(GO/TiO2)N(GO represents graphene oxide,and N represents the period number of alternate superposition of two dielectrics)onedimensional photonic crystal with different lattice constants was prepared via the sol–gel t...(GO/TiO2)N(GO represents graphene oxide,and N represents the period number of alternate superposition of two dielectrics)onedimensional photonic crystal with different lattice constants was prepared via the sol–gel technique,and its transmission characteristics for photocatalysis were tested.The results show that the lattice constant,filling ratio,number of periodic layers,and incident angle had effects on the band gap.When the lattice constant,filling ratio,number of periodic layers,and incident angle were set to 125 nm,0.45,21,and 0°,respectively,a gap width of 53 nm appeared at the central wavelength(322 nm).The absorption peak of the photocatalyst at 357 nm overlapped the blue edge of the photonic band gap.A slow photon effect region above 96%reflectivity appeared.The degradation rate of tetracycline in(GO/TiO2)N photonic crystal was enhanced to 64%within 60 min.Meanwhile,the degradation efficiency of(GO/TiO2)N one-dimensional photonic crystal was effectively improved compared with those of the GO/TiO2 composite film and GO/TiO2 powder.展开更多
The Morpho butterfly is famous for its typical structural color and has increasingly attracted the interest of scholars in a wide variety of research fields. Herein, it was found that the color of Morpho menelaus butt...The Morpho butterfly is famous for its typical structural color and has increasingly attracted the interest of scholars in a wide variety of research fields. Herein, it was found that the color of Morpho menelaus butterfly wings is not only structure-based but also viewing-angle-dependent. Firstly, the discoloration effect of this typical butterfly was confirmed by a series of experiments. Then, the general form, arrangements, and geometrical dimensions of the scales were observed using a stereomicroscope. Scanning electron microscopy was also used to examine the two-dimensional morphologies and structures of a single scale. Afterwards, one model with the optimized three-dimensional profile of the structure was described using Pro-engineer software. The associate model was then analyzed to reconstruct the process between the incident light and the model surface. Finally, the mechanism of the angle-dependent discoloration effect was analyzed by theoretical calculation and optical simulation. Different light propagation paths and the length of the incident light at different angles caused destructive or constructive interference between the light reflected from the different layers. The different spectra of the reflected light make the wings appear with different structural colors, thereby endowing the angle-dependent discoloration effect. The consistency of the calculation and simulation results confirms that these structures possess an excellent angle-dependent discoloration effect. This functional "biomimetic structure" would not only be of great scientific interest but could also have a great impact in a wide range of applications such as reflective displays, credit card security, and military stealth technology.展开更多
基金the National Key R&D Program of China(No.2016YFC0700904)。
文摘(GO/TiO2)N(GO represents graphene oxide,and N represents the period number of alternate superposition of two dielectrics)onedimensional photonic crystal with different lattice constants was prepared via the sol–gel technique,and its transmission characteristics for photocatalysis were tested.The results show that the lattice constant,filling ratio,number of periodic layers,and incident angle had effects on the band gap.When the lattice constant,filling ratio,number of periodic layers,and incident angle were set to 125 nm,0.45,21,and 0°,respectively,a gap width of 53 nm appeared at the central wavelength(322 nm).The absorption peak of the photocatalyst at 357 nm overlapped the blue edge of the photonic band gap.A slow photon effect region above 96%reflectivity appeared.The degradation rate of tetracycline in(GO/TiO2)N photonic crystal was enhanced to 64%within 60 min.Meanwhile,the degradation efficiency of(GO/TiO2)N one-dimensional photonic crystal was effectively improved compared with those of the GO/TiO2 composite film and GO/TiO2 powder.
基金supported by the National Natural Science Foundation of China(Grant Nos.51325501,51505183&51290292)China Postdoctoral Science Foundation Funded Project(Project No.2015 M571360)
文摘The Morpho butterfly is famous for its typical structural color and has increasingly attracted the interest of scholars in a wide variety of research fields. Herein, it was found that the color of Morpho menelaus butterfly wings is not only structure-based but also viewing-angle-dependent. Firstly, the discoloration effect of this typical butterfly was confirmed by a series of experiments. Then, the general form, arrangements, and geometrical dimensions of the scales were observed using a stereomicroscope. Scanning electron microscopy was also used to examine the two-dimensional morphologies and structures of a single scale. Afterwards, one model with the optimized three-dimensional profile of the structure was described using Pro-engineer software. The associate model was then analyzed to reconstruct the process between the incident light and the model surface. Finally, the mechanism of the angle-dependent discoloration effect was analyzed by theoretical calculation and optical simulation. Different light propagation paths and the length of the incident light at different angles caused destructive or constructive interference between the light reflected from the different layers. The different spectra of the reflected light make the wings appear with different structural colors, thereby endowing the angle-dependent discoloration effect. The consistency of the calculation and simulation results confirms that these structures possess an excellent angle-dependent discoloration effect. This functional "biomimetic structure" would not only be of great scientific interest but could also have a great impact in a wide range of applications such as reflective displays, credit card security, and military stealth technology.
