Morphologically Tuned Aluminum Hydrous Oxides and Their Calcined Products

Abstract

Aluminum hydrous oxides and their derivatives were prepared by a facile solvothermal process in the presence of formamide, dimethyl formamide, and diethyl formamide as solvents at 150°C/24 h. The as‐synthesized products were calcined at 500°C/1 h to obtain γ‐Al2O3. The crystallization behavior and microstructure of the pre‐ and postcalcination products were studied by X‐ray diffraction and transmission electron microscopy, respectively. The surface textural properties of the calcined samples were investigated by N2 adsorption–desorption analysis. The formamide and its derivatives played a significant role in tuning textural properties of the calcined products. The diethyl formamide based sample exhibited enhanced Brunauer–Emmett–Teller surface area and pore volume of 517 m2 g−1 and 2 cm3 g−1, respectively. Both the as‐prepared and calcined samples showed variable morphologies and crystallinity using different solvents. The trend in morphological changes as nanosheet → nanorod → nanowire bundles occurred in the presence of formamide, dimethylformamide, and diethylformamide, respectively. A tentative mechanism has been illustrated for the formation of the products.