The photoelectrochemical behavior of Rh cluster-deposited hematite (α-FeO) photoanodes (α-FeO@Rh) was investigated. The interactions between Rh clusters and α-FeO nanorods were elucidated both experimentally and computationally. A facile UV-assisted solution casting deposition method allowed the deposition of 2 nm Rh clusters on α-FeO.
View Article and Find Full Text PDFControlling the dimensional aspect of conductive coordination polymers is currently a key scientific interest. Herein, solution-based dimension control strategies are proposed for copper chloride thiourea (CuCl-TU) coordination polymers that enable centimeter-scale, 2D nanosheet formation for use as transparent electrodes. Despite the wide bandgap of CuCl-TU polymers (4.
View Article and Find Full Text PDFWe, for the first time, report the development of infrared (IR)-driven photoelectrochemical (PEC) cells using up-conversion glass-ceramics as substrates, which is different from the previous strategies of decorating photocatalysts with up-conversion (UC) rare earth-doped fluoride nanoparticles to utilize IR light. Our approach is more efficient since the use of UC glass-ceramics as substrates of photocatalysts could overcome the chemical instability of fluoride nanoparticles, the blockage of incident light, and the limited exposure of photocatalysts to liquid electrolytes. Oxyfluoride glass-ceramics bearing (Yb,Er)-doped YF and (Yb,Tm)-doped YF nanocrystals turned out to generate UC green and ultraviolet/blue emissions, respectively, under 980 nm illumination.
View Article and Find Full Text PDFSingle-atom catalysts are heterogeneous catalysts with atomistically dispersed atoms acting as a catalytically active center, and have recently attracted much attention owing to the minimal use of noble metals. However, a scalable and inexpensive support that can stably anchor isolated atoms remains a challenge due to high surface energy. Here, copper-halide polymer nanowires with sub-nanometer pores are proposed as a versatile support for single-atom catalysts.
View Article and Find Full Text PDFCuprous selenide nanocrystals have hallmark attributes, especially tunable localized surface plasmon resonances (LSPRs) and super-ionic behavior. These attributes of cuprous selenide are now integrated with a one-dimensional morphology. Essentially, Cu Se nanowires (NWs) of micrometer-scale lengths and about 10 nm diameter are prepared.
View Article and Find Full Text PDFDespite tellurium being less abundant in the Earth's crust than gold, platinum, or rare-earth elements, the number of industrial applications of tellurium has rapidly increased in recent years. However, to date, many properties of tellurium and its associated compounds remain unknown. For example, formation mechanisms of many tellurium nanostructures synthesized so far have not yet been verified, and it is unclear why tellurium can readily transform to other compounds like silver telluride by simply mixing with solutions containing silver ions.
View Article and Find Full Text PDFAll-solution processed, high-performance wearable strain sensors are demonstrated using heterostructure nanocrystal (NC) solids. By incorporating insulating artificial atoms of CdSe quantum dot NCs into metallic artificial atoms of Au NC thin film matrix, metal-insulator heterostructures are designed. This hybrid structure results in a shift close to the percolation threshold, modifying the charge transport mechanism and enhancing sensitivity in accordance with the site percolation theory.
View Article and Find Full Text PDFDramatic enhancements in the figure of merit have been obtained in bulk thermoelectric materials by doping, band engineering, and nanostructuring. Especially, in p-type thermoelectrics, high figure of merits near 2.0 have been reported in a few papers through the reduction in lattice thermal conductivity and the advancement in power factors.
View Article and Find Full Text PDFTaper-shaped SnS nanorods were synthesized via mild chemistry, and the self-catalytic solution-liquid-liquid-solid (SLLS) process was proposed as a crystal growth mechanism. There exists a distinct difference in our SLLS growth compared to the well-known SLS growth in that we injected Sn precursors into a hot trioctylphosphine sulfide (TOPS) solution, which is a reverse process of the general SLS growth. This reverse process could prevent the oxidation of Sn precursors and thus it could facilitate the growth of SnS nanorods, since the surface of Sn clusters and droplets could be momentarily passivated by TOPS molecules.
