Seungho Cho

Morphology-controlled growth of ZnO nano- and microstructures was achieved by microwave irradiation. Various basic ZnO structures, including nanorods, nanocandles, nanoneedles, nanodisks, nanonuts, microstars, microUFOs, and microballs were simply synthesized at a low temperature (90 °C) with low power microwave-assisted heating (about 50 W) and a subsequent aging process. These results could be obtained by changing the precursor chemicals, the capping agents, and the aging times. Even more comp

We report the synthesis of carbon-doped zinc oxide nanostructures using vitamin C, and their visible light photocatalytic activity. Amorphous/crystalline vitamin C–ZnO (VitC–ZnO) structures were obtained from a solution of zinc nitrate hexahydrate, HMT, and vitamin C through heating at 95 °C for 1 h. VitC–ZnO structures were calcined in air at 500 °C for 2 h to create C-doped ZnO nanostructures. Calcined structures were polycrystalline, with an average crystal domain size of 7 nm. EDS, XPS, and

We report a method for synthesizing three distinct type II 3D ZnO/ZnSe heterostructures through simple solution-based surface modification reactions in which polycrystalline ZnSe nanoparticles formed on the surfaces of single-crystalline ZnO building blocks of 3D superstructures. The experimental results suggested a possible formation mechanism for these heterostructures. The formation of the ZnO/ZnSe heterostructures was assumed to result from a dissolution-recrystallization mechanism. The opti

We have studied the precursor effects of citric acid and various citrates-including triethyl citrate, tripotassium citrate, trisodium citrate and triammonium citrate-on the formation of ZnO crystals in alkaline solution. These citrate-related chemicals could be divided into three groups (group A, triethyl citrate; group B, tripotassium citrate and trisodium citrate; and group C, citric acid and triammonium citrate) based on their activity for modifying the ZnO growth direction and solution pH de

Photoelectrochemical (PEC) water splitting to hydrogen is an attractive method for capturing and storing the solar energy in the form of chemical energy. Metal oxides are promising photoanode materials due to their low-cost synthetic routes and higher stability than other semiconductors. In this paper, we provide an overview of recent efforts to improve PEC efficiencies via applying a variety of fabrication strategies to metal oxide photoanodes including (i) size and morphology-control, (ii) met

Electrocatalytic nitrate reduction reaction (NO 3 RR) presents an innovative approach for sustainable NH 3 production. However, selective NH 3 production is hindered by the multiple intermediates involved in the NO 3 RR process and the competitive hydrogen evolution reaction. Hence, the development of highly efficient NO 3 RR catalysts is paramount. Herein, we report highly efficient bimetallic catalysts derived from hydroxy double salt (HDS). Under NO 3 RR conditions, Cu 1 Co 1 -HDS undergoes i

Lead-free perovskite oxide thin films prepared by alloying of titanates and materials with lower melting points are shown to have enhanced ferroelectric and dielectric properties. BaTiO 3 (or SrTiO 3 ) with 25% addition of BiFeO 3 has much improved crystalline perfection because of the lower melting point of the BiFeO 3 giving enhanced growth kinetics. The maximum dielectric peak temperature of BaTiO 3 is increased by ~200 C and leakage currents are reduced by up to a factor of ~100. The loss ta

We report the synthesis of porous ZnO-ZnSe nanocomposites for use in visible light photocatalysis. Porous ZnO nanostructures were synthesized by a microwave-assisted hydrothermal reaction then converted into porous ZnO-ZnSe nanocomposites by a microwave-assisted dissolution-recrystallization process using an aqueous solution containing selenium ions. ZnO and ZnSe nanocrystallites of the nanocomposites were well-mixed (rather than forming simple core-shell (ZnO-ZnSe) structures), particularly, in

Resistive switches are non-volatile memory cells based on nano-ionic redox processes that offer energy efficient device architectures and open pathways to neuromorphics and cognitive computing. However, channel formation typically requires an irreversible, not well controlled electroforming process, giving difficulty to independently control ionic and electronic properties. The device performance is also limited by the incomplete understanding of the underlying mechanisms. Here, we report a nove

Abstract Mixed metal oxide (MMO) nanostructures co‐doped uniformly by carbon and nitrogen are synthesized for the first time by annealing a terephthalate‐intercalated layered double hydroxide (LDH) under ammonia gas flow. The interlayer gallery of LDH allows effective access of NH 3 and the carbon source to its crystal lattice for a uniform nitrogen and carbon doping. Such co‐doped MMO exhibit significantly red‐shifted absorption spectra to visible light region relative to pure MMO. Photoelectro

We report a method for synthesizing exposed crystal face controlled 3D ZnO superstructures under mild conditions (at room temperature or 90 degrees C under 1 atm) without organic additives. The exposed crystal faces of the building blocks of the 3D structures were controlled by varying the reactant concentrations and the reaction temperatures. On the basis of the experimental results, we speculated a possible mechanism for the formation of the four distinct 3D ZnO superstructures (structures I,

We report a designed strategy for a synthesis of highly luminescent and photostable composites by incorporating quantum dots (QDs) into layered double hydroxide (LDH) matrices without deterioration of a photoluminescence (PL) efficiency of the fluorophores during the entire processes of composite formations. The QDs synthesized in an organic solvent are encapsulated by polymers, poly(maleic acid-alt-octadecene) to transfer them into water without altering the initial surface ligands. The polymer

Wheat-barley chromosome addition lines are useful genetic resources for a variety of studies. In this study, transcript accumulation patterns in Betzes barley, Chinese Spring wheat, and Chinese Spring-Betzes chromosome addition lines were examined with the Barley1 Affymetrix GeneChip probe array. Of the 4014 transcripts detected in Betzes but not in Chinese Spring, 365, 271, 265, 323, 194, and 369 were detected in wheat-barley disomic chromosome addition lines 2(2H), 3(3H), 4(4H), 7(5H), 6(6H),