Preparation method for gamma-alumina nanotube with prior exposure of (111) face

Abstract

The invention relates to a gamma-alumina nanotube which has a single-crystal structure with the length of 100-200 nanometers and an external diameter of 8-10 nanometers. The gamma-alumina nanotube has a prior exposure of (111) crystal face, and has a hydroxyl density of 1.99mmol / g and acid density of 0.489mmol / g. The invention has the beneficial effects that the gamma-alumina nanotube with the prior exposure of (111) face is prepared by orderly assembling crystallized alumina gel by utilizing the assembling function of inexpensive surfactants, and has a single-crystal structure; the gamma-alumina nanotube with the prior exposure of (111) face has high hydroxyl density and acid density; the invention has simple process which is applicable for large-scale production and has little pollution. The invention also discloses the preparation method thereof.

Description

technical field [0001] The invention relates to a method for preparing gamma-alumina nanotubes with {111} faces preferentially exposed. Background technique [0002] Nanomaterials are new materials developed in recent years. When the size of many materials is as small as nanometers, their magnetic properties, electrical properties, optical properties, and catalytic properties are very different from the macroscopic state. In the nanoscale range, the structure, magnetism, electricity, optics and catalytic properties of many nanomaterials are largely affected by the size and shape of nanoparticles, so the preparation of nanomaterials with uniform morphology and uniform scale distribution Materials are a prerequisite for studying these properties. Among them, relatively simple and reproducible methods for producing nanomaterials with acceptable properties in large quantities are particularly attractive. [0003] γ-alumina is also called activated alumina in industry. In its ...

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Problems solved by technology

[0004] Therefore, there are many reports on the synthesis of alumina nanotubes in recent years, most of which are synthesized by hard template methods, such as Joowon Hwang, etc., who used zinc oxide nanorods as templates to prepare alumina nanotubes by hydrolytic deposition of trimethylaluminum; Z.L.Xiao et al. used porous alumina film corrosion to prepare alumina nanotubes and nanowires, etc. The synthesis route of hard templates is complicated, and chemical methods need to be used to remove templates after synthesis, which is not conducive to large-scale synthesis of nanotube materials.

There are also a few synthesized by soft template method: such as Baochang Cheng et al. with the assistance of cetyltrimethylammonium bromide (CTAB) via Cr 3+ doped layered compound NH 4 Al(OH) 2 CO 3 Curl, and finally form Cr after high-temperature roasting treatment 3+ Doped α-Al 2 o 3 nanotubes; Lihong Qu et al. used sodium dodecylsulfonate as a template to hydrothermally obtain a relatively uniform but amorphous Al 2 o 3 Nanotubes; Hyun Chul Lee et al. Starting from aluminum alkoxides, using a variety of surfactants to hydrothermally prepare AlOOH and Al 2 o 3 Nanotubes, but there are many flakes in the product, and the morphology is not uniform. Similar to this result, Daibin Kuang et al. used CTAB hydrothermal synthesis of AlOOH nanotubes with poor morphology.

There are also a few synthesized by template-free methods. For example, Hongwei Hou et al. used the violent reaction of sodium amide and aluminum chloride to hydrothermally synthesize AlOOH tubes; Bo Tang et al. synthesized AlOOH and Al 2 o 3 Nanotubes, the template-free method is simple, but the uniformity of product morphology is poor

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