Ppm H2S Research Articles

Longevity Demonstration of Methane to C2 via a Nonthermal Plasma Microreactor.

Hydrocarbon processing using plasmas has tremendous potential, yet there still exist many uncertainties pertaining to practical operation over long durations. Previously, it has been demonstrated that a nonthermal plasma operating in a DC glow regime can transform methane into C2 species (acetylene, ethylene, ethane) in a microreactor. Using a DC glow regime in a microchannel reactor allows for lower power consumption, at the expense of greater consequence of fouling. Since biogas can be a source of methane, a longevity study was undertaken to understand how the microreactor system would change over time with a feed mixture of simulated biogas (CO2, CH4) and air. Two different biogas mixtures were used, one of which contained 300 ppm H2S, while the other had no H2S. Potential difficulties observed from previous experiments included carbon deposition on the electrodes, which could interfere with the electrical characteristics of the plasma discharge as well as material deposition in the microchannel, which could affect gas flow. It was found that raising the temperature of the system to 120 °C helped prevent hydrocarbon deposition in the reactor. Purging the reactor periodically with dry air was also found to have positive effects as it removed carbon buildup on the electrodes themselves. Successful operation over a 50 h time period without any significant deterioration was demonstrated.

Sub-ppb mixed potential H2S gas sensor based on YSZ and Nd2AO4 (A=Cu, Ba and Ni) as a new type of sensing electrode

In this paper, for the detection of hazardous gas hydrogen sulfide (H2S), new type YSZ (yttria stabilized-zirconia)-based mixed potential gas sensor is developed and K2NiF4 type oxides Nd2AO4 (A=Cu, Ba and Ni) are successfully synthesized as sensing electrode (SE). XRD results shows the materials have pure phase K2NiF4-type oxides. Compared with other sensors, the sensor based on Nd2NiO4 sensing electrode has the highest response value to 1 ppm H2S. Polarization curve results show that the reason for the highest response value is that it has the strongest electrochemical catalytic activity to H2S. Moreover, the response of the sensor based on Nd2NiO4-SE to 1 ppm H2S is − 28 mV with fast response/recovery time (70 s/135 s). The low detection range is 0.05 ppm, meeting the requirement of security monitoring field. The sensitivities of the sensor to 0.05–0.2 ppm and 0.2–10 ppm H2S are − 5 mV/decade and − 63 mV/decade respectively. Besides, the present device also performs good repeatability, excellent selectivity and acceptable stability during 30 days continuous measurement, which demonstrated that the sensor we fabricated has a good application prospect for the field of real-time and in-situ security monitoring of hydrogen sulfide.

Pd/Pt-Bimetallic-Nanoparticle-Doped In2O3 Hollow Microspheres for Rapid and Sensitive H2S Sensing at Low Temperature

H2S is a poisonous gas that is widespread in nature and human activities. Its rapid and sensitive detection is essential to prevent it from damaging health. Herein, we report Pd- and Pt-bimetallic-nanoparticle-doped In2O3 hollow microspheres that are synthesized using solvothermal and in situ reduction methods for H2S detection. The structure of as-synthesized 1 at% Pd/Pt-In2O3 comprises porous hollow microspheres assembled from In2O3 nanosheets with Pd and Pt bimetallic nanoparticles loaded on its surface. The response of 1 at% Pd/Pt-In2O3 to 5 ppm H2S is 140 (70 times that of pure In2O3), and the response time is 3 s at a low temperature of 50 °C. In addition, it can detect trace H2S (as low as 50 ppb) and has superior selectivity and an excellent anti-interference ability. These outstanding gas-sensing performances of 1 at% Pd/Pt-In2O3 are attributed to the chemical sensitization of Pt, the electronic sensitization of Pd, and the synergistic effect between them. This work supplements the research of In2O3-based H2S sensors and proves that Pd- and Pt-bimetallic-doped In2O3 can be applied in the detection of H2S.

