title: Bismuth hexagons: facile mass synthesis, stability and applications.
abstract: A unique direct electrodeposition technique involving very high current densities, high voltages and high electrolyte concentrations is applied for highly selective mass synthesis of stable, isolable, surfactant-free, single-crystalline Bi hexagons on a Cu wire at room temperature. A formation mechanism of the hexagons is proposed. The morphology, phase purity, and crystallinity of the material are well characterized by FESEM, AFM, TEM, SAED, EDX, XRD, and Raman spectroscopy. The thermal stability of the material under intense electron beam and intense laser light irradiation is studied. The chemical stability of elemental Bi in nitric acid shows different dissolution rates for different morphologies. This effect enables a second way for the selective fabrication of Bi hexagons. Bi hexagons can be oxidized exclusively to α-Bi(2)O(3) hexagons. The Bi hexagons are found to be promising for thermoelectric applications. They are also catalytically active, inducing the reduction of 4-nitrophenol to 4-aminophenol. This electrodeposition methodology has also been demonstrated to be applicable for synthesis of bismuth-based bimetallic hybrid composites for advanced applications.
authors.affiliation: Institut für Chemie, Humboldt-Universität zu Berlin, Brook-Taylor-Strasse 2, 12489 Berlin, Germany.
authors.forename: Tirtha
authors.initials: T
authors.lastname: Som
authors.forename: Anne
authors.initials: A
authors.lastname: Simo
authors.forename: Robert
authors.initials: R
authors.lastname: Fenger
authors.forename: Gerald V
authors.initials: GV
authors.lastname: Troppenz
authors.forename: Roman
authors.initials: R
authors.lastname: Bansen
authors.forename: Norbert
authors.initials: N
authors.lastname: Pfänder
authors.forename: Franziska
authors.initials: F
authors.lastname: Emmerling
authors.forename: Jörg
authors.initials: J
authors.lastname: Rappich
authors.forename: Torsten
authors.initials: T
authors.lastname: Boeck
authors.forename: Klaus
authors.initials: K
authors.lastname: Rademann