H2S Gas Sensor Research Articles

Synthesis and characterization of Au:CdO nanoparticles using laser ablation in liquid as gases sensors

Laser ablation technique in solution has been advanced to achieve single step synthesis of varied gold: oxide nanocomposites with uniform morphology and supreme dispersibility. The core:shell Au:CdO nanoparticles were manufactured by using fundamental Nd:YAG laser (1064 nm) at several energy of laser 600, 800 and 1000 mJ/100pulses, after that deposited on surface of porous-Si (PS). PS is prepared by using photo-electrochemical etching (PECE) method of n-type Si wafer in 16% hydrofluoric acid (HF).Current density 12 mA/cm2 and time of etching was 15 min. The characteristics of Au:CdO NPs that have been synthesized were studied. The structural properties were investigated using X-ray diffraction (XRD). Furthermore, the results of the AFM “atomic force microscope” test indicated a 26.34 nm surface roughness for Au:CdO NPs, TEM “transmission electron microscope) revealed that the fabricated particles of Au:CdO were spherical shape, and Photoluminescence (PL) test. Finally, the effects of different operation temperatures on the gas sensor sensitivity, recovery, and response times of NO2 and H2S gas sensors which created from synthesized samples were investigated. The maximum sensitivity of Au:CdO NPS/PS ablated by energy laser 800 mJ is approximately 93.5% and 67.81% of gas H2S and NO2 respectively.

Room temperature detection of low-concentration H2S based on CuO functionalized ZnFe2O4 porous spheres

Room temperature H2S gas sensor with low detection limit is necessary for practical application. In this work, ZnFe2O4 was synthesized through a simple solvothermal method, and then CuO was decorated onto the surface of ZnFe2O4 via a modified metal organic framework synthesis method. After a series of characterization methods, it was found that CuO/ZnFe2O4 had porous nanosphere morphology. Gas sensing measurements indicating that the synthesized CuO/ZnFe2O4 porous spheres exhibited excellent H2S sensing performance under room temperature, including high sensitivity under low concentration (less than 10 ppm), excellent selectivity, low limit of detection (0.1 ppm), good repeatability, and fast response/recovery time. The sensing mechanism was discussed in detail, which is mainly contributed to the sensitization effect of CuO. This work provides a new strategy for constructing room temperature H2S gas sensor based on ZnFe2O4.

Metal-organic framework-derived ZnO decorated with CuO for ultra-high response and selectivity H2S gas sensor

Fast response recovery time and high response value are very necessary indicators for H2S sensors in the past few years. As H2S is a toxic gas that has great threat to human life, research on H2S gas sensors has received widespread attention. In this work, H2S gas sensors with high response value, excellent selectivity and fast response/recovery time were prepared by liquid phase synthesis method. Firstly, ZIF-8 (zeolite imidazolate framework-8) metal-organic framework derived ZnO was synthesized. Then high performance CuO/ZnO sensing materials modified with different amounts of CuO were synthesized using ZnO as the pristine material and CuO as the sensitizing material. Furthermore, the gas sensing test was conducted and the results show that the synthesized CuO/ZnO has significantly enhanced sensing performance to H2S. The highest response to 10 ppm H2S is 941 at a relatively low working temperature of 175 °C, which is 80 times higher than that of ZIF-8 derived ZnO. Moreover, the sensor based on CuO sensitized ZnO also showed excellent selectivity, fast response/recovery property and good moisture resistance. The enhanced gas sensing performance is mainly attributed to the formation of p-n heterojunction and the strong chemical affinity and catalytic performance of CuO for H2S.

Achieving highly-efficient H2S gas sensor by flower-like SnO2–SnO/porous GaN heterojunction

A flower-like SnO2–SnO/porous GaN (FSS/PGaN) heterojunction was fabricated for the first time via a facile spraying process, and the whole process also involved hydrothermal preparation of FSS and electrochemical wet etching of GaN, and SnO2–SnO composites with p–n junctions were loaded onto PGaN surface directly applied to H2S sensor. Meanwhile, the excellent transport capability of heterojunction between FSS and PGaN facilitates electron transfer, that is, a response time as short as 65 s and a release time up to 27 s can be achieved merely at 150 °C under 50 ppm H2S concentration, which has laid a reasonable theoretical and experimental foundation for the subsequent PGaN-based heterojunction gas sensor. The lowering working temperature and high sensitivity (23.5 at 200 ppm H2S) are attributed to the structure of PGaN itself and the heterojunction between SnO2–SnO and PGaN. In addition, the as-obtained sensor showed ultra-high test stability. The simple design strategy of FSS/PGaN-based H2S sensor highlights its potential in various applications.

