As a novel chemical marker,methanol has been widely applied to evaluate the ageing state of insulating paper in recent years.Methanol gas sensor(MGS)could be applied to detect the methanol content in transformer oil f...As a novel chemical marker,methanol has been widely applied to evaluate the ageing state of insulating paper in recent years.Methanol gas sensor(MGS)could be applied to detect the methanol content in transformer oil for its high portability and stability.However,it has the defects of a high limit of detection(LOD)and poor anti-interference performance.Therefore,a novel method of detecting methanol in transformer oil based on MGS with the solid-phase extraction(SPE)technology was investigated in this paper.A detection platform for methanol in transformer oil based on SPE was established,and the SPE experimental process and the crucial parameters were optimised.The results show that the SPE decreased the LOD of MGS from 0.4 to 0.2 ppm and effectively eliminated the interfering substances in oil.Although a part of methanol would be lost during the SPE process,the regression correction coefficient was proposed to correct the evaluation errors.The results indicate that the average relative errors decreased from 17.09%to 4.38%,and the proposed method has good applicability.展开更多
Gas sensor is an indispensable part of modern society withwide applications in environmental monitoring,healthcare,food industry,public safety,etc.With the development of sensor technology,wireless communication,smart...Gas sensor is an indispensable part of modern society withwide applications in environmental monitoring,healthcare,food industry,public safety,etc.With the development of sensor technology,wireless communication,smart monitoring terminal,cloud storage/computing technology,and artificial intelligence,smart gas sensors represent the future of gassensing due to their merits of real-time multifunctional monitoring,earlywarning function,and intelligent and automated feature.Various electronicand optoelectronic gas sensors have been developed for high-performancesmart gas analysis.With the development of smart terminals and the maturityof integrated technology,flexible and wearable gas sensors play an increasingrole in gas analysis.This review highlights recent advances of smart gassensors in diverse applications.The structural components and fundamentalprinciples of electronic and optoelectronic gas sensors are described,andflexible and wearable gas sensor devices are highlighted.Moreover,sensorarray with artificial intelligence algorithms and smart gas sensors in“Internet of Things”paradigm are introduced.Finally,the challengesand perspectives of smart gas sensors are discussed regarding the future need of gas sensors for smart city and healthy living.展开更多
This study systemmatically investigated the effects of solid content and dispersant content on the physicochemical properties of ZnO-SnO_(2) composite ink.The experimental results show that even with the use of low-mo...This study systemmatically investigated the effects of solid content and dispersant content on the physicochemical properties of ZnO-SnO_(2) composite ink.The experimental results show that even with the use of low-molecular-weight PEG400 dispersant,gas-sensitive ink with high solid content and good suspension stability can be obtained,which is advantageous for low-temperature film formation and can effectively prevent property changes and film crack of high-temperature-sintering-induced material.Under this condition,the ink at a 15wt%solid content and 2wt%-10wt%PEG400 has good film-forming ability and high adhesion strength on the micro-electromechanical system(MEMS)micro-hotplates.Especially,the MEMS sensor printed using the ink of 6wt%PEG400 shows highest sensitivity,favorable impact resistance,thermal shock resistance,and up to 8 years of service life.展开更多
The integration of dual-mesoporous structures,the construction of heterojunctions,and the incorporation of highly concentrated oxygen vacancies are pivotal for advancing metal oxide-based gas sensors.Nonetheless,achie...The integration of dual-mesoporous structures,the construction of heterojunctions,and the incorporation of highly concentrated oxygen vacancies are pivotal for advancing metal oxide-based gas sensors.Nonetheless,achieving an optimal design that simultaneously combines mesoporous structures,precise heterojunction modulation,and controlled oxygen vacancies through a one-step process remains challenging.This study proposes an innovative method for fabricating zinc stannate semiconductors featuring dual-mesoporous structures and tunable oxygen vacancies via a direct solution precursor plasma spray technique.As a proof of concept,the resulting zinc stannate-based coatings are applied to detect 2-undecanone,a key biomarker for rice aging.Remarkably,the zinc oxide/zinc stannate heterojunctions with a well-defined secondary pore structure exhibit exceptional gas-sensing performance for 2-undecanone at room temperature.Furthermore,practical experiments indicate that the developed sensor effectively identifies adulteration in various rice varieties.These results underscore the potential of this method for designing metal oxides with tailored properties for high-performance gas sensors.The enhanced adsorption capacity and dual-mesoporous features of this semiconductor make it a promising candidate for sensing applications in agricultural food safety inspections.展开更多
Thermal runaway(TR)in lithium-ion batteries(LIBs)poses significant safety risks due to its potential to trigger fires and explosions.Early warning of battery TR through gas sensing has emerged as a promising strategy ...Thermal runaway(TR)in lithium-ion batteries(LIBs)poses significant safety risks due to its potential to trigger fires and explosions.Early warning of battery TR through gas sensing has emerged as a promising strategy for hazard mitigation.However,comprehensive reviews critically summarizing recent progress in advanced gas sensing technologies remain scarce.To fill this void,we present a critical review consolidating state-of-the-art advancements in gas sensing for TR early warning.This review first overviews the fundamentals of gas sensing for TR monitoring,encompassing thermodynamics and kinetic principles of gas evolution alongside current gas sensing technologies.We then comprehensively explored multi-scale engineering methods,spanning material innovations,device configurations,and system-level integration,with an emphasis on cutting-edge techniques like additive manufacturing and data-driven design frameworks.Future research priorities are identified,including the enhancement of gas selectivity and environmental robustness,the development of machine learning-driven intelligent gas sensing networks,and the establishment of standardized protocols for practical deployment.By integrating interdisciplinary insights derived from materials science,electrochemistry,and embedded systems engineering,this review is positioned to offer actionable guidelines for advancing scalable and reliable gas-sensing solutions toward boosted LIB safety.展开更多
