As a key biomarker for noninvasive diagnosis of diabetes,the selective detection of trace acetone in exhaled gas using a portable and low-cost device remains a great challenge.Semiconductor metal oxide(SMO)based gas s...As a key biomarker for noninvasive diagnosis of diabetes,the selective detection of trace acetone in exhaled gas using a portable and low-cost device remains a great challenge.Semiconductor metal oxide(SMO)based gas sensors have drawn signification attention due to their potential in miniaturization,user-friendliness,high cost-effectiveness and selective real-time detection for noninvasive clinical diagnosis.Herein,we propose a one-pot solvent evaporation induced tricomponent co-assembly strategy to design a novel ordered mesoporous SMO of silica-implanted WO_(3)(Si O_(2)/WO_(3))as sensing materials for trace acetone detection.The controlled co-assembly of silicon and tungsten precursors and amphiphilic diblock copolymer poly(ethylene oxide)-block-polystyrene(PEO-b-PS),and the subsequent thermal treatment enable the local lattice disorder of WO_(3)induced by the amorphous silica and the formation of ordered mesoporous Si O_(2)/WO_(3)hybrid walls with a unique metastableε-phase WO_(3)framework.The obtained mesoporous SiO_(2)/WO_(3)composites possess highly crystalline framework with large uniform pore size(12.0-13.3 nm),high surface area(99-113 m^(2)/g)and pore volume(0.17-0.23 cm^(3)/g).Typically,the asfabricated gas sensor based on mesoporous 2.5%Si O_(2)/WO_(3)exhibits rapid response/recovery rate(5/17 s),superior sensitivity(R_(air)/R_(gas)=105 for 50 ppm acetone),as well as high selectivity towards acetone.The limit of detection is as low as 0.25 ppm,which is considerably lower than the thresh value of acetone concentration(>1.1 ppm)in the exhaled breath of diabetic patients,demonstrating its great prospect in real-time monitoring in diabetes diagnosis.Moreover,the mesoporous 2.5%Si O_(2)/WO_(3)sensor is integrated into a wireless sensing module connected to a smart phone,providing a convenient real-time detection of acetone.展开更多
Mesoporous semiconducting metal oxides(SMOs)heterojunctions are appealing sensors for gas detecting.However,due to the different hydrolysis and condensation mechanism of every metal precursor and the contradiction bet...Mesoporous semiconducting metal oxides(SMOs)heterojunctions are appealing sensors for gas detecting.However,due to the different hydrolysis and condensation mechanism of every metal precursor and the contradiction between high crystallinity and high surface area,the synthesis of mesoporous SMOs heterojunctions with highly o rdered mesostructures,highly crystallized frameworks,and high surface area remains a huge challenge.In this work,we develop a novel"acid-base pair"adjusted solvent evaporation induced self-assembly(EISA)strategy to prepare highly crystallized ordered mesoporous TiO2/WO3(OM-TiO2/WO3)heterojunctions.The WCl6 and titanium isopropoxide(TIPO)are used as the precursors,respectively,which function as the"acid-base pair",enabling the coassembly with the structure directing agent(PEO-b-PS)into highly ordered meso structures.In addition,PEO-b-PS can be converted to rigid carbon which can protect the meso structures from collapse during the crystallization process.The resultant OM-TiO2/WO3 heterojunctions possess primitive cubic mesostructures,large pore size(~21.1 nm),highly crystalline frameworks and surface area(~98 m2/g).As a sensor for acetone,the obtained OM-TiO2/WO3 show excellent re sponse/recovery perfo rmance(3 s/5 s),good linear dependence,repeatability,selectivity,and long-term stability(35 days).展开更多
