Hydrogen Sensor Research Articles

High-Precision Trace Hydrogen Sensing by Multipass Raman Scattering.

Despite its growing importance in the energy generation and storage industry, the detection of hydrogen in trace concentrations remains challenging, as established optical absorption methods are ineffective in probing homonuclear diatomics. Besides indirect detection approaches using, e.g., chemically sensitized microdevices, Raman scattering has shown promise as an alternative direct method of unambiguous hydrogen chemical fingerprinting. We investigated the suitability of feedback-assisted multipass spontaneous Raman scattering for this task and examined the precision with which hydrogen can be sensed at concentrations below 2 parts per million. A limit of detection of 60, 30, and 20 parts per billion was obtained at a pressure of 0.2 MPa in a 10-min-long, 120-min-long, and 720-min-long measurement, respectively, with the lowest concentration probed being 75 parts per billion. Various methods of signal extraction were compared, including asymmetric multi-peak fitting, which allowed the resolution of concentration steps of 50 parts per billion, determining the ambient air hydrogen concentration with an uncertainty level of 20 parts per billion.

Highly sensitive and wrappable room temperature wireless gasochromic and chemiresistive dual-response H2 sensors using spray coating

Developing highly reliable, sensitive and room temperature operation hydrogen (H2) sensors is essential to adapt successfully to the H2 economy. Despite the development of various H2 sensors, detecting leaks and pinpointing their precise location remains challenging because of the highly diffusive nature of H2 and environmental factors such as the wind direction. This study reports the development of room temperature, wireless, dual-signal, wrappable, chemiresistive, and eye-readable gasochromic H2 sensors using solution-based and low temperature annealed SnO2/WO3 films on polyimide substrate. These sensors can be wrapped around any point source, such as flanges, rendering the early detection and pinpointing of H2 leaks. An optimized spray-coated gasochromic WO3 film achieves a color change value (ΔE) of 11 with a 6 s response time at 4% H2 and low eye detectable limit of 0.2%. Simultaneously, because a patterned spray-coated gasochromic layer does not interfere with the active area of a SnO2-based chemiresistive sensor, the resistance value of the sensor changes by more than 11,000 times at 1% H2 with a wide concentration range from 0.005% to 2% of H2 at room temperature. Such a sensor can be easily applied to various nonplanar surfaces, while the Bluetooth system integration enables wireless monitoring via smartphones. Our study provides a simple strategy to develop wrappable dual-signal wireless sensors for reliable detection and monitoring of H2 leaks at room temperature.

Evaluation of Hydrogen Ions Flowing through Protonic Ceramic Fuel Cell Using Ytterbium-Doped Barium Zirconate as Electrolyte

To measure the proton current in a PCFC (protonic ceramic fuel cell), the proton current detector was developed using a proton conducting oxide. The amount of proton current that flowed in the PCFC can be measured by an apparatus developed based on the electromotive force of an electrochemical cell using 10 mol% In-doped CaZrO3 (hydrogen sensor) and Y-stabilized zirconia (oxygen sensor). The water vapor pressure on the cathode changed when hydrogen ions pass through the PCFC. The hydrogen ion current can be determined by monitoring the water vapor pressure. The electronic leakage was then estimated from the hydrogen ion current and external current. We measured the current of hydrogen flowing through protonic ceramic fuel cell using ytterbium-doped barium zirconate as the electrolyte. Hydrogen ions and holes were found to leak under the OCV at 700°C. The electronic leakage was found to be suppressed with the increasing electrolyte film thickness. On the other hand, no leakage of hydrogen and holes was observed at 500°C.

Shape and composition effects of PdPt bimetallic nanocrystals on hydrogen sensing properties of SnO2 based sensors

