Porous flower-like SnO_(2)/CdSnO_(3) microstructures self-assembled by uniform nanosheets were synthesized using a hydrothermal process followed by calcination,and the sensing performance was measured when a gas senso...Porous flower-like SnO_(2)/CdSnO_(3) microstructures self-assembled by uniform nanosheets were synthesized using a hydrothermal process followed by calcination,and the sensing performance was measured when a gas sensor,based on such microstructures,was exposed to various volatile organic compound(VOC)gases.The response value was found to reach as high as 100.1 when the SnO_(2)/CdSnO_(3) sensor was used to detect 100 ppm formaldehyde gas,much larger than those of other tested VOC gases,indicating the high gas sensitivity possessed by this sensor especially in the detection of formaldehyde gas.Meanwhile,the response/recovery process was fast with the response time and recovery time of only 13 and 21 s,respectively.The excellent gas sensing performance derive from the advantages of SnO_(2)/CdSnO_(3),such as abundant n-n heterojunctions built at the interface,high available specific surface area,abundant porosity,large pore size,and rich reactive oxygen species,as well as joint effects arising from SnO_(2) and CdSnO_(3),suggesting that such porous flower-like SnO_(2)/CdSnO_(3) microstructures composed of nanosheets have a high potential for developing gas sensors.展开更多
A new ultra-fine tungsten carbide(WC)cemented carbide was fabricated by spark plasma sintering(SPS),in which the CoCrNiCuFe high entropy alloy(HEA)was used as the binder and was mixed with WC carbide through the mecha...A new ultra-fine tungsten carbide(WC)cemented carbide was fabricated by spark plasma sintering(SPS),in which the CoCrNiCuFe high entropy alloy(HEA)was used as the binder and was mixed with WC carbide through the mechanical ball milling method.The microstructure of WC-10 wt%HEA compos-ites was investigated through scanning electron microscopy(SEM),high-resolution transmission electron microscopy(HRTEM),X-ray diffraction(XRD),and differential scanning calorimetry-thermogravimetric analysis(DSC-TG).The results show that the interface characteristics of the WC/HEA system include the FCC(111)//HCP(101^(-)1)interface with stable ionic bonds and the interface that reacts due to the formation of the(Fe,Co)_(3)W_(3)C phase.The mechanical properties of WC-10 wt%HEA composites were investigated through the Vickers hardness test,friction and wear tests,and compression test.The WC-10 wt%HEA composites exhibit good fracture toughness and hardness of 10.98 MPa m^(1/2)and 1988.60 HV30,respec-tively.The compressive strength at room temperature and 800℃is up to 3307 and 1747 MPa,respec-tively.The composites exhibited excellent properties attributed to the good wettability of HEA on WC grains and the consequent strengthening effect on the WC/WC interfaces.展开更多
A sea-urchin-like CuO/ZnO porous nanostructure is obtained via a simple solution method followed by a calcination process.There are abundant pores among the resulting nanowires due to the thermal decomposition of copp...A sea-urchin-like CuO/ZnO porous nanostructure is obtained via a simple solution method followed by a calcination process.There are abundant pores among the resulting nanowires due to the thermal decomposition of copper-zinc hydroxide carbonate.The specific surface area of the as-prepared CuO/ZnO sample is determined as 31.3 m^(2)·g^(-1).The gas-sensing performance of the sea-urchin-like CuO/ZnO sensor is studied by exposure to volatile organic compound(VOC)vapors.With contrast to a pure porous sea-urchin-like ZnO sensor,the sea-urchin-like CuO/ZnO sensor shows superior gas-sensing behavior for acetone,formaldehyde,methanol,toluene,isopropanol and ethanol.It exhibits a high response of 52.6-100 ppm acetone vapor,with short response/recovery time.This superior sensing behavior is mainly ascribed to the porous nanowireassembled structure with abundant p-n heterojunctions.展开更多
Porous titanium dioxide （ZiO2） nanowires were synthesized via a surfactant-free hydrothermal method followed by acid-washing process and calcination. The structures and morphologies of products were characterized by...Porous titanium dioxide （ZiO2） nanowires were synthesized via a surfactant-free hydrothermal method followed by acid-washing process and calcination. The structures and morphologies of products were characterized by field emission scanning electron micro- scopy （FESEM）, Transmission electron microscopy （TEM）, X-ray diffraction （XRD）, and Brunauer-Emmett- Teller （BET） N2 adsorption-desorption analyses. The analysis of FESEM suggested the precursor was composed of a vast of uniform nanostructures like wires. The nanowire-like precursor was transformed into the porous nanowire after acid-treatment and calcination at 500~C for 2 h in air. The surface area of as-synthesized TiO2 nanowires calculated by BET is 86.4 m2/g. Furthermore, the photocatalytic properties of synthesized porous TiO2 nanowires were evaluated through the degradation of methylene blue （MB） and Rhodamine B （RhB）. The results clearly suggested that the as-prepared porous TiO2 nanowires showed remarkable photocatalytic performance on the degradation of RhB and MB due to their small size of nanocrystallites and the porous naonstructure.展开更多
基金financially supported by the National Research Foundation of Korea NRF-2019R1A5A8080290the National Natural Science Foundation of China(Grant No.52171148)the Natural Science Foundation of Anhui Province(Grant No.2008085J23).
