Growth of 1D- oxide nanostructures
Résumé
One-dimensional (1D) oxide materials are anisotropic nanocrystals with large aspect ratios (length/diameter). Typically, they display diameters of 1–200 nm and lengths up to several tens of micrometers. Given their specific shape, 1D oxides are found in the literature under different names: nanowires, nanorods, nanotubes, nanobelts, nanofibers, whiskers, etc. To date, different approaches have been proposed to achieve 1D growth of oxides with different degrees of control over the growth process. These approaches are based on (i) taking advantage of the inherent anisotropic crystallographic structure of certain solids to promote the 1D growth, (ii) using organic additives or surfactants to kinetically control the oriented attachment of some crystallographic facets of a seed to finally form 1D nanostructures, (iii) using hard or soft templates (with 1D porosity) to directly grow nanowires and/or nanotubes, or (iv) controlling the condition of supersaturation to modify the tendency of seed to growth. Multinary oxides, also named functional complex oxides, are materials that contain two or more metals in a precise ratio. The preparation of these oxides is to date a key challenge in materials science development.