Sensor For H2S Research Articles

A DFT study of gas molecules adsorption on TM-doped PtS2 gas nanosensors

In this study, we examined the adsorption and sensing capabilities of transition metal doped PtS2 monolayers (TM = Co, Cu, Fe, Ni) towards three industrially relevant toxic and hazardous gases: CO, NO, and H2S, using density functional theory (DFT) calculations. The interaction between the gases and the TM-doped PtS2 monolayer substrates was thoroughly investigated, taking into account various adsorption configurations, charge transfer phenomena, band structures, and state densities. Results indicate that the TM dopants markedly enhances the conductivity and gas adsorption capacity of PtS2 monolayer. Specifically, the TM-doped PtS2 monolayers exhibit strong adsorption properties towards CO, NO, and H2S, with the adsorption process identified as chemisorption. By analyzing the alterations in conductivity subsequent to gas adsorption, we discerned that Ni-PtS2 could potentially serve as an effective sensor for CO, NO, and H2S. Consequently, our results furnish a solid theoretical foundation for the development of PtS2-based sensors aimed at detecting these gases. Furthermore, the findings of this research offer valuable insights into the design of gas nanosensors.

Investigation of the electronic and optical properties of bilayer CdS as a gas sensor: first-principles calculations.

We utilised first-principles computations based on density functional theory to investigate the optical and electronic properties of bilayer CdS before and after the adsorption of gas molecules. Initially, we examined four candidate adsorption sites to determine the best site for adsorbing CO, CO2, SO2, H2S, and SO. In order to achieve the optimal adsorption configurations, we analysed the adsorption energy, distance, and total charge. Our findings reveal that the CdS bilayer forms a unique connection between the O and Cd atoms, as well as the S and Cd atoms, which renders it sensitive to SO2, H2S, and SO through chemical adsorption, and CO and CO2 through strong physical adsorption. The adsorption of gas molecules enhances the optical properties of the CdS bilayer. Consequently, the CdS bilayer proves to be a highly efficient gas sensor for SO2, H2S, and SO gases.

Structural isomerism engineering regulates molecular AIE behavior and application in visualizing endogenous hydrogen sulfide.

Hydrogen sulfide (H2S) is a critical bioregulator implicated in numerous physiological and pathological processes, including cancer and neurodegenerative diseases. Compared with traditional instrument analysis, fluorescence detection technology based on small molecules in real-time and in situ sensing H2S has attracted attention. In this investigation, we developed a system of coumarin-based fluorophores linked with aminopyridine via a dipolar imino-double bond. Their aggregation-induced emission (AIE) behaviors were further regulated via structural isomerism engineering. Owing to restricting intramolecular motions and high molecular dipole moment, 2-amino-pyridyl-substituted coumarin (CMR-o-Py) forms stable AIE nanoaggregates with brighter fluorescence than the others. The CMR-o-Py nanoaggregates serve as probes for sensing H2S with a detection limit of 18.1 μM in a hydrophilic environment via Michael addition between imino-bond and sulfide ions. The 1 : 1 stoichiometric binding energy constant between the probe and H2S is 5.68 × 108 M-1, and its half-time of the first-order binding reaction was estimated to be 4.85 min. Moreover, CMR-o-Py, with excellent biocompatibility, holds promise as an ideal sensor for endogenous H2S in living cells and onion tissues, further highlighting its potential application in biological fields.

Adsorption of NO2, SO2, H2S, and NH3 on Os-Doped WSe2 Monolayers: A First-Principles Study.

In this study, DFT calculations are used to analyze the adsorption of industrial waste gases (NO2, SO2, H2S, and NH3) on WSe2 monolayers. The adsorption energy, energy band, density of states, charge transfer, and recovery time of the adsorption structures between the target gas molecules and the Os-doped WSe2 are studied. Compared with pure WSe2 monolayer, Os surface bonding doping WSe2 (Os-modified WSe2) and Os doping with Se vacancy of WSe2 (Os-embedded WSe2) exhibit improved gas molecule adsorption ability. Among them, the adsorption energy of the Os-modified WSe2 monolayer on NO2, SO2, H2S, and NH3 is greater than that of the WSe2 monolayer. At the same time, it is proved that the Os-embedded WSe2 can be used as a gas sensor for H2S and NH3 gas molecules at a high temperature.