In this work,we realized a room-temperature nitrogen dioxide(NO_(2))gas sensor based on a platinum(Pt)-loaded nanoporous gallium nitride(NP-GaN)sensing material using the thermal reduction method and coreduction with ...In this work,we realized a room-temperature nitrogen dioxide(NO_(2))gas sensor based on a platinum(Pt)-loaded nanoporous gallium nitride(NP-GaN)sensing material using the thermal reduction method and coreduction with the catalysis of polyols.The gas sensor gained excellent sensitivity to NO_(2) at a concentration range of 200 ppm to 100 ppb,benefiting from the loading of Pt nanoparticles,and exhibited a short response time(22 s)and recovery time(170 s)to 100 ppm of NO_(2) at room temperature with excellent selectivity to NO_(2) compared with other gases.This phenomenon was attributed to the spillover effect and the synergic electronic interaction with semiconductor materials of Pt,which not only provided more electrons for the adsorption of NO_(2) molecules but also occupied effective sites,causing poor sites for other gases.The low detection limit of Pt/NP-GaN was 100 ppb,and the gas sensor still had a fast response 70 d after fabrication.Besides,the gas-sensing mechanism of the gas sensor was further elaborated to determine the reason leading to its improved properties.The significant spillover impact and oxygen dissociation of Pt provided advantages to its synergic electronic interaction with semiconductor materials,leading to the improvement of the gas properties of gas sensors.展开更多
Graphene meshes(GMs)have attracted considerable attention as advanced materials for high-performance gas sensing due to their high-density active edge sites and excellent electronic properties.However,the contaminatio...Graphene meshes(GMs)have attracted considerable attention as advanced materials for high-performance gas sensing due to their high-density active edge sites and excellent electronic properties.However,the contamination-free preparation of GMs remains a challenge.Herein,we present a dewdrop-templated chemical vapor deposition approach to directly grow clean and intact graphene micromeshes(GMM)on SiO_(2)/Si substrates.The self-assembled micrometer-sized dewdrops from controlled water vapor condensation serve as a residue-free template for directing the growth of GMM with tunable hole sizes from submicrons to tens of microns.Density functional theory(DFT)calculations reveal that carbon species preferentially adsorb on pristine SiO_(2) regions to form a mesh structure.Contamination-free GMM gas sensors were fabricated using a simple transfer-free process,demonstrating a record-high sensitivity of 7.25%·ppm−1 and an ultra-low detection limit of 1.18 ppb for NO_(2) at room temperature.Complementary DFT studies elucidate that NO_(2) molecules adsorb more strongly on the edges of GMM,leading to a high response of the sensor.This work offers profound insights into dewdrop-templated graphene growth mechanisms and establishes a simple yet effective approach for fabricating high-performance transfer-free GMM sensors,thus paving the way for their practical applications in environmental monitoring and industrial safety fields.展开更多
Organic semiconductor materials have demonstrated extensive potential in the field of gas sensors due to the advantages including designable chemical structure,tunable physical and chemical properties.Through density ...Organic semiconductor materials have demonstrated extensive potential in the field of gas sensors due to the advantages including designable chemical structure,tunable physical and chemical properties.Through density functional theory(DFT)calculations,researchers can investigate gas sensing mechanisms,optimize,and predict the electronic structures and response characteristics of these materials,and thereby identify candidate materials with promising gas sensing applications for targeted design.This review concentrates on three primary applications of DFT technology in the realm of organic semiconductor-based gas sensors:(1)Investigating the sensing mechanisms by analyzing the interactions between gas molecules and sensing materials through DFT,(2)simulating the dynamic responses of gas molecules,which involves the behavior on the sensing interface using DFT combined with other computational methods to explore adsorption and diffusion processes,and(3)exploring and designing sensitive materials by employing DFT for screening and predicting chemical structures,thereby developing new sensing materials with exceptional performance.Furthermore,this review examines current research outcomes and anticipates the extensive application prospects of DFT technology in the domain of organic semiconductor-based gas sensors.These efforts are expected to provide valuable insights for further indepth exploration of DFT applications in sensor technology,thereby fostering significant advancements and innovations in the field.展开更多
A high-performance ammonia(NH3)sensor is prepared based on CeO_(2)/NiO composite,using a hydrothermal method.Experimental findings confirm that the CeO_(2)/NiO composite significantly enhances the performance of the N...A high-performance ammonia(NH3)sensor is prepared based on CeO_(2)/NiO composite,using a hydrothermal method.Experimental findings confirm that the CeO_(2)/NiO composite significantly enhances the performance of the NiO-based NH3 sensor.This improvement is primarily due to the increase in oxygen vacancies(Ov),chemically adsorbed oxygen(Oc),and the proportion of Ni3+on the surface of the CeO_(2)/NiO.The CeO_(2)/NiO sensor shows a high response to NH3,exhibiting response/recovery times of 1.8 s/0.9 s at the NH3 concentration of 5×10^(−6)mL/m^(3),with the theoretical lowest detection limit of 98.651×10^(−9)mL/m^(3).Additionally,the CeO_(2)/NiO sensor has been successfully applied in the simulated detection of Helicobacter pylori infection,highlighting its significant research value and potential application prospects in biomedical diagnostics.展开更多
A new silicon beam resonator design for a novel gas sensor based on simultaneous conductivity and mass change measurement is investigated. High selectivity and sensitivity in gas detection can be obtained by measuring...A new silicon beam resonator design for a novel gas sensor based on simultaneous conductivity and mass change measurement is investigated. High selectivity and sensitivity in gas detection can be obtained by measuring the charge-to-mass ratio of gas molecules. Structures of silicon beam resonators are designed, simulated, and optimized. This gas sensor is fabricated using sacrificial layer microelectronmechanical system technology, and the resonant frequency of the microbeam is measured.展开更多
