Liquefied Petroleum Gas Sensor Research Articles

Optical fiber liquefied petroleum gas sensor based on the fluorescence quenching of CdSe quantum dot

Abstract A flameproof optical fiber liquefied petroleum gas sensor was designed and fabricated. Bare-core CdSe and CdSe@ZnSeS@ZnS@CdZnS were modified with pentafluorobenzoic acid (FBA) and encapsulated in PMMA as fluorescent probes for liquefied petroleum gas, enhancing the quantum dots’ response to liquefied petroleum gas detection. Both materials exhibited significant fluorescence quenching in the presence of liquefied petroleum gas, with the Stern-Volmer plot showing a good linear relationship with the gas. A detection optical path was designed, and the relationship between fluorescence intensity and gas concentration was fitted with an expression with a sensitivity of 0.081 (I0/I100-1), enabling real-time detection of liquefied petroleum gas.

Ultra-sensitive liquefied petroleum gas (LPG) sensor based on monometallic Ag nanospheres synthesized via microwave-assisted facile approach

We present the synthesis, analysis, and utility of polyvinylpyrrolidone (PVP) stabilized monometallic silver nanospheres for liquefied petroleum gas sensing at room temperature. We have synthesised silver nanospheres (Ag-NSs) in the diameter range of 13–21 nm using a microwave assisted method, which is both easy and fast, because microwave irradiation only takes 30 s. A solution of 0.1 M silver nitrate (AgNO3) in an ethanolic medium was microwave-irradiated to produce Ag-NSs. PVP was used as a stabilising agent throughout the process. Spin coating method was used to produce thin films of synthesised monometallic Ag-NSs. X-ray diffraction (XRD), scanning electron microscopy (SEM), acoustic particle sizer (APS), UV–visible absorption (UV–visible) and Fourier Transform Infrared (FT-IR) spectroscopy were used for characterising Ag-NSs. Based on the acoustic attenuation of the prepared sample, the acoustic particle sizer estimated the diameter of Ag-NSs to be around 17 nm. The deposited films were examined for LPG leakage detection at ambient temperature. This is the first report on monometallic Ag-NSs for leakage detection of LPG at room temperature operation below its lower explosive limit (LEL). The significant finding of the developed sensor is that it prompts the quick response (∼16 s) and recovery (∼64 s) as Ag enhances the reaction rate between the sensing film surface and adsorbed LPG, thereby, augments the sensitivity of sensor even below LEL. Moreover, the fabricated LPG sensor shows noteworthy reproducibility (measured up to six cycles) and stability up to 06 months after fabrication.

Influence of reduced graphene oxide layer on sensing characteristics of Co3O4/rGO nanocomposite towards Liquefied Petroleum Gas (LPG)

Liquefied petroleum gas (LPG), a mixture of different hydrocarbons, is a highly inflammable and explosive gas that is harmful to the environment and human health. Thus, it is imperative to fabricate LPG sensors with higher sensitivity, selectivity, stability, and minimal power consumption, functioning at low temperatures. The current study reports on the monitoring and detection of LPG at low functional temperatures using Co3O4-loaded on rGO (rGO-Co) prepared using the hydrothermal method. The microstructural properties of the materials were investigated in detail. The rGO-Co (80 wt%) sensor showed outstanding sensitivity (0.00364 ppm−1) and selectivity toward LPG, as well as a limit of detection of 1 ppm at a temperature of 125 °C. The sensing mechanism showed that an even distribution of Co3O4 throughout the rGO layers, serving as efficient sites for the adsorption and desorption of LPG molecules, was associated with enhanced gas-sensing capabilities. Furthermore, the response to LPG detection was significantly influenced by the combination of the finite spherical nanoparticles with increased pore sizes between them and reduced energy band gaps. Thus, the novel improvement of the sensor towards LPG detection was linked to the ohmic connection formed between rGO and Co3O4 forming a p-p heterojunction at the interface. Additionally, the coupling of Co-O-C bonds validated by high-temperature X-ray diffraction and X-ray photoelectron spectroscopy provided extra active sites from Co3+ for effective LPG adsorption. The sensing mechanism induced by the loading of Co3O4 on the rGO surface was also deliberated.

