Effect of heat treatment on pore structure in nano-crystalline NiO: A small angle neutron scattering study

Nano-crystalline nickel oxide powder was synthesized by a precipitation route. Powder samples were heat treated at 300, 600 and 900 °C, and pore structure evolution was followed by small angle neutron scattering (SANS) technique. SANS measurements were carried out also on pelleted samples in order to study the modifications of pore morphology due to heat treatment. SANS data reveal scattering from pores at two different length scales. The pore structure at various heat treatment temperatures does not follow any scaling behavior.

SEM micrograph shows the microstructure of the nano-crystalline NiO. An average agglomerate size of ∼1 μm is evident from SEM and LS.SANS profiles for the samples heat treated at 300, 600 and 900 °C, respectively, are shown. A significant variation in the profile shape due to the modification in the intra-agglomerate pore structure under heat treatment is visible.Figure optionsDownload as PowerPoint slide