Synthesis and Characterisation of γ-Al₂O₃ with Porous Structure and Nanorod Morphology

Abstract

Mesoporous γ-Al 2 O 3 nanorods can be successfully synthesised using calcination of as-synthesised boehmite at 500 °C. The use of NaOH and KOH as pH adjusting agents in hydrothermal route on the synthesised samples are investigated in detail. X-ray powder diffraction, Fourier transform infrared spectroscopy, thermogravimetric analysis, N 2 adsorption/desorption, field emission scanning electron microscopy (FESEM) and transmission electron microscopy (TEM) are used to characterise the products. The TEM and FESEM micrographs show that the products were nanorod. According to our experimental results, the as-prepared γ-AlOOH and γ-Al 2 O 3 possesses ordered mesoporosity and narrow pore-size distribution. The γ-Al 2 O 3 prepared using KOH as pH adjusting regent show higher surface area compared with other samples prepared by NaOH.

Effects of additives on the hydrogen generation of Al-H2 O reaction at low temperature

“…Especially for the ship propulsion system and the torpedo propulsion system, the hydrogen produced by the reaction between Al and seawater will help to reduce the weight of propulsion system. In addition, the produced AlO(OH) can be used to generate porous γ-Al 2 O 3 by hydrothermal route at 500°C, and the mesoporous γ-Al 2 O 3 nanorods apply more broadly [4].…”

The Role of Urea on the Hydrothermal Synthesis of Boehmite Nanoarchitectures

“…On the other hand, the synthesis of inorganic nanoscale materials with special morphologies has been of great interest in recent years because the intrinsic properties of nano scale materials are mainly determined by their composition, structure, crystallinity, size and morphology [4]. Various methods, such as chemical vapour deposition [5], sol-gel process [6], solvothermal [7], dry gel conversion [8], anodic oxidation [9], co-precipitation [10], hydrothermal [11][12][13], sonochemistry [14], and combustion [15] were employed for the preparation of nanostructures. Among these synthesis methods the hydrothermal route has some distinct advantages such as the moderate condition and the easy control of the solution components [18].…”

“…γ-Alumina is one of the most important oxides which it's can be obtained through the dehydration of the boehmite form of γ-AlOOH at temperatures in the range of 400 -700°C. γ-Al 2 O 3 , which is obtained commonly from boehmite by calcination at 500°C in air [11,12], Also boehmite or aluminium oxide-hydroxide (AlOOH), is a versatile material employed in domains such as ceramics, surface coatings, morphology control, and pharmaceuticals [13,19]. It is also an important precursor of preparing alumina, which is a low cost material most widely used as catalyst or catalyst supports [15][16][17] because of its high surface area, mesoporosity and surface acidity.…”

“…Therefore, it is crucial to control the shape and size on AlOOH materials before use. Aiming at this goal, well-defined AlOOH nanostructures with various morphologies such as nanopowders [20], nanorods and nanoflakes [11,21], nanofibers [22], nanobelts [23], hollow microspheres [3], nanoarchitectures [12,[24][25][26]34], cantaloupe-like [27], microspheres [28] and three-Quarter-Sphere [29] have been prepared via many methods and conditions. Therefore, the method and conditions can be having an important role in the synthesis of special AlOOH.…”

THE EFFECT OF NaOH AND KOH ON THE CHARACTERIZATION OF MESOPOROUS AlOOH IN THE SOLVOTHERMAL ROUTE

“…On the other side, nanostructure materials also provide large surface areas compared with their micro and macro counterparts. Owing to these, several researches have broadly addressed to develop new methods to prepare oxyhydroxides nanostructures [1][2][3][4][5][6][7][8][9][10][11]. Among these, boehmite (AlOOH) has attracted extensive attention because of their nontoxic and low cost characteristics for many applications [12][13][14][15][16][17].…”