The efficient detection of hydrogen leakage is important for the development of hydrogen economy. Semiconductor-based hydrogen sensors still suffer from high temperature and low detection rate. Here, a hydrogen sensor using PdPt nanocrystals with different morphologies such as nano-octahedron, nanocube and nanoflower as sensitizers is proposed. The experimental results demonstrate that PdPt/SnO2 materials exhibit shape-dependent H2 sensing performances, and the response order is NOS (PdPt nano-octahedrons modified SnO2) > NCS (PdPt nanocubes modified SnO2) > NFS (PdPt nanoflowers modified SnO2). The superior H2 sensing characteristics of NOS can be ascribed to the higher catalytic activity of {111} facet of PdPt nanocrystals than {100} facet and abundant oxygen defects. Apart from the shape effect, the atomic ratio of Pd to Pt also affects the H2 sensing capability of PdPt/SnO2. Especially, NOS-3 (Pd3Pt nano-octahedrons modified SnO2) exhibits a superfast response/recovery rate (1/8 s) and ultrahigh response (22821) to 1000 ppm H2 at 25 ℃, which is superior to the MOS-based H2 sensing materials reported so far in terms of operating temperature, response speed and response value. This study establishes a practicable strategy for ultrafast detection of H2 at room temperature.

Wafer-scale hysteresis-free plasmonic hydrogen sensors based on Pd–Au alloy nanoarrays

The prospective market of hydrogen energy has dramatically boosted the demand for accurate and stable detection of ambient hydrogen. In this work, we fabricated wafer-scale plasmonic hydrogen sensors consisting of periodically distributed Pd–Au alloy nanodiscs by holographic lithography and other semiconductor-compatible techniques, thus obtaining reliable and low-cost sensing devices. Light transmittance measurements at specific light wavelength close to the plasmonic absorption peak position are conducted to investigate the hydrogen sensing performance on account that optical signals afford spark-free operation and high tolerance. Upon alloying Pd with appropriate content of Au, the hysteresis between hydrogen absorption and desorption curves is completely suppressed which greatly improves the sensing accuracy throughout the hydrogen pressure range of 102–105 Pa. Moreover, the precisely defined Pd–Au alloy nanodiscs provide satisfactory stability and device-to-device reproducibility. This work demonstrates an attractive route into practical applications of hydrogen detection for the facile fabrication method and satisfactory performance.

Hydrogen Sensing Mechanism of WS2 Gas Sensors Analyzed with DFT and NAP-XPS.

Nanostructured tungsten disulfide (WS2) is one of the most promising candidates for being used as active nanomaterial in chemiresistive gas sensors, as it responds to hydrogen gas at room temperature. This study analyzes the hydrogen sensing mechanism of a nanostructured WS2 layer using near-ambient-pressure X-ray photoelectron spectroscopy (NAP-XPS) and density functional theory (DFT). The W 4f and S 2p NAP-XPS spectra suggest that hydrogen makes physisorption on the WS2 active surface at room temperature and chemisorption on tungsten atoms at temperatures above 150 °C. DFT calculations show that a hydrogen molecule physically adsorbs on the defect-free WS2 monolayer, while it splits and makes chemical bonds with the nearest tungsten atoms on the sulfur point defect. The hydrogen adsorption on the sulfur defect causes a large charge transfer from the WS2 monolayer to the adsorbed hydrogen. In addition, it decreases the intensity of the in-gap state, which is generated by the sulfur point defect. Furthermore, the calculations explain the increase in the resistance of the gas sensor when hydrogen interacts with the WS2 active layer.

Pt=Pd separation modified Ti3C2TX MXene for hydrogen detection at room temperature

Hydrogen sensing with a fast response at room temperature is still a challenge. In this study, a novel Pt=Pd/Ti3C2TX hydrogen sensor was prepared by a straightforward hydrothermal chemical reduction method. The Pt=Pd/Ti3C2TX was characterized by X-ray diffraction, transmission electron microscope, and X-ray photoelectron spectroscopy. The experimental results showed that the response of the Pt=Pd/Ti3C2TX sensor was 24.6% and the response/recovery time was 6/8 s in the case of 200 ppm hydrogen at room temperature. The Pt=Pd/Ti3C2TX sensor could detect the hydrogen concentration as low as 1 ppm. Besides, the Pt=Pd/Ti3C2TX sensor exhibited good linearity, long-term stability, good repeatability, and high selectivity. The Pt=Pd/Ti3C2TX sensor has great potential in the field of hydrogen energy.

