title: Direct Synthesis of Palladium Nanocrystals in Aqueous Solution with Systematic Shape Evolution.
abstract: Palladium octahedra, truncated octahedra, cuboctahedra, truncated cubes, and nanocubes with sizes of tens of nanometers have been synthesized in an aqueous mixture of H2PdCl4 solution, cetyltrimethylammonium chloride (CTAC) surfactant, KBr solution, dilute KI solution, and ascorbic acid solution at 35 °C for 30 min. By tuning the amount of dilute KBr solution introduced, particle shape control can be achieved. Adjusting the volumes of the Pd precursor and KBr solutions added, smaller and larger Pd nanocrystals were obtained with excellent shape control. Extensive structural and optical characterization of these nanocrystals has been performed. Two absorption bands in the ultraviolet region can be discerned for these Pd nanocrystals. Concave Pd cubes can also be prepared. Pd cubes were found to grow at a faster rate than that for the formation of octahedra. The concentrations of KBr and KI in the solution are so low that spectral shifts were not detected upon their addition to the solution. The Pd nanocrystals can readily be used for various applications after simple removal of surfactant.
authors.affiliation: Department of Chemistry and Frontier Research Center on Fundamental and Applied Science of Matter, National Tsing Hua University, Hsinchu 30013, Taiwan.
authors.forename: Shu-Ya
authors.initials: SY
authors.lastname: Liu
authors.affiliation: Department of Chemistry and Frontier Research Center on Fundamental and Applied Science of Matter, National Tsing Hua University, Hsinchu 30013, Taiwan.
authors.forename: Yuan-Ting
authors.initials: YT
authors.lastname: Shen
authors.affiliation: Department of Chemistry and Frontier Research Center on Fundamental and Applied Science of Matter, National Tsing Hua University, Hsinchu 30013, Taiwan.
authors.forename: Chun-Ya
authors.initials: CY
authors.lastname: Chiu
authors.affiliation: Department of Chemistry and Frontier Research Center on Fundamental and Applied Science of Matter, National Tsing Hua University, Hsinchu 30013, Taiwan.
authors.forename: Sourav
authors.initials: S
authors.lastname: Rej
authors.affiliation: Department of Chemistry and Frontier Research Center on Fundamental and Applied Science of Matter, National Tsing Hua University, Hsinchu 30013, Taiwan.
authors.forename: Po-Heng
authors.initials: PH
authors.lastname: Lin
authors.affiliation: Department of Chemistry and Frontier Research Center on Fundamental and Applied Science of Matter, National Tsing Hua University, Hsinchu 30013, Taiwan.
authors.forename: Yu-Chi
authors.initials: YC
authors.lastname: Tsao
authors.affiliation: Department of Chemistry and Frontier Research Center on Fundamental and Applied Science of Matter, National Tsing Hua University, Hsinchu 30013, Taiwan.
authors.forename: Michael H
authors.initials: MH
authors.lastname: Huang