Well ordered porous anodic alumina (PAA) film was prepared on pure Al substrate using sulfuric/oxalic acid mixture as electrolyte with different ratios, the best regular PAA film with an average diameter of 45 nm was ...Well ordered porous anodic alumina (PAA) film was prepared on pure Al substrate using sulfuric/oxalic acid mixture as electrolyte with different ratios, the best regular PAA film with an average diameter of 45 nm was obtained using 1∶1 sulfuric/oxalic (molar concentration) mixed acid at 26 V. Addition of oxalic acid into sulfuric acid electrolyte resulted in the increase of anodizing current density, indicating a faster formation rate of PAA film. In 1∶1 sulfuric/oxalic acid electrolyte, the current density was the biggest, which illustrated that the formed barrier layer was the thinnest. Besides, addition of oxalic acid increased the stress of oxide film, accordingly changed the self-organized process of PAA film. XPS results indicate that the PAA film is mainly composed of amorphous alumina independent of oxalic acid addition.展开更多
Nano-pore array structure of alumina films formed on different aluminum substrate in acid electrolyte by electrochemical anodization has been studied. It is found that dislocation as one of the important parameters in...Nano-pore array structure of alumina films formed on different aluminum substrate in acid electrolyte by electrochemical anodization has been studied. It is found that dislocation as one of the important parameters in self-assembling process not only affects the current density occuring in anodization, but also the nano-pore order. Dislocation leads to the differences of the energy of Al and the speed of Al 3+ forming in dislocation and non-dislocation. Dislocation was also in close relation with the acidity of the electrolyte used. The stronger the acidity of the electrolyte, the greater the influence of the dislocation.展开更多
Porous alumina covered with europium doped silica sol gel film exhibited strong Eu 2+ related photoluminescence at 396 nm at room temperature( λ ex =310 nm). The intensity of the photoluminescence can be increased by...Porous alumina covered with europium doped silica sol gel film exhibited strong Eu 2+ related photoluminescence at 396 nm at room temperature( λ ex =310 nm). The intensity of the photoluminescence can be increased by using porous matrix, thicker gel film and lower annealed temperature due to more photoactive species on the surface. Ag particles can improve the photoluminescence by affecting the surrounding electron field of Eu 2+ .展开更多
文摘Well ordered porous anodic alumina (PAA) film was prepared on pure Al substrate using sulfuric/oxalic acid mixture as electrolyte with different ratios, the best regular PAA film with an average diameter of 45 nm was obtained using 1∶1 sulfuric/oxalic (molar concentration) mixed acid at 26 V. Addition of oxalic acid into sulfuric acid electrolyte resulted in the increase of anodizing current density, indicating a faster formation rate of PAA film. In 1∶1 sulfuric/oxalic acid electrolyte, the current density was the biggest, which illustrated that the formed barrier layer was the thinnest. Besides, addition of oxalic acid increased the stress of oxide film, accordingly changed the self-organized process of PAA film. XPS results indicate that the PAA film is mainly composed of amorphous alumina independent of oxalic acid addition.
文摘Nano-pore array structure of alumina films formed on different aluminum substrate in acid electrolyte by electrochemical anodization has been studied. It is found that dislocation as one of the important parameters in self-assembling process not only affects the current density occuring in anodization, but also the nano-pore order. Dislocation leads to the differences of the energy of Al and the speed of Al 3+ forming in dislocation and non-dislocation. Dislocation was also in close relation with the acidity of the electrolyte used. The stronger the acidity of the electrolyte, the greater the influence of the dislocation.
文摘Porous alumina covered with europium doped silica sol gel film exhibited strong Eu 2+ related photoluminescence at 396 nm at room temperature( λ ex =310 nm). The intensity of the photoluminescence can be increased by using porous matrix, thicker gel film and lower annealed temperature due to more photoactive species on the surface. Ag particles can improve the photoluminescence by affecting the surrounding electron field of Eu 2+ .
