Jun Hyuk Moon

A carbon host capable of effective and uniform sulfur loading is the key for lithium–sulfur batteries (LSBs). Despite the application of porous carbon materials of various morphologies, the carbon hosts capable of uniformly impregnating highly active sulfur is still challenging. To address this issue, we demonstrate a hierarchical pore-structured CNT particle host containing spherical macropores of several hundred nanometers. The macropore CNT particles (M-CNTPs) are prepared by drying the aeros

ADVERTISEMENT RETURN TO ISSUEPREVReviewChemical Aspects of Three-Dimensional Photonic CrystalsJun Hyuk Moon*† and Shu Yang*‡View Author Information Department of Chemical and Biomolecular Engineering, Sogang University, 1 Shinsu-dong, Mapo-gu, Seoul 121-742, Korea, and Department of Materials Science and Engineering, University of Pennsylvania, 3231 Walnut Street, Philadelphia, Pennsylvania 19104* To whom correspondence should be addressed. E-mail addresses: J.H.M., [email protected]; S.Y., [ema

Highly monodispersed nitrogen-doped carbon nanospheres are prepared by the pyrolytic carbonization of emulsion-polymerized polystyrene-based colloidal spheres in the presence of a nitrogen-enriched molecule, melamine (1,3,5-triazine-2,4,6-triamine). The nitrogen-doped carbon spheres are successfully tested for use as electrode materials in supercapacitors. The nitrogen content incorporated into the carbon sphere is controlled by changing the weight ratio of melamine to the polymer spheres. The n

Abstract The fabrication of true three‐dimensional (3D) microstructures both rapidly and economically over a large area with negligible defects is attractive for a wide range of applications. In particular, multi‐beam interference lithography is one of the promising techniques that can mass‐produce polymeric 3D photonic crystals defect‐free over a large area. This review discusses the relationship between beam geometry and the symmetry of the interference patterns, the lithographic process, and

Photonic balls have been fabricated (see Figure) by field‐enhanced electrospray of an aqueous colloidal suspension. The polystyrene (PS) beads inside the suspension droplets self‐organize into opaline balls while the solvent evaporates. The opaline balls are used as templates for inverse opaline photonic balls, and both types exhibit varying reflection colors depending on the diameter of the beads and the reflective index contrast.

We introduce MnO 2 nanoflake/carbon nanotube (CNT) core–shell particles for high-performance supercapacitors. The CNT particles prepared by drying the CNT-dispersed aerosol produce a tightly intertwined CNT assembly by internal capillary force, and the subsequent growth of MnO 2 on the CNT surface produces a high surface area MnO 2 nanoflake shell. We control the amount of MnO 2 decoration on the CNT particles and obtain a specific capacitance of 370 F/g at current density of 0.5 A/g upon their

Dual templating methods to control hierarchical meso- and macroscale pores in TiO2 electrodes for dye-sensitized solar cells are developed. The colloidal assembly of mesoscale particles in holographic lithography macroscopic patterns produces dual templates for hierarchically porous electrodes. The hierarchical TiO2 electrodes show synergistic effects of strong scattering and long charge recombination times, resulting in an efficiency comparable to the efficiency of conventional TiO2 electrodes.

ADVERTISEMENT RETURN TO ISSUEPREVNoteNEXTFabrication of Ordered Macroporous Cylinders by Colloidal Templating in MicrocapillariesJun Hyuk Moon, Sarah Kim, Gi-Ra Yi, Yong-Hee Lee, and Seung-Man YangView Author Information Department of Chemical and Biomolecular Engineering and Department of Physics, Korea Advanced Institute of Science and Technology, 373-1 Guseong-dong, Yuseong-gu, Daejeon 305-701, Korea Cite this: Langmuir 2004, 20, 5, 2033–2035Publication Date (Web):January 30, 2004Publication

We for the first time demonstrated carbon-deposited TiO2 inverse opal (C-TiO2 IO) structures as highly efficient visible photocatalysts. The carbon deposition proceeded via high-temperature pyrolysis of phloroglucinol/formaldehyde resol, which had been coated onto the TiO2 IO structures. Carbon deposition formed a carbon layer and doped the TiO2 interface, which synergistically enhanced visible-light absorption. We directly measured the visible-light photocatalytic activity by constructing solar

Fe–N–C single atom catalysts (SACs) utilize active oxygen from the oxygen evolution reaction for efficient methane-to-ethanol conversion, achieving an ethanol production rate of 11 480.6 μmol g cat −1 h −1 in flow cell reactions.

Electrochemical CH4 oxidation is attractive as a strategy capable of conversion with high selectivity, but improving productivity remains a challenge. We demonstrate that CuO/CeO2 can serve as a catalyst for the room-temperature conversion of CH4 to CH3OH in the presence of CO32–. At an optimized ratio of CuO/CeO2 (Cu:Ce = 6:4), we achieve the highest production rate of 752.9 μmol/gcat/h (6 h reaction) at ambient pressure; among the oxygenates, a CH3OH selectivity of 79% is obtained. In an exper

The combination of the control of CNT assembly density and the control of intrinsic carbon properties by doping can synergistically improve the supercapacitor performance of CNT-based electrodes. We prepared a dense-packed CNT spherical assembly via emulsion-assisted evaporation and subsequently conducted nitrogen (N) doping to make CNT-based supercapacitors. The assembly of CNT spherical particles is applied as the supercapacitor electrode. We control the N doping content and obtain a specific

This paper describes the use of Nb₂O₅-coated TiO₂ 3D ordered porous electrodes in dye-sensitized solar cells. We employed bilayer inverse opal structures as a backbone of 3D porous structures, and the number of Nb₂O₅ coatings was controlled, determining the concentration of Nb₂O₅ coating. XPS measurements confirmed the formation of Nb₂O₅. The uniformity of the Nb₂O₅ coating was characterized by elemental mapping using SEM and TEM measurements. Photovoltaic measurement on dye-sensitized solar cel