Improved cell performance and sulphur tolerance using A-site substituted Sr2Fe1.4Ni0.1Mo0.5O6–δ anodes for solid-oxide fuel cells

AbstractSolid-oxide fuel cells (SOFCs) offer great promise for producing electricity using a wide variety of fuels such as natural gas, coal gas and gasified carbonaceous solids; however, conventional nickel-based anodes face great challenges due to contaminants in readily available fuels, especially sulphur-containing compounds. Thus, the development of new anode materials that can suppress sulphur poisoning is crucial to the realization of fuel-flexible and cost-effective SOFCs. In this work, La0.1Sr1.9Fe1.4Ni0.1Mo0.5O6–δ (LSFNM) and Pr0.1Sr1.9Fe1.4Ni0.1Mo0.5O6–δ (PSFNM) materials have been synthesized using a sol-gel method in air and investigated as anode materials for SOFCs. Metallic nanoparticle-decorated ceramic anodes were obtained by the reduction of LSFNM and PSFNM in H2 at 850°C, forming a Ruddlesden–Popper oxide with exsolved FeNi3 bimetallic nanoparticles. The electrochemical performance of the Sr2Fe1.4Ni0.1Mo0.5O6–δ ceramic anode was greatly enhanced by La doping of A-sites, resulting in a 44% decrease in the polarization resistance in reducing atmosphere. The maximum power densities of Sr- and Mg-doped LaGaO3 (LSGM) (300 μm) electrolyte-supported single cells with LSFNM as the anode reached 1.371 W cm −2 in H2 and 1.306 W cm–2 in 50 ppm H2S–H2 at 850°C. Meanwhile, PSFNM showed improved sulphur tolerance, which could be fully recovered after six cycles from H2 to 50 ppm H2S–H2 operation. This study indicates that LSFNM and PSFNM are promising high-performance anodes for SOFCs.

Experimental and theoretical insights into sulfur resistance of transition metal-doped Cu–Fe spinel during chemical looping combustion

A series of transition-metal doped Cu–Fe spinel oxygen carriers (M-CuFe2O4, M = Mn, Cr, Co and Ni) were synthesized and examined for their sulfur resistance by 500 ppm H2S in N2 atmosphere. The results showed that H2S vulcanized the M-CuFe2O4 surfaces and led to the generation of metal sulfide. The gaseous sulfur product was mainly SO2. The interaction between sulfur and CuFe2O4 was weakened when doping transition-metal into Fe site of CuFe2O4, especially Cr as dopant. The increase of temperature had an obvious impact on the reaction between H2S and the adsorbed oxygen species. Cr dopant reduced the enrichment of sulfur element on the surface, and it showed the weakest affinity towards sulfur because of the lowest orbital hybridization between S and Cr atom below the Fermi level. Moreover, the energies barriers of H2S dissociation over Cr–CuFe2O4 surface were obviously higher than those over CuFe2O4.

Rapid and reversible detection of trace amounts of H2S in air and packaged food using a biogenic bismuth oxide nanorod colorimetric sensor

A colorimetric reversible sensor has been developed for detection of trace amount of H2S gas in air and sealed meat packages. The active sensing area includes high surface area bismuth oxide (Bi2O3) nanorod prepared by green synthesis method. The as fabricated sensor demonstrates a rapid response in just 25 s for sensing 1 ppm H2S gas with distinct colour change in the active sensing area from white to brown. Sensing pellets were used to optimize the performance of the H2S sensor in terms of sensitivity and selectivity in air. Flexible nitrocellulose membrane filter papers coated with Bi2O3 were used to detect spoilage in packaged raw animal food products such as meat, poultry and fish. The sensor is reversible and can be recovered within a short cycle (3 min) of heat treatment at 300 °C. X-ray diffraction, Raman spectroscopy and band gap measurements confirmed partial conversion of Bi2O3 nanorods into Bi2S3 when exposed in the range of 1–100 ppm H2S gas.

Highly selective and sensitive MoS2 nano-sensor for H2S detection

Facile hydrothermal route was employed to prepare MoS2 nanoparticles (NPs) on the glass substrates at low temperature. MoS2 NPs were crystallized into hexagonal lattice. The MoS2 NPs have superior specific surface area (4.33 m2/g). The gas sensing performance of MoS2 NPs nano-sensors were examined towards distinctive gases (H2S, O2, CO, NH3, NO2 and SO2) and operating temperatures (28–100 °C). MoS2 NPs synthesized at 120 °C for 4 h exhibited excellent gas sensing performance. MoS2 NPs nano-sensor delivers outstanding selectivity towards H2S gas. At room temperature, the highest response achieved was 24% towards 100 ppm H2S. MoS2 NPs nano-sensor quickly responds (in 0.28 s) to target H2S gas and speedily recovers (in 15.48 s) to original state. MoS2 NPs nano-sensor has detected the least concentration of the H2S gas was 1 ppm. Impedance measurements were employed to study the adsorption-desorption interaction between the reducing H2S gas molecules and MoS2 NPs nano-sensor surface. The room temperature performance and speedy response-recovery of the MoS2 NPs nano-sensor comprises it in the list of outstanding candidates for H2S gas sensing applications.

