ZnO nanostructure materials doped with different La contents were synthesized by sonochemical method. The products were characterized by X-ray diffraction（XRD）, scanning electron microscopy（SEM）,transmission elect...ZnO nanostructure materials doped with different La contents were synthesized by sonochemical method. The products were characterized by X-ray diffraction（XRD）, scanning electron microscopy（SEM）,transmission electron microscopy（TEM）, Raman spectroscopy, and Fourier transform infrared spectroscopy（FTIR）. In this research, XRD patterns of pure ZnO and La-doped ZnO are specified as hexagonal wurtzite ZnO structure with no detection of La2O3 phase. SEM and TEM characterization revealed the flower shape of pure ZnO built-up from petals of hexagonal prisms with hexagonal pyramid tips. Upon doping with La, the flower-shaped ZnO is broken into individual 1D prism-like nanorods. Photocatalytic activities of the as-synthesized products were determined by measuring the degradation of methylene blue（MB） under ultraviolet–visible（UV） light irradiation.Among them, the 2.0 mol% La-doped ZnO shows better photocatalytic properties than any other products.展开更多
A simple sonochemical route has been successfully developed to synthesize SnO2 hollow microspheres. The obtained sample is characterized by XRD, TEM, XPS and UV-visible spectrophotometer. The TEM image of the sample a...A simple sonochemical route has been successfully developed to synthesize SnO2 hollow microspheres. The obtained sample is characterized by XRD, TEM, XPS and UV-visible spectrophotometer. The TEM image of the sample at high magnification shows that the shell of the hollow sphere is composed of 3-5 nm SnO2 nanoparticles. A possible formation mechanism of the hollow spheres is briefly discussed.展开更多
The preparation of highly active electrocatalysts with good durability and low cost for fuel cells is highly desir- able but still remains a significant challenge. Here we synthesized two dimensional （2D） C3N4 nanos...The preparation of highly active electrocatalysts with good durability and low cost for fuel cells is highly desir- able but still remains a significant challenge. Here we synthesized two dimensional （2D） C3N4 nanosheets supported palladium composites （C3N4/Pd） via a simple and convenient sonochemical approach. We have systematically stud- ied the electrocatalytic performance of as-prepared catalysts. We found that the prepared C3N4/Pd composites pos- sessed excellent catalytic activity and stability for oxygen reduction reaction （ORR） in alkaline media. Encourag- ingly, the C3N4/Pd catalysts exhibit the excellent electrocatalytic activity for methanol oxidation reaction （MOR） in alkaline media, even better than that of the commercial Pt/C catalyst, The excellent electrocatalytic performance of the 2D C3N4 nanosheets supported palladium composites catalysts results from their synergy effect between the ul- trathin substrate material with large surface area and excellent dispersion of palladium nanoparticles. This study demonstrates that sonochemical method opens up a new avenue for the preparation of electrocatalysts for fuel cells. We expect these materials are likely to find uses in a broad range of applications, for example, fuel cells, solar cells, batteries and other electrochemical analysis.展开更多
A new non-covalently bonded 3D supramolecular architecture,namely,[Cd^(Ⅱ)_(2)Cl_(2)(μ-Cl)_(2)(μ-L)]n[where L=1,1,3,3-tetrakis(3,5-dimethyl-1-pyrazolyl)propane]was synthesized and structurally characterized.In this ...A new non-covalently bonded 3D supramolecular architecture,namely,[Cd^(Ⅱ)_(2)Cl_(2)(μ-Cl)_(2)(μ-L)]n[where L=1,1,3,3-tetrakis(3,5-dimethyl-1-pyrazolyl)propane]was synthesized and structurally characterized.In this structure,the N4-coordinated pyrazole-based ligand displayed a chelating-bridging mode and bounds to two neighboring Cd^(Ⅱ)centers to create a 1D sinusoidal chain along the b-axis.Each of the cadmium(Ⅱ)sites adopted a distorted square pyramidal arrangement with a CdN_(2)Cl_(3)core.The chains were further stabilized by non-covalent bonds such as C-H⋯Cl and C-H⋯πto generate a 