A lithium passivated MoO3 nanobelt decorated polypropylene separator for fast-charging long-life Li-S batteries.

Dissolution of lithium polysulfide (LiPS) into the electrolyte during discharging, causing shuttling of LiPS from the cathode to the lithium (Li) metal, is mainly responsible for the capacity decay and short battery life of lithium-sulfur batteries (LSBs). Herein, we designed a separator comprising polypropylene (PP) coated with MoO3 nanobelts (MNBs), prepared through facile grinding of commercial MoO3 powder. The formation of Li2Sn-MoO3 during discharging inhibited the polysulfide shuttling; during charging, Li passivated LixMoO3 facilitated ionic transfer during the redox reaction by decreasing the charge transfer resistance. This dual-interaction mechanism of LiPS-with both Mo and the formation of LixMoO3-resulted in a substantially high initial discharge capacity at a very high current density of 5C, with 29.4% of the capacity retained after 5000 cycles. The simple fabrication approach and extraordinary cycle life observed when using this MNB-coated separator suggest a scalable solution for future commercialization of LSBs.

Development of latent fingerprint by ZnO deposition.

Vacuum metal deposition (VMD) utilizing sequential Au and Zn depositions has been an effective technique to develop latent fingerprint on plastic surfaces. A simplified vacuum deposition process was conducted to develop fingerprint in this study. While pure ZnO was thermally evaporated in a vacuum system, ZnO could condense on polyethylene terephthalate (PET) surface. Direct deposition of ZnO, without applying Au seeding, yielded normal development of latent fingerprint. The development of aged fingerprint by ZnO deposition was more effective than that by Au/Zn VMD.

Silicon nanocone arrays deposited by sputtering.

Silicon nanostructures were produced by sputter deposition of silicon in mixtures of hydrogen and argon, on the surface of a silicon substrate with dispersed gold islands, at a substrate temperature of 450 degrees C. Continuous Si films were deposited when the hydrogen concentration in the working gas was less than 50%. Silicon nanocone arrays were grown when the hydrogen concentration exceeded 50%. The lateral size of silicon nanocones increased with the deposition time. However, the length of the silicon nanocones saturated as the deposition time was increased. Mechanisms of the growth of Si nanocones by sputter deposition in mixtures of hydrogen and argon were discussed.

Origin of the anomalous temperature evolution of photoluminescence peak energy in degenerate InN nanocolumns.

Photoluminescence (PL) behaviour in InN nanocolumns reveal decreasing, increasing and near invariant peak energies (E(PL)) as a function of temperature. Samples, having E(PL)~0.730 eV at 20 K, showed temperature invariance of E(PL). Samples possessing E(PL) on the lower and higher energy side of 0.730 eV demonstrate a normal redshift and anomalous blueshift, respectively, with increasing temperature. This temperature evolution can be effectively explained on the basis of a competition between a conventional red shift from lattice dilation, dominant for low carrier density sample, on one hand, and a blue shift of the electron and hole quasi Fermi-level separation, dominant for high carrier density samples, on the other.

Recent developments in tip-based nanofabrication and its roadmap.

Recent developments of tip-based nanofabrication (TBN) are reviewed. In TBN, a functionalized cantilevered-tip is the common basic apparatus for performing the tasks of nanofabrication. The nanofabrication applications of three major techniques under the TBN family: atomic force microscopy (AFM), dip-pen nanolithography (DPN), and scanning near-field optical microscopy (SNOM), are studied with the focus on their manipulability over the size, orientation, and position of the nanostructures fabricated. The nanostructures made by these techniques are selectively presented in order to illustrate the versatility and advancement of these tip-based techniques. The information reviewed and illustrated is extrapolated to form the basis for the assessment of the needs and challenges facing the TBN community in the future. A preliminary roadmap over the next seven years is then developed. The prospective approaches and focusing areas for future research and development are also discussed.

Nickel nanorods produced by annealing composite oxide films.

Nickel nanorods have been produced by annealing a dense composite film. The nanorods of 45-140 nm in lateral dimensions and 230-1400 nm in longitudinal dimensions were obtained by annealing NiO-YSZ composite films in H2 at 800 degrees C for one hour. The axis of the nanorods at the (220) direction was observed. The dense NiO-YSZ composite film was originally created by co-sputtering Ni and Zr-Y-Ce targets in Ar and O2 environment at 350 degrees C. Reduction of NiOx to Ni nuclei takes place on the surface of the film. The low crystallinity of the original composite film is believed to facilitate the NiO to grow into Ni nanorods on the discrete Ni seeds by diffusion.