Role of Surfactant in Polyaniline/Polypyrrole Heterojunction for Liquefied Petroleum Gas Sensor Application

Role of Surfactant in Polyaniline/Polypyrrole Heterojunction for Liquefied Petroleum Gas Sensor Application

Green synthesized ZnO/NiO heterostructures based quick responsive LPG sensor for the detection of below LEL with DFT calculations

The current research work reports on the detection of liquefied petroleum gas (LPG) at room temperature. The ZnO/NiO heterostructure was synthesized via green method and characterized by various techniques. The surface morphological and structural analysis has been performed by scanning electron microscope, transmission electron microscope and X-ray diffractometer. The Rietveld refinement analysis confirmed the polycrystalline nature of ZnO/NiO and existing hexagonal (ZnO) and cubic (NiO) crystal structures. The optical properties were analyzed by UV–visible spectroscopy and optical band gap of ZnO, NiO and ZnO/NiO were found to be 3.62 eV, 3.81 eV and 3.71 eV respectively. The DFT analysis was performed by B3LYP/LAN2DZ basis set with the interaction from LPG of ZnO, NiO and ZnO/NiO composite for better understanding of the sensing characteristics of devices. The ZnO, NiO, and ZnO/NiO were investigated for the detection of the LPG from below lower explosion limit (LEL) i.e. 0.5 vol% to 2.5 vol%. Sensor response of ZnO/NiO heterostructure-based sensor was found 7.72 at 2.5 vol% which is 2.6 times higher than pure ZnO and NiO. The fast response and recovery times of ZnO/NiO were found to 7.83 s and 11.01 s, respectively at 0.5 vol% LPG. Also, the ZnO/NiO is highly selective for LPG in comparison to other analytes like ethanol, acetone, ammonia, and CO2 etc. Thus ZnO/NiO heterostructures can be effectively used for the detection of LPG at room temperature against below LEL.

Role of Surfactant in Polyaniline/Polypyrrole Heterojunction for Liquefied Petroleum Gas Sensor Application

Role of Surfactant in Polyaniline/Polypyrrole Heterojunction for Liquefied Petroleum Gas Sensor Application

Liquefied petroleum gas (LPG) sensing of biphasic Cu6Sn5:SnO2 nanocomposite thin-films

This study reports the fabrication of a novel biphasic LPG sensor operable at room temperature. The biphasic Cu6Sn5:SnO2 nanocomposite is synthesized in 2 mol% and 4 mol% molar ratios through a facile hydrothermal route and fabricated into thin films. The microstructural details of these films are determined by an X-ray diffractometer (XRD). These films are further characterized for their morphology, elemental composition, optical and electrical properties employing field emission scanning electron microscopy (FE-SEM), energy dispersive x-ray spectroscopy (EDS), Fourier transform infrared (FTIR) spectrum, UV–visible (UV–vis) spectrophotometer and four-probe technique respectively. Liquefied petroleum gas (LPG) sensing results of the nanocomposite thin films suggest enhanced sensitivity and quick response and recovery time of the Cu6Sn5 dominant nanocomposite (4 mol%) thin film at room temperature. Additionally, this particular film exhibits a better humidity and LPG sensing performance with a sensitivity of 269 MΩ/%RH and 280 MΩ/vol. % for 2.0 vol % of LPG at room temperature respectively. The improved humidity and LPG sensing of the Cu6Sn5 dominant phase nanocomposite sample may be due to the formation of crystalline structure.

