介绍了超声喷涂技术在制备质子交换膜燃料电池(PEMFC)膜电极中的应用。对喷涂数据的分析表明,超声喷涂技术喷涂重复性和稳定性好,浆料利用率高。对膜电极进行形貌分析,显示膜电极表面均匀且颗粒分散性良好,微孔层(MPL)和催化层(CL)呈立...介绍了超声喷涂技术在制备质子交换膜燃料电池(PEMFC)膜电极中的应用。对喷涂数据的分析表明,超声喷涂技术喷涂重复性和稳定性好,浆料利用率高。对膜电极进行形貌分析,显示膜电极表面均匀且颗粒分散性良好,微孔层(MPL)和催化层(CL)呈立体孔隙结构,有利于减少传输电阻,形成有效的三相反应区。保持阴极铂载量为0.55 mg·cm^(-2),阳极降载量实验表明,在极低阳极铂载量下,膜电极仍具有良好的性能。在50℃,无外加湿,氢空测试条件下,阳极铂载量为0.05 mg·cm^(-2)时,最高功率密度为370 m W·cm^(-2),而单位阳极铂质量的比功率达7.39 W·mg^(-1),催化剂利用率高。氢闭端400 m A·cm^(-2)长时放电实验表明,0.05 mg·cm^(-2)膜电极仍然表现出与0.30 mg·cm^(-2)膜电极相当的性能。实验表明进一步降低膜电极铂载量是可行的。展开更多
Thin films of SnSx,semiconductors,have been successfully synthesized by ultrasonic spray pyrolysis technique,using two precursors namely：tin（II）chloride and tin（IV）chloride,respectively.The solutions were prepare...Thin films of SnSx,semiconductors,have been successfully synthesized by ultrasonic spray pyrolysis technique,using two precursors namely：tin（II）chloride and tin（IV）chloride,respectively.The solutions were prepared by the dilution of different Sn molarities of the two precursors separately.The precursor molarities were varied from 0.04 to 0.07 mol/L,whereas that of S was fixed at 0.1 mol/L.The present work focuses on the effect of the different precursor’s molarities on the nature and the properties of the prepared thin films in order to optimize the growth conditions.X-ray diffraction analysis reveals that the precursor’s molarities alter the grain size of the prepared films,which varied from 8 to 14 nm and from 12 to 16 nm,according to the used precursor.The films analysis by SEM,shows that the SnS2 films are more dense and smooth than the SnS films.The composition of the elements is analysed with an EDX spectrometer,and the obtained result for M（sn）=0：07 mol/L indicates that the atomic ratio of Sn to S is 51.57：48：43 and 36：64 for films synthesized from the first and second precursors respectively.Electrical measurements show that the conductivity behavior depends on the used precursors and their molarities.展开更多
The aim of this work is to investigate the dependence of Zn S thin films structural and optical properties with the solution flow rate during the deposition using an ultrasonic spray method. The solution flow rate ran...The aim of this work is to investigate the dependence of Zn S thin films structural and optical properties with the solution flow rate during the deposition using an ultrasonic spray method. The solution flow rate ranged from 10 to 50 m L/h and the substrate temperature was maintained at 450 °C. The effect of the solution flow rate on the properties of Zn S thin films was investigated by X-ray diffraction（XRD）, scanning electron microscopy（SEM）, optical transmittance spectroscopy（UV–V） and the four-point method. The X-ray diffraction analysis showed that the deposited material was pure zinc sulphide, it has a cubic sphalerite structure with preferential orientation along the（111） direction. The grain size values were calculated and found to be between 38 to 82 nm.SEM analysis revealed that the deposited thin films have good adherence to the substrate surfaces, are homogeneous and have high density. The average transmission of all films is up more than 65% in the range wavelength from 200 to 1100 nm and their band gap energy values were found between 3.5–3.92 e V. The obtained film thickness varies from 390 to 1040 nm. Moreover, the electric resistivity of the deposited films increases with the increasing of the solution flow rate between 3.51 × 10^5 and 11 × 10^5 Ω·cm.展开更多
Indium oxide （In2O3） thin films are successfully times by an ultrasonic spray technique using Indium chloride deposited on glass substrate at different deposition as the precursor solution; the physical properties o...Indium oxide （In2O3） thin films are successfully times by an ultrasonic spray technique using Indium chloride deposited on glass substrate at different deposition as the precursor solution; the physical properties of these films are characterized by XRD, SEM, and UV-visible. XRD analysis showed that the films are polycrys- talline in nature having a cubic crystal structure and symmetry space group Ia3 with a preferred grain orientation along the （222） plane when the deposition time changes from 4 to 10 min, but when the deposition time equals 13 min we found that the majority of grains preferred the （400） plane. The surface morphology of the In2O3 thin films revealed that the shape of grains changes with the change of the preferential growth orientation. The trans- mittance improvement of In2O3 films was closely related to the good crystalline quality of the films. The optical gap energy is found to increase from 3.46 to 3.79 eV with the increasing of deposition time from 4 to 13 min. The film thickness was varied between 395 and 725 nm. The film grown at 13 min is found to exhibit low resistivity （10-2 Ω.cm）, and relatively high transmittance （- 93%）.展开更多