CuO-sensitized amorphous ZnSnO3 hollow-rounded cubes for highly sensitive and selective H2S gas sensors

Hydrogen sulfide (H2S), a toxic and flammable gas, poses a substantial threat to human health and the ambient environment. Therefore, producing responsive H2S sensors that have excellent selectivity and work at low temperatures has been a goal for researchers. In this study, hollow-rounded cubes composed of copper oxide (CuO)-sensitized amorphous zinc stannate (zinc tin oxide (ZTO)) were prepared by a coprecipitation method combined with an impregnation treatment. Various characterization methods are employed to analyze the crystal phase, morphology, and composition of the synthetic materials. The results showed that the materials were composed of hollow, rounded, amorphous cubes with a 500–700 nm uniform particle size. The as-prepared materials were applied to gas sensors, and their H2S-sensing performance was systematically tested. Compared with the ZTO- and CuO-based sensors, the CuO/ZTO-based sensor exhibited excellent gas-sensing performance toward H2S, with a maximum response value of 574–10 ppm H2S and a low operating temperature of 160 °C. In addition, the sensor showed higher selectivity and a low detection limit of 200 ppb. The findings indicate that the CuO/ZTO composite is promising as an H2S-sensing material with potential applications in the field of environmental air monitoring.

Fabrication of selective gas sensors using Fe3O4 nanoparticles decorated with CuO

Metal-oxide nanoparticles are regarded as favorable candidates for different device applications including gas sensors. Decoration of nanoparticles with smaller ones of different types enables taking advantage of the physical and chemical characteristics of both core and decorate nanoparticles. Fe3O4 nanoparticles decorated with CuO are produced in this work by a coprecipitation method and investigated for their application for H2S gas sensor devices. The average size of Fe3O4 nanoparticles is 33.33∓5.55nm while the average grain size of the CuO nanoparticles is 9.72∓1.39nm. Gas sensors are fabricated by depositing dispersed nanoparticles on substrates with pre-printed interdigitated electrodes. Impedance spectroscopy is utilized to investigate the electrical characteristics of fabricated devices, where their activation energy is evaluated to 0.386±0.076eV. The fabricated sensors are found to be selective to H2S and sensitive to low concentrations, as low as 1.0 ppm, with minimum response time of 1.0 min. The produced sensors indicate potential for field applications due to their various features that include simplified and practical fabrication procedure, low power needs, high sensitivity, reasonable response time, and magnetic properties of nanoparticles that facilitate their recycling.

High sensitivity H2S gas sensors using lead halide perovskite nanoparticles

We report the development of a high sensitivity H2S gas sensor based on perovskite nanoparticles, which can be synthesized using relatively simple solution-growth methods. The gas sensor was fabricated from the metal halide perovskite formamidinium lead bromide (FAPbBr3), which exhibits a high sensitivity to H2S gas in the form of changes to the electrical conductivity. The response of the sensor to H2S gas showed a high sensitivity to gas concentrations in the range 0.5 – 100 ppm, with a fast response time of less than one minute under ambient room conditions.

ZnO-CuO Hollow Nanocages Derived from Metal–Organic Frameworks for Selective H2S Sensing

Metal–organic frameworks (MOFs) are considered potential materials in the gas sensor field because of their extremely porous, adjustable characteristics and high surface area. In this paper, based on a ZIF-8 precursor, ZnO-CuO hollow nanocage heterostructure materials were successfully fabricated by a multistep method, and the prepared ZnO-CuO sensor exhibited excellent respond to H2S. We found that when the mass ratio of CuO reaches 1 wt %, the response to 10 ppm hydrogen sulfide (H2S) was as high as 70, and the recovery time was 55 s at a low temperature of 115 °C. Such a ZnO-CuO sensor has a highly selective response to H2S gas. In addition, the lower detection limit can reach 200 ppb. Furthermore, the gas sensors also had high consistency and repeatability. Gas sensing mechanism studies have shown that the special nanocage structure with larger specific surface area helps to increase gas adsorption and diffusion on the surface of sensing materials, and the formation of p–n heterostructures by the introduction of CuO improves the sensitive and selective response to H2S. This work will improve the practical application of H2S gas sensors for their simple preparation method and research into the response mechanism.