Automatic LPG Sensing Device with Switching Off Mechanism

Abstract: As we know, security has been major issue in today’s scenario. Accidents are on increasing day by day. Here, we are talking about those accidents that are being occurred due to combustible gases, i.e., LPG, CNG. Frequently we hear, explosion in cylinder of household and vehicles. Several people have been injured and some got dead. So, we are making this project for security purpose that will detect combustible gases and alert candidates. Now a day’s, LPG Gas leakage detectors comes in the market with the LPG sensor that only senses any gas leakage and sends a SMS to the emergency no. provided to it and alerts the user via audio or visual indications while we are on a project in which we are using a stepper motor also in addition to the normal LPG Gas leakage detectors which helps in turning off the switch when there an emergency in our absence. One of the preventive methods to stop accidents associated with the gas leakage is to install a gas leakage detection kit at vulnerable places. The main purpose of this project is to achieve a successful working prototype that is capable to detect the presence of gas leakage, which in this case, the Liquefied Petroleum Gas (LPG). The device should also perform automatic response with the implementation of an alarm system and the emergency shut down valve once the leakage has occurred and detected. Keywords: MQ5 Sensor, buzzer, servo motor, spur gear, gas stove, leakage sensor, L324 AMPLIFIER, L239 DRIVE, potentiometer.

Improved room temperature liquefied petroleum gas sensing performance of Ni0.5Zn0.5Fe2O4@Cl–doped polypyrrole nanoweb

Ni0.5Zn0.5Fe2O4@Cl–doped polypyrrole (NZF@PPY) nanoweb type hybrid structure has been prepared using oxidation polymerization method at room temperature. The resultant material is extremely porous and uniform possessing a web-like structure. The liquefied petroleum gas (LPG) sensing film was prepared using a spin coater and characterized with the help of several techniques in order to investigate different properties of the material like, surface morphology, temperature dependence, chemical bondings, optical bandgap, crystallinity etc. The nanohybrid is examined thoroughly for LPG sensing and the outcomes are compared with the results received using only the core material (Ni0.5Zn0.5Fe2O4). It was found that the highly porous, weblike NZF@PPY nanohybrid works as an excellent, ultrafast LPG sensor, showing a minimum response time of 5 sec only at 0.5 vol% LPG exposure. The nanohybrid is found to be 66.21% more sensitive towards LPG than its core counterpart.

Statistical analysis of Sr substituted NiFe2O4 thin films for liquefied petroleum gas sensor applications

In this work, the synthesis of SrxNi(1−x)Fe2O4 thin films and their performance in the detection of Liquefied Petroleum Gas (LPG) are presented. These films were synthesized through a combination of Sol-Gel and Spin-Coating techniques and their LPG gas sensing response was analyzed using a 32 × 23 complete factorial design of experiments with 4 central points. The factors used in the design of experiments were Sr percentage, LPG concentration, heat treatment temperature, number of spin coated layers and testing temperature; sensor response was the main response variable. The morphological and structural properties of the coatings were characterized by Atomic Force Microscopy, Scanning Electron Microscopy and X-ray Diffraction. For the synthesis conditions evaluated, the films presented a spinel structure, and their grain size was found to vary between 20 and 50 nm. Their surface roughness (Sa) was found to be between 0.2 and 2.7 nm. The films were strongly affected by the heat treatment temperature, with higher temperatures leading to higher levels of crystallinity and larger grain size. For the experimental conditions considered in this work, films with one spin coated layer, 20% Sr and treatment at 650 °C showed the best performance in terms of response (28%) against 2000 ppm of LPG. In general, a low heat treatment temperature and a high concentration of Sr led to lower LPG sensing capabilities of the films.

A platinum-doped ZnO-based LPG sensor with high sensitivity

In environment air quality monitoring, toxic and flammable gas detection plays an important role. Due to the extreme concern for safety standards in industrial and residential applications, real-time observation of toxic gas and notification of inadvertent leaks is necessary. This paper delves into a simple and cost-effective way for fabricating extremely sensitive zinc oxide (ZnO) thin film gas sensors for the detection of Liquefied Petroleum Gas (LPG) at low concentrations. Sol-gel method is used to fabricate the ZnO thin films. Platinum (Pt) nanoparticles have been placed on the semiconducting material to behave as catalysts in order to enhance sensing performance. The platinum doping is done via the RF Sputtering technique. For different concentration of LPG, the variation in electrical resistance of a semiconductor material was evaluated. Sensor characterization was carried out using XRD, and FESEM. ZnO thin films are optimized at different thickness varying from 70 nm to 550 nm. Then annealing of thin films of ZnO is carried out at temperatures range from 450 °C to 675 °C. LPG shows a maximum response for thin film of 170 nm annealed at 625 °C, at operating temperature of 150 °C, for 1000 ppm concentration. Sensing response for ZnO thin film has been enhanced to 2.586 post doping which was 1.896 for annealed bare ZnO thin film. Comparing to bare ZnO thin films, there had been a significant improvement in sensor response with platinum doped ZnO thin films.

