In this work,the two-dimensional MoS2 film was prepared by sulfuring the molybdenum atomic layer on SiO2/Si substrate.The reaction temperature,heating rate,holding time and carrier gas flow rate were inve stigated com...In this work,the two-dimensional MoS2 film was prepared by sulfuring the molybdenum atomic layer on SiO2/Si substrate.The reaction temperature,heating rate,holding time and carrier gas flow rate were inve stigated compre hensively.The quality of MoS2 film was characterized by optical microscopy,atomic fo rce microscopy,Raman and photoluminescence spectro scopy.The characte rization results showed that the optimum synthesis parameters were heating rate of 25℃/min,reaction temperature of 750℃,holding time of 30 min and carrier gas velocity of 100 sccm.The MoS2 gas sensor was fabricated and its gas sensing performance was tested.The test results indicated that the sensor had a good response to both reducing gas(NH3)and oxidizing gas(NO2)at room temperature.The sensitivity to 100 ppm of NO2 was 31.3%,and the response/recovery times were 4 s and 5 s,respectively.In addition,the limit of detection could be as low as 1 ppm.This work helps us to develop low power and integrable room temperature NO2 sensors.展开更多
In this paper,a novel SnSe/SnO_(2) nanoparticles(NPs) composite has been successfully fabricated through hydrothermal method and surface oxidation treatment.The as-prepared sample was characterized by X-ray diffractio...In this paper,a novel SnSe/SnO_(2) nanoparticles(NPs) composite has been successfully fabricated through hydrothermal method and surface oxidation treatment.The as-prepared sample was characterized by X-ray diffraction(XRD),scanning electron microscopy(SEM),X-ray photoelectron spectroscopy(XPS) and transmission electron microscopy(TEM).A series of morphological and structural characteristics confirm that the SnSe/SnO_(2) NPs composite shows a core-shell structure with a SnO_(2) shell with thickness of 6 nm.The prepared SnO_(2) NPs and SnSe/SnO_(2) NPs composite were applied as gas-sensing materials,and their gas-sensing properties were investigated at room temperature systematically.Experimental results show that the response value of the SnSe/SnO_(2) composite sensor toward 100×10^(-6) SO_(2) is 15.15%,which is 1.32 times higher than that of pristine SnSe(11.43%).And the SnSe/SnO_(2) composite sensor also has a detection limit as low as 74×10^(-9) and an ultra-fast response speed.The enhanced gas-sensing performance is attributed to the formation of p-n heterojunction between SnSe and SnO_(2) and the appropriate SnO_(2) shell thickness.展开更多
基金supports from the National Natural Science Foundation of China(Nos.51572173,51602197,51771121 and 51702212)Shanghai Municipal Science and Technology Commission(Nos.19ZR1435200,18511110600 and 19JC1410402)+1 种基金Innovation Program of Shanghai Municipal Education Commission(No.2019-01-07-00-07-E00015)Shanghai Academic/Technology Research Leader Program(No.19XD1422900)。
文摘In this work,the two-dimensional MoS2 film was prepared by sulfuring the molybdenum atomic layer on SiO2/Si substrate.The reaction temperature,heating rate,holding time and carrier gas flow rate were inve stigated compre hensively.The quality of MoS2 film was characterized by optical microscopy,atomic fo rce microscopy,Raman and photoluminescence spectro scopy.The characte rization results showed that the optimum synthesis parameters were heating rate of 25℃/min,reaction temperature of 750℃,holding time of 30 min and carrier gas velocity of 100 sccm.The MoS2 gas sensor was fabricated and its gas sensing performance was tested.The test results indicated that the sensor had a good response to both reducing gas(NH3)and oxidizing gas(NO2)at room temperature.The sensitivity to 100 ppm of NO2 was 31.3%,and the response/recovery times were 4 s and 5 s,respectively.In addition,the limit of detection could be as low as 1 ppm.This work helps us to develop low power and integrable room temperature NO2 sensors.
基金financially supported by the National Natural Science Foundation of China (No.51777215)the Key Laboratory of Engineering Dielectrics and Its Application (Harbin University of Science and Technology),Ministry of Education (No.KFZ1801)。
文摘In this paper,a novel SnSe/SnO_(2) nanoparticles(NPs) composite has been successfully fabricated through hydrothermal method and surface oxidation treatment.The as-prepared sample was characterized by X-ray diffraction(XRD),scanning electron microscopy(SEM),X-ray photoelectron spectroscopy(XPS) and transmission electron microscopy(TEM).A series of morphological and structural characteristics confirm that the SnSe/SnO_(2) NPs composite shows a core-shell structure with a SnO_(2) shell with thickness of 6 nm.The prepared SnO_(2) NPs and SnSe/SnO_(2) NPs composite were applied as gas-sensing materials,and their gas-sensing properties were investigated at room temperature systematically.Experimental results show that the response value of the SnSe/SnO_(2) composite sensor toward 100×10^(-6) SO_(2) is 15.15%,which is 1.32 times higher than that of pristine SnSe(11.43%).And the SnSe/SnO_(2) composite sensor also has a detection limit as low as 74×10^(-9) and an ultra-fast response speed.The enhanced gas-sensing performance is attributed to the formation of p-n heterojunction between SnSe and SnO_(2) and the appropriate SnO_(2) shell thickness.
