Hydrothermal synthesis and photoluminescence of Eu(2-x)Sm(x)Sn2O7 (x = 0-2.0) nanophosphors.

Eu(2-x)Sm(x)Sn2O7 (x = 0, 0.1, 0.5, 1.0, 1.5, and 2.0) solid solutions were successfully synthesized by a simple, mild hydrothermal process. The crystal structure, particle size, and chemical composition of the solid solutions were characterized by X-ray diffraction, transmission electron microscopy, and energy dispersive X-ray spectroscopy. X-ray diffraction patterns and transmission electron microscopy images reveal that all the products were cubic pyrochlore-type Eu(2-x)Sm(x)Sn2O7 nanocrystals with the diameter of approximately 20 nm. Due to efficient energy transfer from Sm3+ to Eu3+, the Eu(2-x)Sm(x)Sn2O7 (x = 0.1, 0.5, 1.0, and 1.5) nanocrystals exhibited strong 5D0 --> 7F1 photoluminescence emission of Eu3+. The dominant 5D0 --> 7F1 transition revealed good monochromaticity and low distortion of the Eu(2-x)Sm(x)Sn2O7 nanophosphors.

Hydrothermal synthesis of Zn2SnO4 nanorods in the diameter regime of sub-5 nm and their properties.

Single crystalline Zn(2)SnO(4) (ZTO) nanorods 2-4 nm in diameter and around 20 nm in length were successfully synthesized by a simple hydrothermal process with use of hydrazine hydrate as an alkaline mineralizer instead of NaOH or NH(3).H(2)O. By analyzing the UV-vis diffuse reflectance spectrum, the optical band gap (E(g)) of the nanorods was found to be 3.87 eV, which indicates a blue shift of 0.27 eV from that of bulk ZTO (3.6 eV). In situ high-temperature X-ray diffraction was employed to study the thermal expansion coefficient and the variation of lattice parameter with temperature of the product. Furthermore, we discussed the chemical mechanism and key factors to the hydrothermal formation of the sub-5 nm ZTO nanorods.

InOOH hollow spheres synthesized by a simple hydrothermal reaction.

Novel micrometer-sized indium oxyhydroxide (InOOH) hollow spheres were successfully synthesized via a citric acid (CA) assisted hydrothermal process. The morphology, crystal structure, and optical properties of the product were characterized by X-ray diffraction, transmission electron microscopy, scanning electron microscopy, Fourier transform infrared spectroscopy, and UV-vis diffuse reflectance spectroscopy (DRS). The optical band gap, E(g), was estimated to be 3.5 eV from the DRS spectrum, which is almost equal to that of indium oxide. Furthermore, on the basis of a series of SEM observations, phenomenological elucidation of a mechanism for the growth of the InOOH hollow spheres has been presented; key factors for the formation of the structures have been proposed.

Microemulsion-based synthesis of porous zinc ferrite nanorods and its application in a room-temperature ethanol sensor.

Porous zinc ferrite (ZnFe(2)O(4)) nanorods with a diameter of around 50 nm and a length of several micrometers have been synthesized by a microemulsion-based method in combination with calcination at 500 °C. The morphology and structure of the ZnFe(2)O(4) nanorods and its precursor (ZnFe(2)(C(2)O(4))(3) nanorods) were systematically characterized by x-ray powder diffraction, transmission electron microscopy, field emission scanning electron microscopy and high-resolution transmission electron microscopy. The formation mechanism for the porous ZnFe(2)O(4) nanorods is also discussed. Moreover, the porous ZnFe(2)O(4) nanorods were applied in a room-temperature ethanol sensor and exhibited much better sensing performance than ZnFe(2)O(4) nanoparticles.