Synthesis and characterization of layered and hexagonal nickel-aluminum oxides

Layered and hexagonal mesostructures of nickel-aluminum oxides templated by alkyl sulfate assemblies were synthesized for the first time by the homogeneous precipitation method using urea. X-ray diffraction patterns and transmission electron microscopy (TEM) proved that there was a transformation from layered to hexagonal mesostructure within a prolonged time of 20 h. The Brunauer-Emmett-Teller surface area was reported after solvent extraction and calcinations at a large range of temperatures. The mesostructured hexagonal solid by the anion-exchange with acetate species results in a mesoporous material with a specific surface area of as large as 277 m² g^-1. The specific surface area decreased from 299 to 71 m² g^-1 as the temperatures of calcination increasing from 523 to 1033 K.