CuO-decorated MOF derived ZnO polyhedral nanostructures for exceptional H2S gas detection

Considering that H2S is a hazardous gas that poses a significant risk to people's lives, research into H2S gas sensors has garnered a lot of interest. This work reports a CuO/ZnO multifaceted nanostructures(NS) created by heat treating Cu2+/ZIF-8 impregnation precursors, and their microstructure and gas sensing characteristics were examined using various characterization techniques (XRD, XPS, SEM, TEM, and BET). The as-prepared hollow CuO/ZnO multifunctional nanostructures had a high gas response value (425@50 ppm H2S gas), quick response and recovery times (57/191s @20 ppm), a low limit of detection (1.6@500 ppb H2S), good humidity resistance and highly selective towards H2S gas. The hollow CuO/ZnO multifaceted nanostructures possessed enhanced gas sensing capabilities which may be related to their porous hollow nanostructures, the manufactured p-CuO/n-ZnO heterojunctions, and the spillover effect between CuO and H2S.

Two-dimensional black phosphorus/tin oxide heterojunctions for high-performance chemiresistive H2S sensing

Hydrogen sulfide (H2S) emission from industrial fields and bacteria decomposing of sulfur-containing organic matter poses a significant impact on human health and atmospheric environment, thus necessitating the development of a H2S sensor with high sensitivity and exclusive selectivity especially at a very low dose. Chemiresistive sensors based on traditional metal oxides were readily limited by the elevated operating temperature and severe cross-sensitivity. To overcome these obstacles, we prepared two dimensional (2D) tin oxide (SnO2) nanosheets decorated with thin black phosphorus (BP) as the sensing layer of MEMS H2S sensors. Compared with pure SnO2 counterparts, BP-SnO2 sensors demonstrated lower optimal working temperature (130 °C vs. 160 °C), higher response (8.1 vs. 4.6) and faster response/recovery speeds (39.8 s/47.4 s vs. 79 s/140 s) toward 5 ppm H2S as well as larger sensitivity (1.3/ppm vs. 0.342/ppm). In addition, favorable repeatability, long-term stability, selectivity and humidity tolerance were exhibited. Thin BP not only served as an excellent conductivity platform within the composites, but enriched the adsorption sites by constructing p-n heterojunctions and introducing more oxygen vacancy, thus separately accelerating and strengthening the gas-solid interaction. This study showcased the application superiorities of BP nanosheets in the field of gas sensing, simultaneously providing a new strategy for trace H2S sensing via the 2D heterojunctions.

Cobalt ions induced morphology control of metal-organic framework-derived indium oxide nanostructures for high performance hydrogen sulfide gas sensors

Real-time gas sensors with high response and selectivity are highly desirable for hydrogen sulfide (H2S) monitoring concentration changes in the environment, especially at the ultra-trace level. Herein, cobalt-doped indium oxide (In2O3) with shorter-length nanorings was synthesized by foreign metal cobalt ions. By controlling the morphology of the material and calcinating the indium-based metal-organic frameworks (In-MOFs), the nanostructures of the obtained materials have a larger specific surface area, which further improves the sensing performance. The sensor prepared with a suitable amount of cobalt doping materials can exhibit the best gas-sensing performance. The Co-doped In2O3 sensor shows a high response to 2 ppm H2S (∼12.6) at 225 °C, low detection limits (100 ppb), and excellent selectivity, which is 5.34 times higher than pure In2O3 at 300 °C. Moreover, the potential growth mechanism speculates that the presence of Cobalt ions leads to a change in material morphology from nanorods to nanorings. This work provides an implementable method for controlling the morphology of the materials, which could facilitate the development of high-performance gas sensors.