First-principles study on α/β/γ-FeB6 monolayers as potential gas sensor for H2S and SO2.

The adsorptions of toxic gases SO2 and H2S on 2D α/β/γ-FeB6 monolayer were investigated using density functional theory calculations. To analyze the interaction between gas molecule H2S/SO2 and α/β/γ-FeB6 monolayer, we calculated adsorption energy, adsorption distance, Mullikan charge, charge density difference, band structure, the density of states, work function, and theoretical recovery time. The adsorption energies show that H2S/SO2 is chemisorbed on α/β-FeB6 while H2S/SO2 is physiosorbed on γ-FeB6 monolayer. As a result, γ-FeB6 has a short recovery time for H2S (5.71×10-8 s)/SO2 (1.94×10-5 s) due to modest adsorption. Therefore, γ-FeB6 may be a promising candidate for reusable H2S/SO2 sensors at room temperature. Although H2S is chemisorbed on α/β-FeB6, as the working temperature rises to 500 K, the recovery time of α/β-FeB6 for H2S can decrease to 1.13×10-1 s and 2.08×10-1 s, respectively, which are well within the detectable range. So, α/β-FeB6 monolayer also may be a good candidate for H2S gas sensor. Calculations were performed at GGA-PBE/DNP level using the Dmol3 module implemented in the Material Studio 2018 software package.

Fast-response hydrogen sulfide gas sensor based on electrospinning Co3O4 nanofibers-modified CuO nanoflowers: Experimental and DFT calculation

In this paper, copper oxide nanoflower/cobalt tetroxide nanofiber (CuO/Co3O4) composites are synthesized by hydrothermal method and electrospinning technology, and a high-performance gas sensor for H2S is successfully prepared. The morphology, microstructure and elemental composition of the materials are characterized by XRD, SEM, TEM and XPS. The CuO/Co3O4 sensor has the best response to H2S when the mass percentage of Co3O4 is 25 wt%, and the response is the highest at the operating temperature of 200 °C. By comparison, CuO/Co3O4 sensor has higher response (194 %@25 ppm) and faster response/recovery time (6 s/25 s@25 ppm) at the optimum temperature. It also has excellent repeatability, long-term stability and selectivity. According to the analysis, the improvement of H2S gas sensing properties of CuO/Co3O4 sensor is mainly due to the larger specific surface area brings more active sites, which promotes the adsorption of gas on the material surface. At the same time, the p-p heterojunction at the contact interface of CuO/Co3O4 nanocomposites also plays a very important role. In addition, theoretical calculation based on the first principle further reveals the improvement of H2S gas sensing performance of CuO/Co3O4 nanocomposites.

MWCNT-based material as a gas sensor for H2S and NO2, synthesise and characterisation

MWCNT-based material as a gas sensor for H2S and NO2, synthesise and characterisation

C6N7 monolayer as an innovative sensor and scavenger for NO, H2S and SO2: A first-principles study

The adsorption, electronic, gas-sensing and capture properties of molecules (NO, H2S, SO2, NO2, NH3, N2, CO, CH4, CO2, and H2O) on the C6N7 monolayer were systematically studied to explore the possibilities of C6N7-based toxic gas sensor and scavenger by using first-principles methods. We found only NO, H2S, and SO2 are adsorbed on the monolayer with large adsorption energy (ranging of -0.853∼-0.931 eV), meanwhile the other molecules are all weakly physisorbed on the monolayer with Ead of -0.193∼-0.547 eV. The NO and H2S adsorption could remarkably affect the electronic properties and work function (Φ) of the C6N7 monolayer, indicating it is highly sensitive and selective towards NO and H2S. The recovery time (τ) of NO and H2S was predicted respectively to be 25 and 1.9 s at 350 K, while the τ of the other molecules was too short to make the sensor device be difficult to measure these gases. The C6N7 monolayer can be promising resistance-type (Φ-type) gas sensors for H2S and NO detection at 350 K. However, the presence of humidity effects the gas sensing of C6N7-based resistance-type sensor, so that it should operate in a dry environment, but as Φ-type sensor can operate regardless of the existence of humidity and concentrations. In addition, the high adsorption capacity and desired recovery time of the C6N7 monolayer make it be an optimal scavenger for toxic gases.