3D network.This structure has the ability to incorporate Fe_(3)O_(4)@SiO_(2)-NH_(2)nanoparticles and build up an Fe_(3)O_(4)@SiO_(2)-NH_(2)@Cd(Ⅱ)-CP hybrid using a sonochemical method.The bonding established between the Cd(Ⅱ)-CP and aminofunctionalized Fe_(3)O_(4)nanoparticles improved the separation of the CP by magnetic decantation.The products exhibited a high capacity and high selectivity to adsorb Congo red(CR)from an aqueous solution.The sorption kinetics and equilibrium isotherm were studied in detail using four kinetics and three isotherm models.According to the results that were obtained,the mechanism of the sorption process followed the pseudo-second-order kinetic and Langmuir isotherm models.In general,the magnetic hybrid under consideration can be proposed as a reversible catalyst for the selective adsorption of CR with facile separation from the environment using a magnetic bar.展开更多
Nanomaterials have emerged as an active area of research.This is because of their broad spectrum of applications such as sensors,white light emitting diodes(LEDs),electronic displays,and other optoelectronic devices i...Nanomaterials have emerged as an active area of research.This is because of their broad spectrum of applications such as sensors,white light emitting diodes(LEDs),electronic displays,and other optoelectronic devices in the optics and electronic industries owing to their size-and shape-dependent properties.The synthesis technique plays a crucial role in tuning the size and shape of the materials.Herein,we briefly describe these nanomaterials'fundamental aspects,properties,and applications.Various nanomaterial synthesis methods are discussed.Their advantages and disadvantages are highlighted in conjunction with the criteria for selecting a synthesis method.The principle underlying the sonochemical method and its applicability in synthesizing diverse sub-15 nm size nanoparticles(NPs)are presented.The main objective of this article is to review recent studies on lanthanide-doped nanophosphors and the various parameters that play key roles in achieving optimum luminescence emission.Both down-conversion and up-conversion mechanisms are discussed.The importance of the combinations and concentrations of the synthesizer/activator,color tuning,and host material are emphasized.展开更多
基金financially supported by the National Research University Project for Chiang Mai University (CMU) from the Thailand’s Office of the Higher Education Commission, Thailand
文摘ZnO nanostructure materials doped with different La contents were synthesized by sonochemical method. The products were characterized by X-ray diffraction（XRD）, scanning electron microscopy（SEM）,transmission electron microscopy（TEM）, Raman spectroscopy, and Fourier transform infrared spectroscopy（FTIR）. In this research, XRD patterns of pure ZnO and La-doped ZnO are specified as hexagonal wurtzite ZnO structure with no detection of La2O3 phase. SEM and TEM characterization revealed the flower shape of pure ZnO built-up from petals of hexagonal prisms with hexagonal pyramid tips. Upon doping with La, the flower-shaped ZnO is broken into individual 1D prism-like nanorods. Photocatalytic activities of the as-synthesized products were determined by measuring the degradation of methylene blue（MB） under ultraviolet–visible（UV） light irradiation.Among them, the 2.0 mol% La-doped ZnO shows better photocatalytic properties than any other products.
文摘A simple sonochemical route has been successfully developed to synthesize SnO2 hollow microspheres. The obtained sample is characterized by XRD, TEM, XPS and UV-visible spectrophotometer. The TEM image of the sample at high magnification shows that the shell of the hollow sphere is composed of 3-5 nm SnO2 nanoparticles. A possible formation mechanism of the hollow spheres is briefly discussed.
基金We greatly appreciate the support of the National Natural Science Foundation of China （Nos. 21475057, 21335004,） and the Program B tbr Outstanding PhD Candidates of Nanjing University. This work was also supported by the Program for New Century Excellent Talents in University （No. NCET-12-0256）.