Assessing the improved luminescence of SrCe1-xSmxO3 perovskite by concentration controlled extra oxidizer substitution

Strontium cerate perovskite nano phosphors when doped with rare earth elements show improved functional properties such as electrical conductivity and photoluminescence. Electrical conductivity investigations on doped strontium cerates have been studied widely over decades for application in electrochemical cells, hydrogen sensors, hydrogen extractors, etc. But only minimal research has been developed in the amelioration of photoluminescence in rare earth-doped strontium cerates. In the present study, samarium-doped strontium cerate perovskite nanophosphors were considered for utilization in optoelectronic applications. The perovskites SrCe1-xSmxO3 (x = 0.01,0.02,0.03) were prepared via a low-temperature gel combustion approach with citric acid as chelating agent and ammonia solution as an extra oxidizer. The influence of concentration variation on the evolution behaviour of the crystalline phase as well as the luminescence characteristics of ceramic powders are investigated using X-ray diffraction and Photoluminescence characterization techniques. Experimental results indicate that the calcinating temperature of 1223 K in gel combustion synthesis, much lower than the conventional solid-state reaction is only needed for the single-phase perovskite formation. Also, a comparison study of the luminescence behaviour by replacing internal constituent extra oxidizer ammonia solution with ammonium nitrate is observed in this study, and conditions for maximum luminescence intensity are hence discussed. The observed results on photoluminescence studies indicate that an enhancement in the luminescence intensity of SrCe0.98Sm0.02O3 occurred when we replaced extra oxidizer ammonia solution with ammonium nitrate. Thus, a bright orange-scarlet red emitting perovskite nano phosphor SrCe0.98Sm0.02O3 by the later technique can be synthesized and can act as an inevitable red phosphor coating the chip in LEDs, which can be a great revolution in energy savings applications.

Structure-dependent room-temperature hydrogen sensing of Nb2O5 nanorods prepared by topological transformation process

The development of reliable low-power-consumption hydrogen gas sensors is of great significance for the accurate detection of hydrogen leakage in the hydrogen-related industries. Nb2O5 nanomaterials have exhibited great potential for building highly selective hydrogen sensors owing to its outstanding hydrogen catalytic capability, but still suffer from relatively low hydrogen sensitivity at room temperature. Herein, the orthorhombic and hexagonal Nb2O5 nanorods with different defect states are prepared through a combined topological transformation process. The Nb2O5 nanorods with polycrystalline orthorhombic structures exhibit much higher room-temperature hydrogen response comparing with the single-crystalline hexagonal Nb2O5 nanorods. Moreover, both phases of the Nb2O5 nanorods exhibit certain amounts of oxygen vacancies, as well as the interstitial Nb4+ and related oxygen defects. The elimination of the Nb4+ and related oxygen defects can significantly enhance the surface reactivity of the Nb2O5 nanorods and improve the sensor response of the chemiresistor devices. The sensor based on the defect-modified orthorhombic Nb2O5 nanorods shows sensitive and highly selective room-temperature hydrogen sensing performance with the detection limit of 160 ppm. The structure-dependent hydrogen sensing behavior of the Nb2O5 nanorods can be attributed to the redox reaction between hydrogen and pre-adsorbed oxygens, which can be promoted by the superior gas adsorption and pathway effect of the orthorhombic Nb2O5 lattice.

Introduction of Level Sensor Assembly in Korea Space Launch Vehicles II

Level sensors are widely used in the aerospace field to measure the quantity of propellant. Especially, measuring the quantity of the propellant is very important in launch vehicles because the performance of launch vehicles strongly depends on the weight of the propellant. Many launch vehicles use cryogenic propellants, such as oxygen, hydrogen, and methane, and level sensors for cryogenic propellants are needed in these applications. In this study, the development process for the newly designed level sensor assembly based on a magnetostrictive level transmitter is introduced. Based on the thermal analysis, a level sensor assembly using a magnetostrictive level transmitter for cryogenic propellants was proposed. Several experimental studies have been conducted for the assembly level and the complete integrated system level to confirm the performance of the level sensor assembly. Finally, this newly designed level sensor assembly is successfully validated by flight tests of Test Launch Vehicle and Korea Space Launch Vehicle II.