文摘Porous flower-like SnO_(2)/CdSnO_(3) microstructures self-assembled by uniform nanosheets were synthesized using a hydrothermal process followed by calcination,and the sensing performance was measured when a gas sensor,based on such microstructures,was exposed to various volatile organic compound(VOC)gases.The response value was found to reach as high as 100.1 when the SnO_(2)/CdSnO_(3) sensor was used to detect 100 ppm formaldehyde gas,much larger than those of other tested VOC gases,indicating the high gas sensitivity possessed by this sensor especially in the detection of formaldehyde gas.Meanwhile,the response/recovery process was fast with the response time and recovery time of only 13 and 21 s,respectively.The excellent gas sensing performance derive from the advantages of SnO_(2)/CdSnO_(3),such as abundant n-n heterojunctions built at the interface,high available specific surface area,abundant porosity,large pore size,and rich reactive oxygen species,as well as joint effects arising from SnO_(2) and CdSnO_(3),suggesting that such porous flower-like SnO_(2)/CdSnO_(3) microstructures composed of nanosheets have a high potential for developing gas sensors.
基金supported by the Key Program of Scientific Research of Higher Education of Hebei Province(No.ZD2021099)Qinhuangdao Science and Technology Research and Development Plan Project(No.202302B005)+2 种基金National Natural Science Foundation of China(No.52104384)China Postdoctoral Science Foundation(No.2020M683675XB)NSF of Shaanxi Provincial Department of Education(No.21JK0761).
文摘A new ultra-fine tungsten carbide(WC)cemented carbide was fabricated by spark plasma sintering(SPS),in which the CoCrNiCuFe high entropy alloy(HEA)was used as the binder and was mixed with WC carbide through the mechanical ball milling method.The microstructure of WC-10 wt%HEA compos-ites was investigated through scanning electron microscopy(SEM),high-resolution transmission electron microscopy(HRTEM),X-ray diffraction(XRD),and differential scanning calorimetry-thermogravimetric analysis(DSC-TG).The results show that the interface characteristics of the WC/HEA system include the FCC(111)//HCP(101^(-)1)interface with stable ionic bonds and the interface that reacts due to the formation of the(Fe,Co)_(3)W_(3)C phase.The mechanical properties of WC-10 wt%HEA composites were investigated through the Vickers hardness test,friction and wear tests,and compression test.The WC-10 wt%HEA composites exhibit good fracture toughness and hardness of 10.98 MPa m^(1/2)and 1988.60 HV30,respec-tively.The compressive strength at room temperature and 800℃is up to 3307 and 1747 MPa,respec-tively.The composites exhibited excellent properties attributed to the good wettability of HEA on WC grains and the consequent strengthening effect on the WC/WC interfaces.
基金This study was funded by grant Anhui Laboratory of Functional Coordinated Complexes for Materials Chemistry and Application(LFCCMCA-09)Anhui Laboratory of Clean Energy Materials and Chemistry for Sustainable Conversion of Natural Resources(LCECSC-01)Natural Science Research Project for Universities in Anhui Province(KJ2019A0480).
文摘A sea-urchin-like CuO/ZnO porous nanostructure is obtained via a simple solution method followed by a calcination process.There are abundant pores among the resulting nanowires due to the thermal decomposition of copper-zinc hydroxide carbonate.The specific surface area of the as-prepared CuO/ZnO sample is determined as 31.3 m^(2)·g^(-1).The gas-sensing performance of the sea-urchin-like CuO/ZnO sensor is studied by exposure to volatile organic compound(VOC)vapors.With contrast to a pure porous sea-urchin-like ZnO sensor,the sea-urchin-like CuO/ZnO sensor shows superior gas-sensing behavior for acetone,formaldehyde,methanol,toluene,isopropanol and ethanol.It exhibits a high response of 52.6-100 ppm acetone vapor,with short response/recovery time.This superior sensing behavior is mainly ascribed to the porous nanowireassembled structure with abundant p-n heterojunctions.
文摘Porous titanium dioxide （ZiO2） nanowires were synthesized via a surfactant-free hydrothermal method followed by acid-washing process and calcination. The structures and morphologies of products were characterized by field emission scanning electron micro- scopy （FESEM）, Transmission electron microscopy （TEM）, X-ray diffraction （XRD）, and Brunauer-Emmett- Teller （BET） N2 adsorption-desorption analyses. The analysis of FESEM suggested the precursor was composed of a vast of uniform nanostructures like wires. The nanowire-like precursor was transformed into the porous nanowire after acid-treatment and calcination at 500~C for 2 h in air. The surface area of as-synthesized TiO2 nanowires calculated by BET is 86.4 m2/g. Furthermore, the photocatalytic properties of synthesized porous TiO2 nanowires were evaluated through the degradation of methylene blue （MB） and Rhodamine B （RhB）. The results clearly suggested that the as-prepared porous TiO2 nanowires showed remarkable photocatalytic performance on the degradation of RhB and MB due to their small size of nanocrystallites and the porous naonstructure.
