title: Monodisperse colloidal gallium nanoparticles: synthesis, low temperature crystallization, surface plasmon resonance and Li-ion storage.
abstract: We report a facile colloidal synthesis of gallium (Ga) nanoparticles with the mean size tunable in the range of 12-46 nm and with excellent size distribution as small as 7-8%. When stored under ambient conditions, Ga nanoparticles remain stable for months due to the formation of native and passivating Ga-oxide layer (2-3 nm). The mechanism of Ga nanoparticles formation is elucidated using nuclear magnetic resonance spectroscopy and with molecular dynamics simulations. Size-dependent crystallization and melting of Ga nanoparticles in the temperature range of 98-298 K are studied with X-ray powder diffraction, specific heat measurements, transmission electron microscopy, and X-ray absorption spectroscopy. The results point to delta (δ)-Ga polymorph as a single low-temperature phase, while phase transition is characterized by the large hysteresis and by the large undercooling of crystallization and melting points down to 140-145 and 240-250 K, respectively. We have observed size-tunable plasmon resonance in the ultraviolet and visible spectral regions. We also report stable operation of Ga nanoparticles as anode material for Li-ion batteries with storage capacities of 600 mAh g(-1), 50% higher than those achieved for bulk Ga under identical testing conditions.
authors.affiliation: Laboratory for Inorganic Chemistry, Department of Chemistry and Applied Biosciences, ETH Zürich , CH-8093 Zürich, Switzerland.
authors.forename: Maksym
authors.initials: M
authors.lastname: Yarema
authors.forename: Michael
authors.initials: M
authors.lastname: Wörle
authors.forename: Marta D
authors.initials: MD
authors.lastname: Rossell
authors.forename: Rolf
authors.initials: R
authors.lastname: Erni
authors.forename: Riccarda
authors.initials: R
authors.lastname: Caputo
authors.forename: Loredana
authors.initials: L
authors.lastname: Protesescu
authors.forename: Kostiantyn V
authors.initials: KV
authors.lastname: Kravchyk
authors.forename: Dmitry N
authors.initials: DN
authors.lastname: Dirin
authors.forename: Karla
authors.initials: K
authors.lastname: Lienau
authors.forename: Fabian
authors.initials: F
authors.lastname: von Rohr
authors.forename: Andreas
authors.initials: A
authors.lastname: Schilling
authors.forename: Maarten
authors.initials: M
authors.lastname: Nachtegaal
authors.forename: Maksym V
authors.initials: MV
authors.lastname: Kovalenko