ZnO nanobelts, hollow microspheres, and urchins have been prepared on copper foil via a simply low temperature evaporation route. The microstructure, morphologies, and photolu-minescence of the ZnO nanostructures were...ZnO nanobelts, hollow microspheres, and urchins have been prepared on copper foil via a simply low temperature evaporation route. The microstructure, morphologies, and photolu-minescence of the ZnO nanostructures were studied with X-ray diffraction, Raman spectra, scanning electron microscopy and photoluminescence spectra. The width of the nanobelts was about 500 nm and the length was longer than 10μm. The diameter of the hollow microspheres was between 5 and 10μm. A possible growth mechanism of the nanobelts, microspheres and urchins was proposed. The photoluminescence spectrum exhibited strong deep level energy emissions and a weak near band edge emission. These ZnO nanostructures on a copper substrate have the advantages of naturally good adhesion and electrical connection between the ZnO nanostructures and the conductive substrate.展开更多
Micrometer-sized MoO2 hollow spheres were synthesized hydrothermally with ammonium heptamolybdate tetrahydrate as molybdenum source, Cetyltrimethylammonium bromide as structure-directing agent and C2H5OH as reducing a...Micrometer-sized MoO2 hollow spheres were synthesized hydrothermally with ammonium heptamolybdate tetrahydrate as molybdenum source, Cetyltrimethylammonium bromide as structure-directing agent and C2H5OH as reducing agent, respectively. The products were investigated by X-ray diffraction, thermo gravimetry and differential thermal analysis, scanning electron microscopy, transmission electron micraseopy and X-ray photoelectron spectroscopy. A morphology transition of ＂blocks-solid spheres-hollow spheres＂ during the growth procfess was observed and the possible mechanism for the formation of MoO2 samples was proposed to be through a microscale Kirkendall effcct.展开更多
Water electrolysis has attracted a lot of attention in recent years for hydrogen production.CoP has been widely investigated as a traditional electrocatalyst for hydrogen evolution reaction(HER).However,the strong bon...Water electrolysis has attracted a lot of attention in recent years for hydrogen production.CoP has been widely investigated as a traditional electrocatalyst for hydrogen evolution reaction(HER).However,the strong bond strength of P-H bond and weak chemical stability are still the key problems in affecting catalytic performance of CoP.In this work,we synthesized rambutan-like CoP@Mo-Co-O hollow microspheres as HER electrocatalyst,solving the two problems of CoP as electrocatalyst.Benefiting from the unique three-dimensional space structure and interface effect between CoP and Mo-Co-O,the synthesized CoP@Mo-Co-O shows a small overpotential of 62 mV at the current density of 10 mA cm^-2 for HER,which is much lower than the corresponding overpotential of pure CoP microspheres(117 mV).Rambutan-like CoP@Mo-Co-O hollow microspheres also show robust long-term stability and excellent cycling stability.This work provides a new method for the design and improvement of non-precious HER electrocatalysts.展开更多
基金ACKNOWLEDGMENTS This work was supported by the Natural Science Foundation of Fujian Province of China （No.2007J0317 and No.JB06104） and the Key project of Fujian Provincial Department of Science and Technology （No.2007H0019）.
文摘ZnO nanobelts, hollow microspheres, and urchins have been prepared on copper foil via a simply low temperature evaporation route. The microstructure, morphologies, and photolu-minescence of the ZnO nanostructures were studied with X-ray diffraction, Raman spectra, scanning electron microscopy and photoluminescence spectra. The width of the nanobelts was about 500 nm and the length was longer than 10μm. The diameter of the hollow microspheres was between 5 and 10μm. A possible growth mechanism of the nanobelts, microspheres and urchins was proposed. The photoluminescence spectrum exhibited strong deep level energy emissions and a weak near band edge emission. These ZnO nanostructures on a copper substrate have the advantages of naturally good adhesion and electrical connection between the ZnO nanostructures and the conductive substrate.
文摘Micrometer-sized MoO2 hollow spheres were synthesized hydrothermally with ammonium heptamolybdate tetrahydrate as molybdenum source, Cetyltrimethylammonium bromide as structure-directing agent and C2H5OH as reducing agent, respectively. The products were investigated by X-ray diffraction, thermo gravimetry and differential thermal analysis, scanning electron microscopy, transmission electron micraseopy and X-ray photoelectron spectroscopy. A morphology transition of ＂blocks-solid spheres-hollow spheres＂ during the growth procfess was observed and the possible mechanism for the formation of MoO2 samples was proposed to be through a microscale Kirkendall effcct.
文摘Water electrolysis has attracted a lot of attention in recent years for hydrogen production.CoP has been widely investigated as a traditional electrocatalyst for hydrogen evolution reaction(HER).However,the strong bond strength of P-H bond and weak chemical stability are still the key problems in affecting catalytic performance of CoP.In this work,we synthesized rambutan-like CoP@Mo-Co-O hollow microspheres as HER electrocatalyst,solving the two problems of CoP as electrocatalyst.Benefiting from the unique three-dimensional space structure and interface effect between CoP and Mo-Co-O,the synthesized CoP@Mo-Co-O shows a small overpotential of 62 mV at the current density of 10 mA cm^-2 for HER,which is much lower than the corresponding overpotential of pure CoP microspheres(117 mV).Rambutan-like CoP@Mo-Co-O hollow microspheres also show robust long-term stability and excellent cycling stability.This work provides a new method for the design and improvement of non-precious HER electrocatalysts.