文摘The preparation of highly active electrocatalysts with good durability and low cost for fuel cells is highly desir- able but still remains a significant challenge. Here we synthesized two dimensional （2D） C3N4 nanosheets supported palladium composites （C3N4/Pd） via a simple and convenient sonochemical approach. We have systematically stud- ied the electrocatalytic performance of as-prepared catalysts. We found that the prepared C3N4/Pd composites pos- sessed excellent catalytic activity and stability for oxygen reduction reaction （ORR） in alkaline media. Encourag- ingly, the C3N4/Pd catalysts exhibit the excellent electrocatalytic activity for methanol oxidation reaction （MOR） in alkaline media, even better than that of the commercial Pt/C catalyst, The excellent electrocatalytic performance of the 2D C3N4 nanosheets supported palladium composites catalysts results from their synergy effect between the ul- trathin substrate material with large surface area and excellent dispersion of palladium nanoparticles. This study demonstrates that sonochemical method opens up a new avenue for the preparation of electrocatalysts for fuel cells. We expect these materials are likely to find uses in a broad range of applications, for example, fuel cells, solar cells, batteries and other electrochemical analysis.
基金Shahid Chamran University of Ahvaz for financial support(grant number:95/3/02/31579).
文摘A new non-covalently bonded 3D supramolecular architecture,namely,[Cd^(Ⅱ)_(2)Cl_(2)(μ-Cl)_(2)(μ-L)]n[where L=1,1,3,3-tetrakis(3,5-dimethyl-1-pyrazolyl)propane]was synthesized and structurally characterized.In this structure,the N4-coordinated pyrazole-based ligand displayed a chelating-bridging mode and bounds to two neighboring Cd^(Ⅱ)centers to create a 1D sinusoidal chain along the b-axis.Each of the cadmium(Ⅱ)sites adopted a distorted square pyramidal arrangement with a CdN_(2)Cl_(3)core.The chains were further stabilized by non-covalent bonds such as C-H⋯Cl and C-H⋯πto generate a 3D network.This structure has the ability to incorporate Fe_(3)O_(4)@SiO_(2)-NH_(2)nanoparticles and build up an Fe_(3)O_(4)@SiO_(2)-NH_(2)@Cd(Ⅱ)-CP hybrid using a sonochemical method.The bonding established between the Cd(Ⅱ)-CP and aminofunctionalized Fe_(3)O_(4)nanoparticles improved the separation of the CP by magnetic decantation.The products exhibited a high capacity and high selectivity to adsorb Congo red(CR)from an aqueous solution.The sorption kinetics and equilibrium isotherm were studied in detail using four kinetics and three isotherm models.According to the results that were obtained,the mechanism of the sorption process followed the pseudo-second-order kinetic and Langmuir isotherm models.In general,the magnetic hybrid under consideration can be proposed as a reversible catalyst for the selective adsorption of CR with facile separation from the environment using a magnetic bar.
文摘Nanomaterials have emerged as an active area of research.This is because of their broad spectrum of applications such as sensors,white light emitting diodes(LEDs),electronic displays,and other optoelectronic devices in the optics and electronic industries owing to their size-and shape-dependent properties.The synthesis technique plays a crucial role in tuning the size and shape of the materials.Herein,we briefly describe these nanomaterials'fundamental aspects,properties,and applications.Various nanomaterial synthesis methods are discussed.Their advantages and disadvantages are highlighted in conjunction with the criteria for selecting a synthesis method.The principle underlying the sonochemical method and its applicability in synthesizing diverse sub-15 nm size nanoparticles(NPs)are presented.The main objective of this article is to review recent studies on lanthanide-doped nanophosphors and the various parameters that play key roles in achieving optimum luminescence emission.Both down-conversion and up-conversion mechanisms are discussed.The importance of the combinations and concentrations of the synthesizer/activator,color tuning,and host material are emphasized.
