In this study, YiO2 nanoforest films consisting of nanotubes have been synthesized by a simple hydrothermal method and a subsequent sintering technique. The hydrothermal reaction time is important for the controlling ...In this study, YiO2 nanoforest films consisting of nanotubes have been synthesized by a simple hydrothermal method and a subsequent sintering technique. The hydrothermal reaction time is important for the controlling of the nanotube diameter and the specific surface area of holistic TiO2 films. When the hydrothermal process reaction time is up to 8 hours, the diameter of the nanotuhe is about 10 nm, and the specific surface area of TiO2 nanoforest films reaches the maximum. CdS nanoparticles are synthesized on TiO2 nanoforest films by the successive ionic layer adsorption and reaction （SILAR） technique. The transmission electron microscope （TEM） and energy dispersive x-ray spectroscopy （EDX） mapping results verify that TiOz/CdS heterostructures are realized. A significant red-shift of the absorption edge from 380 nm to 540 nm can be observed after the pure TiO2 film is sensitized by CdS nanoparticles. Under irradiation of light, the current density of the optimal TiO2/CdS photoanode is 2.30 mA.cm-2 at 0 V relative to the saturated calomel electrode （SCE）, which is 6 times stronger than that of the pure TiO2 photoanode. This study suggests that the TiO2 nanoforest consisting of interlinked pony-size nanotubes is a promising nanostructure for photoelectrochemical.展开更多
利用简单的两步水热法,制备了由底层一维TiO2纳米杆阵列以及上层三维TiO2纳米花团簇结构构成的TiO2纳米森林光阳极薄膜及其染料敏化太阳能电池（dye-sensitized solar cell,DSSC）.本文分别研究了TiO2纳米颗粒、一维TiO2纳米杆阵列以及...利用简单的两步水热法,制备了由底层一维TiO2纳米杆阵列以及上层三维TiO2纳米花团簇结构构成的TiO2纳米森林光阳极薄膜及其染料敏化太阳能电池（dye-sensitized solar cell,DSSC）.本文分别研究了TiO2纳米颗粒、一维TiO2纳米杆阵列以及纳米森林结构对光阳极和DSSC性能的影响.实验结果显示,TiO2纳米森林结构可提高光阳极对入射光和散射光的利用以及对光生载流子的收集和传输速率.因此,基于TiO2纳米森林结构光阳极的DSSC经过TiCl4后处理后具有最佳性能,其短路电流密度（short-circuit photocurrent density,J（sc））为16.31mA·cm^-2,光电转换效率（photoelectric conversion efficiency,PCE）为6.47%,与基于TiO2纳米颗粒光阳极的DSSC相比,分别提高了约30.7%和17.4%.展开更多
An intelligent humidity sensing system has been developed for real-time monitoring of human behaviors through respiration detection.The key component of this system is a humidity sensor that integrates a thermistor an...An intelligent humidity sensing system has been developed for real-time monitoring of human behaviors through respiration detection.The key component of this system is a humidity sensor that integrates a thermistor and a micro-heater.This sensor employs porous nanoforests as its sensing material,achieving a sensitivity of 0.56 pF/%RH within a range of 60–90%RH,along with excellent long-term stability and superior gas selectivity.The micro-heater in the device provides a high operating temperature,enhancing sensitivity by 5.8 times.This significant improvement enables the capture of weak humidity variations in exhaled gases,while the thermistor continuously monitors the sensor’s temperature during use and provides crucial temperature information related to respiration.With the assistance of a machine learning algorithm,a behavior recognition system based on the humidity sensor has been constructed,enabling behavior states to be classified and identified with an accuracy of up to 96.2%.This simple yet intelligent method holds great potential for widespread applications in medical assistance analysis and daily health monitoring.展开更多
This work proposes a fabrication technique that can achieve wafer-level preparation of flexible interdigital electrodes(IDEs)with high-density and large-thickness(HD<).Utilizing these HD< flexible IDEs,we ...This work proposes a fabrication technique that can achieve wafer-level preparation of flexible interdigital electrodes(IDEs)with high-density and large-thickness(HD<).Utilizing these HD< flexible IDEs,we developed a flexible humidity sensor that employs a composite material made of nanowire bundles with carbon quantum dots(CQDBs)for humidity sensitivity.In this device,the composite material facilitates high absorption and capillary condensation of water molecules across various relative humidity(RH)conditions,while the HD< IDEs enhance the effective sensing area.Consequently,we achieve a flexible humidity sensor with exceptional performance.This sensor not only boasts key attributes such as low cost,easy fabrication,and straightforward operation but also establishes a foundation for extensive humidity sensing applications.In comparison to other devices utilizing small-thickness and low-density IDEs,our sensor demonstrates remarkable 2.5-fold and 5.8-fold increase in sensitivity across humidity ranges of 7%-59%RH and 59%-97%RH,respectively.To explore the practical applications of the device,we demonstrate its functionality in diaper humidity detection.With characteristics of wearability and durability,the sensor shows significant potential for humidity monitoring in wearable electronics.展开更多
