Solid‐Based Hydrothermal Synthesis and Characterization of Alumina Nanofibers with Controllable Aspect Ratios

Abstract

Nanofibers of AlOOH with controllable aspect ratios have been synthesized by a facile steam-assisted solid-phase crystallization route. The morphology and aspect ratios of resulting AlOOH nanofibers were significantly influenced by the alkaline medium used in the preparation of solid precipitates from Al(NO 3 ) 3 solution. When tetramethylammonium hydroxide was used for precipitation, straight rod-like nanofibers with aspect ratios of 10-20 were obtained. The use of other tetra-alkylated ammonium hydroxides, such as tetraethylammonium hydroxide, tetrapropylammonium hydroxide or tetrabutylammonium hydroxide, led to the formation of long wire-like nanofibers with aspect ratios up to 150. After thermal treatment at 6001C, the morphologies of the one-dimensional nanostructures were well preserved while the crystal structure was converted to c-alumina. The wire-like nanofibers of alumina possessed higher thermal stability than alumina nanorods, and both exhibited much higher stability as compared with alumina micropowder. E. Suvaci-contributing editor

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