Young Uk Kwon

We report the syntheses and characterization of ternary nanoparticles of Fe<italic>x</italic>@(PtRu)_(1−x)/2(<italic>x</italic>= 0.0–0.44) with Fe cores and PtRu alloy shells, which exhibit greatly improved electrocatalytic properties for methanol oxidation reaction.

A mesoporous silica film acts as a template and a potential equalizer between the edge/defect sites and the basal plane of a graphene sheet. Using an electrochemical deposition method of CdSe on these graphene sheets covered with a silica film results in CdSe quantum dots that are evenly distributed in regular hexagonal arrays (see figure).

We have performed ionothermal reactions between Zn(NO3)2 and H3BTC in 1-alkyl-3-methylimidazolium bromide ionic liquids with the alkyl group varying from ethyl to amyl. Six 3-D metal-organic frameworks (MOFs), including two isomeric compounds [Zn3(BTC)2(H2O)2] x 2H2O (1 and 2) (H3BTC = 1,3,5-benzenetricarboxylate acid), [EMI][Zn(BTC)] (3) (E = ethyl, MI = 3-methylimidazolium), [PMI][Zn(BTC)](4) (P = propyl), [BMI]2[Zn4(BTC)3(OH)(H2O)3] (5) (B = butyl), and [AMI][Zn2(BTC)(OH)Br] (6) (A = amyl), h

Controlled aging of TiO2 nanoparticles blended with diblock copolymers and processed into dip-coated thin films led to ordered mesostructures with cubic and hexagonal symmetries that can be transformed into mesoporous TiO2 by calcination.

Ni(OAc)(2)-H(3)BTC system in various ionic liquids, [RMI]X (R = ethyl, n-propyl, n-butyl; X = Cl, Br, I), produced five MOFs in two structure types; their relative thermodynamic stability varies with the size of RMI(+), and the X(-) ions govern the kinetic factors so that their combination effects determine the final product.

2–3 nm sized Pt3Co nanoparticles (NPs) with Pt-enriched shells on a carbon support were prepared by a one-step ultrasound polyol process on Pt(acac)2 (acac = acetylacetonate) and Co(acac)2. The ultrasound facilitates the conversion of Co(acac)2 and retards the conversion of Pt(acac)2 into NPs, which can be explained with the different vapour pressures of the metal precursors. The Pt-enriched shell structure of the NPs by this method, as opposed to the alloy-like elemental distribution of the NPs

We fabricated dye-sensitized solar cells (DSSCs) with SnO 2 nanoparticles coated with thin layers of CdO on the surfaces into a core−shell-type structure with various Cd/Sn ratios, and studied their effects on the DSSC performance as a function of the CdO shell thickness. CdO is an n-type semiconductor with a conduction band edge lower than that of SnO 2 and, thus, has not been considered as a blocking layer material in the previous studies. The overall conversion efficiency of the DSSC was incr

By reacting Keggin-type polyoxometalate cluster anions H(2)W(12)O(40)(6)(-) (metatungstate) or Co(II)W(12)O(40)(6)(-) (tungstocobaltate) with the large aluminum cluster polycation [Al(30)O(8)(OH)(56)(H(2)O)(26)](18+), Keggin ion based molecular ionic compounds [delta-Al(13)O(4)(OH)(24)(H(2)O)(12)][XW(12)O(40)](OH).nH(2)O (X = H(2) (1) and Co (2); n congruent with 20) and [W(2)Al(28)O(18)(OH)(48)(H(2)O)(24)][H(2)W(12)O(40)](2).55H(2)O (3) were obtained. The polygon-shaped cluster ions are packed

An unprecedented series of Mn 2+ -based metal–organic framework (MOF) materials prepared and isolated in ionic liquids (ILs) is reported. Ionothermal reactions of Mn(OAc) 2 with H 3 btc (benzene-1,3,5-tricarboxylic acid) in two groups of [rmi]X (rmi = 1-alkyl-3-methylimidazolium; r = ethyl or propyl, X = Cl, Br, or I) ILs produced three slightly different 3D MOFs formulated as [rmi][Mn(btc)] [r = ethyl ( 1 ), propyl ( 2 ), and ( 3 )], whose architectures can be envisaged as (3,6)-connected pyr t