Humidity-activated H2S sensor based on SnSe2/WO3 composite for evaluating the spoilage of eggs at room temperature

Hydrogen sulfide (H2S), as a representative food spoilage gas produced by the breakdown of sulfur-containing proteins, is highly irritant and toxic. Designing gas sensors sensitive to H2S for food spoilage evaluation is of great significance for automated quality control in the modern food industry. However, humidity in the environment can generally deteriorate the detection performance of conventional metal oxide semiconductor gas sensors. Therefore, it is critical to develop H2S sensors based on novel materials that can operate effectively in atmospheric humidity conditions. In this work, tin diselenide (SnSe2) nanosheets decorated with tungsten trioxide (WO3) nanoparticles are synthesized by a one-step ultrasound strategy, and used as sensing layers for H2S gas sensors. The water molecule activated charge-transfer of the SnSe2/WO3 composite boosts H2S sensing ability at high relative humidity (RH) levels. At room temperature (25 °C), the SnSe2/WO3 composite sensor with optimal mass ratio exhibits enhanced H2S response value (33.80%@10 ppm) compared with that of the pristine SnSe2 sensor (14.29%@10 ppm) at 82% RH. In addition, the fabricated sensor is proven to be practically effective for evaluating the spoilage of eggs by comparing the sensing response of a fresh egg with that of a spoiled egg. This study offers possibilities for evaluating the spoilage of foods in poultry, aquatic, and food processing industries using a rapid and sensitive humidity-activated H2S gas sensor.

Facile Fabrication of ZnO-ZnFe2O4 Hollow Nanostructure by a One-Needle Syringe Electrospinning Method for a High-Selective H2S Gas Sensor.

Herein, a facile fabrication process of ZnO-ZnFe2O4 hollow nanofibers through one-needle syringe electrospinning and the following calcination process is presented. The various compositions of the ZnO-ZnFe2O4 nanofibers are simply created by controlling the metal precursor ratios of Zn and Fe. Moreover, the different diffusion rates of the metal oxides and metal precursors generate a hollow nanostructure during calcination. The hollow structure of the ZnO-ZnFe2O4 enables an enlarged surface area and increased gas sensing sites. In addition, the interface of ZnO and ZnFe2O4 forms a p-n junction to improve gas response and to lower operation temperature. The optimized ZnO-ZnFe2O4 has shown good H2S gas sensing properties of 84.5 (S = Ra/Rg) at 10 ppm at 250 °C with excellent selectivity. This study shows the good potential of p-n junction ZnO-ZnFe2O4 on H2S detection and affords a promising sensor design for a high-performance gas sensor.

Bimetallic Aupt Alloy Nanoparticles Decorated on Zno Nanowires Towards Efficient and Selective H2s Gas Sensing

Bimetallic Aupt Alloy Nanoparticles Decorated on Zno Nanowires Towards Efficient and Selective H2s Gas Sensing

Binder-Free Ceo2 Coated/Pd-Decorated Cuxo Nanowires Based on Cu Foam for Humidity-Independent Enhanced H2s Gas Sensing

Binder-Free Ceo2 Coated/Pd-Decorated Cuxo Nanowires Based on Cu Foam for Humidity-Independent Enhanced H2s Gas Sensing

Enhanced Room Temperature H2s Gas Sensing Performance of Vo2(A) Nanowires by Aspect Ratio

Enhanced Room Temperature H2s Gas Sensing Performance of Vo2(A) Nanowires by Aspect Ratio

Room Temperature H2s Gas Sensing Performance of Vo2(A) Nanowires with High Aspect Ratio

Room Temperature H2s Gas Sensing Performance of Vo2(A) Nanowires with High Aspect Ratio

Hexagonal Annular-Nio Nanoarchitecture with Local P-N Homojunctions: Novel Formation Mechanism and H2s Gas Sensing Properties

Hexagonal Annular-Nio Nanoarchitecture with Local P-N Homojunctions: Novel Formation Mechanism and H2s Gas Sensing Properties

Sub-Ppb Mixed Potential H2s Gas Sensor Based on Ysz and Newtype Sensing Electrode Nd2ao4 (A=Cu, Ba and Ni)

Sub-Ppb Mixed Potential H2s Gas Sensor Based on Ysz and Newtype Sensing Electrode Nd2ao4 (A=Cu, Ba and Ni)

Computational design and molecular modeling of the interaction of nicotinic acid hydrazide nickel-based complexes with H2S gas.