Few layer graphene/silver nanocomposite based flexible and resistive liquefied petroleum gas sensor

Few layer graphene/silver nanocomposite based flexible and resistive liquefied petroleum gas sensor

Battery-operated resistive sensor based on electrochemically exfoliated pencil graphite core for room temperature detection of LPG

The present paper illustrates a description on material synthesis, sensor fabrication and electronic prototyping of a cost effective, reusable, stable and highly sensitive and selective device for the sensing and quantification of trace concentrations of liquefied petroleum gas (LPG) in ambient conditions. Conductive colloidal solution of graphene synthesized via electrochemical exfoliation of 9B pencil graphite core was used for sensing LPG at ppm levels in air. In comparison to other metal oxide semiconducting (MOS) materials, electrochemically exfoliated graphene is very well recognized owing to its very economic prices and abundant availability of its raw material i.e. graphite, ease of fabrication and simple modification techniques. A self-assembled network of exfoliated graphene successfully fabricated on flexible polymer substrate exhibited appreciably high sensitivity to inflammable LPG. The principal of operation of the present resistive LPG sensor relies on the variation in the electrical resistance of the self-embedded exfoliated graphene network on its exposure to the gaseous analyte i.e. LPG in a two-pole format. The degree of variation in electrical resistance of the sensitive film depends on the concentration of the LPG to which it is exposed. On the basis of this fact qualitative as well as quantitative detection of the LPG with sensor response of 24.5 % and response time of 18 s at sensing limit as low as 50 parts-per-million (ppm) is achieved. Experimental investigations unveiled a competent LPG sensor which can sense and compute LPG leakage with prolonged high constancy and reproducibility.

Effect of annealing temperature on a highly sensitive nickel oxide-based LPG sensor operated at room temperature

In the present work, nanostructured nickel oxide (NiO) powder has been synthesized using the sol–gel method and is annealed at different temperatures to study the impact of annealing temperature on its structural, optical, morphological, and LPG sensing properties. The obtained powder was analyzed by several characterization techniques such as field-emission scanning electron microscopy (FESEM), X-ray diffraction (XRD), UV–Visible spectroscopy (UV–Vis), particle analyzer, and Fourier-transform infrared spectroscopy. XRD patterns show that NiO nanoparticles have a cubic unit cell structure. The average crystallite size for each of the samples was calculated to be 27–77 nm using the Debye–Scherrer formula and Williamson-Hall uniform deformation model plot. FESEM images revealed the mesoporous morphology of prepared NiO nanoparticles and found that the particle size increases with an increase in annealing temperature. The UV–Vis absorption spectrum shows that the energy band gap decreases with an increase in annealing temperature for NiO nanoparticles. Liquefied petroleum gas (LPG) sensing properties of the prepared pellets were also examined at room temperature (300 K) in the range of 0.5–2.0 vol% concentration of LPG. The gas sensing response of the NiO:500 sample is 244.4% which is the highest among all the samples due to the combined effect of nanocrystal defects and specific surface area. The sensing response of the synthesized material increased significantly as the concentration of the test gas rose.

