A new approach to synthesis and growth of nanocrystalline AlOOH with high pore volume

Abstract

In this study, AlOOH nanostructures were successfully synthesized using the solvothermal method at 180 °C. The effects of the pH of the solution (3, 4.5, 6.5, 10 and 12.5) on the synthesized samples were investigated sys­tem­atically in detail, when ethanol and NaOH were the solvent and pH-adjusting agent, respectively. Fourier transform infrared spectroscopy, X-ray powder diffraction and field emission scanning electron microscopy were used to char­acterize the synthesized samples. The specific sur­face area, pore size distri­bution and pore structure of different AlOOH structures at various pH levels were also discussed in terms of the N2 adsorption/desorption test. According to the experimental results, the FESEM micrographs showed that the products were nanostructures, and the AlOOH nanoparticles larger on increasing the pH from 4.5 to 12.5. The structure characterization revealed that the resulting AlOOH nanostructures were pure and had a well-defined crystalline structure with a crystal size of 9.3–20.5 nm. Furthermore, the boehmite obtained at pH 12.5 exhibited a large surface area of 131 m2 g-1 and a high total pore volume of 1.24 cm3 g-1.