on the h-BPML, the value of workfunction of a monolayer decreased from 1.54 to 0.47 eV. This amount of decrease was the greatest among the other gasses absorbed. By comparing the investigated parameters, it can be concluded that the h-BPML has a greater tendency to interact with NO gas compared to other gasses, and it can be proposed as a sensor for NO gas. METHOD: Within this piece of research, the sensitivity of the h-BPML to four nitrogenous toxic gasses, namely, N2O, NH3, NO2, and NO, was investigated using the DFT with HSE06 hybrid functional by using GAMESS software. For this purpose, we computed the DOS, workfunction, and the Bader charges for the four adhesion systems with most stability.

5.
Food Chem ; 456: 140068, 2024 Jun 11.
Article in English | MEDLINE | ID: mdl-38878549

ABSTRACT

This study investigated the application of a hybrid nanocomposite of tin oxide nanorods (SnO2 NRs) and graphene oxide (GO) for the chemoresistive detection of some volatile compounds (hexanal, benzaldehyde, octanal, 1-octanol, and ethyl acetate vapours) emitted by Aspergillus flavus under simulated conditions. The synthesised materials were characterised using various analytical techniques, including high-resolution transmission electron microscopy (HR-TEM), X-ray photoelectron spectroscopy (XPS), Raman spectroscopy, X-ray diffraction (XRD), Brunauer-Emmett-Teller (BET) analysis, and Fourier transform infrared spectroscopy (FTIR). Three sensors were fabricated: individual nanomaterials (i.e., SnO2 and GO) and composites (SnO2-GO). The results showed that SnO2 NRs had limited sensitivity as a sensor, while GO-based sensors responded to various analyte vapours. However, the incorporation of SnO2 NRs into GO layers resulted in synergistic effects and improved sensor performance. The sensors' sensitivity, selectivity, recovery, and response times were quantitatively determined from the sensors' response curves. The nanocomposite sensor demonstrated superior sensitivity and selectivity for analyte vapours with acceptable response and recovery times. In addition, the sensor was insensitive to humidity and showed robust performance up to 62% RH, although sensor drift occurred at 70% RH. This study highlights the promising potential of using SnO2 NRs-GO composite-based sensor for sensitive and selective detection of analyte vapours, which has significant implications for food safety and environmental monitoring applications.

6.
Sensors (Basel) ; 24(11)2024 Jun 03.
Article in English | MEDLINE | ID: mdl-38894388

ABSTRACT

Fabry-Perot interferometers (FPIs), comprising foundry-compatible dielectric thin films on sapphire wafer substrates, were investigated for possible use in chemical sensing. Specifically, structures comprising two vertically stacked distributed Bragg reflectors (DBRs), with the lower DBR between a sapphire substrate and a silicon-oxide (SiO2) resonator layer and the other DBR on top of this resonator layer, were investigated for operation in the near-ultraviolet (near-UV) range. The DBRs are composed of a stack of nitride-rich silicon-nitride (SiNx) layers for the higher index and SiO2 layers for the lower index. An exemplary application would be formaldehyde detection at sub-ppm concentrations in air, using UV absorption spectroscopy in the 300-360 nm band, while providing spectral selectivity against the main interfering gases, notably NO2 and O3. Although SiNx thin films are conventionally used only for visible and near-infrared optical wavelengths (above 450 nm) because of high absorbance at lower wavelengths, this work shows that nitride-rich SiNx is suitable for near-UV wavelengths. The interplay between spectral absorbance, transmittance and reflectance in a FPI is presented in a comparative study between one FPI design using stoichiometric material (Si3N4) and two designs based on N-rich compositions, SiN1.39 and SiN1.49. Spectral measurements confirm that if the design accounts for phase penetration depth, sufficient performance can be achieved with the SiN1.49-based FPI design for gas absorption spectroscopy in near-UV, with peak transmission at 330 nm of 64%, a free spectral range (FSR) of 20 nm and a full-width half-magnitude spectral resolution (FWHM) of 2 nm.

7.
Sensors (Basel) ; 24(11)2024 Jun 06.
Article in English | MEDLINE | ID: mdl-38894485

ABSTRACT

A novel NH3 gas sensor is introduced, employing polyaniline (PANI) with a unique structure called a graft film. The preparation method was simple: polydopamine (PD) was coated on a flexible polyethylene terephthalate (PET) film and PANI graft chains were grown on its surface. This distinctive three-layer sensor showed a response value of 12 for 50 ppm NH3 in a dry atmosphere at 50 °C. This value surpasses those of previously reported sensors using structurally controlled PANI films. Additionally, it is on par with sensors that combine PANI with metal oxide semiconductors or carbon materials, the high sensitivity of which have been reported. To confirm our film's potential as a flexible sensor, the effect of bending on the its characteristics was investigated. This revealed that although bending decreased the response value, it had no effect on the response time or recovery. This indicated that the sensor film itself was not broken by bending and had sufficient mechanical strength.

