In nature,many living organisms exhibit low-angle-dependent or even angle-independent structural colors for wide viewing angle,such as the blue skin of mandrill,feather of blue bird and shell of longhorn beetle,etc.To...In nature,many living organisms exhibit low-angle-dependent or even angle-independent structural colors for wide viewing angle,such as the blue skin of mandrill,feather of blue bird and shell of longhorn beetle,etc.To mimic these structural colors,based on periodic semicircular micro-grooved(PSMG) substrate,silica colloidal photonic crystals provide anisotropic angle-independent structural colors.The PSMG photonic crystals were fabricated by self-assembling monodispersed silica nanoparticles on a micro-grooved template,which can be easily prepared in large scale by a hot embossing method,and no additional materials are needed in the whole preparation process.The PSMG photonic crystals exhibit identical structural colors around the groove axis,whereas it is angle-dependent along the groove axis.In addition,this PSMG surface of photonic crystal also leads to color separation effect and monocolor polarization conversion.This system provides a facile and scalable means to prepare anisotropically angleindependent colloidal photonic crystal,which is considered important in applications in the field of anti-counterfeiting or the manufacture of monochromatic light reflector with wide viewing angles and other novel optical devices.展开更多
A facile design of Pt nanostructures from submonolayer to monolayer has been realized by ion adsorption-in situ electrochemical reduction on Au nanoparticles supported on multiwall carbon nanotubes （CNTs）. The as pr...A facile design of Pt nanostructures from submonolayer to monolayer has been realized by ion adsorption-in situ electrochemical reduction on Au nanoparticles supported on multiwall carbon nanotubes （CNTs）. The as prepared Au@Pt/CNTs catalysts display coverage-specific electrocatalysis. Au@Pt/CNTs with low Pt coverage is inactive towards methanol oxidation whereas it oxidizes formic acid effectively through a direct pathway with mass specific activity 90 times that of a commercial Pt/C catalyst. Due to its inertness to methanol, it shows high performance in the oxygen reduction reaction （ORR） with high methanol tolerance. In contrast, simply increasing the Pt coverage to above 40% switches the formic acid oxidation process to both direct and indirect catalytic pathways, and also results in high methanol oxidation activity.展开更多
基金supported by the National Key Research and Development Program of China(2016YFA0200800, 2013CB834505)he National Natural Science Foundation of China(U1430128,21503244)
文摘In nature,many living organisms exhibit low-angle-dependent or even angle-independent structural colors for wide viewing angle,such as the blue skin of mandrill,feather of blue bird and shell of longhorn beetle,etc.To mimic these structural colors,based on periodic semicircular micro-grooved(PSMG) substrate,silica colloidal photonic crystals provide anisotropic angle-independent structural colors.The PSMG photonic crystals were fabricated by self-assembling monodispersed silica nanoparticles on a micro-grooved template,which can be easily prepared in large scale by a hot embossing method,and no additional materials are needed in the whole preparation process.The PSMG photonic crystals exhibit identical structural colors around the groove axis,whereas it is angle-dependent along the groove axis.In addition,this PSMG surface of photonic crystal also leads to color separation effect and monocolor polarization conversion.This system provides a facile and scalable means to prepare anisotropically angleindependent colloidal photonic crystal,which is considered important in applications in the field of anti-counterfeiting or the manufacture of monochromatic light reflector with wide viewing angles and other novel optical devices.
文摘A facile design of Pt nanostructures from submonolayer to monolayer has been realized by ion adsorption-in situ electrochemical reduction on Au nanoparticles supported on multiwall carbon nanotubes （CNTs）. The as prepared Au@Pt/CNTs catalysts display coverage-specific electrocatalysis. Au@Pt/CNTs with low Pt coverage is inactive towards methanol oxidation whereas it oxidizes formic acid effectively through a direct pathway with mass specific activity 90 times that of a commercial Pt/C catalyst. Due to its inertness to methanol, it shows high performance in the oxygen reduction reaction （ORR） with high methanol tolerance. In contrast, simply increasing the Pt coverage to above 40% switches the formic acid oxidation process to both direct and indirect catalytic pathways, and also results in high methanol oxidation activity.
