Báo cáo hóa học: Single-crystalline nanoporous Nb2O5 nanotubes

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: Single-crystalline nanoporous Nb2O5 nanotubes
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Báo cáo hóa học: " Single-crystalline nanoporous Nb2O5 nanotubes"Liu et al. Nanoscale Research Letters 2011, 6:138http://www.nanoscalereslett.com/content/6/1/138 NANO EXPRESS Open AccessSingle-crystalline nanoporous Nb2O5 nanotubesJun Liu, Dongfeng Xue*, Keyan Li Abstract Single-crystalline nanoporous Nb2O5 nanotubes were fabricated by a two-step solution route, the growth of uniform single-crystalline Nb2O5 nanorods and the following ion-assisted selective dissolution along the [001] direction. Nb2O5 tubular structure was created by preferentially etching (001) crystallographic planes, which has a nearly homogeneous diameter and length. Dense nanopores with the diameters of several nanometers were created on the shell of Nb2O5 tubular structures, which can also retain the crystallographic orientation of Nb2O5 precursor nanorods. The present chemical etching strategy is versatile and can be extended to different-sized nanorod precursors. Furthermore, these as-obtained nanorod precursors and nanotube products can also be used as template for the fabrication of 1 D nanostructured niobates, such as LiNbO3, NaNbO3, and KNbO3.Introduction Recently, the authors have rationally designed a general thermal oxidation strategy to synthesize polycrystallineNanomaterials, which have received a wide recognition porous metal oxide hollow architectures including 1 Dfor their size- and shape-dependent properties, as well nanotubes [15]. In this article, a solution-etching routeas their practical applications that might complement for the fabrication of single-crystalline nanoporoustheir bulk counterparts, have been extensively investi- Nb 2 O 5 nanotubes with NH 4 F as an etching reagent,gated since last century [1-8]. Among them, one-dimen-sional (1D) tubular nanostructures with hollow interiors which can be easily transformed from Nb2O5 nanorodhave attracted tremendous research interest since the precursors is presented. As a typical n-type wide bandgap semiconductor (Eg =discovery of carbon nanotubes [1,9-14]. Most of theavailable single-crystalline nanotubes structurally possess 3.4 eV), Nb 2 O 5 is the most thermodynamically stablelayered architectures; the nanotubes with a non-layered phase among various niobium oxides [16]. Nb2O5 hasstructure have been mostly fabricated by employing por- attracted great research interest due to its remarkableous membrane films, such as porous anodized alumina applications in gas sensors, catalysis, optical devices, andas template, which are either amorphous, polycrystalline, Li-ion batteries [9-11,16-21]. Even monoclinic Nb2 O5or only in ultrahigh vacuum [13,14]. The fabrication of nanotube arrays were successfully synthesized through asingle-crystalline semiconductor nanotubes is advanta- phase transformation strategy accompanied by the voidgeous in many potential nanoscale electronics, optoelec- formation [10], which can only exist as non-poroustronics, and biochemical-sensing applications [1]. polycrystalline nanotubes. In this study, a new chemicalParticularly, microscopically endowing these single-crys- etching route for the synthesis of single-crystallinetalline nanotubes with a nanoporous feature can further nanoporous Nb2O5 nanotubes, according to the prefer-broaden their practical applications in catalysis, bioengi- ential growth habit along [001] of Nb2O5 nanorods, isneering, environments protection, sensors, and related reported. The current chemical etching route can beareas due to their intrinsic pores and the high surface- applied to the fabrication of porous and tubular featuresto-volume ratio. However, it still remains a big long- in single-crystalline phase oxide materials.term challenge to develop those simple and ...