On-chip CuFe2O4 nanofiber for conductometric NO2 and H2S gas-sensors

xCuO-(1-x)Fe2O3 composite nanofibers (NFs) for gas-sensing applications were thoroughly investigated in this work employing on-chip electrospinning. The fabricated NFs had a characteristic spider-net-like morphology and had diameters of 50–100 nm. The NFs composed of nanograins with diameters ranging from 16 to 35 nm have multi-porous structures. The composite NFs enhanced sensor response compared to that of single metal oxides. At the optimal composition of 0.5CuO-0.5Fe2O3 NFs, which formed a complex oxide of copper ferrite (CuFe2O4), the sensor showed the highest response (15.3 and 10) to 1 ppm H2S gas at 350 °C and 10 ppm NO2 gas at 300 °C, respectively. Additionally, the detection of on-chip NF sensors to target gases was considerably impacted by the electrospinning time. The maximum response to H2S gas was achieved after 30 min of the electrospinning process, while that to NO2 gas is 10 min. The enhanced gas-sensing performance was attributed to nanograin-based NF structure, the formation of binary complex CuFe2O4 oxide, and the heterojunctions between CuFe2O4 and single oxide (CuO or α-Fe2O3) in composite NFs. Furthermore, the high sensitivity and selectivity of the CuFe2O4 NF sensor toward target gases are also discussed by using density functional theory (DFT) calculation.

Sulfur-resistant MoO2/TS-1 zeolite armored PdCu alloy composite membrane for hydrogen separation under H2S containing steam

Sulfur poisoning could result in fast deterioration of Pd-based membranes by the formation of metal sulfides and reduction of hydrogen purity. The introduction of an MoO2/TS-1 layer could provide an effective protection of the Pd layer. Therefore, in this paper a synthetic method is presented for preparation of sulfur-resistant MoO2/TS-1 zeolite modified PdCu alloy composite membranes and their application in hydrogen separation under H2S containing steam. According to the stability test results, the MoO2/TS-1 zeolite armored layer obviously prolonged the stability of Pd based membrane. After 50 h stability test with 100 ppm H2S, there were no obvious structural changes and metal sulfide formation detected in the PdCu bulk from SEM images and XRD patterns, indicating that MoO2/TS-1 armor structure was good enough for protecting the PdCu alloy bulk.

H2S Alleviates Propofol-Induced Impaired Learning and Memory by Promoting Nuclear Translocation of Nrf2 and Inhibiting Apoptosis and Pyroptosis in Hippocampal Neurons.

Repeated exposure to propofol can affect their learning and memory functions, but the mechanism remains unclear. The current study aimed to investigate the mechanism underlying the effect of hydrogen sulfide (H2S) on the alleviation of propofol-induced learning and memory impairment, mediated by promoting nuclear translocation of the nuclear factor erythroid 2-related factor 2 (Nrf2) and inhibiting apoptosis and pyroptosis in hippocampal neurons. Rats used in this study were successively exposed to 200 mg/kg propofol for 8 consecutive weeks, followed by inhalation of 10, 40 or 80 ppm H2S. Subsequently, the effects of different concentrations of H2S on learning and memory were assessed using the water maze assay. Additionally, the effects of H2S on cell apoptosis and pyroptosis and nuclear translocation of Nrf2 in hippocampal neurons were also determined. Furthermore, NaHS (200 μmol/L) was used as an in vitro donor for H2S, and rescue experiments were carried out following Nrf2 knockdown in H19-7 cells. Moreover, Nrf2 function was inhibited following treatment with an intraperitoneal injection of ML385 (30 mg/kg) in the rats. The effects of H2S on reactive oxygen species (ROS) generation, cell apoptosis, and pyroptosis in propofol-treated and Nrf2-deficient H19-7 cells were also investigated. Exposure to propofol for 8 weeks affected the ability of the rats to find underwater platforms (p < 0.01). Further, the exposure induced cell apoptosis and NLR family pyrin domain containing 3 (NLRP3)-related pyroptosis (p < 0.01). Although inhalation of 10 ppm H2S did not attenuate the aforementioned effects (p > 0.05), exposure to 40 and 80 ppm H2S significantly alleviated propofol-induced injury in the hippocampal neurons (p < 0.01). However, the protective effect of 80 ppm H2S was more obvious as compared to that of the other two doses (p < 0.01). In addition, Nrf2 knockdown aggravated the propofol-induced cell pyroptosis and apoptosis as well as reversed the protective effect of H2S against these processes (p < 0.01). In vivo experiments in this study demonstrated that Nrf2 inhibition abrogated the protective effects of H2S inhalation against learning and memory impairment as well as propofol-induced cell apoptosis and pyroptosis in rats (p < 0.01). H2S could attenuate propofol-induced damage in hippocampal neurons by promoting the nuclear translocation of Nrf2 and inhibiting cell apoptosis and pyroptosis.

Comparison of Inflation and Ventilation with Hydrogen Sulfide during the Warm Ischemia Phase on Ischemia-Reperfusion Injury in a Rat Model of Non-Heart-Beating Donor Lung Transplantation.

