tailieunhanh - Báo cáo hóa học: " Quasi-radial growth of metal tube on si nanowires template"

Tuyển tập báo cáo các nghiên cứu khoa học quốc tế ngành hóa học dành cho các bạn yêu hóa học tham khảo đề tài: Quasi-radial growth of metal tube on si nanowires template | Huang et al. Nanoscale Research Letters 2011 6 165 http content 6 1 165 o Nanoscale Research Letters a SpringerOpen Journal NANO EXPRESS Open Access Quasi-radial growth of metal tube on si nanowires template Zhipeng Huang 1 Lifeng Liu2 Nadine Geyer2 Abstract It is reported in this article that Si nanowires can be employed as a positive template for the controllable electrochemical deposition of noble metal tube. The deposited tube exhibits good crystallinity. Scanning electron microscope and transmission electron microscope characterizations are conducted to reveal the growth process of metal tube showing that the metal tube grows quasi-radially on the wall of Si nanowire. The quasi-radial growth of metal enables the fabrication of thickness-defined metal tube via changing deposition time. Inner-diameter-defined metal tube is achieved by choosing Si nanowires with desired diameter as a template. Metal tubes with inner diameters ranging from 1 gm to sub-50 nm are fabricated. Introduction Owing to a considerably enhanced surface-to-volume ratio compared to bulk one-dimensional metallic tubular structure has shown promising application potential in the fields of energy storage and conversion 1 2 catalysis 3-5 and magnetism 6 7 and therefore has gained increasing attention. Similar to the case of other nanostructures controllable fabrication is essential for the device application of tubular structure. Various approaches . electrochemical deposition 8-10 electroless deposition 11 12 etc. have been developed to fabricate metal tubes. Meanwhile templates with specific aspect ratio and packing manner are used to define the geometries of nanotubes. Nowadays two insulating masks namely porous anodic aluminum oxide AAO and ion-track-etched polymer membrane are widely used for the fabrication of nanotubes. However chemical modification introducing molecular anchor of pore wall 9 13 14 or metal pre-deposition as seed layer on pore wall 12 15 is .