Structural, optical and LPG sensing properties of zinc-doped nickel oxide pellets operated at room temperature

Liquefied Petroleum Gas (LPG) sensing properties of pure and zinc-doped nickel oxide nanoparticles (Ni1-xZnxO; where x = 0.00, 0.01, 0.02 and 0.03) in the form of pellets along with synthesis and characterization have been reported in this paper. Several characterization studies such as Field emission scanning electron microscopy (FESEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), Elemental dispersive X-ray analysis (EDX), Ultraviolet–visible absorption analysis (UV–vis), particle analyzer and four-probe setup were used to study morphological, elemental, structural, optical and electrical properties of the synthesized NiO powder. XRD results reveal that the nickel oxide (NiO) nanoparticles having an average crystallite size in a range of 30−43 nm are formed. FESEM images show that the prepared material is porous and has spherical-shaped morphology. The characterization results indicate that the synthesized zinc-doped nickel oxide is a promising material for the LPG sensor. The pellets of pure and zinc-doped nickel oxide nanoparticles were bring under the exposure of LPG and variation in resistance was recorded with respect to time at various concentrations of gas (0.5–2.0 vol%). NiO doped with 2 mol% Zn has the maximum sensor response of 5.33 % for 2 vol% of LPG along with recovery and response time of 31 s and 42 s respectively. The optimized properties of NiO nanoparticles in terms of structure and morphology for LPG sensing application by modifying preparatory conditions, is the novel approach in this work.

Studying the Effect of Seed-layers of Zinc Oxide Nanostructured Thin Film for Liquefied Petroleum Gas Sensor Application

Gas sensors are devices that can convert the concentration of an analyte gas into an electronic signal. Zinc oxide (ZnO) is one of the most important n-type metal oxide semiconductor which has been utilized as gas sensor for many years. In this work, ZnO nanostructured films were synthesized by a hydrothermal growth from ZnO seeds and used as a liquefied petroleum gas (LPG) sensor. At first ZnO seed layers were deposited on glass substrates by using spin coating method, then ZnO nanostructured were grown on these substrates by using hydrothermal growth method. The effect of seed layers of ZnO nanostructured on its structural, optical, and electrical properties was studied. These nanostructures were characterized by scanning electron microscopy, X-ray diffraction, optical spectroscopy, and sheet resistance measurement unit. The sensing performances of the synthetic ZnO nanostructures were investigated for LPG. XRD showed that all the ZnO nanostructures were hexagonal crystal structure. ZnO nanostructured thin film showed high sensitivity towards LPG gas. The sensitivity of the film is observed to increase with increase in number of seed layers. The sensitivity of the film was investigated by measured change in sheet resistance under with LPG gas.

Highly sensitive room temperature liquefied petroleum gas sensor based on CoSnO2 nanoislands deposited graphene layers

In this present work, an effective Liquefied Petroleum Gas (LPG) detecting nanocomposite of r-GO-CoSnO2 operable at room temperature was exhibited. Nanoparticles of Cobalt (Co) doped Tin Oxide (SnO2) nanoparticles were decorated uniformly over the reduced graphene oxide (rGO) layers. Reduction of graphene oxide (GO) into rGO and combination of metal oxide decoration was synthesized by one step using cost effective hydrothermal method using reductant hydrazine hydrate. Nanoparticles of CoSnO2 were self assembled over rGO via high pressure built inside the Teflon autoclave chamber. Structural and surface morphological characterizations confirmed the structure, size and shape of the prepared materials with distinct properties which are essential for a reliable sensing device. Distribution of metal oxide throughout the graphene layers act as an active site for the LPG molecules adsorption and desorption processes. For selectivity various analyte gases such as Hydrogen, Oxygen and Ammonia were examined. The proposed unique nanocomposite has exhibits low level detection of 2 ppm with quick response time of 4 s and recovery time of 5 s at room temperature. From these results it suggests that the proposed material will be a promising potential candidate for the fabrication of LPG sensor devices.