Donor lung ventilation and inflation during the warm ischemia could attenuate ischemia-reperfusion injury (IRI) after lung transplantation. Hydrogen sulfide (H2S), as a kind of protective gas, has demonstrated the antilung IRI effect. This study is aimed at observing the different methods of administering H2S in the setting of warm ischemia, ventilation, and inflation on the lung graft from a rat non-heart-beating donor. After 1 h of cardiac arrest, donor lungs in situ were inflated with 80 ppm H2S (FS group), ventilated with 80 ppm H2S (VS group), or deflated (control group) for 2 h. Then, the lung transplantation was performed after 3 h cold ischemia. The rats without ischemia and reperfusion were in the sham group. Pulmonary surfactant in the bronchoalveolar lavage fluid was measured in donor lung. The inflammatory response, cell apoptosis, and lung graft function were assessed at 3 h after reperfusion. The lung injury was exacerbated in the control group, which was attenuated significantly after the H2S treatment. Compared with the FS group, the pulmonary surfactant in the donor was deteriorated, the lung oxygenation function was decreased, and the inflammatory response and cell apoptosis were increased in the graft in the VS group (P < 0.05). In conclusion, H2S inflation during the warm ischemia phase improved the function of lung graft via regulating pulmonary surfactant stability and decreased the lung graft IRI via decreasing the inflammatory response and cell apoptosis.

Influences of Impurity Gases in Air on Room-Temperature Hydrogen-Sensitive Pt–SnO2 Composite Nanoceramics: A Case Study of H2S

The slight but cumulative influence of impurity gases in air poses a great threat to the long-term stability of room-temperature gas sensors. Room-temperature hydrogen-sensitive Pt–SnO2 composite nanoceramics of 5 wt% Pt were prepared through pressing and sintering. The response of a sample was over 10,000 after being exposed to 500 ppm H2S–20% O2–N2 at room temperature, and the room-temperature hydrogen sensing capacity was seriously degraded even for samples that had aged dozens of days since H2S exposure. Mild heat treatments such as 160 °C for 10 min were found able to fully activate those H2S-exposed samples. As the peak of S 2p electron was clearly detected in H2S-exposed samples, it was proposed that for room-temperature hydrogen-sensitive Pt–SnO2 composite nanoceramics, H2S exposure induced degradation results from the poisoning of Pt by H2S deposited on it, which can be removed through a mild heat treatment. Periodic mild heat treatment should be a convenient and effective measure for room-temperature metal oxide gas sensors to achieve long-term stability through preventing the accumulation of impurity gases in air deposited on them.

MoS2-NiO nanocomposite for H2S sensing at room temperature.

The layered 2-D materials, such as molybdenum disulfide (MoS2), are among the most promising candidates for detecting H2S gas at very low concentrations. Herein, we have designed a series of novel nanocomposites consisting of MoS2 and NiO. These materials were synthesized via a simple hydrothermal method. The microstructure and morphology of nanocomposites were studied using different characterization techniques, such as X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HRTEM), Brunauer-Emmett-Teller (BET) analysis, and X-ray photoelectron spectroscopy (XPS). These nanocomposites were used as gas sensors, and the highest response (6.3) towards 10 ppm H2S was detected by the MNO-10 gas sensor among all the tested sensors. The response value (Rg/Ra) was almost three times that of pure NiO (Rg/Ra = 2). Besides, the MNO-10 sensor exposed good selectivity, short response/recovery time (50/20 s), long-term stability (28 days), reproducibility (6 cycles), and a low detection limit (2 ppm) towards H2S gas at RT. The excellent performance of MNO-10 may be attributed to some features of MoS2, such as a layered structure, higher BET surface area, higher active sites, and a synergistic effect between MoS2 and NiO. This simple fabrication sensor throws a novel idea for detecting H2S gas.

