Wuhong Xin

Two-dimensional SixGe1−x films with variable composition made via multilayer colloidal template-guided ionic liquid electrodeposition

The binary alloy system Si(x)Ge(1-x) provides a continuous series of materials with gradually varying properties. In this paper, we report on a fundamental basis a method to make large-area macroporous Si(x)Ge(1-x) films with variable Ge content by electrodeposition in an ionic liquid, with SiCl(4) and GeCl(4) as precursors. The chemical composition of the products can be modified by changing the molar ratio of the precursors. Periodical macroporous Si(x)Ge(1-x) was made by a multilayer polystyrene (PS) template assembled as face-centered cubic lattice. Two-dimensional (2-D) Si(x)Ge(1-x) bowl-like and fishing-net structures can be obtained by applying different deposition temperatures. The results highlight the potential applications, including photonic bandgap and battery materials, as well as ultra-thin gratings, due to the effect of modification of light and improved tunability of composition, although Si(x)Ge(1-x) made by our method is sensitive to oxidation by air.

Controllable synthesis of Cu2O petalody octahedral microcrystals and multi-patterned evolution.

The fabrication of cuprous oxide (Cu(2)O) with various morphologies has attracted extensive interest due to its applications in solar energy conversion, electrode materials, sensors, and catalysts. Herein, we report a facile controllable route for Cu(2)O microcrystals with various architectures via a hydrothermal method without using templates or surfactants. Six types of Cu(2)O microcrystals including petalody octahedral, concave truncated octahedron, truncated octahedron, octahedron, sphere-like, and sphere are obtained accompanying with Cu precipitation or urchin-like CuO particles due to the modifying of pH values. The petalody octahedral pattern of Cu(2)O is for the first time found here under the condition of pH 7-8. Additionally, possible growth mechanism for multi-patterned Cu(2)O and compositional evolution is discussed via preferential growths induced by selective absorption of acrylic acid and decomposition of lactic acid in the present reaction system. These experimental results prove a versatile and facile strategy for Cu(2)O microcrystals with special and complex architectures, which may highlights their potential applications due to the improved surface activity, catalytic, or photoelectric performance.

Fabrication of three-dimensionally ordered macroporous gadolinia-doped ceria films

In this paper, three-dimensionally ordered macroporous (3-DOM) gadolinia-doped ceria (CGO) thin films were prepared by an aqueous organic gel method through the interstitial spaces between polystyrene spheres assembled on glass substrates. The concentration of CGO precursor, the pH value and infiltration times had important effects on the formation of the ordered porous structure. The morphologies of the porous CGO films were characterized by scanning electron microscopy (SEM). Phase development of PS–CGO composites with increasing calcination temperature, and the interactions between PS templates and the CGO precursor were investigated by Fourier transform infrared spectroscopy (FT-IR). X-Ray diffraction (XRD) spectra indicated the thin film calcined at 600 °C had a cubic structure and the CGO phase was formed directly by thermal decomposition of the precursor gel. The chemical composition of the porous CGO films was also studied by X-ray photoelectron spectroscopy (XPS).