Pt/SnO2-Pd nanoelectrode applied for hydrogen sensor with zero-power consumption and low detection limit

The detection of low-concentration hydrogen at room temperature is still a challenge, which contributes to taking precautions as soon as possible when hydrogen leaks. In this study, we prepared Pt/SnO2-Pd nanomaterial as nanoelectrode applied for a fuel cell-type hydrogen sensor with zero power consumption. The sensing results show that such fuel cell-type H2 gas sensor has high selectivity and good sensitivity to H2 gas, with an unprecedented low detection limit of 1 ppm, and the humidity has little impact on the sensor's performance. Based on DFT calculations, the low adsorption energy and the electron transfer interaction between Pd and H promote the adsorption and dissociation processes of H2 molecules, which lead to the hydrogen oxidation reaction acceleration and shorter times of response and recovery. In addition, this Pt/SnO2-Pd based sensor has also advantages of high selectivity and zero-power consumption, which may provide a broad application prospect for fuel cell vehicles and voltage transformers, etc.

Enhancing the Potentiometric H2 Sensing of Pr0.1Ce0.9O2−δ Using Fe2O3 Surface Modification

Monitoring the concentration of hydrogen is very important as it is a flammable and explosive gas. Non-Nernstian potentiometric hydrogen sensors hold promising potentials for the sensitive detection of hydrogen. This paper reports the improved H2-sensing performance of a mixed oxide ion-electron conducting (MIEC) Pr0.1Ce0.9O2−δ (PCO) electrode using Fe2O3 surface modification. The Fe2O3-modified PCO exhibited a high response of −184.29 mV to 1000 ppm H2 at 450 °C. The response values exhibited a linear or logarithmic dependence on the H2 concentration for below or above 20 ppm, respectively. A sensitivity of −74.9 mV/decade in the concentration range of 20–1000 ppm was achieved, and the theoretical limit of detection was calculated to be 343 ppb. Moreover, a power-law relationship between the response time and the concentration value was also found. Electrochemical impedance analyses revealed that the excellent H2-sensing performance may be attributed to the large ratio of the electrochemical activity of the hydrogen oxidation reaction (HOR) over the oxygen exchange reaction (OER). In addition, the distribution of relaxation time (DRT) results reveal that the enhanced electrochemical kinetics caused by H2 presence in air is mainly related to acceleration of the electrode surface processes.

Broccoli-shaped nano florets-based gastrointestinal diseases detection by copper oxide chitosan

This report describes a simple and inexpensive room-temperature chemo-resistive CuO-Chitosan-based hydrogen sensor for detecting gastrointestinal diseases (GIDs). A clinical analysis shows that GID patients exhale more than 10–20 ppm of hydrogen compared to healthy people, which is considered a biomarker for the non-invasive diagnosis of GIDs. This allows for a portable, non-intrusive, effective, and fast-detecting sensor in treating GIDs. To our knowledge, no GIDs study has used chitosan for H2 sensing. The current study prepares CuO-Chi nanocomposites and tests their hydrogen sensitivity for GIDs detection. Different ratios of CuO: chitosan [CuO: Chi (A(1:2), B(1:1), C(1:0.5), D(1:0.25), E(1:0.125), and F(1:0.0625)]were synthesized using novel co-precipitation cum probe sonication technique. Compared to other CuO composites in the literature, our synthesized CuO: Chi-B (1:1) can detect as low as 10 ppm of hydrogen gas at room temperature, with a lower limit of detection (0.07 ppm) and a regression coefficient (R2) of 0.9566. The Contact angle explains the anti-wettability property with the increase in the hydrophilicity due to the presence of electronegative atoms like N in NH2 and O in the OH group. Field emission scanning electron microscopy reveals several single broccoli nano florets. Most importantly, the sensor's calculated Brunauer–Emmett–Teller surface area is 5.1565 m2/g with a pore volume of 0.02173cm2/gm and pore size of 16.897 nm. It has excellent sensitivity, response, recovery, reproducibility, stability, and selectivity. The reaction mechanism for sensor performance is elaborately discussed by the Grotthuss mechanism. The above studies suggest and show that CuO: Chi-B (1:1) is a new material for hydrogen sensors that can be used for the breath analysis to detect GIDs at 10 ppm.

Ultrahigh-response sensor based on hierarchical Pd-WO3 nanoflowers for rapid hydrogen detection

In this research, four tungsten trioxide materials were synthesized in precursor solutions with different pH values by hydrothermal method. Then, Pd nanoparticles were loaded on the hierarchical WO3 nanoflowers, which exhibited the best hydrogen sensitivity among the four as-synthesized materials. The hydrogen sensing test results demonstrated that the 0.50 at% Pd-WO3 sensor showed a fairly high response of 8658.98, a fast response/recovery time of 1/3 s and excellent selectivity to 500 ppm H2 at a working temperature of 150 °C, which properties were superior to previous WO3-based hydrogen sensors. The wonderful H2 sensing property was shown due to the increase of oxygen vacancies, adjustment of basic sensor resistance and spill-over effect of Pd. This work will provide a feasible strategy for designing H2 sensors with a fairly high response and fast response/recovery speed.

