title: Cu(II) galvanic reduction and deposition onto iron nano- and microparticles: resulting morphologies and growth mechanisms.
abstract: The galvanic reduction of heavy metal ions by zerovalent iron nanoparticles is a key process occurring extensively in wastewater remediation, as well as for the synthesis of materials, including catalysts. In this work, we studied the growth of copper species on nano- and micrometer-sized iron particles and investigated the morphologies of the resulting structures. The growth proceeds via sacrificial oxidation of iron particles and reduction of Cu(2+) cations from aqueous solutions. Based on the results of transmission and scanning electron microscopy (TEM and SEM), coupled with energy-dispersive X-ray spectroscopy (EDX), electron energy loss spectroscopy (EELS), and X-ray photoelectron spectroscopy (XPS), we proposed two growth mechanisms for the morphologies seen for the copper exposed nano- and microiron particles at varying copper/iron ratios. We observed that, in low Cu/Fe ratios (≤1/100), copper particles decorated the oxide shell of the iron nano/microparticles, while in higher Cu/Fe ratios (≥1/10), Cu-rich hollow structures were formed. Iron microparticles also led to the formation of interesting Cu-fern structures. This study provides insight into the fate of particles used in remediation, as well as recommendations for the synthesis of well-defined materials tailored for precise applications.
authors.affiliation: Centre for Green Chemistry and Catalysis, Department of Chemistry, McGill University , 801 Sherbrooke Street, West Montreal, QC, H3A 0B8, Canada.
authors.forename: Mitra
authors.initials: M
authors.lastname: Masnadi
authors.forename: Nan
authors.initials: N
authors.lastname: Yao
authors.forename: Nadi
authors.initials: N
authors.lastname: Braidy
authors.forename: Audrey
authors.initials: A
authors.lastname: Moores