Facile synthesis of Ge1-x Snx nanowires

We report a facile one-pot solution phase synthesis of one-dimensional Ge1-x Sn x nanowires. These nanowires were synthesized in situ via a solution-liquid-solid (SLS) approach in which triphenylchlorogermane was reduced by sodium borohydride in the presence of tin nanoparticle seeds. Straight Ge1-x Sn x nanowires were obtained with an average diameter of 60 ± 20 nm and an approximate aspect ratio of 100. Energy-dispersive x-ray spectroscopy (EDX) and powder x-ray diffraction (PXRD) analysis revealed that tin was homogeneously incorporated within the germanium lattices at levels up to 10 at%, resulting in a measured lattice constant of 0.5742 nm. The crystal structure and growth orientation of the nanowires were investigated using high-resolution transmission electron microscopy (HRTEM). The nanowires adopted a face-centred-cubic structure with individual wires exhibiting growth along either the 111, 110 or 112 directions, in common with other group IV nanowires. Growth in the 112 direction was found to be accompanied by longitudinal planar twin defects. © 2020 The Author(s). Published by IOP Publishing Ltd.

Facile synthesis of Ge1-x Snx nanowires

We report a facile one-pot solution phase synthesis of one-dimensional Ge1-x Sn x nanowires. These nanowires were synthesized in situ via a solution-liquid-solid (SLS) approach in which triphenylchlorogermane was reduced by sodium borohydride in the presence of tin nanoparticle seeds. Straight Ge1-x Sn x nanowires were obtained with an average diameter of 60 ± 20 nm and an approximate aspect ratio of 100. Energy-dispersive x-ray spectroscopy (EDX) and powder x-ray diffraction (PXRD) analysis revealed that tin was homogeneously incorporated within the germanium lattices at levels up to 10 at%, resulting in a measured lattice constant of 0.5742 nm. The crystal structure and growth orientation of the nanowires were investigated using high-resolution transmission electron microscopy (HRTEM). The nanowires adopted a face-centred-cubic structure with individual wires exhibiting growth along either the 111, 110 or 112 directions, in common with other group IV nanowires. Growth in the 112 direction was found to be accompanied by longitudinal planar twin defects. © 2020 The Author(s). Published by IOP Publishing Ltd.

Structure and Electronic Properties of InSb Nanowires Grown in Flexible Polycarbonate Membranes

A dense array of vertically aligned indium antimonide (InSb) nanowires with high aspect ratio (diameter 150 nm, length 20 μ m) were grown in the pores of a track-etched polycarbonate membrane via a one-step electrochemical method. There are several reports on InSb nanowire growth in the pores of a mechanically rigid, nano-channel alumina template (NCA), where nanowire growth occurs in the pores of the NCA. This work on InSb nanowire growth in pores of track-etched polycarbonate (PC) membrane sheds light on the various factors that affect nucleation and nanowire growth. The average length and diameter of the as-grown nanowires was about 10 μ m and 150 nm, respectively. Two possible mechanisms accounting for two different morphologies of the as-grown nanowires are proposed. The polycrystallinity observed in some of the nanowires is explained using the 3D ‘nucleation-coalescence’ mechanism. On the other hand, single crystal nanowires with a high density of twin defects and stacking faults grow epitaxially by a two-dimensional (2D) nucleation/growth mechanism. To assess the electrical quality of the nanowires, two- and four-terminal devices were fabricated using a single InSb nanowire contacted by two Ni electrodes. It was found that, at low bias, the ohmic current is controlled by charge diffusion from the bulk contacts. On the other hand, at high bias, the effects of space charge limited current (SCLC) are evident in the current–voltage behavior, characteristic of transport through structures with reduced electrostatic screening. A cross-over from ohmic to SCLC occurs at about 0.14 V, yielding a free carrier concentration of the order of 10 14 cm − 3 .

Seed-mediated synthesis of Au@PtCu nanostars with rich twin defects as efficient and stable electrocatalysts for methanol oxidation reaction

We present a seed-mediated approach to generate Au@PtCu nanostars with a five-fold twinned structure. The Au@PtCu nanostars exhibited better electrocatalytic properties in terms of activity and stability toward MOR relative to commercial Pt/C.

Pt–Cu hierarchical quasi great dodecahedrons with abundant twinning defects for hydrogen evolution

Hierarchical metal nanostructures which exhibit an open structure and a high density of twin defects accessible to reactants hold great promise in catalysis.