Enhanced photocatalytic performance of sandwiched ZnO@Ag@Cu 2 O nanorod films: the distinct role of Ag NPs in the visible light and UV region

Sandwiched ZnO@Ag@Cu 2 O nanorod films were synthesized by successive electrodeposition, magnetron sputtering and the second electrodeposition. The as-synthesized composites were characterized by x-ray diffraction patterns, field emission scanning electron microscopy, low- and high-resolution transmission electron microscopy and a UV–vis spectrophotometer. Their photocatalytic performance was estimated by the degradation of a methyl orange solution under UV or visible-light irradiation, respectively. In the visible region, due to localized surface plasmon resonance absorption of Ag NPs, ZnO@Ag@Cu 2 O showed a significantly enhanced photocatalytic performance. The enhancement factor of Ag NPs on the catalytic performance of ZnO@Ag@Cu 2 O was estimated as a function of the Cu 2 O deposition time, and the corresponding enhancement mechanism was also evaluated by the monochromatic photocatalytic experiment and discrete dipole approximation simulati...



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Dielectrophoretic stretching of DNA tethered to a fiber tip

In this work, we studied the stretching of λ phage DNA molecules immobilized on an optical fiber tip attached to a force sensitive tuning fork under ac electric fields. We designed a two electrodes stretching system in a small chamber: one is a gold-coated optical fiber tip electrode, and the other is a gold-coated flat electrode. By applying a dielectrophoretic (DEP) force, the immobilized λ DNA molecules on the tip are stretched and the stretching process is monitored by a fluorescent microscope. The DNA stretching in three-dimensional space is optimized by varying electrode shape, electrode gap distance, ac frequency, and solution conductivity. By observing the vibrational amplitude change of a quartz tuning fork, we measured the effects due to Joule heating and the DEP force on the tethered DNA molecules in solution. This work demonstrates a method to manipulate and characterize immobilized λ DNA molecules on a probe tip for further study of single DNA mo...

Changbae Hyun, Harpreet Kaur, David S McNabb and Jiali Li

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Pick-up and drop transfer of diamond nanosheets

Nanocrystalline diamond (NCD) is a promising material for electronic and mechanical micro- and nanodevices. Here we introduce a versatile pick-up and drop technique that makes it possible to investigate the electrical, optical and mechanical properties of as-grown NCD films. Using this technique, NCD nanosheets, as thin as 55 nm, can be picked-up from a growth substrate and positioned on another substrate. As a proof of concept, electronic devices and mechanical resonators are fabricated and their properties are characterized. In addition, the versatility of the method is further explored by transferring NCD nanosheets onto an optical fiber, which allows measuring its optical absorption. Finally, we show that NCD nanosheets can also be transferred onto two-dimensional crystals, such as MoS 2 , to fabricate heterostructures. Pick-up and drop transfer enables the fabrication of a variety of NCD-based devices without requiring lithography or wet processing.

V Seshan, J O Island, R van Leeuwen, W J Venstra, B H Schneider, S D Janssens, K Haenen, E J R Sudhölter, L C P M de Smet, H S J van der Zant, G A Steele and A Castellanos-Gomez

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Atomic resolution observation of conversion-type anode RuO 2 during the first electrochemical lithiation

Transition metal oxides have attracted great interest as alternative anode materials for rechargeable lithium-ion batteries. Among them, ruthenium dioxide is considered to be a prototype material that reacts with the Li ions in the conversion type. In situ transmission electron microscopy reveals a two-step process during the initial lithiation of the RuO 2 nanowire anode at atomic resolution. The first step is characterized by the formation of the intermediate phase Li x RuO 2 due to the Li-ion intercalation. The following step is manifested by the solid-state amorphization reaction driven by advancing the reaction front. The crystalline/amorphous interface is consisted of {011} atomic terraces, revealing the orientation-dependent mobility. In the crystalline matrix, lattice disturbance and dislocation are identified to be two major stress-induced distortions. The latter can be effective diffusion channels, facilitating transportation o...

