Xianming Liu

Synthesis of rod-, twinrod-, and tetrapod-shaped CdS nanocrystals using a highly oriented solvothermal recrystallization technique

Rod-, twinrod- and tetrapod-shaped CdS nanocrystals have been successfully prepared from the starting spherical CdS nanocrystals via a highly oriented solvothermal recrystallization technique. X-Ray powder diffraction, X-ray photoelectron spectroscopy, transmission electron microscopy and high-resolution transmission electron microscopy have been used to characterize the crystal structure and growth direction of the obtained sample. The present technique may open a new doorway to one-dimensional nanosized semiconductors from the same kind of materials with irregular shape or larger size.

Synthesis of yttrium hydroxide and oxide nanotubes

Abstract Yttrium hydroxide nanotubes were hydrothermally synthesized via a metastable precursor, PEG–Y(NO 3 ) 3 complex. XRD patterns showed the product was a pure hexagonal phase of Y(OH) 3 . TEM images displayed that the nanotubes have outer diameters ranging from 80 to 200xa0nm, wall thicknesses of about 30xa0nm, and lengths up to several micrometers. The nanotube growth may have three stages: formation of a metastable PEG–Y(NO 3 ) 3 complex; nucleation and formation of Y(OH) 3 nanorods; developing Y(OH) 3 nanotubes. We proposed the Y(OH) 3 nanotubes growth mechanism to be a nucleation-diffusion growth based on the characterization results. Y 2 O 3 nanotubes were formed with smaller diameters after post-treatment at 500°C for 2xa0h.

A simple, convenient, mild solvothermal route to nanocrystalline Cu3P and Ni2P

Abstract Sheet-like nanocrystalline Cu 3 P and spherical nanocrystalline Ni 2 P with hexagonal phases were successfully obtained under mild solvothermal conditions based on the reactions of CuCl 2 ·2H 2 O, NiCl 2 ·6H 2 O with elemental phosphorus in ammonia liquor systems. The phase, grain size, morphology and purity were determined by XRD, TEM and XPS, respectively. The ammonia system and active yellow phosphorus played important roles in the formation of nanocrystalline Cu 3 P and Ni 2 P. A possible mechanism is proposed.

Dendritic growth of PbS crystals with different morphologies

Abstract PbS dendritic crystals with different morphologies have been successfully prepared via a solvothermal process. TEM observations show that the as-prepared PbS dendrites exhibit cross-like morphology for primary arms and fishbone shape for secondary arms. The reactive precursors and solvents have much influence on the growth behavior of PbS dendrites. The possible growth mechanisms are briefly discussed, while the orthogonal growth of PbS dendrites are assigned to 〈1xa00xa00〉 directions.

Room temperature growth of nanocrystalline tin (II) selenide from aqueous solution

Sheet-like nanocrystalline SnSe with an orthorhombic phase has been prepared via a reaction between a selenium alkaline aqueous solution and tin (II) complex at room temperature under atmospheric pressure. The XRD pattern indicated that the selenium alkaline solution as a selenium source, made the product to crystallize well at room temperature. The XPS analysis indicated that the purity of the product was quite high. The mechanism of the formation of tin (II) selenide was discussed.

Preparation of cerium hydroxycarbonate by a surfactant-assisted route

Abstract Cerium hydroxycarbonate (CeOHCO 3 ) with shuttle-like morphology has been conveniently synthesized at 90xa0°C from aqueous solution in the presence of polyvinylpyrrolidone (PVP). The products were characterized by X-ray diffraction, transmission electron microscopy and photoluminescent (PL) techniques. The as-prepared CeOHCO 3 was found to have a PL emission at about 347xa0nm. Experimental conditions as well as the role of PVP played in the reaction were also explored.

Hydrothermal preparation of uniform cubic-shaped PbS nanocrystals

Abstract Uniform cubic-shaped PbS nanocrystals have been prepared by a hydrothermal reaction between Pb(Ac) 2 ⋅2H 2 O and Na 2 S 2 O 3 in the presence of surfactant of C 17 H 33 COOK. The product was characterized through XRD, TEM, and HRTEM. Essentially all the face-centered cubic phase of PbS nanocrystals are well-defined cube with (2xa00xa00) lattice planes as surfaces and easy to arrange orderly.

Coexistence of wurtzite GaN with zinc blende and rocksalt studied by x‐ray power diffraction and high‐resolution transmission electron microscopy

X‐ray powder diffraction and high‐resolution transmission electron microscopy (HRTEM) have found coexistence of three structures of GaN: wurtzite, zinc blende, and rocksalt in the samples prepared through benzene thermal process at 280–300u2009°C under pressure about 5 MPa. Previously, GaN with rocksalt structure only appeared at high pressure more than 37 GPa. HRTEM showed that there was a transitional region between the two cubic phases of GaN with zinc blende and rocksalt. X‐ray photoelectron spectra analysis of the sample gave the average composition of Ga0.95N.

Solvothermal route to CoTe2 nanorods

Abstract CoTe 2 nanorods with the diameter of 30nm and the length of more than 1.2μm were directly synthesized by the reaction of CoCl 2 ·6H 2 O and tellurium in an autoclave with ethylenediamine as solvent at 160°C for 10h. X-ray powder diffraction (XRD) patterns, X-ray photoelectron spectra (XPS) confirmed the as-prepared nanorods are orthorhombic CoTe 2 phase with the lattice parameters a = 5.314A, b = 6.320A and c = 3.882A.

Preparation of multiply twinned palladium particles with five-fold symmetry via a convenient solution route

Palladium particles having a decahedral or an icosahedra shapes were synthesized at 160°C through a convenient solvothermal process in the presence of acetylacetone and ethylene glycol. Scanning electron microscope and transmission electron microscope investigation revealed that these particles were multiply twinned with an average diameter around 1 μm. The role of the solvents played was explored and acetylacetone was found to play a key role in the formation of multiply twinned palladium particles.