title: Crystalline phase reduction of cuprous oxide (Cu2O) nanoparticles accompanied by a morphology change during ethanol-assisted spray pyrolysis.
abstract: Metallic copper nanoparticles are produced by spray pyrolysis of copper nitrates with an addition of ethanol as cosolvent at 600 degrees C. Depending on the synthesis temperature, two interesting reaction pathways are found: below 525 degrees C, approximately 10% of hollow Cu(2)O parent particles are oxidized to CuO and then reduced to Cu, but at higher temperature, the remaining Cu(2)O takes a direct path to Cu, accompanied by a morphology change. These interesting reaction regimes are discussed in the aspects of phase-transformation kinetics, gas-phase and solid-phase thermodynamics, force balance, and their possible influences on structural instability. Experimental observations are fairly consistent with the predictions by the present models.
authors.affiliation: School of Mechanical Engineering, Pusan Clean Coal Center, Pusan National University, Busan 609-735, South Korea.
authors.forename: Dudi Adi
authors.initials: DA
authors.lastname: Firmansyah
authors.forename: Taeil
authors.initials: T
authors.lastname: Kim
authors.forename: Songkil
authors.initials: S
authors.lastname: Kim
authors.forename: Kyle
authors.initials: K
authors.lastname: Sullivan
authors.forename: Michael R
authors.initials: MR
authors.lastname: Zachariah
authors.forename: Donggeun
authors.initials: D
authors.lastname: Lee