Three-dimensional （3D） hierarchical Co3O4 microcrystal with radial dendritic morphologies was prepared through hydrothermal reactions followed by subsequent annealing treatment. Structural and morphological characte...Three-dimensional （3D） hierarchical Co3O4 microcrystal with radial dendritic morphologies was prepared through hydrothermal reactions followed by subsequent annealing treatment. Structural and morphological characterizations were performed by X-ray diffraction, scan-ning electron microscopy and transmission electron microscopy. The gas sensing properties of the as-obtained microcrystal were investigated at 110 oC, which revealed that the 3D hierarchical porous Co3O4 microcrystal exhibited high sensitivity to ammonia, as well as a short response time of 10 s. The response characteristic indicates that the sensor has a good stability and reversibility. Detections of toxic and flammable gases, such as ethanol, acetone and benzene were also carried out at a relative low temperature. The results indicate that such hierarchical Co3O4 microcrystal would be a potential material in the field of gas sensing.展开更多
In order to simplify the fabrication process,distribute the temperature uniformly and reduce the power consumption of the micro-hotplate（MHP） gas sensor,a planar-type gas sensor based on SnO2 thin film with suspende...In order to simplify the fabrication process,distribute the temperature uniformly and reduce the power consumption of the micro-hotplate（MHP） gas sensor,a planar-type gas sensor based on SnO2 thin film with suspended structure is designed through a MEMS process.Steady-state thermal analysis of the gas sensor and the closed membrane type sensor where the membrane overlaps the Si substrate is carried out with the finite element model,and it is shown that the suspended planar-type gas sensor has a more homogeneous temperature distribution and a lower power consumption.When the maximum temperature on the sensor reaches 383℃,the power consumption is only 7 mW,and the temperature gradient across the thin film is less than 14℃.To overcome the fragility of the suspended beams,a novel fabrication process in which the deposition of the gas sensing film occurs prior to the formation of suspended beams is proposed.The back side of the Si substrate is etched through deep reactive ion etching（DRIE） to avoid chemical pollution of the front side.The fabrication steps in which only four masks are used for the photolithography are described in detail.The Fe doped SnO2 thin film synthesized by sol-gel spin-coating is used as the gas sensing element.The device is tested on hydrogen and exhibits satisfactory sensing performance.The sensitivity increases with the rise of the concentration from 50×10-6 to 2000×10-6,and reaches about 30 at 2000×10-6.展开更多
In-system programmable devices are products that combined modern electronic techniques and semiconductor techniques.They are indispensable devices in designing modern circuits and systems.This paper presents two pract...In-system programmable devices are products that combined modern electronic techniques and semiconductor techniques.They are indispensable devices in designing modern circuits and systems.This paper presents two practical circuits designed with programmable devices and its design method.By introducing programmable devices into gas sensor circuits,we can further improve system reliability,stability,sensitivity and integration degree,and enhance flexibility of system design.展开更多
SnO2 nanofibers were synthesized by electrospinning and modified with Co3O4 via impregnation in this work. Chemical composition and morphology of the nanofibers were system- atically characterized, and their gas sensi...SnO2 nanofibers were synthesized by electrospinning and modified with Co3O4 via impregnation in this work. Chemical composition and morphology of the nanofibers were system- atically characterized, and their gas sensing properties were investigated. Results showed that Co3O4 modification significantly enhanced the sensing performance of SnO2 nanofibers to ethanol gas. For a sample with 1.2 mol% Co3O4, the response to 100 ppm ethanol was 38.0 at 300 ℃, about 6.7 times larger than that of SnO2 nanofibers. In addition, the response/recovery time was also greatly reduced. A power-law dependence of the sensor response on the ethanol concentration as well as excellent ethanol selectivity was observed for the Co3O4/SnO2 sensor. The enhanced ethanol sensing performance may be attributed to the formation of p-n heterojunctions between the two oxides.展开更多
Room-temperature gas sensors have aroused great attention in current gas sensor technology because of deemed demand of cheap,low power consumption and portable sensors for rapidly growing Internet of things applicatio...Room-temperature gas sensors have aroused great attention in current gas sensor technology because of deemed demand of cheap,low power consumption and portable sensors for rapidly growing Internet of things applications.As an important approach,light illumination has been exploited for room-temperature operation with improving gas sensor's attributes including sensitivity,speed and selectivity.This review provides an overview of the utilization of photoactivated nanomaterials in gas sensing field.First,recent advances in gas sensing of some exciting different nanostructures and hybrids of metal oxide semiconductors under light illumination are highlighted.Later,excellent gas sensing performance of emerging two-dimensional materialsbased sensors under light illumination is discussed in details with proposed gas sensing mechanism.Originated impressive features from the interaction of photons with sensing materials are elucidated in the context of modulating sensing characteristics.Finally,the review concludes with key and constructive insights into current and future perspectives in the light-activated nanomaterials for optoelectronic gas sensor applications.展开更多
With the rapid development of the Internet of Things,there is a great demand for portable gas sensors.Metal oxide semiconductors(MOS)are one of the most traditional and well-studied gas sensing materials and have been...With the rapid development of the Internet of Things,there is a great demand for portable gas sensors.Metal oxide semiconductors(MOS)are one of the most traditional and well-studied gas sensing materials and have been widely used to prepare various commercial gas sensors.However,it is limited by high operating temperature.The current research works are directed towards fabricating high-performance flexible room-temperature(FRT)gas sensors,which are effective in simplifying the structure of MOS-based sensors,reducing power consumption,and expanding the application of portable devices.This article presents the recent research progress of MOS-based FRT gas sensors in terms of sensing mechanism,performance,flexibility characteristics,and applications.This review comprehensively summarizes and discusses five types of MOS-based FRT gas sensors,including pristine MOS,noble metal nanoparticles modified MOS,organic polymers modified MOS,carbon-based materials(carbon nanotubes and graphene derivatives)modified MOS,and two-dimensional transition metal dichalcogenides materials modified MOS.The effect of light-illuminated to improve gas sensing performance is further discussed.Furthermore,the applications and future perspectives of FRT gas sensors are also discussed.展开更多