Minmin Mao, Anmin Nie, Jiabin Liu, Hongtao Wang, Scott X Mao, Qingxiao Wang, Kun Li and Xi-Xiang Zhang

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Enhancement in photoluminescence performance of carbon-decorated T-ZnO

The facile preparation of ZnO possessing high visible luminescence intensity remains challenging due to an unclear luminescence mechanism. Here, two basic approaches are proposed to enhance the luminescent intensity based on the theoretical analysis over surface defects. Based on the deduction, we introduce a methodology for obtaining hybrid tetrapod-like zinc oxide (T-ZnO), decorated by carbon nanomarterials on T-ZnO surfaces through the catalytic chemical vapor deposition approach. The intensity of the T-ZnO green emission can be modulated by topography and the proportion of carbon. Under proper experiment conditions, the carbon decorating leads to dramatically enhanced luminescence intensity of T-ZnO from 400 to 700 nm compared with no carbon decorated, which elevates this approach to a simple and effective method for the betterment of fluorescent materials in practical applications.

Xian Jian, Guozhang Chen, Chao Wang, Liangjun Yin, Gang Li, Ping Yang, Lei Chen, Bao Xu, Yang Gao, Yanyu Feng, Hui Tang, Chunhong Luan, Yinglin Liang, Jing Jiang, Yu Cao, Siyuan Wang and Xin Gao

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Detection of DNA and poly-l-lysine using CVD graphene-channel FET biosensors

A graphene channel field-effect biosensor is demonstrated for detecting the binding of double-stranded DNA and poly-l-lysine. Sensors consist of chemical vapor deposition graphene transferred using a clean, etchant-free transfer method. The presence of DNA and poly-l-lysine are detected by the conductance change of the graphene transistor. A readily measured shift in the Dirac voltage (the voltage at which the graphene’s resistance peaks) is observed after the graphene channel is exposed to solutions containing DNA or poly-l-lysine. The ‘Dirac voltage shift’ is attributed to the binding/unbinding of charged molecules on the graphene surface. The polarity of the response changes to positive direction with poly-l-lysine and negative direction with DNA. This response results in detection limits of 8 pM for 48.5 kbp DNA and 11 pM for poly-l-lysine. The biosensors are easy to fabricate, reusable and are promising as sensors of a wide variety of charged biomolecules.

Aniket Kakatkar, T S Abhilash, R De Alba, J M Parpia and H G Craighead

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ZnO nanowires growth via reduction of ZnO powder by H 2

A unique approach of ZnO nanowire growth mediated via reduction of ZnO by H 2 is presented. It is less complex and more controllable than the conventional carbothermal method (reduction of ZnO by C). The chemical vapor deposition system employed allows precise control of all deposition parameters: (1) source and substrate temperatures, (2) carrier gas compositions, flow and pressure of several gases, (3) growth along a large range of distances from the source. In situ residual gas analysis allows real-time feedback of the process reactions. Controlled, stabilized, homogenous growth (characterized by scanning electron microscopy and x-ray diffraction) over relatively large areas is demonstrated.



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Conductive Lewis Base Matrix to Recover the Missing Link of Li2S8 during the Sulfur Redox Cycle in Li–S Battery

Chemistry of Materials

DOI: 10.1021/cm5044667

Jia-Jia Chen, Ru-Ming Yuan, Jia-Min Feng, Qian Zhang, Jing-Xin Huang, Gang Fu, Ming-Sen Zheng, Bin Ren and Quan-Feng Dong

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Computational Identification and Experimental Realization of Lithium Vacancy Introduction into the Olivine LiMgPO4

Chemistry of Materials

DOI: 10.1021/cm504518q

Leopoldo Enciso-Maldonado, Matthew S. Dyer, Michael D. Jones, Ming Li, Julia L. Payne, Michael J. Pitcher, Mona K. Omir, John B. Claridge, Frédéric Blanc and Matthew J. Rosseinsky

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Monolithic High Performance Surface Anchored Metal−Organic Framework Bragg Reflector for Optical Sensing

Chemistry of Materials

DOI: 10.1021/cm503908g

Jianxi Liu, Engelbert Redel, Stefan Walheim, Zhengbang Wang, Vanessa Oberst, Jinxuan Liu, Stefan Heissler, Alexander Welle, Markus Moosmann, Torsten Scherer, Michael Bruns, Hartmut Gliemann and Christof Wöll