8.
Biosensors (Basel) ; 14(6)2024 Jun 05.
Article in English | MEDLINE | ID: mdl-38920597

ABSTRACT

Zinc oxide (ZnO) is considered to be one of the most explored and reliable sensing materials for UV detection due to its excellent properties, like a wide band gap and high exciton energy. Our current study on a photodetector based on tetrapodal ZnO (t-ZnO) reported an extremely high UV response of ~9200 for 394 nm UV illumination at 25 °C. The t-ZnO network structure and morphology were investigated using XRD and SEM. The sensor showed a UV/visible ratio of ~12 at 25 °C for 394 nm UV illumination and 443 nm visible illumination. By increasing the temperature, monotonic decreases in response and recovery time were observed. By increasing the bias voltage, the response time was found to decrease while the recovery time was increased. The maximum responsivity shifted to higher wavelengths from 394 nm to 400 nm by increasing the operating temperature from 25 °C to 100 °C. The t-ZnO networks exhibited gas-sensing performances at temperatures above 250 °C, and a maximum response of ~1.35 was recorded at 350 °C with a good repeatability and fast recovery in 16 s for 100 ppm of n-butanol vapor. This study demonstrated that t-ZnO networks are good biosensors that can be used for diverse biomedical applications like the sensing of VOCs (volatile organic compounds) and ultraviolet detection under a wide range of temperatures, and may find new possibilities in biosensing applications.


Subject(s)
Biosensing Techniques , Ultraviolet Rays , Volatile Organic Compounds , Zinc Oxide , Zinc Oxide/chemistry , Volatile Organic Compounds/analysis , Bioengineering
9.
ACS Sens ; 9(6): 2728-2776, 2024 Jun 28.
Article in English | MEDLINE | ID: mdl-38828988

ABSTRACT

The escalating development and improvement of gas sensing ability in industrial equipment, or "machine olfactory", propels the evolution of gas sensors toward enhanced sensitivity, selectivity, stability, power efficiency, cost-effectiveness, and longevity. Two-dimensional (2D) materials, distinguished by their atomic-thin profile, expansive specific surface area, remarkable mechanical strength, and surface tunability, hold significant potential for addressing the intricate challenges in gas sensing. However, a comprehensive review of 2D materials-based gas sensors for specific industrial applications is absent. This review delves into the recent advances in this field and highlights the potential applications in industrial machine olfaction. The main content encompasses industrial scenario characteristics, fundamental classification, enhancement methods, underlying mechanisms, and diverse gas sensing applications. Additionally, the challenges associated with transitioning 2D material gas sensors from laboratory development to industrialization and commercialization are addressed, and future-looking viewpoints on the evolution of next-generation intelligent gas sensory systems in the industrial sector are prospected.


Subject(s)
Gases , Gases/analysis , Gases/chemistry , Smell , Industry , Odorants/analysis
10.
ACS Sens ; 9(6): 3085-3095, 2024 Jun 28.
Article in English | MEDLINE | ID: mdl-38840550

ABSTRACT

Wearable gas sensors have drawn great attention for potential applications in health monitoring, minienvironment detection, and advanced soft electronic noses. However, it still remains a great challenge to simultaneously achieve excellent flexibility, high sensitivity, robustness, and gas permeability, because of the inherent limitation of widely used traditional organic flexible substrates. Herein, an electrospinning polyacrylonitrile (PAN) nanofiber network was designed as a flexible substrate, on which an ultraflexible wearable gas sensor was prepared with in situ assembled polyaniline (PANI) and multiwalled carbon nanotubes (MWCNTs) as a sensitive layer. The unique nanofiber network and strong binding force between substrate and sensing materials endow the wearable gas sensor with excellent robustness, flexibility, and gas permeability. The wearable sensor can maintain stable NH3 sensing performance while sustaining extreme bending and stretching (50% of strain). The Young's modulus of wearable PAN/MWCNTs/PANI sensor is as low as 18.9 MPa, which is several orders of magnitude smaller than those of reported flexible sensors. The water vapor transmission rate of the sensor is 0.38 g/(cm2 24 h), which enables the wearing comfort of the sensor. Most importantly, due to the effective exposure of sensing sites as well as the heterostructure effect between MWCNTs and PANI, the sensor shows high sensitivity to NH3 at room temperature, and the theoretical limit of detection is as low as 300 ppb. This work provides a new avenue for the realization of reliable and high-performance wearable gas sensors.