Nitrogen dioxide(NO2),a hazardous gas with acidic nature,is continuously being liberated in the atmosphere due to human activity.The NO2 sensors based on traditional materials have limitations of high-temperature requ...Nitrogen dioxide(NO2),a hazardous gas with acidic nature,is continuously being liberated in the atmosphere due to human activity.The NO2 sensors based on traditional materials have limitations of high-temperature requirements,slow recovery,and performance degradation under harsh environmental conditions.These limitations of traditional materials are forcing the scientific community to discover future alternative NO2 sensitive materials.Molybdenum disulfide(MoS2)has emerged as a potential candidate for developing next-generation NO2 gas sensors.MoS2 has a large surface area for NO2 molecules adsorption with controllable morphologies,facile integration with other materials and compatibility with internet of things(IoT)devices.The aim of this review is to provide a detailed overview of the fabrication of MoS2 chemiresistance sensors in terms of devices(resistor and transistor),layer thickness,morphology control,defect tailoring,heterostructure,metal nanoparticle doping,and through light illumination.Moreover,the experimental and theoretical aspects used in designing MoS2-based NO2 sensors are also discussed extensively.Finally,the review concludes the challenges and future perspectives to further enhance the gas-sensing performance of MoS2.Understanding and addressing these issues are expected to yield the development of highly reliable and industry standard chemiresistance NO2 gas sensors for environmental monitoring.展开更多
Highly sensitive gas sensors with remarkably low detection limits are attractive for diverse practical application fields including real-time environmental monitoring,exhaled breath diagnosis,and food freshness analys...Highly sensitive gas sensors with remarkably low detection limits are attractive for diverse practical application fields including real-time environmental monitoring,exhaled breath diagnosis,and food freshness analysis.Among various chemiresistive sensing materials,noble metal-decorated semiconducting metal oxides(SMOs)have currently aroused extensive attention by virtue of the unique electronic and catalytic properties of noble metals.This review highlights the research progress on the designs and applications of different noble metal-decorated SMOs with diverse nanostructures(e.g.,nanoparticles,nanowires,nanorods,nanosheets,nanoflowers,and microspheres)for high-performance gas sensors with higher response,faster response/recovery speed,lower operating temperature,and ultra-low detection limits.The key topics include Pt,Pd,Au,other noble metals(e.g.,Ag,Ru,and Rh.),and bimetals-decorated SMOs containing ZnO,SnO_(2),WO_(3),other SMOs(e.g.,In_(2)O_(3),Fe_(2)O_(3),and CuO),and heterostructured SMOs.In addition to conventional devices,the innovative applications like photo-assisted room temperature gas sensors and mechanically flexible smart wearable devices are also discussed.Moreover,the relevant mechanisms for the sensing performance improvement caused by noble metal decoration,including the electronic sensitization effect and the chemical sensitization effect,have also been summarized in detail.Finally,major challenges and future perspectives towards noble metal-decorated SMOs-based chemiresistive gas sensors are proposed.展开更多
This paper reports a high-performance H2S gas sensing material that is made of ZnO nanowires(NWs)modified by an optimal amount of ZnS to form nano-hete rojunctions.Compared with the intrinsic ZnONWs,the three differen...This paper reports a high-performance H2S gas sensing material that is made of ZnO nanowires(NWs)modified by an optimal amount of ZnS to form nano-hete rojunctions.Compared with the intrinsic ZnONWs,the three differently modified nano-heterostructure material ZnO-ZnS-x(x=5,10,15)shows significant improvement in sensing performance to H2S at the working temperatures of 100-400℃,especially in the low temperature range(<300℃).The chemiresistive sensor with ZnO-ZnS-10 sensingmaterial exhibits the largest response signal to H2S among all the other ZnO-ZnS-x(x=5,10,15,20)sensors.Its response signal to 5 ppm H2S at 150℃is about 2.7 times to that of the ZnO-NWs sensor.Besides,the ZnO-ZnS-10 sensor also features satisfactory selectivity and repeatability at 150℃.With the technical advantage attributed to the reduction of the redesigned band gap at the interface between ZnO and ZnS,the ZnO-ZnS hete ro structure sensor rather than the traditional ZnO-NWs sensor can be used for high-sensitivity application at low working temperature.展开更多
Real-time rapid detection of toxic gases at room temperature is particularly important for public health and environmental monitoring.Gas sensors based on conventional bulk materials often suffer from their poor surfa...Real-time rapid detection of toxic gases at room temperature is particularly important for public health and environmental monitoring.Gas sensors based on conventional bulk materials often suffer from their poor surface-sensitive sites,leading to a very low gas adsorption ability.Moreover,the charge transportation efficiency is usually inhibited by the low defect density of surface-sensitive area than that in the interior.In this work,a gas sensing structure model based on CuS quantum dots/Bi_(2)S_(3) nanosheets(CuS QDs/Bi_(2)S_(3) NSs)inspired by artificial neuron network is constructed.Simulation analysis by density functional calculation revealed that CuS QDs and Bi_(2)S_(3) NSs can be used as the main adsorption sites and charge transport pathways,respectively.Thus,the high-sensitivity sensing of NO_(2) can be realized by designing the artificial neuron-like sensor.The experimental results showed that the CuS QDs with a size of about 8 nm are highly adsorbable,which can enhance the NO_(2) sensitivity due to the rich sensitive sites and quantum size effect.The Bi_(2)S_(3) NSs can be used as a charge transfer network channel to achieve efficient charge collection and transmission.The neuron-like sensor that simulates biological smell shows a significantly enhanced response value(3.4),excellent responsiveness(18 s)and recovery rate(338 s),low theoretical detection limit of 78 ppb,and excellent selectivity for NO_(2).Furthermore,the developed wearable device can also realize the visual detection of NO2 through real-time signal changes.展开更多
基金supported by the State Grid Heilongjiang Electric Power Company Ltd.,Electric Power Research Institute Project(52243724000M)the China Postdoctoral Science Foundation(2020M670921)the National Natural Science Foundation of China(52307164).