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Trends in the Hydrogen Activation and Storage by Adsorbed 3d Transition Metal Atoms onto Graphene and Nanotube Surfaces: A DFT Study and Molecular Orbital Analysis

The Journal of Physical Chemistry C

DOI: 10.1021/jp512920f

Hubert Valencia, Adrià Gil and Gilles Frapper

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Reduced Grain Boundary Resistance by Surface Modification

The Journal of Physical Chemistry C

DOI: 10.1021/jp510077z

Hirotoshi Yamada, Daisuke Tsunoe, Shota Shiraishi and Gakuho Isomichi

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Layer Number Dependence of MoS2 Photoconductivity Using Photocurrent Spectral Atomic Force Microscopic Imaging

ACS Nano

DOI: 10.1021/nn506924j

Youngwoo Son, Qing Hua Wang, Joel A. Paulson, Chih-Jen Shih, Ananth G. Rajan, Kevin Tvrdy, Sojin Kim, Bassam Alfeeli, Richard D. Braatz and Michael S. Strano

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Probing the Influence of Citrate-Capped Gold Nanoparticles on an Amyloidogenic Protein

ACS Nano

DOI: 10.1021/nn506161j

Giorgia Brancolini, Alessandra Corazza, Marco Vuano, Federico Fogolari, Maria Chiara Mimmi, Vittorio Bellotti, Monica Stoppini, Stefano Corni and Gennaro Esposito

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Metal Nanoparticle Dispersion, Alignment, and Assembly in Nematic Liquid Crystals for Applications in Switchable Plasmonic Color Filters and E-Polarizers

ACS Nano

DOI: 10.1021/nn5074644

Yuan Zhang, Qingkun Liu, Haridas Mundoor, Ye Yuan and Ivan I. Smalyukh

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Synthesis of Zeolites via Interzeolite Transformations without Organic Structure-Directing Agents

Chemistry of Materials

DOI: 10.1021/cm504510f

Sarika Goel, Stacey I. Zones and Enrique Iglesia

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Multidecker Sandwich Complexes VnBenn+1 (n = 1, 2, 3) as Stronger Electron Donor Relative to Ferrocene for Designing High-Performance Organometallic Second-Order NLO Chromophores: Evident Layer Effect on the First Hyperpolarizability and Two-Dimensional NLO Character

The Journal of Physical Chemistry C

DOI: 10.1021/jp5123272

Shu-Jian Wang, Yin-Feng Wang and Chenxin Cai

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Design of Wall-Functionalized Hybrid Silicas Containing Diazene Radical Precursors. EPR Investigation of Their Photolysis and Thermolysis

The Journal of Physical Chemistry C

DOI: 10.1021/jp5117382

François Vibert, Sylvain R. A. Marque, Emily Bloch, Séverine Queyroy, Michèle P. Bertrand, Stéphane Gastaldi and Eric Besson

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Observation of Single-Spin Dirac Fermions at the Graphene/Ferromagnet Interface

Nano Letters

DOI: 10.1021/nl504693u

Dmitry Usachov, Alexander Fedorov, Mikhail M. Otrokov, Alla Chikina, Oleg Vilkov, Anatoly Petukhov, Artem G. Rybkin, Yury M. Koroteev, Evgueni V. Chulkov, Vera K. Adamchuk, Alexander Grüneis, Clemens Laubschat and Denis V. Vyalikh

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Superlinear Composition-Dependent Photocurrent in CVD-Grown Monolayer MoS2(1–x)Se2x Alloy Devices

Nano Letters

DOI: 10.1021/acs.nanolett.5b00190

Velveth Klee, Edwin Preciado, David Barroso, Ariana E. Nguyen, Chris Lee, Kristopher J. Erickson, Mark Triplett, Brandon Davis, I-Hsi Lu, Sarah Bobek, Jessica McKinley, Joseph P. Martinez, John Mann, A. Alec Talin, Ludwig Bartels and François Léonard

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