View Article and Find Full Text PDFSolution-grown ZnO nanorods (NRs) were successfully conjugated with CdSe/ZnS quantum dots (QDs) and Ag nanoparticles (NPs) to suppress intrinsic defect emission and to enhance band-edge emission at the same time. First, high-density and high-crystallinity ZnO NRs of diameter 80–90 nm and length 1.2–1.
View Article and Find Full Text PDFHigh quality single-crystalline indium tin oxide (ITO) nanowires with controlled Sn contents of up to 32.5 at.% were successfully synthesized via a thermal metal co-evaporation method, based on a vapor-liquid-solid growth mode, at a substrate temperature of as low as 540 °C.
View Article and Find Full Text PDFWe propose a Metal-Oxide-Nitride-Oxide-Silicon (MONOS) structure whose blocking oxide is formed by radical oxidation on the silicon nitride (Si3N4) layer to improve the electrical and reliability characteristics. We directly compare the electrical and reliability properties of the MONOS capacitors with two different blocking oxide (SiO2) layers, which are called a "radical oxide" grown by the radical oxidation and a "CVD oxide" deposited by chemical vapor deposition (CVD) respectively. The MONOS capacitor with a radical oxide shows a larger C-V memory window of 3.
View Article and Find Full Text PDFA new electrochemical technique for the detection of vascular endothelial growth factors (VEGFs) as a cancer-related biomarker is presented in this paper. Gold nanoparticles (Au NPs) were self-assembled onto an indium tin oxide (ITO) electrode to prepare a modified sandwich type electrochemical immunoassay platform. VEGF antibodies were cleaved into two half-fragments by 2-mercaptoethylamine-HCl (2-MEA) and the fragments were immobilized onto the Au NP substrates by their thiol groups.
View Article and Find Full Text PDFWe studied the effects of post-annealing in H2 and O2 ambients on field-emission properties of vertically-aligned ZnO nanowire arrays synthesized by carbothermal reduction process. The turn-on electric field was dramatically decreased from 3.78 to 2.
View Article and Find Full Text PDFWe demonstrate the formation of a highly conductive, Fe0/Fe3O4 nanocomposite electrode by the hydrogen reduction process. Fe2O3 nanobundles composed of one-dimensional nanowires were initially prepared through thermal dehydrogenation of hydrothermally synthesized FeOOH. The systematic phase and morphological evolutions from Fe2O3 to Fe2O3/Fe3O4, Fe3O4, and finally to Fe/Fe3O4 by the controlled thermochemical reduction at 300 degrees C in H2 were characterized using x-ray diffraction (XRD) and transmission electron microscopy (TEM).
View Article and Find Full Text PDFHigh-sensitivity, high-specificity detection of platelet derived growth factor (PDGF)-BB was realized using the change in fluorescence resonance energy transfer (FRET) occurring between quantum dot (QD) donors and black hole quencher (BHQ) acceptors. CdSe/ZnS QD/mercaptoacetic acid (MAA)/PDGF aptamer bioconjugates were successfully synthesized using ligand exchange. Black hole quencher (BHQ)-bearing oligonucleotide molecules showing partial sequence matching to PDGF aptamer were attached to PDGF aptamers and photoluminescence (PL) quenching was obtained through FRET.
View Article and Find Full Text PDFKinetic analysis on the nanocrystal solid-solution formation was performed by heat treating CdSe/ZnSe core/shell nanocrystals, synthesized via a typical TOP/TOPO approach, at different temperatures for different time periods. X-ray diffraction (XRD) peak shifts in Cd1-xZnxSe cores according to the solid-solution treatments were monitored and used for the estimation of the lattice parameter change. The degree of solid-solution formation was determined considering the compositional variation in Cd1-xZnxSe cores, which was obtained from the Vegard's law.
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