Fabrication of Y-junction Metal Nanowires by AAO Template-assisted AC Electrodeposition

In this communication,we report a synthetic approach to fabricate Y-junction Co nanowires and Y-junction Cu nanowires by AC electrodeposition using a hierarchically designed anodized aluminum oxide template.Morphology study showe that diameters of the stems and branches of the Y-junction nanowires were about 40 nm and 20 nm respectively.Structural analysis indicates that Co nanowires had a mixture of face-center-cubic and hexagonal-close-packed structures,whereas Cu nanowires had a face-center-cubic structure with a <110> texture.The Y-junction Co nanowires exhibited a longitudinal coercivity of 1300 Oe and remnant magnetization of 56%,which was affected by the growth direction and microstructure.The present method can be extended to other metallic systems and thus provides a simple and efficient way to fabricate Y-junction metal nanowires.

Functionalization of Semi-terminated Silica Nanotubes

The semi-terminated silica nanotubes with 80-100 nm porous diameter were prepared with AI/Al2O3 （AAO） template by the sol-gel method, and then were functionalized by 3-aminopropyltriethoxysilane （APTES）. The functionalized silica nanotubes were characterized by transmission electron microscope （TEM）, fourier transform infrared spectroscopy （FT-IR）, nuclear magnetic resonance （1H-NMR and 29Si-NMR）. The results indicated that APTES was successfully functionalized onto the internal surface and the mouth of the silica nanotubes. It would provide the material base for silica nanotubes corking and delivery drug.

A mini review： Functional nanostructuring with perfectly-ordered anodic aluminum oxide template for energy conversion and storage

Nanostructures have drawn great attentions for functional device applications. Among the various techniques developed for fabricating arrayed nanostructures of functional materials, nanostructuring technique with porous anodic aluminum oxide （AAO） membrane as templates becomes more attractive owing to the superior geometrical characteristics and low-cost preparation process. In this mini review, progress about functional we summarize our recent nanostructuring based on perfectly-ordered AAO membrane to prepare perfectly- ordered nanostructure arrays of functional materials toward constructing high-performance energy conversion and storage devices. By employing the perfectly-ordered AAO membrane as templates, arrayed nanostructures in the form ofnanodot, nanorod, nanotube and nanopore have been synthesized over a large area. These as-obtained nanostructure arrays have large specific surface area, high regularity, large-scale implementation, and tunable nanos- cale features. All these advanced features enable them to be of great advantage for the performance improvement of energy conversion and storage devices, including photo- electrochemical water splitting cells, supercapacitors, and batteries, etc.

Templated self-assembly of Au-TiO_2 binary nanoparticles-nanotubes

In this work, we developed a templated self-assembly approach to fabricate self-supporting Au/TiO2 binary nanoparticles-nanotubes （NPNTs） for the first time. The stable Au/TiO2 nanoparticles colloids were pre-synthesized and then deposited onto an AAO template, following by a mild calcination process. Au/TiO2 binary NPNTs can be achieved after removing the AAO template by NaOH solution. In addition, Au/TiO2 NPNTs with different thicknesses and size distributions could be achieved by tailoring the process parameters, such as the molar ratio of AuNPs to TiO2NPs, deposition modes and calcinations conditions. Therefore, these findings made controllable formation of Au/TiO2 NPNTs attractive for promising fabrication methodologies of metal/metal oxides NPNTs.

Enhanced light trapping in periodically truncated cone silicon nanowire structure

Light trapping plays an important role in improving the conversion efficiency of thin-film solar cells. The good wideband light trapping is achieved using our periodically truncated cone Si nanowire （NW） structures, and their inherent mechanism is analyzed and simulated by FDTD solution software. Ordered cylinder Si NW structure with initial size orS0 nm and length of 200 nm is grown by pattern transfer and selective epitaxial growth. Truncated cone Si NW array is then obtained by thermal oxidation treatment. Its mean reflection in the range of 300-900 nm is lowered to be 5% using 140 nm long truncated cone Si NW structure, compared with that of 20% using cylinder counterparts. It indicates that periodically truncated Si cone structures trap the light efficiently to enhance the light harvesting in a wide spectral range and have the potential application in highly efficient NW solar cells.

A Ga_2O·11Al_2O_3 nanonet prepared by interfacial reaction growth approach and its application in fabricating GaN nanowires

A Ga2O·11Al2O3 nanonet was synthesized by using Ga2O3 powder as the precursor to generate Ga2O vapor in H2 atmosphere which further reacted with Al2O3 at 730 °C to form Ga2O·11Al2O3 at the interfaces of a porous anodic aluminum oxide (AAO) template. The prepared Ga2O·11Al2O3 nanonet then served as a Ga2O-stablizing reservoir to fabricate single crystal GaN nanowires. The residual Ga2O3 powder at the surface of the produced Ga2O·11Al2O3 nanonet and the metallic Ga or Ga2O from the Ga2O·11Al2O3 decomposition reacted with ammonia to yield GaN nanowires at 780 °C. The reaction mechanisms were investigated.