Air pollution containing particulate matter(PM)and volatile organic compounds has caused magnificent burdens on indi-vidual health and global economy.Although advances in highly efficient or multifunctional nanofiber ...Air pollution containing particulate matter(PM)and volatile organic compounds has caused magnificent burdens on indi-vidual health and global economy.Although advances in highly efficient or multifunctional nanofiber filters have been achieved,many existing filters can only deal with one type of air pollutant,such as capturing PM or absorbing and detecting toxic gas.Here,highly efficient,dual-functional,self-assembled electrospun nanofiber(SAEN)filters were developed for simultaneous PM removal and onsite eye-readable formaldehyde sensing fabricated on a commercial fabric mask.With the use of an electrolyte solution containing a formaldehyde-sensitive colorimetric agent as a collector during electrospinning,the one-step fabrication of the dual-functional SAEN filter on commercial masks,such as a fabric mask and a daily dispos-able mask,was achieved.The electrolyte solution also allowed the uniform deposition of electrospun nanofibers,thereby achieving the high efficiency of PM filtration with an increased quality factor up to twice that of commercial masks.The SAEN filter enabled onsite and eye-readable formaldehyde gas detection by changing its color from yellow to red under a 5 ppm concentrated formaldehyde gas atmosphere.The repetitive fabrication and detachment of the SAEN filter on a fabric mask minimized the waste of the mask while maintaining high filtration efficiency by replenishing the SAEN filters and reusing the fabric mask.Given the dual functionality of SAEN filters,this process could provide new insights into design-ing and developing high performance and dual-functional electrospun nanofiber filters for various applications,including individual protection and indoor purification applications.展开更多
Semiconducting metal oxides have been considered as effective approach for designing highperformance chemical sensing materials.In this paper,a kind of metal-organic frameworks ZIF-8 was used as sacrificed template to...Semiconducting metal oxides have been considered as effective approach for designing highperformance chemical sensing materials.In this paper,a kind of metal-organic frameworks ZIF-8 was used as sacrificed template to prepare porous ZnO hollow nanocubes for the application in gas sensing.It is found that changing calcination temperature and solvent can greatly influence the morphology of the material,which finally affects the gas sensing performance.Acetylene-sensing properties of the sensors were investigated in detail.It can be clearly seen that the material used methanol as reaction solvent with the decomposition at 350℃for 2 h(ZnO-350-M)showed the optimal formaldehyde-sensing behaviors compared with other materials prepared in this experiment.The dynamic transients of the ZnO-350-M-based sensors demonstrated a high response value(about 10),fast response and recovery rate(4 s and 4 s,respectively)and good selectivity towards 100 ppm(part per million)formaldehyde as well as a low detectable limit(1 ppm).As exemplified for the sensing inve stigation towards formaldehyde,the porous ZnO hollow nanocubes showed a significantly improved chemical sensitivity due to the highly syne rgistic effects from the well exposed surfaces,defect states and the robust ZnO.展开更多
SnO 2 nanospheres with diameters of 30∼50 nm and Pt x Cu 1-x bimetallic nanoparticles with sizes of approxi-mately 10 nm were synthesized via hydrothermal and solvothermal methods,respectively.The Pt x Cu 1-x bimetal...SnO 2 nanospheres with diameters of 30∼50 nm and Pt x Cu 1-x bimetallic nanoparticles with sizes of approxi-mately 10 nm were synthesized via hydrothermal and solvothermal methods,respectively.The Pt x Cu 1-x bimetal-lic nanoparticles were impregnated on the surface of the SnO 2 spheres to form Pt x Cu 1-x-SnO 2 nanocomposites.By varying the atomic ratios between platinum(Pt)and copper(Cu),we found that Pt 0.75 Cu 0.25-SnO 2,with a large specific surface area of 89.21 m 2/g,enabled the selective and accurate detection of low-concentration formalde-hyde compared to other metal-deposited samples and pure SnO 2.The response value of Pt 0.75 Cu 0.25-SnO 2 to 500×10−9 formaldehyde was approximately 20 at an operating temperature of 160◦C with an extremely high-speed response(15 s).The porous structures with large specific surface areas,as well as the improved catalytic effects of Pt 0.75 Cu 0.25,comprehensively contributed to the enhanced sensing performance towards formaldehyde.展开更多
