Hui Liang

Phase-controlled synthesis of monodispersed porous In2O3 nanospheres via an organic acid-assisted hydrothermal process

Phase-pure porous nanospheres, both In(OH)3 and InOOH, have been prepared through a facile hydrothermal method using different organic acids as the assistant agents. The organic acids play an important role in the phase change, and the phase composition of the precursors could be deliberately controlled by adjusting the organic acid (citric acid or tartaric acid). Cubic and hexagonal In2O3 monodispersed nanospheres with porosity can be obtained from In(OH)3 and InOOH, respectively, while size and morphology can be maintained to a certain extent. The as-synthesized porous In2O3 nanospheres are composed of numerous small nanocrystallites and possess good size uniformity. Influencing factors such as the reaction time and the type and amount of organic acids were systematically investigated. A possible ethylenediamine or tartaric acid coordinated mechanism of the phase-control synthesis of In2O3 was proposed based on the experimental results. Furthermore, the potentialities of the porous In2O3 nanospheres were also studied by room-temperature photoluminescence (PL) spectroscopy.

The size-controlled synthesis of uniform Mn2O3 octahedra assembled from nanoparticles and their catalytic properties

Uniform Mn(2)O(3) octahedral nanoparticles were synthesized by a mediated N, N-dimethylformamide (DMF) solvothermal route. On the basis of a time-dependent experiment, we propose that the Mn(2)O(3) octahedra were formed through oriented aggregation of primary nanocrystals. Meanwhile, poly(vinyl-pyrrolidone) (PVP) was applied as a surfactant to facilitate the oriented aggregation of small Mn(2)O(3) nanoparticles into octahedral crystallites. By tuning the amount of Mn(NO(3))(2), particles with average sizes 1 µm to 300 nm, with a narrow size distribution, could be fabricated. The catalytic test results show that the as-obtained Mn(2)O(3) octahedra exhibited desirable CO catalytic oxidation properties and the surface texture and particle size significantly affected the catalytic activity. By contrast, the larger Mn(2)O(3) octahedral nanoparticles prepared at a lower concentration of Mn(NO(3))(2) exhibited relatively high activities.

Controllable synthesis of γ-AlOOH micro/nanoarchitectures via a one-step solution route

Large-scale uniform γ-AlOOH micro/nanoarchitectures (ellipsoidal flower-like, rotor-like, carambola-like and leaf-like) were synthesized through a facile one-step solution phase route. The products were examined by X-ray diffraction (XRD), Fourier transform infrared (FT-IR) spectra, scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Influencing factors such as the volume ratio of DMF to water, the content of AlCl3, reaction temperature and reaction time were systematically investigated. A possible formation mechanism of the novel γ-AlOOH micro/nanostructures was proposed based on the experimental results. The room-temperature photoluminescence (PL) spectra of the obtained γ-AlOOH structures were also studied and the results indicate that the luminescence properties of the products are dependent on their morphologies.