Gas sensors built with metal oxide semiconductors have attracted tremendous attention due to the growing demand for the detection of inflammable,explosive and toxic gases.Herein,to improve the sensing response,WO_(3) ...Gas sensors built with metal oxide semiconductors have attracted tremendous attention due to the growing demand for the detection of inflammable,explosive and toxic gases.Herein,to improve the sensing response,WO_(3) nanoparticles decorated with Ag and Pt bimetals(Ag and Pt/WO_(3) NPs)have been developed via combined hydrolysis and hydrothermal strategies.Such sensors prototypes show high response to acetone(Ra/Rg=250@100×10^(-6),140℃),which is 6.1 fold as high as that of the pristine WO_(3) NPs(Ra/Rg=41@100×10^(-6),140℃).Moreover,the recovery time of Ag and Pt/WO_(3) NPs was reduced from 138 to 13 s compared with that of the pristine WO_(3) NPs.The improved acetone sensing performance may be attributed to that the chemical and electronic sensitization of Ag and Pt to WO_(3) NPs increases adsorbed oxygen species,speeds up the reaction and thus boosts the sensing response.Our strategy that decoration of dual precious metals onto WO_(3) NPs improves the acetone sensing performance may be applied to the gas sensors of other sensing materials.展开更多
Zinc oxide （ZnO） thin films were prepared onto glass substrates at moderately low growth tempera- ture by two-stage spray pyrolysis technique. The effects of growth temperature on structural, optical and acetone det...Zinc oxide （ZnO） thin films were prepared onto glass substrates at moderately low growth tempera- ture by two-stage spray pyrolysis technique. The effects of growth temperature on structural, optical and acetone detection properties were investigated with X-ray diffractometry, a UV-visible spectrophotometer, photoluminescence （PL） spectroscopy and a homemade gas sensor testing unit, respectively. All the films are polycrystalline with a hexagonal wurtzite phase and exhibit a preferential orientation along [002] direction. The film crystallinity is gradually enhanced with an increase in growth temperature. The optical measurements show that all the films are physically highly transparent with a transmittance greater than 82% in the visible range. The band gap of the film is observed to exhibit a slight red shift with an increasing growth temperature. The PL studies on the films show UV/violet PL band at - 395 nm. Among all the films investigated, the film deposited at 250℃ demonstrates a maximum sensitivity of 13% towards 20 ppm of acetone vapors at 300℃ operating temperature.展开更多
基金financially supported by National Natural Science Foundation of China(Nos.62104045,22125501,U22A20152)State Key Laboratory of Transducer Technology of China(No.SKT2207)+1 种基金Medical Engineering Jiont Fund of Fudan University(No.yg2023-10)Fundamental Research Funds for the Central Universities(No.20720220010)。
文摘As a key biomarker for noninvasive diagnosis of diabetes,the selective detection of trace acetone in exhaled gas using a portable and low-cost device remains a great challenge.Semiconductor metal oxide(SMO)based gas sensors have drawn signification attention due to their potential in miniaturization,user-friendliness,high cost-effectiveness and selective real-time detection for noninvasive clinical diagnosis.Herein,we propose a one-pot solvent evaporation induced tricomponent co-assembly strategy to design a novel ordered mesoporous SMO of silica-implanted WO_(3)(Si O_(2)/WO_(3))as sensing materials for trace acetone detection.The controlled co-assembly of silicon and tungsten precursors and amphiphilic diblock copolymer poly(ethylene oxide)-block-polystyrene(PEO-b-PS),and the subsequent thermal treatment enable the local lattice disorder of WO_(3)induced by the amorphous silica and the formation of ordered mesoporous Si O_(2)/WO_(3)hybrid walls with a unique metastableε-phase WO_(3)framework.The obtained mesoporous SiO_(2)/WO_(3)composites possess highly crystalline framework with large uniform pore size(12.0-13.3 nm),high surface area(99-113 m^(2)/g)and pore volume(0.17-0.23 cm^(3)/g).Typically,the asfabricated gas sensor based on mesoporous 2.5%Si O_(2)/WO_(3)exhibits rapid response/recovery rate(5/17 s),superior sensitivity(R_(air)/R_(gas)=105 for 50 ppm acetone),as well as high selectivity towards acetone.The limit of detection is as low as 0.25 ppm,which is considerably lower than the thresh value of acetone concentration(>1.1 ppm)in the exhaled breath of diabetic patients,demonstrating its great prospect in real-time monitoring in diabetes diagnosis.Moreover,the mesoporous 2.5%Si O_(2)/WO_(3)sensor is integrated into a wireless sensing module connected to a smart phone,providing a convenient real-time detection of acetone.
