Hierarchical alumina: from pure phase to nanocomposites.

Recent advances in nanotechnology make it possible to create nanomaterials based on gamma-alumina with novel hierarchical structure and physicochemical properties. Hierarchical gamma-alumina can be synthesized using chemical or physical methods. The nanostructures based on gamma-alumina exhibit unique properties, which are utilized in the design of efficient applications. These superior properties are often due to their hierarchical organizations from the nanosize scale to the macroscopic level. The present review is devoted to the contemporary state of the studies on the methods to produce hierarchical gamma-alumina. We tried to summarize herein the literature data on the methods of synthesis of hierarchical gamma-AlOOH and gamma-Al2O3 with controlled morphology and the application of these methods for the synthesis of hierarchical gamma-AlOOH and gamma-Al2O3 nanocomposites.