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A simple and facile sonochemical route has been demonstrated for the shape-selective preparation of highly crystalline ZnO nanostructures, such as nanorods, nanocups, nanodisks, nanoflowers, and nanospheres. The concentration of precursor chemicals, the kind of hydroxide anion-generating agents, the ultrasonication time, and the use of a capping agent are key factors in the morphological control of ZnO nanostructures. This method is fast, simple, convenient, economical, and environmentally benign. On the basis of our shape-control of the ZnO nanostructures by the sonochemical technique, growth mechanisms of ZnO nanostructures were also proposed. We believe this technique will be readily adopted in realizing other forms of various nanostructured materials.

We report mesoporous composite materials (m-GeO2, m-GeO2/C, and m-Ge-GeO2/C) with large pore size which are synthesized by a simple block copolymer directed self-assembly. m-Ge/GeO2/C shows greatly enhanced Coulombic efficiency, high reversible capacity (1631 mA h g(-1)), and stable cycle life compared with the other mesoporous and bulk GeO2 electrodes. m-Ge/GeO2/C exhibits one of the highest areal capacities (1.65 mA h cm(-2)) among previously reported Ge- and GeO2-based anodes. The superior electrochemical performance in m-Ge/GeO2/C arises from the highly improved kinetics of conversion reaction due to the synergistic effects of the mesoporous structures and the conductive carbon and metallic Ge.

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Semiconducting two-dimensional (2D) materials, particularly extremely thin molybdenum disulfide (MoS) films, are attracting considerable attention from academia and industry owing to their distinctive optical and electrical properties. Here, we present the direct growth of a MoS monolayer with unprecedented spatial and structural uniformity across an entire 8 inch SiO/Si wafer. The influences of growth pressure, ambient gases (Ar, H), and S/Mo molar flow ratio on the MoS layered growth were explored by considering the domain size, nucleation sites, morphology, and impurity incorporation. Monolayer MoS-based field effect transistors achieve an electron mobility of 0.47 cm V s and on/off current ratio of 5.4 × 10. This work demonstrates the potential for reliable wafer-scale production of 2D MoS for practical applications in next-generation electronic and optical devices.

Anodic aluminum oxide (AAO) templates were fabricated by anodizing Al films. After the Co catalyst had been electrochemically deposited into the bottom of the AAO template, carbon nanotubes (CNTs) were grown by the catalytic pyrolysis of C2H2 at 650 °C. Overgrowth of CNTs on the AAO templates was observed. The diameter of the CNTs strongly depends on the size of the pores in the AAO template. The electron field emission measurements on the samples showed a turn-on field of 1.9–2.1 V/μm and a field enhancement factor of 3360–5200. Our observation concerning the low turn-on field and high field enhancement factors is explained in terms of a low field screening effect.

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