Plasmonic systems based on metal nanoparticles on a metal film have generated great interest for surface-enhanced Raman spectroscopy (SERS) chemical sensors. In this study, we describe the fabrication of ultrasensitive SERS substrates based on high-density gold nanostar assemblies on silver films with tailored surface plasmons, where multiple field enhancements from particle-film and interparticle plasmon couplings and lightening rod effects of sharp tips of nanostars contribute to the enormous Raman enhancements. We show that the interplay between interparticle and particle-film plasmon couplings of high-density gold nanostars (GNSs) on metal and dielectric films as a function of interparticle separation can be tailored to provide maximum SERS effects. We observe that the SERS enhancement factor (EF) of GNSs on a metal film as a function of interparticle separation follows a broken power law function, where the EF increases with the interparticle separation for the strong interparticle coupling range below an interparticle separation of ~0.8 times the GNS size, but decreases for the weak interparticle coupling range (for an interparticle separation of >0.8 times the GNS size). Finally, we demonstrate the use of tailored plasmonic substrates as ultrasensitive SERS chemical sensors with an attomole level of detection capability of 2,4-dinitrotoluene, a model compound of nitroaromatic explosives.

A PTMA-impregnated CNT electrode achieves the enhancement of discharge capacity, cycleability and rate capability of sodium batteries.

Ultralight and flexible perovskite solar cells with the orthogonal AgNW electrodes exhibit an excellent power-per-weight of 29.4 W g−1.

An aqueous Na-ion based hybrid capacitor has been successfully developed by highly porous graphitic carbon (HPGC) derived by waste writing paper and a new electrode material as negative and positive electrode, respectively. HPGC was prepared via hydrothermal carbonization and subsequent KOH activation of waste writing paper which showed highly porous stacked sheet like morphology with exceptionally high BET specific surface area (1254 m 2 g -1 ). HPGC exhibited typical electrical double layer capacitor (EDLC) behavior with a high specific capacitance of 384 F g -1 and good negative working potential (-1.0 V) in aqueous electrolyte. On the other hand, Ni2P2O7 was synthesized by simple co-precipitation technique and tested as cathode material which delivered a maximum specific capacitance of 1893 F g -1 at 2 A g -1 current density. The fabricated HPGC||Ni2P2O7 hybrid device displayed excellent cyclic stability up to 2000 cycles and delivered maximum energy density of 65 W h kg -1 at 800 W kg -1 power density in Na-ion based aqueous electrolyte.capacitive electrode by hemp carbonization and assembled

We first report the all-electrical spin injection and detection in CoFe/MgO/ moderately doped n-Ge contact at room temperature (RT), employing threeterminal Hanle measurements. A sizable spin signal of ~170 2 μm kΩ has been observed at RT, and the analysis using a single-step tunneling model gives a spin lifetime of ~120 ps and a spin diffusion length of ~683 nm in Ge. The observed spin signal shows asymmetric bias and temperature dependences which are strongly related to the asymmetry of the tunneling process.Recently, the n-type Ge in conjunction with a crystalline bcc FM/MgO(001) [20][21][22][23] has attracted much attention as a promising candidate for the efficient spin injection in terms of a high tunnel spin polarization (TSP), a small conductivity mismatch, and a negligible interdiffusion/intermixing in FM/Oxide/SC contacts. Moreover, considering a high electron mobility in Ge (at least twice higher than Si) and its weak dependence on doping concentration, Ge prospectively represents a SC channel with a long spin diffusion length. 2,24 Several important achievements 25,26 have been recently reported in the field of spin transport in Ge at low temperature, but the spin injection and detection in Ge at RT is yet to be investigated.Here we first demonstrate the electrical spin injection in spin tunnel contacts consisting of crystalline bcc CoFe/MgO (001)/moderately doped n-Ge and the electrical detection of the induced spin accumulation at RT. We have analyzed the spin 3 accumulation, spin life time, spin diffusion length in Ge from the measured spin signal, and studied their bias and temperature dependences. II. EXPERIMENTAL DETAILSA. Principle of the approach Figure 1(a) illustrates the device geometry and measurement scheme used in the present study. We have fabricated a symmetric device consisting of five single crystalline CoFe/MgO/n-Ge tunnel contacts (a-e) spaced as shown in the inset of Fig.