Subject(s)
Acrylic Resins , Ammonia , Aniline Compounds , Nanofibers , Nanotubes, Carbon , Wearable Electronic Devices , Nanofibers/chemistry , Nanotubes, Carbon/chemistry , Aniline Compounds/chemistry , Acrylic Resins/chemistry , Ammonia/analysis , Humans , Gases/analysis , Gases/chemistry
11.
ACS Sens ; 9(6): 3126-3136, 2024 Jun 28.
Article in English | MEDLINE | ID: mdl-38843033

ABSTRACT

Given the widespread utilization of gas sensors across various industries, the detection of diverse and complex target gases presents a significant challenge in designing sensors with multigas detection capability. Although constructing a sensor array with widely used chemiresistive gas sensors is one solution, it is difficult for a single chemiresistive gas sensor to simultaneously detect different gases, as it can only detect a single target gas. The intrinsic reason for this bottleneck is that chemiresistive gas sensors rely entirely on the resistivity as the unique parameter to evaluate the diverse gas sensing properties of sensors, such as sensitivity, selectivity, etc. Herein, a field-effect transistor (FET) with abundant electrical parameters is employed to prepare a gas sensor for the detection of a variety of gases. Semiconducting carbon nanotubes (CNTs) are selected as the channel material, which is modified by Pd nanoparticles to enhance the gas sensing properties of the sensors. By extracting various electrical parameters such as transconductance, threshold voltage, etc. from the transfer characteristic curves of FET, a correlation between multielectrical parameters and various gas detection information is established for subsequent data analysis. Through the utilization of the principal component analysis algorithm, the identification of six gases can be finally achieved by relying solely on a single carbon-based FET-type gas sensor. We hope our work can solve the bottleneck of multigas identification by a single sensor in principle and is expected to reduce the system complexity and cost caused by the design of sensor arrays, offering a valuable guidance for multigas identification technology.


Subject(s)
Gases , Nanotubes, Carbon , Transistors, Electronic , Nanotubes, Carbon/chemistry , Gases/analysis , Gases/chemistry
12.
ACS Sens ; 9(6): 3327-3337, 2024 Jun 28.
Article in English | MEDLINE | ID: mdl-38863381

ABSTRACT

Oxide semiconductor-supported metal nanoparticles often suffer from a high-temperature gas sensing process, resulting in agglomeration and coalescence, which significantly decrease their surface activity and stability. Here, we develop an in situ pyrolysis strategy to redisperse commercial Ir particles (∼15.6 nm) into monodisperse Ir species (∼5.4 nm) on ZnO supports, exhibiting excellent sintering-resistant properties and H2 sensing. We find that large-size Ir nanoparticles can undergo an unexpected splitting decomposition process and spontaneously migrate along the encapsulated carbon layer surface during high-temperature pyrolysis of ZIF-8. This resultant monodisperse status can be integrally reserved, accompanying further oxidation sintering. The final Irred/ZnO-450-based sensor exhibits outstanding stability, H2 response (10-2000 ppm), fast response/recovery capability (7/9.7 s@100 ppm), and good moisture resistance. In situ Raman and ex situ XPS further experimentally verify that highly dispersive Ir species can promote the electron transfer process during the gas sensing process. Our strategy thus provides important insights into the design of agglomeration-resistant gas sensing materials for highly effective H2 detection.


Subject(s)
Carbon , Hydrogen , Iridium , Metal Nanoparticles , Pyrolysis , Zinc Oxide , Hydrogen/chemistry , Hydrogen/analysis , Carbon/chemistry , Metal Nanoparticles/chemistry , Iridium/chemistry , Zinc Oxide/chemistry
13.
ACS Sens ; 9(6): 3282-3289, 2024 Jun 28.
Article in English | MEDLINE | ID: mdl-38864828

ABSTRACT

A new type of carbonized polymer dot was prepared by the one-step hydrothermal method of triethoxylsilane (TEOS) and citric acid (CA). The sensor made from carbonized polymer dots (CPDs) showed superior gas sensing performance toward ammonia at room temperature. The Si, O-codoped CPDs exhibited superior ammonia sensing performance at room temperature, including a low practical limit of detection (pLOD) of 1 ppm (Ra/Rg: 1.10, 1 ppm), short response/recovery time (30/36 s, 1 ppm), high humidity resistance (less than 5% undulation when changing relative humidity to 80 from 30%), high stability (less than 5% initial response undulation after 120 days), reliable repeatability, and high selectivity against other interferential gases. The gas sensing mechanism was investigated through control experiments and in situ FTIR, indicating that Si, O-codoping essentially improves the electron transfer capability of CPDs and synergistically dominates the superior ammonia sensing properties of the CPDs. This work presents a facile strategy for constructing novel high-performance, single-component carbonized polymer dots for gas sensing.


