Convex and Concave Square Arrays of Vertical SnO2 Nanowire Bundles toward Lithium-Ion Storage Electrodes

We report on the convex and concave square arrays of tin dioxide nanowire bundles for use in rechargeable lithium-ion storage electrodes. The well-aligned and periodic patterns of the nanowire bundles were fabricated over current collectors by means of a photolithography process. The electrochemical properties, which were investigated by varying the pattern geometries of the nanowire electrodes, show that the convex and concave arrays lead to more improved charge/discharge dynamics in lithium-ion storage than the nonpatterned one. The empty spaces formed between the array patterns can facilitate the access of the liquid electrolyte to the electrode structures as well as the strain relaxation of electrode materials during repeated lithiation/delithiation processes. Interestingly, the convex square patterns promote more efficient ion transfer than the concave ones. To this end, the full-cell battery is successfully and explicitly demonstrated, which suggests that these tailored electrode platforms could stimulate scientific interest in the design and development of nano-wire-based electrode architectures.115sciescopu

Ultrathin Amorphous α-Co(OH)2 Nanosheets Grown on Ag Nanowire Surfaces as Highly Active and Durable Elect

11117Nsciescopu

An Overview of One-dimensional Metal Nanostructures for Electrocatalysis

Nanostructures of metals are of great importance in the area of catalysis due to their distinct physicochemical properties compared to their bulk counterparts. Size and morphology dependent properties of metal nanostructures provide a rational approach toward designing a highly efficient catalytic materials. In particular, one-dimensional (1D) metallic nanostructures in the shapes of wires, rods and tubes have recently been studied with great interest due to their potential uses as electrocatalysts for oxidations of fuels and reduction of oxidants in fuel cell applications. Compared to the conventional nanoparticle catalysts that are generally supported on carbon, these 1D materials can offer significant opportunities to improve catalytic performance under fuel cell reaction conditions by their structural characteristics such as preferential exposure of reactive crystal facets, high stability, and facile electron transport. Great advances in the synthesis of electrocatalysts based on the metallic nanowires and nanotubes have been made with enhanced electrocatalytic activity and durability. This review summarizes the research progress made on synthesizing 1D metal electrocatalysts using different synthetic strategies, including template-assisted method, electrospinning, and template-free wet-chemical synthesis, with an emphasis on the electrocatalytic performance of these 1D nanomaterials.111312sciescopu

Formation of Carbon-coated ZnFe2O4 Nanowires and Their Highly Reversible Lithium Storage Properties

In this paper, carbon-decorated ZnFe2O4 nanowires, having one-dimensional geometry with diameters of 70-150 nm and lengths of several micrometers, were prepared and used as a highly reversible lithium ion anode material. They can be obtained from calcination of glucose-coated ZnFe2(C2O4)(3) nanowires, which were prepared in glucose containing microemulsion solutions. The physicochemical properties of carbon-coated ZnFe2O4 nanowires were investigated by scanning electron microscopy, X-ray diffraction, Raman spectroscopy, transmission electron microscopy, and X-ray photoelectron spectroscopy. The carbon-coated ZnFe2O4 nanowires showed a substantially increased discharge capacity of ca. 1285.1 mA h g(-1) at the first cycle as compared with non-carbon-coated ZnFe2O4 nanowires (ca. 1024.3 mA h g(-1)) and ZnFe2O4 nanoparticles (ca. 1148.7 mA h g(-1)). Moreover, the discharge capacity of the carbon-coated ZnFe2O4 nanowires was maintained with no degradation even after 100 charge/discharge cycles. The high cycling durability, rate capability, and coulombic efficiency suggest that the carbon-coated ZnFe2O4 nanowires prepared here can be promising anode candidates for a highly reversible lithiumstorage electrode.113123sciescopu

MnCo2O4 Nanowires Anchored on Reduced Graphene Oxide Sheets as Effective Bifunctional Catalysts for Li–O2 Battery Cathodes

A hybrid composite system of MnCo2O4 nanowires (MCO NWs) anchored on reduced graphene oxide (RGO) nanosheets was prepared as the bifunctional catalyst of a Li-O-2 battery cathode. The catalysts can be obtained from the hybridization of one-dimensional MCO NWs and two-dimensional RGO nanosheets. As O-2-cathode catalysts for Li-O-2 cells, the MCO@RGO composites showed a high initial discharge capacity (ca. 11092.1 mAhgcarbon(-1)) with a high rate performance. The Li-O-2 cells could run for more than 35 cycles with high reversibility under a limited specific capacity of 1000 mAhgcarbon(-1) with a low potential polarization of 1.36 V, as compared with those of pure Ketjenblack and MCO NWs. The high cycling stability, low potential polarization, and rate capability suggest that the MCO@ RGO composites prepared here are promising catalyst candidates for highly reversible Li-O-2 battery cathodes.113938sciescopu

Synthesis of Sn catalysts by solar electro-deposition method for electrochemical CO2 reduction reaction to HCOOH

The electrochemical conversions of CO2 to valuable products have gained much interest to mitigate the increasing CO2 concentration in the atmosphere. Selective syntheses of differently shaped tin (Sn) catalysts of rod, rectangular sheet, and dendrite structures were reported here using a new solar electro-deposition method, and their catalytic performance was investigated for the electrochemical reduction of CO2 to liquid fuel in an electrolyte solution of CO2 dissolved pure water. The crystal orientation and structural properties of the prepared Sn catalysts were investigated by XRD and SEM analyses. The selective formation of HCOOH on the prepared Sn electrocatalyst was observed with high faradaic efficiency and HCOOH formation rate over the rod shaped Sn catalysts, resulted in a maximum faradaic efficiency of 94.5% at 1.6 V vs Ag/AgCl and a maximum formation rate of about 0.5 mol/gcat h at 2 V vs Ag/AgCl. The present work may open up a new approach for a selective catalyst synthesis of known structural properties for effective CO2 reduction reaction.11sciescopu

Honeycomb-like nitrogen-doped carbon 3D nanoweb@Li₂S cathode material for use in lithium sulfur batteries

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The size-engineered graphene nanosheets as support for Pd catalysts and its application to electrooxidation of alcholos

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Boosting electrochemical CO₂ reduction on N-doped carbon nanowebs with sulfur engineering

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