文摘As a novel chemical marker,methanol has been widely applied to evaluate the ageing state of insulating paper in recent years.Methanol gas sensor(MGS)could be applied to detect the methanol content in transformer oil for its high portability and stability.However,it has the defects of a high limit of detection(LOD)and poor anti-interference performance.Therefore,a novel method of detecting methanol in transformer oil based on MGS with the solid-phase extraction(SPE)technology was investigated in this paper.A detection platform for methanol in transformer oil based on SPE was established,and the SPE experimental process and the crucial parameters were optimised.The results show that the SPE decreased the LOD of MGS from 0.4 to 0.2 ppm and effectively eliminated the interfering substances in oil.Although a part of methanol would be lost during the SPE process,the regression correction coefficient was proposed to correct the evaluation errors.The results indicate that the average relative errors decreased from 17.09%to 4.38%,and the proposed method has good applicability.
基金supported by the National Natural Science Foundation of China(No.22376159)the Fundamental Research Funds for the Central Universities.
文摘Gas sensor is an indispensable part of modern society withwide applications in environmental monitoring,healthcare,food industry,public safety,etc.With the development of sensor technology,wireless communication,smart monitoring terminal,cloud storage/computing technology,and artificial intelligence,smart gas sensors represent the future of gassensing due to their merits of real-time multifunctional monitoring,earlywarning function,and intelligent and automated feature.Various electronicand optoelectronic gas sensors have been developed for high-performancesmart gas analysis.With the development of smart terminals and the maturityof integrated technology,flexible and wearable gas sensors play an increasingrole in gas analysis.This review highlights recent advances of smart gassensors in diverse applications.The structural components and fundamentalprinciples of electronic and optoelectronic gas sensors are described,andflexible and wearable gas sensor devices are highlighted.Moreover,sensorarray with artificial intelligence algorithms and smart gas sensors in“Internet of Things”paradigm are introduced.Finally,the challengesand perspectives of smart gas sensors are discussed regarding the future need of gas sensors for smart city and healthy living.
基金Funded by the National Natural Science Foundation of China(No.62171331)the Hubei Provincial Natural Science Foundation of China(No.2020CFB188)the Sanya Science and Education Innovation Park of Wuhan University of Technology(No.2020KF0030)。
文摘This study systemmatically investigated the effects of solid content and dispersant content on the physicochemical properties of ZnO-SnO_(2) composite ink.The experimental results show that even with the use of low-molecular-weight PEG400 dispersant,gas-sensitive ink with high solid content and good suspension stability can be obtained,which is advantageous for low-temperature film formation and can effectively prevent property changes and film crack of high-temperature-sintering-induced material.Under this condition,the ink at a 15wt%solid content and 2wt%-10wt%PEG400 has good film-forming ability and high adhesion strength on the micro-electromechanical system(MEMS)micro-hotplates.Especially,the MEMS sensor printed using the ink of 6wt%PEG400 shows highest sensitivity,favorable impact resistance,thermal shock resistance,and up to 8 years of service life.
基金supported by the Outstanding Youth Foundation of Jiangsu Province of China(Grant No.BK20211548)the Yangzhou Science and Technology Plan Project(Grant No.YZ2023246)。
文摘The integration of dual-mesoporous structures,the construction of heterojunctions,and the incorporation of highly concentrated oxygen vacancies are pivotal for advancing metal oxide-based gas sensors.Nonetheless,achieving an optimal design that simultaneously combines mesoporous structures,precise heterojunction modulation,and controlled oxygen vacancies through a one-step process remains challenging.This study proposes an innovative method for fabricating zinc stannate semiconductors featuring dual-mesoporous structures and tunable oxygen vacancies via a direct solution precursor plasma spray technique.As a proof of concept,the resulting zinc stannate-based coatings are applied to detect 2-undecanone,a key biomarker for rice aging.Remarkably,the zinc oxide/zinc stannate heterojunctions with a well-defined secondary pore structure exhibit exceptional gas-sensing performance for 2-undecanone at room temperature.Furthermore,practical experiments indicate that the developed sensor effectively identifies adulteration in various rice varieties.These results underscore the potential of this method for designing metal oxides with tailored properties for high-performance gas sensors.The enhanced adsorption capacity and dual-mesoporous features of this semiconductor make it a promising candidate for sensing applications in agricultural food safety inspections.
基金financial support from the National Natural Science Foundation of China(Nos.52325801,52402052)。
文摘Thermal runaway(TR)in lithium-ion batteries(LIBs)poses significant safety risks due to its potential to trigger fires and explosions.Early warning of battery TR through gas sensing has emerged as a promising strategy for hazard mitigation.However,comprehensive reviews critically summarizing recent progress in advanced gas sensing technologies remain scarce.To fill this void,we present a critical review consolidating state-of-the-art advancements in gas sensing for TR early warning.This review first overviews the fundamentals of gas sensing for TR monitoring,encompassing thermodynamics and kinetic principles of gas evolution alongside current gas sensing technologies.We then comprehensively explored multi-scale engineering methods,spanning material innovations,device configurations,and system-level integration,with an emphasis on cutting-edge techniques like additive manufacturing and data-driven design frameworks.Future research priorities are identified,including the enhancement of gas selectivity and environmental robustness,the development of machine learning-driven intelligent gas sensing networks,and the establishment of standardized protocols for practical deployment.By integrating interdisciplinary insights derived from materials science,electrochemistry,and embedded systems engineering,this review is positioned to offer actionable guidelines for advancing scalable and reliable gas-sensing solutions toward boosted LIB safety.
基金supported by the National Natural Science Foundation of China(Nos.62031022 and 52375572)the Key R&D Program of Shanxi Province,China(No.202102030201003)+1 种基金Shanxi-Zheda Institute of Advanced Materials and Chemical Engineering,China(No.2022SXAT001)Key Core Technological Breakthrough Program of Taiyuan City,China(No.2024TYJB0126).
