Controllable Fabrication of GeSi Nanowires in Diameter of About 10 nm Using the Top-Down Approach

Ordered GeSi nanowires with a ～ 10nm cross section are fabricated utilizing top-down and Ge condensation techniques. In transmission electron microscopy measurements, the obtained GeSi nanowires exhibit a single-crystal structure and a smooth Ge/SiO2 interface. Due to the linear relationship between the cross-section area and the initial pattern size under the self-limited oxidation condition, the cross-section size of GeSi nanowires can be precisely controlled. The Raman spectra reveal a high Ge fraction （up to 97%） and a biaxial strain of the GeSi nanowires. This top-down technique is promising for fabrication of high-performance GeSi nanowire based optoelectronic devices.

Microfluidic platform serves as controllable fabrication of binary Mo/Ir nanodots/carbon hetero-material for efficient electrocatalytic nitrogen reduction

Electrocatalytic nitrogen reduction reaction(NRR)is regarded as a potential routine to achieve environment-friendly ammonia production,because of its abundant nitrogen resources,clean energy utilization and flexible operation.However,it is hindered by low activity and selectivity,in which con-dition well-designed catalysts are urgently in need.In this work,a binary Mo/Ir nanodots/carbon(Mo/Ir/C)hetero-material is efficiently constructed via microfluidic strategy,of which the nanodots are ho-mogeneously distributed on the carbon skeleton and the average size is approximately 1 nm.Excellent performance for NRR is obtained in 1 mol L^(-1) KOH,of which the optimized ammonia yield and faradic efficiency are 7.27μg h^(-1) cm^(-2) and 2.31%respectively.Moreover,the optimized ammonia yield of 6.20μg h-1 cm-2 and faradic efficiency of 10.59%are also obtained in 0.005 mol L^(-1) H_(2)SO_(4).This work achieves the continuous-flow synthesis and controllable adjustment of hetero-materials for favorable morphologies,which provides an innovative pathway for catalyst design and further promotes the development of ammonia production field.

Controlled Fabrication of Cd-Bi Nanoparticles via Sonochemical Method

A sonochemical method for the direct controlled synthesis of Cd-Bi nanoparticles from a bulk Cd-Bi alloy is introduced. The nanoparticles were found to be monodispersed and the size distribution can be easily controlled by adjusting the ultrasonic power. The formation and the constituent of the as-prepared Cd-Bi nanoparticles were revealed by means of X-ray diffraction, differential thermal analysis and thermogravimetry, transmission electron microscopy, and electron diffraction. It was found that the Cd-Bi eutectic alloy nanoparticles are made of the hexagonal phase of metal cadmium and the rhombohedral phase of metal bismuth. In addition, we also found through tribological tests that the powder has an excellent antiwear property.

Self-aligned fiber-based dual-beam source for STED nanolithography

A fiber-based source that can be exploited in a stimulated emission depletion(STED) inspired nanolithography setup is presented.Such a source maintains the excitation beam pulse, generates a ring-shaped depletion beam, and automatically realizes dual-beam coaxial alignment that is critical for two beam nanolithography.The mode conversion of the depletion beam is realized by using a customized vortex fiber, which converts the Gaussian beam into a donut-shaped azimuthally polarized beam.The pulse width and repetition frequency of the excitation beam remain unchanged, and its polarization states can be controlled.According to the simulated point spread function of each beam in the focal region, the full width at half-maximum of the effective spot size in STED nanofabrication could decrease to less than 28.6 nm.

Tadpole-shaped Au nano-particles fabricated by laser fragmentation of Au nano-spheres in liquid

Tadpole-shaped Au nano-particles with controllable tails are successfully fabricated by simply using laser fragmentation of separated Au nano-spheres in liquid. The optimum laser power densities（1.5–3 GW∕cm-2） can enable part of the individual Au nano-sphere to be re-melted, released, and ultra-rapidly recondensed/crystallized on the outside of the original region. We find that the length of the tail in a tadpole-shaped Au nano-particle significantly increases from about 10 to 25 nm by increasing the laser power density. Benefiting from the unique structural features, the localized surface plasmon resonance（LSPR） absorption spectra of the tadpole-shaped Au nano-particles become broader by increasing the tail length. Moreover, the LSPR absorption band also exhibits a noticeable red shift from about 520 to 650 nm. Our results provide a convenient and valuable strategy to fabricated novel anisotropic-shaped nano-structures with fascinating properties.