Formaldehyde is a common atmospheric pollutant produced in industrial production and daily life.However,the traditional semiconductor formaldehyde gas sensor cannot work at room temperature,which limits its practical ...Formaldehyde is a common atmospheric pollutant produced in industrial production and daily life.However,the traditional semiconductor formaldehyde gas sensor cannot work at room temperature,which limits its practical application.Therefore,developing high-performance gas sensors for rapidly and accurately detecting formaldehyde at room temperature is an important topic.In this study,Ti_(3)C_(2)Tx/SnO_(2)heterostructures were constructed,which could selectively detect formaldehyde at room temperature with a response value of 29.16%(10×10^(-6)).In addition,the sensor shows a remarkable theoretical detection limit of 5.09×10^(-9)and good longterm stability.Density functional theory(DFT)simulations reveal that SnO_(2)nano spheres provide the majority of adsorption sites that strongly interact with formaldehyde.Meanwhile,Ti_(3)C_(2)T_(x)acting as a conductive layer facilitates the transfer of charge carriers so that they show a sensing response to formaldehyde at room temperature.Moreover,the formation of p-n heterostructures between SnO_(2)and Ti_(3)C_(2)T_(x)boosts the Schottky barrier at the interface,which is the critical factor in enhancing the sensing properties by turning the Schottky barrier upon introducing formaldehyde gas.This perspective is expected to provide instructive guidance for utilizing MXene/metal oxide nanocomposites to improve the gas sensing performance at room temperature.展开更多
A modulated photoluminescence nanosensor was developed for the quantitative detection of formaldehyde with nitrogen-doped graphene quantum dots and melamine. The sensing system was based on the different activated eff...A modulated photoluminescence nanosensor was developed for the quantitative detection of formaldehyde with nitrogen-doped graphene quantum dots and melamine. The sensing system was based on the different activated effects of melamine and hydrogen peroxide on the photoluminescence intensity of nitrogendoped graphene quantum dots. Under the optimal conditions, the modulated photoluminescence sensing system can be used to detect formaldehyde with a good linear relationship between the nitrogen-doped graphene quantum dots photoluminescence difference and the concentration of formaldehyde. The novel sensing system provided new directions for the detection of formaldehyde with high selectivity and quick response.展开更多
基金supported by the National Research Foundation of Korea(NRF)grant funded by the Korea government(MSIT)(no.RS-2023-00209094,2020R1C1C100944311)BK21 FOUR Program by Pusan National University Research Grant,2021.
文摘Air pollution containing particulate matter(PM)and volatile organic compounds has caused magnificent burdens on indi-vidual health and global economy.Although advances in highly efficient or multifunctional nanofiber filters have been achieved,many existing filters can only deal with one type of air pollutant,such as capturing PM or absorbing and detecting toxic gas.Here,highly efficient,dual-functional,self-assembled electrospun nanofiber(SAEN)filters were developed for simultaneous PM removal and onsite eye-readable formaldehyde sensing fabricated on a commercial fabric mask.With the use of an electrolyte solution containing a formaldehyde-sensitive colorimetric agent as a collector during electrospinning,the one-step fabrication of the dual-functional SAEN filter on commercial masks,such as a fabric mask and a daily dispos-able mask,was achieved.The electrolyte solution also allowed the uniform deposition of electrospun nanofibers,thereby achieving the high efficiency of PM filtration with an increased quality factor up to twice that of commercial masks.The SAEN filter enabled onsite and eye-readable formaldehyde gas detection by changing its color from yellow to red under a 5 ppm concentrated formaldehyde gas atmosphere.The repetitive fabrication and detachment of the SAEN filter on a fabric mask minimized the waste of the mask while maintaining high filtration efficiency by replenishing the SAEN filters and reusing the fabric mask.Given the dual functionality of SAEN filters,this process could provide new insights into design-ing and developing high performance and dual-functional electrospun nanofiber filters for various applications,including individual protection and indoor purification applications.
基金National Natural Science Foundation of China(Nos.61874048,11874348,U1831113,61974175,61974055)Project of Science and Technology Plan of Jilin Province(No.20180414020GH)Project of Jilin Provincial Development and Reform Commission(No.2018C040-2)。
文摘Semiconducting metal oxides have been considered as effective approach for designing highperformance chemical sensing materials.In this paper,a kind of metal-organic frameworks ZIF-8 was used as sacrificed template to prepare porous ZnO hollow nanocubes for the application in gas sensing.It is found that changing calcination temperature and solvent can greatly influence the morphology of the material,which finally affects the gas sensing performance.Acetylene-sensing properties of the sensors were investigated in detail.It can be clearly seen that the material used methanol as reaction solvent with the decomposition at 350℃for 2 h(ZnO-350-M)showed the optimal formaldehyde-sensing behaviors compared with other materials prepared in this experiment.The dynamic transients of the ZnO-350-M-based sensors demonstrated a high response value(about 10),fast response and recovery rate(4 s and 4 s,respectively)and good selectivity towards 100 ppm(part per million)formaldehyde as well as a low detectable limit(1 ppm).As exemplified for the sensing inve stigation towards formaldehyde,the porous ZnO hollow nanocubes showed a significantly improved chemical sensitivity due to the highly syne rgistic effects from the well exposed surfaces,defect states and the robust ZnO.