基金supported by the National Natural Science Foundation of China(Nos.51822202 and 51772050)China Postdoctoral Science Foundation(No.2019M651342)+2 种基金Shanghai Rising-Star Program(No.18QA1400100)Youth Top-notch Talent Support Program of Shanghai,the Shanghai Committee of Science and Technology,China(No.19520713200)DHU Distinguished Young Professor Program and Fundamental Research Funds for the Central Universities。
文摘Mesoporous semiconducting metal oxides(SMOs)heterojunctions are appealing sensors for gas detecting.However,due to the different hydrolysis and condensation mechanism of every metal precursor and the contradiction between high crystallinity and high surface area,the synthesis of mesoporous SMOs heterojunctions with highly o rdered mesostructures,highly crystallized frameworks,and high surface area remains a huge challenge.In this work,we develop a novel"acid-base pair"adjusted solvent evaporation induced self-assembly(EISA)strategy to prepare highly crystallized ordered mesoporous TiO2/WO3(OM-TiO2/WO3)heterojunctions.The WCl6 and titanium isopropoxide(TIPO)are used as the precursors,respectively,which function as the"acid-base pair",enabling the coassembly with the structure directing agent(PEO-b-PS)into highly ordered meso structures.In addition,PEO-b-PS can be converted to rigid carbon which can protect the meso structures from collapse during the crystallization process.The resultant OM-TiO2/WO3 heterojunctions possess primitive cubic mesostructures,large pore size(~21.1 nm),highly crystalline frameworks and surface area(~98 m2/g).As a sensor for acetone,the obtained OM-TiO2/WO3 show excellent re sponse/recovery perfo rmance(3 s/5 s),good linear dependence,repeatability,selectivity,and long-term stability(35 days).
基金financially supported by the National Natural Science Foundation of China(No.52072184)the Fundamental Research Funds for the Central Universities,Nankai University(No.63201179)。
文摘Gas sensors built with metal oxide semiconductors have attracted tremendous attention due to the growing demand for the detection of inflammable,explosive and toxic gases.Herein,to improve the sensing response,WO_(3) nanoparticles decorated with Ag and Pt bimetals(Ag and Pt/WO_(3) NPs)have been developed via combined hydrolysis and hydrothermal strategies.Such sensors prototypes show high response to acetone(Ra/Rg=250@100×10^(-6),140℃),which is 6.1 fold as high as that of the pristine WO_(3) NPs(Ra/Rg=41@100×10^(-6),140℃).Moreover,the recovery time of Ag and Pt/WO_(3) NPs was reduced from 138 to 13 s compared with that of the pristine WO_(3) NPs.The improved acetone sensing performance may be attributed to that the chemical and electronic sensitization of Ag and Pt to WO_(3) NPs increases adsorbed oxygen species,speeds up the reaction and thus boosts the sensing response.Our strategy that decoration of dual precious metals onto WO_(3) NPs improves the acetone sensing performance may be applied to the gas sensors of other sensing materials.
基金Project supported by the Dong-Eui University Grant(No.2014AA342)
文摘Zinc oxide （ZnO） thin films were prepared onto glass substrates at moderately low growth tempera- ture by two-stage spray pyrolysis technique. The effects of growth temperature on structural, optical and acetone detection properties were investigated with X-ray diffractometry, a UV-visible spectrophotometer, photoluminescence （PL） spectroscopy and a homemade gas sensor testing unit, respectively. All the films are polycrystalline with a hexagonal wurtzite phase and exhibit a preferential orientation along [002] direction. The film crystallinity is gradually enhanced with an increase in growth temperature. The optical measurements show that all the films are physically highly transparent with a transmittance greater than 82% in the visible range. The band gap of the film is observed to exhibit a slight red shift with an increasing growth temperature. The PL studies on the films show UV/violet PL band at - 395 nm. Among all the films investigated, the film deposited at 250℃ demonstrates a maximum sensitivity of 13% towards 20 ppm of acetone vapors at 300℃ operating temperature.