基金Project supported by the National Natural Science Foundation of China(Grant Nos.51272086 and 11704004)the Technology Development Program of Jilin Province,China(Grant No.20130206078GX)the Natural Science Foundation of Anhui Province,China(Grant No.1808085QA20)
文摘In this study, YiO2 nanoforest films consisting of nanotubes have been synthesized by a simple hydrothermal method and a subsequent sintering technique. The hydrothermal reaction time is important for the controlling of the nanotube diameter and the specific surface area of holistic TiO2 films. When the hydrothermal process reaction time is up to 8 hours, the diameter of the nanotuhe is about 10 nm, and the specific surface area of TiO2 nanoforest films reaches the maximum. CdS nanoparticles are synthesized on TiO2 nanoforest films by the successive ionic layer adsorption and reaction （SILAR） technique. The transmission electron microscope （TEM） and energy dispersive x-ray spectroscopy （EDX） mapping results verify that TiOz/CdS heterostructures are realized. A significant red-shift of the absorption edge from 380 nm to 540 nm can be observed after the pure TiO2 film is sensitized by CdS nanoparticles. Under irradiation of light, the current density of the optimal TiO2/CdS photoanode is 2.30 mA.cm-2 at 0 V relative to the saturated calomel electrode （SCE）, which is 6 times stronger than that of the pure TiO2 photoanode. This study suggests that the TiO2 nanoforest consisting of interlinked pony-size nanotubes is a promising nanostructure for photoelectrochemical.
基金supported by National Natural Science Foundation of China(Grant Nos.62474192 and 62201567)Youth Innovation Promotion Association,Chinese Academy of Sciences(Grant Nos.2022048 and 2022117)State Key Laboratory of Dynamic Test jointly built by Province and Ministry Open Fund(Grant No.2022-SYSJJ-07).
文摘An intelligent humidity sensing system has been developed for real-time monitoring of human behaviors through respiration detection.The key component of this system is a humidity sensor that integrates a thermistor and a micro-heater.This sensor employs porous nanoforests as its sensing material,achieving a sensitivity of 0.56 pF/%RH within a range of 60–90%RH,along with excellent long-term stability and superior gas selectivity.The micro-heater in the device provides a high operating temperature,enhancing sensitivity by 5.8 times.This significant improvement enables the capture of weak humidity variations in exhaled gases,while the thermistor continuously monitors the sensor’s temperature during use and provides crucial temperature information related to respiration.With the assistance of a machine learning algorithm,a behavior recognition system based on the humidity sensor has been constructed,enabling behavior states to be classified and identified with an accuracy of up to 96.2%.This simple yet intelligent method holds great potential for widespread applications in medical assistance analysis and daily health monitoring.
基金supported by the National Natural Science Foundation of China(62474192,62201567)the Youth Innovation Promotion Association of the Chinese Academy of Sciences(2022048,2022117)the State Key Laboratory of Dynamic Test,which is jointly established by the Province and Ministry,under Open Fund(2022SYSJJ-07)。
文摘This work proposes a fabrication technique that can achieve wafer-level preparation of flexible interdigital electrodes(IDEs)with high-density and large-thickness(HD<).Utilizing these HD< flexible IDEs,we developed a flexible humidity sensor that employs a composite material made of nanowire bundles with carbon quantum dots(CQDBs)for humidity sensitivity.In this device,the composite material facilitates high absorption and capillary condensation of water molecules across various relative humidity(RH)conditions,while the HD< IDEs enhance the effective sensing area.Consequently,we achieve a flexible humidity sensor with exceptional performance.This sensor not only boasts key attributes such as low cost,easy fabrication,and straightforward operation but also establishes a foundation for extensive humidity sensing applications.In comparison to other devices utilizing small-thickness and low-density IDEs,our sensor demonstrates remarkable 2.5-fold and 5.8-fold increase in sensitivity across humidity ranges of 7%-59%RH and 59%-97%RH,respectively.To explore the practical applications of the device,we demonstrate its functionality in diaper humidity detection.With characteristics of wearability and durability,the sensor shows significant potential for humidity monitoring in wearable electronics.