The application of nickel complexes of nicotinic acid hydrazide ligand as a potential gas-sensor and adsorbent material for H2S gas was examined using appropriate density functional theory (DFT) calculations with the ωB97XD/Gen/6-311++G(d,p)/LanL2DZ method. The FT-IR spectrum of the synthesized ligand exhibited a medium band at 3178 cm-1 attributed to ν(NH) stretching vibrations and strong bands at 1657 and 1600 cm-1 corresponding to the presence of ν(C[double bond, length as m-dash]O) and ν(C[double bond, length as m-dash]N) vibration modes. In the spectrum of the nickel(ii) complex, the ν(C[double bond, length as m-dash]O) and ν(C[double bond, length as m-dash]N) vibration bands experience negative shifts to 1605 cm-1 and 1580 cm-1, respectively, compared to the ligand. This indicates the coordination of the carbonyl oxygen and the azomethine nitrogen atoms to the Ni2+ ion. Thus, the sensing mechanism of the complexes indicated a short recovery time and that the work function value increases for all complexes, necessitating an excellent H2S gas sensor material. Thus, a profound assertion was given that the complex sensor surfaces exhibited very dense stability with regards to their relevant binding energies corresponding to various existing studies.

H2s Gas Sensor Based on Biodegradable-Electroactive Polyurethane-Urea and Activated Carbon Composite Derived from Coconut Shell Waste

H2s Gas Sensor Based on Biodegradable-Electroactive Polyurethane-Urea and Activated Carbon Composite Derived from Coconut Shell Waste

AZO-Based ZnO Nanosheet MEMS Sensor with Different Al Concentrations for Enhanced H2S Gas Sensing.

The properties of H2S gas sensing were investigated using a ZnO nanostructure prepared with AZO (zinc oxide with aluminium) and Al surfaces which were developed on a MEMS (Micro Electromechanical System) device. Hydrothermal synthesis was implemented for the deposition of the ZnO nanostructure. To find the optimal conditions for H2S gas sensing, different ZnO growth times and different temperatures were considered and tested, and the results were analysed. At 250 °C and 90 min growth time, a ZnO sensor prepared with AZO and 40 nm Al recorded an 8.5% H2S gas-sensing response at a 200 ppb gas concentration and a 14% sensing response at a gas concentration of 1000 ppb. The dominant sensing response provided the optimal conditions for the ZnO sensor, which were 250 °C temperature and 90 min growth time. Gas sensor selectivity was tested with five different gases (CO, SO2, NO2, NH3 and H2S) and the sensor showed great selectivity towards H2S gas.

Highly sensitive fiber-optic SPR sensor with surface coated TiO2/MWCNT composite film for hydrogen sulfide gas detection

Hydrogen sulfide (H2S) gas has a severe effect on the respiratory system of the human body and ambient environment, necessitating development of on-line H2S gas sensors with high performance for safety and health concerns. Here, we proposed a fiber-optic surface plasmon resonance sensor for H2S detection employing TiO2 nanoparticles and multilayer carbon nanotubes composite (TiO2/MWCNT) as sensing film, featuring desirable advantages of high sensitivity, selectivity, and real-time detection. Benefiting from special structure and large specific surface area of MWCNTs, the adsorption capacity of sensing surface to gas molecules can be significantly enhanced. Moreover, the high carrier mobility of MWCNTs can further promote the charge transfer between TiO2 and H2S. These unique features of TiO2/MWCNT composite film result in an obvious improvement of sensitivity for H2S detection. Experimental results show that the maximum sensitivity of 21.76 pm ppm−1 (picometer/part-per-million) and detection limit of 0.2 ppm can be obtained by appropriately optimizing the componential constitutions of TiO2/MWCNT composite. Such detection limit is strikingly lower than the threshold concentrations in workplace set by Federal Institute for Occupational Safety (10 ppm). In addition, the favorable selectivity, response/recovery times, repeatability and stability were demonstrated as well. This facile and cost-effective work provides a novel strategy for constructing high performance H2S gas sensor with fast response and real-time detection, which has prospective application in the fields of human health and environmental conservation.