Morphologies and properties of NiO particles prepared from NiCl2·6H2O by spray pyrolysis

Abstract

Nickel oxide particles were prepared by spray pyrolysis of aqueous solution of NiCl 2 ·6H 2 O. In the reactor the salt droplets were first converted to hollow particles by drying and then they were collapsed by oxidation to reduce their size. Each oxide particle was composed of many small nuclei with voids among them due to extremely low rate of sintering. The particle size decreased with the temperature as the sintering and crystallization proceeded. The size as well as the crystallinity of the particles increased with the initial salt concentration. When the salt droplets were preliminarily dried in diffusion dryer before entering the reactor, the collapse of the particles was considerably reduced, resulting in lower hollowness and higher sphericity. Numerical simulation on the drying of the droplets provided insight on the initial stage of spray pyrolysis.

Growth of a Carbon Micro‐ and Nanocoils Mixture using NiSO4 as the Catalyst Precursor

“…With the increase in temperature, the removal of crystalline water occurs for NiSO 4 . 6H 2 O, however this loss occurs in two steps . It is observed that, when the calcination temperature rises to 550 °C, the material has changed from the original NiSO 4 .…”