Particle generation by cosolvent spray pyrolysis: Effects of ethanol and ethylene glycol

摘要

A cosolvent spray pyrolysis process was used for the generation of micrometer-sized pure copper particles. Ethylene glycol (EG) and ethanol (ET) were selected as cosolvents, and their effects on particle morphology and composition were systematically investigated. Experimental results showed that oxide-free copper particles could be generated at temperatures greater than 400 ℃ with either cosolvent. Hollow particles with cracks were generated with ET at temperatures from 400 to 1000 ℃, whereas EG promoted the formation of porous particles at temperatures up to 600 ℃ and hollow shell particles with smooth surfaces at 875 and 1000 ℃. Results from short residence time experiments indicated that, during the generation process, lamellar and fragment-like copper hydroxy nitrate [Cu_2(OH)_3NO_3] precipitated when EG and ET were used respectively. Cu_2(OH)_3NO_3 then decomposed to cupric oxide (CuO) and cuprous oxide (Cu_2O). Finally the oxides were reduced to copper (Cu) in the reducing atmosphere created by EG and ET.