resumo
A methodology providing access to dumbbell-tipped, metal semiconductor and metal oxide semiconductor heterostructured nanorods has been developed. The synthesis and characterization of CdSe@CdS nanorods incorporating ferromagnetic cobalt nanoinclusions at both nanorod termini (i.e., dumbbell morphology) are presented. The key step in the synthesis of these heterostructured nanorods was the decoration of CdSe@CdS nanorods with platinum nanoparticle tips, which promoted the deposition of metallic CoNPs onto Pt-tipped CdSe@CdS nanorods. Cobalt nanoparticle tips were then selectively oxidized to afford CdSe@CdS nanorods with cobalt oxide domains at both termini. In the case of longer cobalt-tipped nanorods, heterostructured nanorods were observed to self-organize into complex dipolar assemblies, which formed as a consequence of magnetic associations of terminal CoNP tips. Colloidal polymerization of these cobalt-tipped nanorods afforded fused nanorod assemblies from the oxidation of cobalt nanoparticle tips at the ends of nanorods via the nanoscale Kirkendall effect Wurtzite CdS nanorods survived both the deposition of metallic CoNP tips and conversion into cobalt oxide phases, as confirmed by both XRD and HRTEM analysis. A series of CdSe@CdS nanorods of four different lengths ranging from 46 to 174 nm and comparable diameters (6-7 rim) were prepared and modified with both cobalt and cobalt oxide tips. The total synthesis of these heterostructured nanorods required five steps from commercially available reagents. Key synthetic considerations are discussed, with particular emphasis on reporting isolated yields of all intermediates and products from scale up of intermediate precursors.
palavras-chave
ONE-POT SYNTHESIS; VISIBLE-LIGHT; NANOCRYSTAL HETEROSTRUCTURES; METAL NANOPARTICLES; SEEDED-GROWTH; QUANTUM RODS; SEMICONDUCTOR NANOCRYSTALS; ARCHITECTURAL CONTROL; HYBRID NANOPARTICLES; OPTICAL-PROPERTIES
categoria
Chemistry; Science & Technology - Other Topics; Materials Science
autores
Hill, LJ; Bull, MM; Sung, Y; Simmonds, AG; Dirlam, PT; Richey, NE; DeRosa, SE; Shim, IB; Guin, D; Costanzo, PJ; Pinna, N; Willinger, MG; Vogel, W; Char, K; Pyun, J
nossos autores
Nicola Pinna
InvestigadorGrupos
agradecimentos
This work was funded by the Division of Chemical Science, Geosciences and Biosciences, Office of Basic Energy Sciences of the U.S. Department of Energy (DE-FG03-02ER15753) (L.J.H., J.P.), the NSF CAREER Program (DMR-0645618) (M.M.B., N.E.R., D.G., J.P.), the World Class University Program through the National Research Foundation of Korea funded by the Ministry of Education, Science and Technology (R31-10013) (Y.S.), and the Alfred P. Sloan Foundation (P.T.D., J. P.) are acknowledged for synthetic support of this work. K.C. acknowledges financial support from NRF for the National Creative Research Initiative Center for Intelligent Hybrids (2010-0018290).