Layers of transparent and conductive Sn-doped zinc oxide (ZnO) have been prepared using chemical reactive liquid phase (spray) method on glass substrates. X-ray diffraction analysis shows that the obtained layers show...Layers of transparent and conductive Sn-doped zinc oxide (ZnO) have been prepared using chemical reactive liquid phase (spray) method on glass substrates. X-ray diffraction analysis shows that the obtained layers show preferential grains orientation along the direction (002). Microstructural analysis indicates that the thickness of the deposited films is independent of Sn content, i.e. 408 nm, and that the average grain size increases with increasing Sn content, ranging from 31 nm to 42 nm. The value of the optical gap obtained using UV-visible transmission spectroscopy method increases slightly from 3.1 eV to 3.3 eV. Moreover, transmission curves reveal that the prepared thin films are transparent in the visible domain.展开更多
文摘介绍了超声喷涂技术在制备质子交换膜燃料电池(PEMFC)膜电极中的应用。对喷涂数据的分析表明,超声喷涂技术喷涂重复性和稳定性好,浆料利用率高。对膜电极进行形貌分析,显示膜电极表面均匀且颗粒分散性良好,微孔层(MPL)和催化层(CL)呈立体孔隙结构,有利于减少传输电阻,形成有效的三相反应区。保持阴极铂载量为0.55 mg·cm^(-2),阳极降载量实验表明,在极低阳极铂载量下,膜电极仍具有良好的性能。在50℃,无外加湿,氢空测试条件下,阳极铂载量为0.05 mg·cm^(-2)时,最高功率密度为370 m W·cm^(-2),而单位阳极铂质量的比功率达7.39 W·mg^(-1),催化剂利用率高。氢闭端400 m A·cm^(-2)长时放电实验表明,0.05 mg·cm^(-2)膜电极仍然表现出与0.30 mg·cm^(-2)膜电极相当的性能。实验表明进一步降低膜电极铂载量是可行的。
文摘Thin films of SnSx,semiconductors,have been successfully synthesized by ultrasonic spray pyrolysis technique,using two precursors namely：tin（II）chloride and tin（IV）chloride,respectively.The solutions were prepared by the dilution of different Sn molarities of the two precursors separately.The precursor molarities were varied from 0.04 to 0.07 mol/L,whereas that of S was fixed at 0.1 mol/L.The present work focuses on the effect of the different precursor’s molarities on the nature and the properties of the prepared thin films in order to optimize the growth conditions.X-ray diffraction analysis reveals that the precursor’s molarities alter the grain size of the prepared films,which varied from 8 to 14 nm and from 12 to 16 nm,according to the used precursor.The films analysis by SEM,shows that the SnS2 films are more dense and smooth than the SnS films.The composition of the elements is analysed with an EDX spectrometer,and the obtained result for M（sn）=0：07 mol/L indicates that the atomic ratio of Sn to S is 51.57：48：43 and 36：64 for films synthesized from the first and second precursors respectively.Electrical measurements show that the conductivity behavior depends on the used precursors and their molarities.
文摘The aim of this work is to investigate the dependence of Zn S thin films structural and optical properties with the solution flow rate during the deposition using an ultrasonic spray method. The solution flow rate ranged from 10 to 50 m L/h and the substrate temperature was maintained at 450 °C. The effect of the solution flow rate on the properties of Zn S thin films was investigated by X-ray diffraction（XRD）, scanning electron microscopy（SEM）, optical transmittance spectroscopy（UV–V） and the four-point method. The X-ray diffraction analysis showed that the deposited material was pure zinc sulphide, it has a cubic sphalerite structure with preferential orientation along the（111） direction. The grain size values were calculated and found to be between 38 to 82 nm.SEM analysis revealed that the deposited thin films have good adherence to the substrate surfaces, are homogeneous and have high density. The average transmission of all films is up more than 65% in the range wavelength from 200 to 1100 nm and their band gap energy values were found between 3.5–3.92 e V. The obtained film thickness varies from 390 to 1040 nm. Moreover, the electric resistivity of the deposited films increases with the increasing of the solution flow rate between 3.51 × 10^5 and 11 × 10^5 Ω·cm.
文摘Indium oxide （In2O3） thin films are successfully times by an ultrasonic spray technique using Indium chloride deposited on glass substrate at different deposition as the precursor solution; the physical properties of these films are characterized by XRD, SEM, and UV-visible. XRD analysis showed that the films are polycrys- talline in nature having a cubic crystal structure and symmetry space group Ia3 with a preferred grain orientation along the （222） plane when the deposition time changes from 4 to 10 min, but when the deposition time equals 13 min we found that the majority of grains preferred the （400） plane. The surface morphology of the In2O3 thin films revealed that the shape of grains changes with the change of the preferential growth orientation. The trans- mittance improvement of In2O3 films was closely related to the good crystalline quality of the films. The optical gap energy is found to increase from 3.46 to 3.79 eV with the increasing of deposition time from 4 to 13 min. The film thickness was varied between 395 and 725 nm. The film grown at 13 min is found to exhibit low resistivity （10-2 Ω.cm）, and relatively high transmittance （- 93%）.
文摘Layers of transparent and conductive Sn-doped zinc oxide (ZnO) have been prepared using chemical reactive liquid phase (spray) method on glass substrates. X-ray diffraction analysis shows that the obtained layers show preferential grains orientation along the direction (002). Microstructural analysis indicates that the thickness of the deposited films is independent of Sn content, i.e. 408 nm, and that the average grain size increases with increasing Sn content, ranging from 31 nm to 42 nm. The value of the optical gap obtained using UV-visible transmission spectroscopy method increases slightly from 3.1 eV to 3.3 eV. Moreover, transmission curves reveal that the prepared thin films are transparent in the visible domain.