文摘In this work,we realized a room-temperature nitrogen dioxide(NO_(2))gas sensor based on a platinum(Pt)-loaded nanoporous gallium nitride(NP-GaN)sensing material using the thermal reduction method and coreduction with the catalysis of polyols.The gas sensor gained excellent sensitivity to NO_(2) at a concentration range of 200 ppm to 100 ppb,benefiting from the loading of Pt nanoparticles,and exhibited a short response time(22 s)and recovery time(170 s)to 100 ppm of NO_(2) at room temperature with excellent selectivity to NO_(2) compared with other gases.This phenomenon was attributed to the spillover effect and the synergic electronic interaction with semiconductor materials of Pt,which not only provided more electrons for the adsorption of NO_(2) molecules but also occupied effective sites,causing poor sites for other gases.The low detection limit of Pt/NP-GaN was 100 ppb,and the gas sensor still had a fast response 70 d after fabrication.Besides,the gas-sensing mechanism of the gas sensor was further elaborated to determine the reason leading to its improved properties.The significant spillover impact and oxygen dissociation of Pt provided advantages to its synergic electronic interaction with semiconductor materials,leading to the improvement of the gas properties of gas sensors.
基金supported by the National Natural Science Foundation of China(Nos.52188101,52272051,52122202,12174086,and 12404009)High-level Talent Research Start-up Project Funding of Henan Academy of Sciences(No.231820055)+2 种基金the Fundamental Research Fund of Henan Academy of Sciences(No.240620057)the Scientific and Technological Research Project of Henan(No.242102230153)Cultivation and Enhancement Project of Technology Innovation Platform of Henan Academy of Sciences(No.241020004).
文摘Graphene meshes(GMs)have attracted considerable attention as advanced materials for high-performance gas sensing due to their high-density active edge sites and excellent electronic properties.However,the contamination-free preparation of GMs remains a challenge.Herein,we present a dewdrop-templated chemical vapor deposition approach to directly grow clean and intact graphene micromeshes(GMM)on SiO_(2)/Si substrates.The self-assembled micrometer-sized dewdrops from controlled water vapor condensation serve as a residue-free template for directing the growth of GMM with tunable hole sizes from submicrons to tens of microns.Density functional theory(DFT)calculations reveal that carbon species preferentially adsorb on pristine SiO_(2) regions to form a mesh structure.Contamination-free GMM gas sensors were fabricated using a simple transfer-free process,demonstrating a record-high sensitivity of 7.25%·ppm−1 and an ultra-low detection limit of 1.18 ppb for NO_(2) at room temperature.Complementary DFT studies elucidate that NO_(2) molecules adsorb more strongly on the edges of GMM,leading to a high response of the sensor.This work offers profound insights into dewdrop-templated graphene growth mechanisms and establishes a simple yet effective approach for fabricating high-performance transfer-free GMM sensors,thus paving the way for their practical applications in environmental monitoring and industrial safety fields.
基金supported by National Natural Science Foundation of China(Nos.92263109 and 61904188)the Shanghai Rising-Star Program(No.22QA1410400)。
文摘Organic semiconductor materials have demonstrated extensive potential in the field of gas sensors due to the advantages including designable chemical structure,tunable physical and chemical properties.Through density functional theory(DFT)calculations,researchers can investigate gas sensing mechanisms,optimize,and predict the electronic structures and response characteristics of these materials,and thereby identify candidate materials with promising gas sensing applications for targeted design.This review concentrates on three primary applications of DFT technology in the realm of organic semiconductor-based gas sensors:(1)Investigating the sensing mechanisms by analyzing the interactions between gas molecules and sensing materials through DFT,(2)simulating the dynamic responses of gas molecules,which involves the behavior on the sensing interface using DFT combined with other computational methods to explore adsorption and diffusion processes,and(3)exploring and designing sensitive materials by employing DFT for screening and predicting chemical structures,thereby developing new sensing materials with exceptional performance.Furthermore,this review examines current research outcomes and anticipates the extensive application prospects of DFT technology in the domain of organic semiconductor-based gas sensors.These efforts are expected to provide valuable insights for further indepth exploration of DFT applications in sensor technology,thereby fostering significant advancements and innovations in the field.
基金supported by the Natural Science Foundation of Xinjiang Uygur Autonomous Region of China“Preparation and application of self-powered carbon nitride/metal oxide humidity sensors”(2023D01C05).
文摘A high-performance ammonia(NH3)sensor is prepared based on CeO_(2)/NiO composite,using a hydrothermal method.Experimental findings confirm that the CeO_(2)/NiO composite significantly enhances the performance of the NiO-based NH3 sensor.This improvement is primarily due to the increase in oxygen vacancies(Ov),chemically adsorbed oxygen(Oc),and the proportion of Ni3+on the surface of the CeO_(2)/NiO.The CeO_(2)/NiO sensor shows a high response to NH3,exhibiting response/recovery times of 1.8 s/0.9 s at the NH3 concentration of 5×10^(−6)mL/m^(3),with the theoretical lowest detection limit of 98.651×10^(−9)mL/m^(3).Additionally,the CeO_(2)/NiO sensor has been successfully applied in the simulated detection of Helicobacter pylori infection,highlighting its significant research value and potential application prospects in biomedical diagnostics.
文摘A new silicon beam resonator design for a novel gas sensor based on simultaneous conductivity and mass change measurement is investigated. High selectivity and sensitivity in gas detection can be obtained by measuring the charge-to-mass ratio of gas molecules. Structures of silicon beam resonators are designed, simulated, and optimized. This gas sensor is fabricated using sacrificial layer microelectronmechanical system technology, and the resonant frequency of the microbeam is measured.
基金ACKNOWLEDGMENTS This work was supported by the 211 project of Anhui University, the National Natural Science Foundation of China （No.11374013, No.61290301, No.51072001, No.51272001, and No.51272003）, Anhui Provincial Natural Science Fund （No.l1040606M49）, Higher Educational Natural Science Foundation of Anhui Province （No.KJ2012A007）, and the PhD Start-up Fund of Anhui University （No.33190209）. Ming-zai Wu thanks Dr. Fan-li Meng and Miss Hui-hua Li from the Institute of Intelligent Machines, CAS for the help with gas sensing experiment.