Two-dimensional Aluminum Oxide Nanosheets Decorated with Palladium Oxide Nanodots for Highly Stable and Selective Hydrogen Sensing.

Hydrogen (H2 ) sensing materials such as semiconductor metal oxides may suffer from poor long-term stability against humidity and unsatisfactory selectivity against other interfering gases. To address the above issues, highly stable and selective H2 sensing built with palladium oxide nanodots decorating aluminum oxide nanosheets (PdO NDs//Al2 O3 NSs) has been achieved via combined template synthesis, photochemical deposition, and oxidation. Typically, the PdO NDs//Al2 O3 NSs are observed with thin NSs (≈17nm thick) decorated with nanodots (≈3.3nm in diameter). Beneficially, the sensor prototypes built with PdO NDs//Al2 O3 NSs show excellent long-term stability for 278 days, high selectivity against interfering gases, and outstanding stability against humidity at 300°C. Remarkably, the sensor prototypes enable detection of a wide-range of 20ppm - 6V/V% H2 , and the response and recovery times are ≈5 and 16 s to 1V/V% H2 , respectively. Theoretically, the heterojunctions of PdO NDs-Al2 O3 NSs with a large specific surface ratio and Al2 O3 NSs as the support exhibit excellent stability and selective H2 sensing. Practically, a sensing device integrated with the PdO NDs//Al2 O3 NSs sensor prototype is simulated for detecting H2 with reliable sensing response.

The ZnO nanostructured hydrogen sensor fabricated by combining electrospinning technology and hydrothermal method

In this study, a composite structure of zinc oxide (ZnO) nanofibers and nanorods was prepared on a silicon substrate by combining electrospinning and hydrothermal methods. ZnO/PVP nanofibers are prepared by electrospinning components containing polyvinylpyrrolidone (PVP), ethanol (Ethanol) and zinc acetate, and then calcined at 500°C for 4 hours. Crystallized ZnO nanofibers are then used as the ZnO seed layer, and ZnO nanorods are grown on the nanofibers by hydrothermal method. Combining these two low-cost processes can prepare a ZnO nanostructure with a high specific surface area, which can improve the sensitivity of ZnO to hydrogen. The ZnO nanostructure was analyzed by electron microscope (SEM), and X-ray diffraction (XRD). The experimental results show that the ZnO/PVP nanofibers obtained by electrospinning for 2 hours have the best crystallinity after being calcined. ZnO nanorods are then hydrothermally grown on the surface of the nanofibers. As a component material for hydrogen sensing, the sensitivity can reach 61.7% at a hydrogen concentration of 4500 ppm.

Hybrid Microstrip Device for Hydrogen Detection at Microwave Frequencies

This article describes the analysis, design, and construction of a microstrip device capable of detecting hydrogen at microwave frequencies. The proposed structure is a hybrid microstrip line, 10-cm-long, having part of the copper (Cu) line replaced by a strip of palladium (Pd) film 10-nm-thick. A simple formulation has been developed to estimate the device’s insertion loss, as well as the spectral dependence of the <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${S}_{{21}}$ </tex-math></inline-formula> parameter. For a device having a 2-cm-long Pd section, exposed to 1.6% hydrogen at a 0.4-bar pressure in nitrogen gas, detection was accomplished by measuring the changes produced on one of the resonances of the scattering parameter <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${S}_{{21}}$ </tex-math></inline-formula> in the frequency region around 3.2 GHz. The experimental results, corroborated by the theoretical modeling of the device’s response, indicated that, if on one hand, a Pd thickness much smaller than the skin depth, yields a negligible change in attenuation due to hydrogen absorption, on the other, it favors the phase of the <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${S}_{{21}}$ </tex-math></inline-formula> parameter to become a highly sensitive function of Pd conductivity, in turn facilitating hydrogen detection. This finding opens the possibility of constructing simple hydrogen sensors by incorporating ultrathin Pd films into planar microwave circuits.

