Control of size and morphology in NiO particles prepared by a low-pressure spray pyrolysis

Abstract Nickel oxides (NiO) nano- and submicron particles were synthesized by a low-pressure spray pyrolysis system. Conversion of micrometer droplets into particles in the gas phase using NiO synthesis as a model was studied. Different types of precursors (aqueous Ni(NO 3 ) 2 ·6H 2 O, NiCl 2 , and Ni(HCO 2 ) 2 ·2H 2 O) and temperatures from 400 to 900 °C have great influences on controlling the size and morphology of final particles. The results show that operation of a low-pressure system leads to substantial changes in size and morphology of particles, and that the NiO particles having size around 20 nm can be generated under a limited of conditions.