Kcywortls Oil palmGlacis ftnneenxis Jaxq Binderless board Self-binding mechanism BjOrkman lignin Wall polysaccharidcs Pyrolysis-gaschromatogruphy-niuss spcciromctry L t-NMR Ή-ΝΜΚ ITIR Alditol acetate Uronic acid Furfural derivatives SummaryOil palm (Elaeis xtiinccHsix Jacq.) is one of the most abundant, unutilised waste biomass from plantation in South-East Asia. The binder I ess boards were prepared from steam-exploded pulps of oil palm fronds und characterised for the mechanical strengths and chemical natures to discuss mechanism of self-binding. The mechanical strength of these boards satisfied the requirements of the relevant standard specifications (J1S: Japanese Industrial Standards) for the boards, To make clear the mechanism of the self-bonding of these bindcrlcss hoards, oil palm fronds themselves, their steam exploded pulps, boards and lignins isolated by Bj rkman's procedure from extract-free oil palm fronds and steam exploded pulps, were analysed by chemical and spectrometrical methods and pyrolysis-gaschromatography/mass spcctromctry. Lignin of oil palm frond was characterised by the presence of significant amounts of esierified /?-hydroxyben/oic acid together with small amounts of cthcrified /;-hydroxyben/oie acid, Vanillic and syringic acids were esterified or ethcrified to lignin. Some extents of these ester bonds and -O-4 interunit linkages of lignin were cleaved during steam explosion, in addition to great condensation of guaiacyl nuclei, as revealed by Ή-and L t-NMR spectra of isolated lignins from the steam exploded pulps, of which yields were quite high, suggesting that lignin has been released from other wall polymers. Wall polysaccharides of oil palm frond are composed of cellulose and significantly high concentration of urabinoxylan. which produced great abundance of 5-hydroxymethyl-furlural and furfural during steam explosion, respectively, and even hot pressing at I25°C to prepare binderless boards. It is suggested that released lignin and furfural derivatives generated during steam explosion contribute to self-binding of the steam exploded pulps. However, severe conditions of steam explosion caused great damages in lignin macromolecules, and gave poor quality of binderless boards.

Porous graphene nanostructures are of great interest for applications in catalysis and energy storage. However, the fabrication of three-dimensional (3D) macroporous graphene nanostructures with controlled morphology, porosity and surface area still presents significant challenges. Here we introduce an ice-templated self-assembly approach for the integration of two-dimensional graphene nanosheets into hierarchically porous graphene nanoscroll networks, where the morphology of porous structures can be easily controlled by varying the pH conditions during the ice-templated self-assembly process. We show that freeze-casting of reduced graphene oxide (rGO) solution results in the formation of 3D porous graphene microfoam below pH 8 and hierarchically porous graphene nanoscroll networks at pH 10. In addition, we demonstrate that graphene nanoscroll networks show promising electrocatalytic activity for the oxygen reduction reaction (ORR).

Near-field electrospinning (NFES) was developed to overcome the intrinsic instability of traditional electrospinning processes and to facilitate the controllable deposition of nanofibers under a reduced electric field. This technique offers a straightforward and versatile method for the precision patterning of two-dimensional (2D) nanofibers. However, three-dimensional (3D) stacked structures built by NFES have been limited to either micron-scale sizes or special shapes. Herein, we report on a direct-write 3D NFES technique to construct self-aligned, template-free, 3D stacked nanoarchitectures by simply adding salt to the polymer solution. Numerical simulations suggested that the electric field could be tuned to achieve self-aligned nanofibers by adjusting the conductivity of the polymer solution. This was confirmed experimentally by using poly(ethylene oxide) (PEO) solutions containing 0.1−1.0 wt% NaCl. Using 0.1 wt% NaCl, nanowalls with a maximum of 80 layers could be built with a width of 92 ± 3 nm, height of 6.6 ± 0.1 μm, and aspect ratio (height/width) of 72. We demonstrate the 3D printing of nanoskyscrapers with various designs, such as curved "nanowall arrays", nano "jungle gyms," and "nanobridges". Further, we present an application of the 3D stacked nanofiber arrays by preparing transparent and flexible polydimethylsiloxane films embedded with Ag-sputtered nanowalls as 3D nanoelectrodes. The conductivity of the nanoelectrodes can be precisely tuned by adjusting the number of 3D printed layers, without sacrificing transmittance (98.5%). The current NFES approach provides a simple, reliable route to build 3D stacked nanoarchitectures with high-aspect ratios for potential application in smart materials, energy devices, and biomedical applications.