Localized surface plasmon resonance sensing of SO2 and H2S using zeolitic imidazolate framework-8

A localized surface plasmon resonance (LSPR) sensor for SO2 and H2S has been developed by coating a Au nanopattern with zeolitic imidazolate framework-8 (ZIF-8), which is one of the most common metal–organic frameworks. SO2 and H2S were detected by the change in the absorbance at a certain wavelength in the LSPR spectrum. The sensitivity to SO2 and H2S was enhanced by ZIF-8 and with increasing relative humidity, and 0.1–20 ppm SO2 and 0.1–10 ppm H2S could be detected within 5 min at 70% relative humidity. The ZIF-8-coated sensor was more sensitive to SO2. The changes in the absorbance increased during exposure to SO2 and H2S, and only slightly decreased for SO2 and remained almost constant for H2S after stopping exposure. These responses indicate that the sensor can measure the integrated concentrations of SO2 and H2S. If the sensor was not exposed to ≥ 20 ppm SO2 or ≥ 10 ppm H2S, the sensitivity and LSPR spectrum of the sensor could be recovered approximately a dozen times by heating it at 200 °C in air. This study demonstrates the potential of metal–organic-framework-coated LSPR sensors for highly sensitive detection of SO2 and H2S.

Novel preparation method of fullerene and its ability to detect H2S and NO2 gases

In this study, a new system for fullerene preparation was designed based on the incomplete combustion of liquid asphalt. Transmission electron microscopy, field emission scanning electron microscopy and energy-dispersive X-ray (EDX) techniques were used to characterise fullerene. The sizes of the synthesised fullerene ranged from 48.20 nm to 73 nm. The EDX technique was used to determine the amounts of elements in a component, thereby revealing the formation of fullerene. The produced fullerene was evaluated as a gas sensor for H2S and NO2 gases at various temperatures and time intervals. The sensitivity of the gas sensor decreased with the increased operating temperature reaching 150 °C. Then, the sensitivity increased as the temperature increased. The maximum gas sensitivities for NO2 and H2S were 72.86% at 25 °C and 75.89% at 200 °C, respectively.

Exploring monolayer Janus MoSSe as potential gas sensor for Cl2, H2S and SO2

Based on first-principles calculations, the adsorption performance of several common poisonous gases (Cl2, H2S, SO2) on the monolayer Janus MoSSe and MoSSe-C are systematically studied. It can be found that Cl2, H2S and SO2 can all be adsorbed on MoSSe and MoSSe-C. The adsorption performance of MoSSe doped with C atom is better, and the binding strengths of gas molecules adsorbed on the S-layer doped with C atom are much stronger than those on Se-layer doped with C atom. The electronic structure of MoSSe-C changes differently under the adsorption of different gas molecules. By calculating the charge density difference and bader charge, the gas adsorption process and charge transfer are revealed. The charge transfer of MoSSe is enhanced by doping C atoms. Cl2, H2S and SO2 are easy to be adsorbed on the monolayer Janus MoSSe doped with C atoms. The monolayer MoSSe doped C atom is a sensitive gas sensor for Cl2, H2S and SO2, and it has potential application as an excellent gas sensor.