Subject(s)
Ammonia , Polymers , Temperature , Ammonia/analysis , Polymers/chemistry , Carbon/chemistry , Gases/analysis , Gases/chemistry , Silicon/chemistry , Limit of Detection , Quantum Dots/chemistry , Oxygen/chemistry
14.
Discov Nano ; 19(1): 107, 2024 Jun 24.
Article in English | MEDLINE | ID: mdl-38913270

ABSTRACT

The imperative development of a cutting-edge environmental gas sensor is essential to proficiently monitor and detect hazardous gases, ensuring comprehensive safety and awareness. Nanostructures developed from metal oxides are emerging as promising candidates for achieving superior performance in gas sensors. NO2 is one of the toxic gases that affects people as well as the environment so its detection is crucial. The present study investigates the gas sensing capability of copper oxide-based sensor for 5 ppm of NO2 gas at 100 °C. The sensing material was synthesized using a facile precipitation method and characterized by XRD, FE-SEM, UV-visible spectroscopy, photoluminescence spectroscopy, XPS and BET techniques. The developed material shows a response equal to 67.1% at optimal temperature towards 5 ppm NO2 gas. The sensor demonstrated an impressive detection limit of 300 ppb, along with a commendable percentage response of 5.2%. Under optimized conditions, the synthesized material demonstrated its high selectivity, as evidenced by the highest percentage response recorded for NO2 gas among NO2, NH3, CO, CO2 and H2S.

15.
J Hazard Mater ; 474: 134709, 2024 Aug 05.
Article in English | MEDLINE | ID: mdl-38823107

ABSTRACT

Developing high-sensitivity TEA sensors has extremely important significance for human health. Design of three-dimensional (3D) nanostructures assembled from one-dimensional nanomaterials can effectively improve sensing performance. In this work, a nest-like structure assembled by Cr-doped MoO3 (Cr-MoO3) nanorods with relatively higher specific surface area was prepared. In order to improve the sensing performance, Cr-MoO3 skeleton was combined with ZnSe nanospheres of different mass ratios as sensing materials (ZnSe/Cr-MoO3), and the successful construction of the heterojunction structure was supported by various spectroscopies and charge density calculation. The prepared composite with an optimal moiety ratio showed very high response values of 371 and 1301 for 10 ppm and 50 ppm for TEA at 200 °C, respectively. Simultaneously, the composite sensor also exhibited a low detection limit (1.7 ppb). The improvement of the sensing performance of ZnSe/Cr-MoO3 was attributed to the formation of oxygen vacancies induced by Cr doping, the 3D nest-like structure provided an efficient network for charge transport/collection and the n-n heterojunctions between Cr-MoO3 nanorods and ZnSe nanospheres. The simulation analysis based on density functional theory (DFT) calculations indicated that the heterojunctions could effectively enhance the adsorption energy of TEA and the more charges transferring from TEA to the Cr-MoO3 nanorods.

16.
J Mol Model ; 30(7): 215, 2024 Jun 17.
Article in English | MEDLINE | ID: mdl-38884691

ABSTRACT

CONTEXT: The performance of pristine and Pd-doped WO3 acetone gas sensors is calculated theoretically and compared with available experimental results. Temperature, humidity, and acetone concentration variation are considered in the present work. Transition state theory calculates Gibbs free energy of transition, including its components enthalpy and entropy of transition or activation. The variation of Pd doping concentration is used to obtain the maximum response and lowest response time for the optimum performance of the gas sensor. The present theory considers the reduction of acetone gas concentration as acetone reaches its autoignition temperature. Acceptable agreement between theory and experiment is obtained. The acceptance includes the decrease of Gibbs free energy with doping percentage, variation of temperature exponent to the power twelve in the considered reactions, and reduction of response time with the increase of temperature. METHODS: Density functional theory at the B3LYP level is used. 6-311G** basis set (for O atoms) and SDD (for heavy Pd and W atoms) are used to optimize the structures examined in the present work. The Gaussian 09 program and accompanying software were used to perform the current tasks.