基金This study was supported by the Natural Science Foundation of Shan-dong Province(No.ZR2019QF012)the Natural Science and Develop-ment Foundation of Shenzhen(JCYJ20190807093205660)the Na-tional Natural Science Foundation of China(No.21902085).
文摘SnO 2 nanospheres with diameters of 30∼50 nm and Pt x Cu 1-x bimetallic nanoparticles with sizes of approxi-mately 10 nm were synthesized via hydrothermal and solvothermal methods,respectively.The Pt x Cu 1-x bimetal-lic nanoparticles were impregnated on the surface of the SnO 2 spheres to form Pt x Cu 1-x-SnO 2 nanocomposites.By varying the atomic ratios between platinum(Pt)and copper(Cu),we found that Pt 0.75 Cu 0.25-SnO 2,with a large specific surface area of 89.21 m 2/g,enabled the selective and accurate detection of low-concentration formalde-hyde compared to other metal-deposited samples and pure SnO 2.The response value of Pt 0.75 Cu 0.25-SnO 2 to 500×10−9 formaldehyde was approximately 20 at an operating temperature of 160◦C with an extremely high-speed response(15 s).The porous structures with large specific surface areas,as well as the improved catalytic effects of Pt 0.75 Cu 0.25,comprehensively contributed to the enhanced sensing performance towards formaldehyde.
基金financially supported by the National Natural Science Foundation of China(No.61973223)the Innovative Talents in Colleges and Universities in Liaoning Province(No.2020389)+3 种基金Liao Ning Revitalization Talents Program(No.XLYC2007051)Liaoning Educational Department Foundation(No.LJKMZ20220762)the Natural Science Foundation of Liaoning Province(No.2021-MS-257)the Young and Middle-aged Scientific and Technological Innovation Talents of Shenyang Science and Technology Bureau(No.RC200352)。
文摘Formaldehyde is a common atmospheric pollutant produced in industrial production and daily life.However,the traditional semiconductor formaldehyde gas sensor cannot work at room temperature,which limits its practical application.Therefore,developing high-performance gas sensors for rapidly and accurately detecting formaldehyde at room temperature is an important topic.In this study,Ti_(3)C_(2)Tx/SnO_(2)heterostructures were constructed,which could selectively detect formaldehyde at room temperature with a response value of 29.16%(10×10^(-6)).In addition,the sensor shows a remarkable theoretical detection limit of 5.09×10^(-9)and good longterm stability.Density functional theory(DFT)simulations reveal that SnO_(2)nano spheres provide the majority of adsorption sites that strongly interact with formaldehyde.Meanwhile,Ti_(3)C_(2)T_(x)acting as a conductive layer facilitates the transfer of charge carriers so that they show a sensing response to formaldehyde at room temperature.Moreover,the formation of p-n heterostructures between SnO_(2)and Ti_(3)C_(2)T_(x)boosts the Schottky barrier at the interface,which is the critical factor in enhancing the sensing properties by turning the Schottky barrier upon introducing formaldehyde gas.This perspective is expected to provide instructive guidance for utilizing MXene/metal oxide nanocomposites to improve the gas sensing performance at room temperature.
基金Funded by the National Natural Science Foundation of China(Nos.21275063 and 21005029)the Development and Reform Commission of Jilin Province(No.2015Y048)the Youth Science Fund of Jilin Province(20140520081JH)
文摘A modulated photoluminescence nanosensor was developed for the quantitative detection of formaldehyde with nitrogen-doped graphene quantum dots and melamine. The sensing system was based on the different activated effects of melamine and hydrogen peroxide on the photoluminescence intensity of nitrogendoped graphene quantum dots. Under the optimal conditions, the modulated photoluminescence sensing system can be used to detect formaldehyde with a good linear relationship between the nitrogen-doped graphene quantum dots photoluminescence difference and the concentration of formaldehyde. The novel sensing system provided new directions for the detection of formaldehyde with high selectivity and quick response.
