Redoxaktive Nanoröhren aus Vanadiumoxid

Abstract

Anders als die viel kleineren Kohlenstoffnanoröhren erhält man VOx‐Nanoröhren (Bild rechts) als Hauptprodukt einer direkten chemischen Synthese bei recht niedrigen Temperaturen. Die Röhrenwände sind mehrschichtig, und zwischen den Schichten befinden sich Templatmoleküle, die durch Kationenaustausch unter Erhaltung der Röhren entfernt werden können.

Developments in Nanostructured Cathode Materials for High‐Performance Lithium‐Ion Batteries

“…Pioneering work on the synthesis and electrochemical properties of vanadium oxide nanorolls was carried out by Spahr et al [53] In their synthesis, a combination of sol-gel reaction and hydrothermal treatment of vanadium oxide precursor is conducted in the presence of an amine that acts as structure-directing template. [53,[54][55][56][57] The resultant nanoroll is either constructed in closed concentric cylinders (nanotubes) or formed by scrolling one or more layers (nanoscrolls). If amine is replaced by ammonia during the hydrolysis step, a new type of vanadium oxide nanoroll (nanotube) with alternating interlayer distances is obtained.…”

Strong reduction of V4+ amount in vanadium oxide/hexadecylamine nanotubes by doping with Co2+ and Ni2+ ions: Electron paramagnetic resonance and magnetic studies

“…The VO x NT's present several potential technological applications, such as sensing elements [13], catalysis [14] and Li-ion batteries cathodes [15]. In the last case, it was found that the amount of V 4+ in the structure is critical as it affects and reduce notabily the performance of the cathode.…”

Nanotubes and Nanowires

“…Nanotubes of oxides of several transition metals, as well as of other metals, have been synthesized by employing different methodologies [24,[216][217][218][219][220]. Silica nanotubes were first produced as a spin-off product during the synthesis of spherical silica particles by the hydrolysis of tetraethylorthosilicate (TEOS) in a mixture of water, ammonia, ethanol and D,L-tartaric acid [216].…”

“…Redox catalytic activity is also retained in the nanotubular structure. There have been efforts to prepare V 2 O 5 nanotubes by chemical methods as well [219].…”

“…Thus, nanotubes of several metal oxides (e.g., SiO 2 [235], V 2 O 5 [219], ZnO [236]) have been produced hydrothermally. Nanotubes of oxides such as V 2 O 5 are also conveniently prepared from a suitable metal oxide precursor in the presence of an organic amine or a surfactant [237].…”