文摘Three-dimensional （3D） hierarchical Co3O4 microcrystal with radial dendritic morphologies was prepared through hydrothermal reactions followed by subsequent annealing treatment. Structural and morphological characterizations were performed by X-ray diffraction, scan-ning electron microscopy and transmission electron microscopy. The gas sensing properties of the as-obtained microcrystal were investigated at 110 oC, which revealed that the 3D hierarchical porous Co3O4 microcrystal exhibited high sensitivity to ammonia, as well as a short response time of 10 s. The response characteristic indicates that the sensor has a good stability and reversibility. Detections of toxic and flammable gases, such as ethanol, acetone and benzene were also carried out at a relative low temperature. The results indicate that such hierarchical Co3O4 microcrystal would be a potential material in the field of gas sensing.
基金The National Natural Science Foundation of China (No.58175122)the Natural Science Foundation of Jiangsu Province (No.BK2007185)+1 种基金the Natural Science Foundation of Higher Education Institutions of Jiangsu Province(No.07KJB460044)the Scientific Research Innovation Project for College Graduates in Jiangsu Province (No.CXZZ11_0340)
文摘In order to simplify the fabrication process,distribute the temperature uniformly and reduce the power consumption of the micro-hotplate（MHP） gas sensor,a planar-type gas sensor based on SnO2 thin film with suspended structure is designed through a MEMS process.Steady-state thermal analysis of the gas sensor and the closed membrane type sensor where the membrane overlaps the Si substrate is carried out with the finite element model,and it is shown that the suspended planar-type gas sensor has a more homogeneous temperature distribution and a lower power consumption.When the maximum temperature on the sensor reaches 383℃,the power consumption is only 7 mW,and the temperature gradient across the thin film is less than 14℃.To overcome the fragility of the suspended beams,a novel fabrication process in which the deposition of the gas sensing film occurs prior to the formation of suspended beams is proposed.The back side of the Si substrate is etched through deep reactive ion etching（DRIE） to avoid chemical pollution of the front side.The fabrication steps in which only four masks are used for the photolithography are described in detail.The Fe doped SnO2 thin film synthesized by sol-gel spin-coating is used as the gas sensing element.The device is tested on hydrogen and exhibits satisfactory sensing performance.The sensitivity increases with the rise of the concentration from 50×10-6 to 2000×10-6,and reaches about 30 at 2000×10-6.
文摘In-system programmable devices are products that combined modern electronic techniques and semiconductor techniques.They are indispensable devices in designing modern circuits and systems.This paper presents two practical circuits designed with programmable devices and its design method.By introducing programmable devices into gas sensor circuits,we can further improve system reliability,stability,sensitivity and integration degree,and enhance flexibility of system design.
基金This work was supported by the National Natural Science Foundation of China （No.U1432108） and the Fundamental Research Funds for the Central Universities （No.WK2320000034）.
文摘SnO2 nanofibers were synthesized by electrospinning and modified with Co3O4 via impregnation in this work. Chemical composition and morphology of the nanofibers were system- atically characterized, and their gas sensing properties were investigated. Results showed that Co3O4 modification significantly enhanced the sensing performance of SnO2 nanofibers to ethanol gas. For a sample with 1.2 mol% Co3O4, the response to 100 ppm ethanol was 38.0 at 300 ℃, about 6.7 times larger than that of SnO2 nanofibers. In addition, the response/recovery time was also greatly reduced. A power-law dependence of the sensor response on the ethanol concentration as well as excellent ethanol selectivity was observed for the Co3O4/SnO2 sensor. The enhanced ethanol sensing performance may be attributed to the formation of p-n heterojunctions between the two oxides.
基金the financial support of the Department of Science and Engineering Research Board (SERB) (Sanction Order No. CRG/2019/000112)。
文摘Room-temperature gas sensors have aroused great attention in current gas sensor technology because of deemed demand of cheap,low power consumption and portable sensors for rapidly growing Internet of things applications.As an important approach,light illumination has been exploited for room-temperature operation with improving gas sensor's attributes including sensitivity,speed and selectivity.This review provides an overview of the utilization of photoactivated nanomaterials in gas sensing field.First,recent advances in gas sensing of some exciting different nanostructures and hybrids of metal oxide semiconductors under light illumination are highlighted.Later,excellent gas sensing performance of emerging two-dimensional materialsbased sensors under light illumination is discussed in details with proposed gas sensing mechanism.Originated impressive features from the interaction of photons with sensing materials are elucidated in the context of modulating sensing characteristics.Finally,the review concludes with key and constructive insights into current and future perspectives in the light-activated nanomaterials for optoelectronic gas sensor applications.
基金This work is supported by This work was supported by the National Key R&D Program of China(Nos.2020YFB2008604 and 2021YFB3202500)the National Natural Science Foundation of China(Nos.61874034 and 51861135105)+1 种基金the International Science and Technology Cooperation Program of Shanghai Science and Technology Innovation Action Plan(No.21520713300)Fudan University-CIOMP Joint Fund(E02632Y7H0).
文摘With the rapid development of the Internet of Things,there is a great demand for portable gas sensors.Metal oxide semiconductors(MOS)are one of the most traditional and well-studied gas sensing materials and have been widely used to prepare various commercial gas sensors.However,it is limited by high operating temperature.The current research works are directed towards fabricating high-performance flexible room-temperature(FRT)gas sensors,which are effective in simplifying the structure of MOS-based sensors,reducing power consumption,and expanding the application of portable devices.This article presents the recent research progress of MOS-based FRT gas sensors in terms of sensing mechanism,performance,flexibility characteristics,and applications.This review comprehensively summarizes and discusses five types of MOS-based FRT gas sensors,including pristine MOS,noble metal nanoparticles modified MOS,organic polymers modified MOS,carbon-based materials(carbon nanotubes and graphene derivatives)modified MOS,and two-dimensional transition metal dichalcogenides materials modified MOS.The effect of light-illuminated to improve gas sensing performance is further discussed.Furthermore,the applications and future perspectives of FRT gas sensors are also discussed.