Sm2O3 rice-like nanorods decorated on rGO flexible resistive sensor for room temperature LPG detection

Flexible electrochemical sensors have gained huge attention over their significant properties and the probability of applying to any wearable electronic devices. LPG traces in definite concentrations leads to a fire accident, adverse health effects, and even causes death. The current study focuses on a flexible, room temperature LPG sensor based on Sm2O3/rGO hybrid nanocomposite with different loading factors (1, 3, and 5 wt%) coated on flexible polyethylene terephthalate (PET) substrate working electrodes. Eggshell membrane (ESM) template constituents are acts as a reducing agent during the hydrothermal synthesis of Sm2O3 nanorods. Flexible Sm2O3/rGO hybrid Chemiresistive gas sensor was tested for various gas sensing parameters. The decoration of Sm2O3 nanorods on 3 wt% rGO sheets exhibited good selectivity to liquefied petroleum gas (LPG) at room temperature gives a response of 116% at 700 ppm of LPG with a short response, recovery time and gained 99% response after bending with 94.5% stability of the sensor.

Electronic and Simple Oscillatory Conduction in Ferrite Gas Sensors: Gas-Sensing Mechanisms, Long-Term Gas Monitoring, Heat Transfer, and Other Anomalies.

The early detection and warning of the presence of hazardous gases have been well studied. We present a study that focuses on some fundamental properties of gas sensors for liquefied petroleum gas (LPG) using spinel nanoferrites, namely, CoSm0.1Fe1.9O4, CoCe0.1Fe1.9O4, MgCe0.1Fe1.9O4, and MgFe2O4. A highly sensitive and selective response of 846.34 at 225 °C toward 10,000 ppm concentration of LPG was recorded. Other flammable gases tested were hydrogen, methane, propane, and butane. Electronic conduction of LPG sensors near saturation showed simple electrical oscillations that can be attributed to the self-dissociation of water molecules physically adsorbed on the surface of the chemisorbed oxygen species due to proton transfer. The oscillatory behaviors follow fluctuations in the operating temperature attributed to heat transfer between the physisorbed water molecules and the hot sensor surface. This depends on the LPG concentration because higher LPG concentration gives rise to greater heat transfer from the sensors. The adsorption and desorption of these water molecule multilayers take a few hundreds of seconds at low concentrations, while the adsorption formation process takes longer at higher concentrations. Other parameters such as LPG exposure time, bias voltage, relative humidity, ambient conditions, operating temperatures, and temperature of the gas not only affect electrical oscillations and thermal fluctuations but also switch the dominant charge carriers from p- to n-type or vice versa. The type of sensor surface, either p- or n-type, did not appear to affect the oscillatory behavior, while the exposure time, short or long, determined the appearance and further behavior of the oscillations. The long-time exposure to 10,000 ppm concentration resulted in the resistance gradually decreasing due to the lack of oxygen supply, while at 5000 ppm, this was constant, stable, and oscillated indefinitely. Changing the dry air to argon gas as a carrier and for dilution of the hazardous gas prevented the electrical oscillations and thermal fluctuations and significantly lowered the response values. Both the inert ambient (argon gas) and changing operating temperature flipped the dominant charge carriers of these sensors. The concentration of these chemisorbed oxygen species governs the charge space and depletion layers. In addition, the spinel nanoferrites used contained higher oxygen vacancies than the lattice oxygen and chemisorbed oxygen. When using dry air, the oscillations were observed at 3000 ppm concentration, while using argon gas, they were observed at 7000 ppm concentration. The room-temperature LPG responses were about 35 and 80 under 45% relative humidity using dry air and argon gas, respectively. These room-temperature measurements showed electrical oscillations but did not show any thermal fluctuations or heat transfer phenomena. This study presents a deeper insight into the fundamentals of gas-sensing mechanisms and energy costs involved.

SILAR deposited nanocrystalline ZnO films as LPG sensor

Abstract A facile successive ionic layer adsorption and reaction (SILAR) method is used for the deposition of nanocrystalline zinc oxide (ZnO) thin films. The XRD pattern shows ZnO films are polycrystalline in nature with wurtzite crystal structure. The surface morphology reveals ZnO nanograins embedded conical morphology, which shows hydrophobic behavior. The Liquefied Petroleum Gas (LPG) sensing properties of nanocrystalline ZnO films are investigated. The nanograined ZnO thin film shows maximum gas response of 20% at 673 K upon exposure to 5200 ppm of LPG.