Azevedo João, Fernández-García M P, Magén César, Mendes Adélio, Araújo João P, Sousa Célia T
LEPABE - Faculdade de Engenharia, Universidade do Porto, Rua Dr. Roberto Frias, 4200-465, Porto, Portugal.
IFIMUP and Departamento de Física e Astronomia da Faculdade de Ciências da Universidade do Porto, Rua do Campo Alegre 687, 4169-007, Porto, Portugal.
Sci Rep. 2019 Aug 19;9(1):11994. doi: 10.1038/s41598-019-47704-5.
Double-walled oxide nanotube structures are interesting for a wide range of applications, from photocatalysis to drug delivery. In this work, a progressive oxidation method to fabricate double-walled nanotube structures is reported in detail. The approach is based on the electrodeposition of metallic iron nanowires, in porous alumina templates, followed by a selective chemical etching, nanoscale Kirkendall effect, a fast oxidation and out-diffusion of the metallic core structure during thermal annealing. To validate the formation mechanism of such core-shell structure, chemical composition and atomic structure were assessed. The resulting hematite nanotubes have a high degree of uniformity, along several microns, and a nanoscopic double-walled structure.
双壁氧化物纳米管结构因其在从光催化到药物递送等广泛应用中具有吸引力。在这项工作中，详细报道了一种制备双壁纳米管结构的渐进氧化方法。该方法基于在多孔氧化铝模板中电沉积金属铁纳米线，随后进行选择性化学蚀刻、纳米级柯肯达尔效应、热退火过程中金属核心结构的快速氧化和向外扩散。为了验证这种核壳结构的形成机制，对化学成分和原子结构进行了评估。所得的赤铁矿纳米管在几微米的长度上具有高度的均匀性以及纳米级的双壁结构。