A Novel Turn-On the Fluorescence Sensor for H2S and its Applications in Bioimaging

A Novel Turn-On the Fluorescence Sensor for H2S and its Applications in Bioimaging

Strain-Assisted Single Pt Sites on High-Curvature MoS 2 Surface for Ultrasensitive H 2 S Sensing

Strain-Assisted Single Pt Sites on High-Curvature MoS ₂ Surface for Ultrasensitive H ₂ S Sensing

A highly sensitive naphthalimide based fluorescent “turn-on” sensor for H2S and its bio-imaging applications

A novel fluorescent sensor based on intramolecular charge transfer (ICT) for detecting the H2S ion has been successfully designed and developed. The H2S amount was determined using a sensor probe of 6-azido-2-(pyridin-2-ylmethyl)-1H-benzo[de]isoquinoline-1,3(2H)-dione (NPN-N3) with high selectivity. The fluorescence intensity ratio of NPN-N3 was shown to be linearly related to the concentration of H2S, with a LOD of 1.2 μM. Besides that, there was an apparent fluorescent colour changes from colorless to green. Fluorescence bio-imaging with various emission channels could be used with the current sensor probe to detect H2S ions in living cells. The real-time application of H2S was proved by test strip experiments.

Dual-Site Fluorescent Sensor for Tracking Lysosomal Atp and H2s During Liver Injury

Dual-Site Fluorescent Sensor for Tracking Lysosomal Atp and H2s During Liver Injury

Fabrication, characterization and exploration of cobalt (II) ion doped, modified zinc oxide thick film sensor for gas sensing characteristics of some pernicious gases

The present research deals with the synthesis of zinc oxide (ZnO) nanoparticles by the co-precipitation (CPT) method. The CPT method was successfully utilized for the synthesis of ZnO nanoparticles. The structural properties of undoped ZnO and cobalt doped ZnO were confirmed by employing an X-ray diffraction (XRD) study, from which the average particle size for each prepared material was calculated from the Debye Scherer formula. The average particle size confirms the nano range fabrication of undoped and cobalt doped ZnO material. The surface characteristics, morphology, texture, and porosity properties of undoped ZnO and cobalt doped ZnO were investigated from scanning electron microscopy (SEM). The elemental composition was investigated from energy dispersive spectroscopy (EDS). The High-resolution transmission electron microscopy (HRTEM) results revealed the hexagonal phase of prepared material. Furthermore, the undoped ZnO and 5% cobalt doped ZnO gas sensors prepared by screen printing technology were utilized for gas sensing purposes for testing the gases like H2S, NO2, SO2, and methanol. For the gases examined, the cobalt modified ZnO sensor proved to be quite effective, especially for H2S and NO2 gas vapors. The Co2+ doped ZnO sensor showed 70.12% sensitivity for H2S gas at 150 0C and 68.75% gas response for NO2 gas vapors at 120 0C. In addition, the cobalt modified sensor was also investigated for reusability test to get concrete gas response results with the time interval of 15 days. In conclusion, it can be mentioned that the cobalt doped ZnO thick film sensor is a promising sensor for H2S and NO2 gas vapors.

Evaluate the potential utilization of B24N24 fullerene in the recognition of COS, H2S, SO2, and CS2 gases (environmental pollution)

We employed density functional theory calculations for evaluating the possible usage of B24N24 fullerene in detecting COS, H2S, CS2, SO2 gases. The interaction stability sequence for the gases under investigation is generally as follows: SO2 > H2S > COS > CS2. Seemingly, there is an association between molecules’ electric dipole moment and absorption energy. B24N24 fullerene as Ф-type sensor for SO2 and CS2 is regarded as an electronic sensor. It is found that CS2 and SO2 can be recognized by B24N24 fullerene at the H2S presence and COS as a Ф-type sensor. Besides, it has the ability of selective operating between SO2 and CS2 as an electronic sensor for changing varying electrical conductivity values when they are present. It is not a function-type or electronic sensor for H2S and COS gases. For desorbing CS2 and SO2 gases from the surface at ambient temperature, The B24N24 fullerene takes advantage of a short recovery time (0.19 s and 0.4 μs). Thus, this fullerene is able to work in a wet environment.

