Synthesis of nickel nanoparticles dispersed in γ-alumina by heterogeneous precipitation

A heterogeneous precipitation method is described for obtaining nanocomposite powders consisting of Ni nanoparticles homogeneously dispersed within γ-Al2O3. The amorphous Al(OH)3 was nucleated on the surfaces of NiO nanoparticles and crystallized to γ-Al2O3 at 900 °C. The porosity of γ-Al2O3 allowed the growth of NiO nanoparticles during calcinations. After the calcined nanocomposite powders were selectively reduced at 700 °C in a hydrogen atmosphere, NiO nanoparticles were converted to Ni with the size of 25–35 nm. TEM observation and AES analysis showed Ni nanoparticles were uniformly dispersed in the γ-Al2O3 matrix.