基金the Department of Atomic Energy(DAE)under Project No.34/20/09/2015/BRNSthe Department of Physics,IIT Ropar for providing financial support and the research facility。
文摘Nitrogen dioxide(NO2),a hazardous gas with acidic nature,is continuously being liberated in the atmosphere due to human activity.The NO2 sensors based on traditional materials have limitations of high-temperature requirements,slow recovery,and performance degradation under harsh environmental conditions.These limitations of traditional materials are forcing the scientific community to discover future alternative NO2 sensitive materials.Molybdenum disulfide(MoS2)has emerged as a potential candidate for developing next-generation NO2 gas sensors.MoS2 has a large surface area for NO2 molecules adsorption with controllable morphologies,facile integration with other materials and compatibility with internet of things(IoT)devices.The aim of this review is to provide a detailed overview of the fabrication of MoS2 chemiresistance sensors in terms of devices(resistor and transistor),layer thickness,morphology control,defect tailoring,heterostructure,metal nanoparticle doping,and through light illumination.Moreover,the experimental and theoretical aspects used in designing MoS2-based NO2 sensors are also discussed extensively.Finally,the review concludes the challenges and future perspectives to further enhance the gas-sensing performance of MoS2.Understanding and addressing these issues are expected to yield the development of highly reliable and industry standard chemiresistance NO2 gas sensors for environmental monitoring.
基金supported by the National Key R&D Program of China(No.2020YFB2008604,2021YFB3202500)the National Natural Science Foundation of China(No.61874034)the International Science and Technology Cooperation Program of Shanghai Science and Technology Innovation Action Plan(No.21520713300)。
文摘Highly sensitive gas sensors with remarkably low detection limits are attractive for diverse practical application fields including real-time environmental monitoring,exhaled breath diagnosis,and food freshness analysis.Among various chemiresistive sensing materials,noble metal-decorated semiconducting metal oxides(SMOs)have currently aroused extensive attention by virtue of the unique electronic and catalytic properties of noble metals.This review highlights the research progress on the designs and applications of different noble metal-decorated SMOs with diverse nanostructures(e.g.,nanoparticles,nanowires,nanorods,nanosheets,nanoflowers,and microspheres)for high-performance gas sensors with higher response,faster response/recovery speed,lower operating temperature,and ultra-low detection limits.The key topics include Pt,Pd,Au,other noble metals(e.g.,Ag,Ru,and Rh.),and bimetals-decorated SMOs containing ZnO,SnO_(2),WO_(3),other SMOs(e.g.,In_(2)O_(3),Fe_(2)O_(3),and CuO),and heterostructured SMOs.In addition to conventional devices,the innovative applications like photo-assisted room temperature gas sensors and mechanically flexible smart wearable devices are also discussed.Moreover,the relevant mechanisms for the sensing performance improvement caused by noble metal decoration,including the electronic sensitization effect and the chemical sensitization effect,have also been summarized in detail.Finally,major challenges and future perspectives towards noble metal-decorated SMOs-based chemiresistive gas sensors are proposed.
基金the support from National Key R&D Program of China(No.2016YFA0200800)the National Natural Science Foundation of China(Nos.61527818,61834007,61604165,61571430,61874130,61674160)Science and Technology Development Fund of Shanghai Institute of Technology。
文摘This paper reports a high-performance H2S gas sensing material that is made of ZnO nanowires(NWs)modified by an optimal amount of ZnS to form nano-hete rojunctions.Compared with the intrinsic ZnONWs,the three differently modified nano-heterostructure material ZnO-ZnS-x(x=5,10,15)shows significant improvement in sensing performance to H2S at the working temperatures of 100-400℃,especially in the low temperature range(<300℃).The chemiresistive sensor with ZnO-ZnS-10 sensingmaterial exhibits the largest response signal to H2S among all the other ZnO-ZnS-x(x=5,10,15,20)sensors.Its response signal to 5 ppm H2S at 150℃is about 2.7 times to that of the ZnO-NWs sensor.Besides,the ZnO-ZnS-10 sensor also features satisfactory selectivity and repeatability at 150℃.With the technical advantage attributed to the reduction of the redesigned band gap at the interface between ZnO and ZnS,the ZnO-ZnS hete ro structure sensor rather than the traditional ZnO-NWs sensor can be used for high-sensitivity application at low working temperature.
基金supported by the National Natural Science Foundation of China(61971284)the Oceanic Interdisciplinary Program of Shanghai Jiao Tong University(SL2020ZD203 and SL2020MS031)+2 种基金Scientific Research Fund of Second Institute of Oceanography,Ministry of Natural Resources of P.R.China(SL2003)Shanghai Sailing Program(21YF1421400)Startup Fund for Youngman Research at Shanghai Jiao Tong University.
文摘Real-time rapid detection of toxic gases at room temperature is particularly important for public health and environmental monitoring.Gas sensors based on conventional bulk materials often suffer from their poor surface-sensitive sites,leading to a very low gas adsorption ability.Moreover,the charge transportation efficiency is usually inhibited by the low defect density of surface-sensitive area than that in the interior.In this work,a gas sensing structure model based on CuS quantum dots/Bi_(2)S_(3) nanosheets(CuS QDs/Bi_(2)S_(3) NSs)inspired by artificial neuron network is constructed.Simulation analysis by density functional calculation revealed that CuS QDs and Bi_(2)S_(3) NSs can be used as the main adsorption sites and charge transport pathways,respectively.Thus,the high-sensitivity sensing of NO_(2) can be realized by designing the artificial neuron-like sensor.The experimental results showed that the CuS QDs with a size of about 8 nm are highly adsorbable,which can enhance the NO_(2) sensitivity due to the rich sensitive sites and quantum size effect.The Bi_(2)S_(3) NSs can be used as a charge transfer network channel to achieve efficient charge collection and transmission.The neuron-like sensor that simulates biological smell shows a significantly enhanced response value(3.4),excellent responsiveness(18 s)and recovery rate(338 s),low theoretical detection limit of 78 ppb,and excellent selectivity for NO_(2).Furthermore,the developed wearable device can also realize the visual detection of NO2 through real-time signal changes.