Gas sensing properties of mixtures of copper and titanium oxides thin films

The subject of the current studies were mixtures of copper and titanium oxide thin films,with various elemental compositions, deposited by magnetron sputtering and annealed in the postprocess.The effect of elemental composition and annealing temperature on the morphology of thinfilms was determined using scanning electron microscope images. The crystal structure and chemicalcomposition of copper‒titanium oxide (CuTi)Ox mixtures were investigated by X-ray diffraction.Hydrogen gas sensing experiments were performed for hydrogen with concentrations ranging from 100to 1,000 ppm. The resistance of the prepared (CuTi)Ox mixtures increased during hydrogen exposure,demonstrating the applicability of these oxides in hydrogen sensing. In addition, better sensor responseswere obtained for the mixtures in comparison to single copper oxides or titanium oxides. Mixturesof copper oxides and titanium oxides may be promising materials for hydrogen sensor applications.Keywords: mixtures of copper and titanium oxides, hydrogen gas sensors, mixed copper and titaniumoxides, thin films, magnetron sputtering

Toward a synthetic hydrogen sensor in cyanobacteria: Functional production of an oxygen-tolerant regulatory hydrogenase in Synechocystis sp. PCC 6803.

Cyanobacteria have raised great interest in biotechnology, e.g., for the sustainable production of molecular hydrogen (H2) using electrons from water oxidation. However, this is hampered by various constraints. For example, H2-producing enzymes compete with primary metabolism for electrons and are usually inhibited by molecular oxygen (O2). In addition, there are a number of other constraints, some of which are unknown, requiring unbiased screening and systematic engineering approaches to improve the H2 yield. Here, we introduced the regulatory [NiFe]-hydrogenase (RH) of Cupriavidus necator (formerly Ralstonia eutropha) H16 into the cyanobacterial model strain Synechocystis sp. PCC 6803. In its natural host, the RH serves as a molecular H2 sensor initiating a signal cascade to express hydrogenase-related genes when no additional energy source other than H2 is available. Unlike most hydrogenases, the C. necator enzymes are O2-tolerant, allowing their efficient utilization in an oxygenic phototroph. Similar to C. necator, the RH produced in Synechocystis showed distinct H2 oxidation activity, confirming that it can be properly matured and assembled under photoautotrophic, i.e., oxygen-evolving conditions. Although the functional H2-sensing cascade has not yet been established in Synechocystis yet, we utilized the associated two-component system consisting of a histidine kinase and a response regulator to drive and modulate the expression of a superfolder gfp gene in Escherichia coli. This demonstrates that all components of the H2-dependent signal cascade can be functionally implemented in heterologous hosts. Thus, this work provides the basis for the development of an intrinsic H2 biosensor within a cyanobacterial cell that could be used to probe the effects of random mutagenesis and systematically identify promising genetic configurations to enable continuous and high-yield production of H2 via oxygenic photosynthesis.

Structure and Technological Parameters’ Effect on MISFET-Based Hydrogen Sensors’ Characteristics

The influence of structure and technological parameters (STPs) on the metrological characteristics of hydrogen sensors based on MISFETs has been investigated. Compact electrophysical and electrical models connecting the drain current, the voltage between the drain and the source and the voltage between the gate and the substrate with the technological parameters of the n-channel MISFET as a sensitive element of the hydrogen sensor are proposed in a general form. Unlike the majority of works, in which the hydrogen sensitivity of only the threshold voltage of the MISFET is investigated, the proposed models allow us to simulate the hydrogen sensitivity of gate voltages or drain currents in weak and strong inversion modes, taking into account changes in the MIS structure charges. A quantitative assessment of the effect of STPs on MISFET performances (conversion function, hydrogen sensitivity, gas concentration measurement errors, sensitivity threshold and operating range) is given for a MISFET with a Pd-Ta2O5-SiO2-Si structure. In the calculations, the parameters of the models obtained on the basis of the previous experimental results were used. It was shown how STPs and their technological variations, taking into account the electrical parameters, can affect the characteristics of MISFET-based hydrogen sensors. It is noted, in particular, that for MISFET with submicron two-layer gate insulators, the key influencing parameters are their type and thickness. Proposed approaches and compact refined models can be used to predict performances of MISFET-based gas analysis devices and micro-systems.