17.
Talanta ; 277: 126383, 2024 Jun 06.
Article in English | MEDLINE | ID: mdl-38852345

ABSTRACT

Chemical warfare agents (CWAs) are toxic that pose a threat to the environment and human health, even trace amounts of CWAs can be fatal. In view of this, there is an urgent need to develop gas sensors for trace detection and ultrafast response of CWAs. Herein, an optical gas sensor has been proposed based on metal-organic frameworks (MOFs) three-dimensional (3D) photonic crystal to detect trace CWAs' simulant (dimethyl methylphosphonate, DMMP) in different atmospheric humidity (RH 20 %, RH 40 %, RH 60 %, RH 80 %). At relative humidity (RH) of 20 %, the sensor shows excellent selectivity of DMMP due to the specific interactions of van der Waals force between UiO-67 and phosphoryl oxygen (OP) group of DMMP (C3H9O3P), the ultrahigh sensitivity (42.7 ppb), ultrafast response (0.5 s) are profit from the ordered superstructure of 3D photonic crystal and its complete photonic bandgap. At higher humidity (RH 40%-80 %), the sensor shows excellent stability, long-term repeatability, and it still keeps ultrahigh sensitivity (12.1 ppb), ultrafast response (0.49 s) for DMMP at RH 80 %. Moreover, an optical gas sensor array has been prepared to solve the problem of cross-sensitive between DMMP and other CWAs at highest humidity (RH ≥ 80 %), the average classification accuracy can reach 98.6 %.

18.
Article in English | MEDLINE | ID: mdl-38832687

ABSTRACT

This study presents the development of gas sensors based on the PEDOT:PSS@ZnO hybrid active layer slot-die printing aqueous ink. Two different zinc oxide (ZnO) nanoparticles were studied to form the nanocomposites, as well as the use of glass and PET substrates to manufacture the devices. Despite the influence of the morphology of the active layer, all device variations studied here exhibited high response values for methanol gas at room temperature, in addition to presenting good repeatability, reversibility, and the possibility of technology transfer to flexible substrates. Furthermore, PEDOT:PSS@ZnO showed good selectivity to methanol compared to ethanol, ammonia, and CO2. The best devices showed responses greater than 700% in detecting methanol.

19.
Mikrochim Acta ; 191(7): 371, 2024 Jun 05.
Article in English | MEDLINE | ID: mdl-38839652

ABSTRACT

Industrialization and agricultural demand have both improved human life and led to environmental contamination. Especially the discharge 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 100 ppm NH3 at room temperature, which is a 3.5-fold improvement over the pure Ti3C2Tx MXene sensor. Moreover, it provides swift response time (20 s), high response to low NH3 concentrations (≤ 10 ppm), and excellent long-term stability (30 days). These exceptional characteristics indicate the immense potential of our In(OH)3/Ti3C2Tx gas sensor in ammonia detection.

20.
Environ Geochem Health ; 46(8): 261, 2024 Jun 25.
Article in English | MEDLINE | ID: mdl-38916678

ABSTRACT

A simple sol-gel combustion process was employed for the creation of MFe2O4 (M=Ni, Co) nanoparticles. The synthesized nanoparticles, acting as both photocatalysts and gas sensors, were analyzed using various analytical techniques. MFe2O4 (M=Ni, Co) material improved the degradation of methylene blue (MB) under UV-light irradiation, serving as an enhanced electron transport medium. UV-vis studies demonstrated that NiFe2O4 achieved a 60% degradation, while CoFe2O4 nanostructure exhibited a 76% degradation efficacy in the MB dye removal process. Furthermore, MFe2O4 (M=Ni, Co) demonstrated chemosensitive-type sensor capabilities at ambient temperature. The sensor response and recovery times for CoFe2O4 at a concentration of 100 ppm were 15 and 20, respectively. Overall, the synthesis of MFe2O4 (M=Ni, Co) holds the potential to significantly improve the photocatalytic and gas sensing properties, particularly enhancing the performance of CoFe2O4. The observed enhancements make honey MFe2O4 (M=Ni, Co) a preferable choice for environmental remediation applications.


Subject(s)
Cobalt , Ferric Compounds , Methylene Blue , Nickel , Cobalt/chemistry , Cobalt/analysis , Nickel/chemistry , Nickel/analysis , Ferric Compounds/chemistry , Methylene Blue/chemistry , Metal Nanoparticles/chemistry , Gases , Catalysis , Ultraviolet Rays , Environmental Restoration and Remediation/methods , Nanoparticles/chemistry , Aluminum Oxide , Magnesium Oxide
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