Carbonaceous ZnO nanocomposite for sensing of H2S at sub-ppm concentrations

The present work describes the pyrolysis of zinc acetylacetonate carried out at 700 °C in a sealed quartz tube under inert ambient conditions. The resulting carbonaceous powder material was characterised by XRD and Raman analysis, electron microscopy, X-ray photoelectron spectroscopy, and elemental analysis. These analyses reveal that nanometre-sized hexagonal wurtzite ZnO is embedded in graphitic carbon and graphite oxide, forming a nanocomposite, designated ZnO/C/GO. A pellet of ZnO/C/GO was tested as a conductometric gas sensor for detecting hydrogen sulphide (H2S). The composite shows a rapid and significant response of 220% at 150 °C to 5 ppm of H2S gas, with response and recovery time of 20 s and 30 s, respectively. The detection limit is found to be 250 ppb of H2S, with good selectivity over SO2, NO2, CH4 and ammonia. The novel way to synthesise a carbonaceous nanocomposite, its sensitivity to H2S at a relatively low temperature (implying low power consumption), and its selectivity, promise a cost-effective carbonaceous oxide composite-based sensor for H2S at ppm concentrations.

Preparation of Nanopore-Containing Metal Oxide Particles and Their Gas Sensing Characteristics

We reported the successful formation of nanopores within core-shell type metal oxide particles using the shell layer as a template. Using the polyol method, core-shell type metal oxide particles such as cerium oxide, zinc oxide, and cobalt oxide with primary particles of ~10 nm and secondary particle sizes between 20 and 300 nm were prepared, where the polymer shells comprised 10-20 wt% of the total mass. These particles were easily dispersed in water and organic solvents without the use of dispersants. In addition, the core-shell type metal oxide particles were composed of an agglomeration of several tens of nanometer-sized core-shell primary particles, with sintering at 400 °C generating the desired nanopore-containing metal oxide particles. It was reported that in the SnO2 gas sensor for H2S sensing, nanopore manipulation in the sensor response layer leads to an increased response and selectivity toward H2S compared to the smaller and more reactive hydrogen gas. We therefore expected that an increase in the specific surface area of sensing films through the formation of nanopores in the secondary particles could result in additional reaction sites to lead to a higher gas responsiveness. Indeed, this was assumed to account for the high selectivities of high specific surface area cobalt nanofiber and nanosheet gas sensors toward acetone gas and ethanol gas. In this work, metal oxide particles with nanopores were prepared by a polyol method and sintering. The gas sensor characteristics of the particles with nanopores were compared with those of the particles without nanopores, and the effectiveness of 3D-nanostructure for gas sensing was also examined.Figure. Schematic representation of the strategy used to prepare the 3D nanostructure of metal oxide particles with nanopores. Figure 1

Fluorinated ZnFeIII Hollow Metal-Organic Framework as a 19F NMR Probe for Highly Sensitive and Selective Detection of Hydrogen Sulfide.

Hydrogen sulfide (H2S) is considered as a highly toxic environmental pollutant and an important signal transmitter in physiological processes, and the selective and reliable detection of H2S is of great concern and remains challenging. Herein, we report a smart sensitive “off–on” 19F NMR sensor for H2S by partially introducing a fluorinated ligand to construct a hollow dual metal–organic framework (MOF) nanosystem, F-ZnFeIII hMOF, in which the fluorinated ligand acts as the 19F signal source but is initially quenched due to the strong paramagnetic relaxation enhancement (PRE) effect from neighboring Fe3+ nodes. Upon exposure to sulfide ions, reduction of Fe3+ to Fe2+ is specifically triggered, which attenuates PRE efficiency, thus turning on the 19F NMR signal. The unique hollow MOF architecture benefits the mobility of 19F atoms, thereby improving the response sensitivity. Meanwhile, the desirable H2S-sorption feature and appropriate redox potential of Fe3+/Fe2+ account for the favorable selectivity. The increase in the 19F signal is linear with the concentration of sulfide in the range of 20 to 150 μM with a detection limit of 2.8 μM. The probe is well demonstrated by analyzing H2S in complex matrixes such as biological and foodstuff samples.