Fe2O3/Ti3C2Tx derived TiO2 hierarchical heterostructure for the detection of low-concentration H2S at room temperature

The development of high-performance room temperature gas sensors remains a great challenge. Herein, a novel three-dimensional (3D) Fe2O3 nanoflowers (NFs)/Ti3C2Tx derived TiO2 nanosheets (NSs) hierarchical heterostructure was prepared by hydrothermal treatment and chemical bath deposition (CBD) method. With the unique structure, two-dimensional (2D) Ti3C2Tx derived TiO2 NSs provide an ideal platform for the nucleation and growth of the Fe2O3 NFs. By controlling the CBD time, the growth evolution of Fe2O3 NFs onto Ti3C2Tx derived TiO2 NSs can be effectively regulated. At room temperature, the Fe2O3/Ti3C2Tx derived TiO2 sensor with optimal CBD time (45 min) exhibits the highest sensitivity of 48.6% for 10 ppm H2S, while both the Fe2O3 and Ti3C2Tx derived TiO2 sensors have nearly no response to 50 ppm H2S. Additionally, the Fe2O3/Ti3C2Tx derived TiO2 sensor displays the high selectivity to H2S, low limit of detection (200 ppb) and good repeatability. The constructing of 3D Fe2O3/Ti3C2Tx derived TiO2 hierarchical heterostructure opens a new route to develop other high-performance room temperature gas-sensing materials.

Metal-organic frameworks-derived In2O3/ZnO porous hollow nanocages for highly sensitive H2S gas sensor

The detection of hydrogen sulfide (H2S) is critical because of its potential harm and widespread presence in the oil and gas sectors. The zeolitic imidazolate framework-8 (ZIF-8) derived ZnO nanostructures manufactured as gas sensors have exceptional sensitivity and selectivity for H2S gas. In/Zn-ZIF-8 template material was synthesized by a simple one-step co-precipitation method followed by thermal annealing in air. The heat treatment resulted in In2O3/ZnO nanostructures with mixed heterostructures. The crystal structure (XRD), morphology (SEM/TEM), chemical state (XPS), surface area (BET), etc were investigated to ascertain the nature of the as-prepared material. SEM imagery revealed that the as-prepared In2O3/ZnO sensitive material had a microstructure of porous hollow nanocages with an average particle size of about 200 nm, which is beneficial to the diffusion and adsorption of gas molecules. The gas sensing performance test results of the In2O3/ZnO hollow nanocages show that their response to H2S gas is significantly improved 67.5 @50 ppm H2S (about 11 times that of pure ZnO nanocages) at an optimal temperature of 200 °C, better selectivity, lower theoretical detection limit and good linearity between gas concentration and response values. The enhanced gas sensing feat to H2S gas is mainly attributed to the formation of n-n heterojunction and the wide surface area of the newly formed In2O3/ZnO porous hollow nanocages.

Sulfur-Resistant CeO2-Supported Pt Catalyst for Waste-to-Hydrogen: Effect of Catalyst Synthesis Method

To improve the sulfur tolerance of CeO2-supported Pt catalysts for water gas shift (WGS) using waste-derived synthesis gas, we investigated the effect of synthesis methods on the physicochemical properties of the catalysts. The Pt catalysts using CeO2 as a support were synthesized in various pathways (i.e., incipient wetness impregnation, sol-gel, hydrothermal, and co-precipitation methods). The prepared samples were then evaluated in the WGS reaction with 500 ppm H2S. Among the prepared catalysts, the Pt-based catalyst prepared by incipient wetness impregnation showed the highest catalytic activity and sulfur tolerance due to the standout factors such as a high oxygen-storage capacity and active metal dispersion. The active metal dispersion and oxygen-storage capacity of the catalyst showed a correlation with the catalytic performance and the sulfur tolerance.

In situ growth of hierarchical NiO microspheres via ionic liquid-assisted synthesis for ppb-level detection of H2S

Well-defined hierarchical NiO microspheres were in situ deposited on ceramic tubes by a simple ionic liquid (IL)-assisted solvothermal method with subsequent calcination, and the characterization was exclusively confirmed through XRD, SEM, TEM and nitrogen adsorption-desorption techniques. Morphological characterization demonstrated that the nanostructures were constructed of interlaced porous nanosheets. Such NiO microspheres in situ grew onto ceramic tubes to form deposited film sensors, which displayed enhanced H2S sensing properties compared with the coated film sensors painted with the powder prepared in the same reaction system. Specifically, the deposited film sensor achieved a response value of 154.2–100 ppm H2S at a low working temperature of 92 °C, a fast recovery time of 7.5 s, with the lowest detection limit of 0.1 ppb. The excellent sensing performance should be attributed to the superior reactivity of the porous hierarchical architecture with large specific surface area, which facilitated the gas molecules to adsorb onto the surface and the consequent electron transfer. The reaction mechanism of the sensor to H2S was also discussed in detail based on XPS analysis, and was eventually interpreted as the two different kinds of kinetics occurring simultaneously: the oxidation of H2S molecules by chemisorbed oxygen, and the NiS formation along with the reaction of H2S with NiO.