Xue-Hong Liao

Preparation of nanocrystalline ceria particles by sonochemical and microwave assisted heating methods

Nanocrystalline ceria (CeO2) particles have been successfully prepared via sonochemical and microwave assisted heating routes from aqueous solutions containing (NH4)2Ce(NO3)6, hexamethylenetetramine and poly (ethylene glycol)-19000 (PEG). The products were characterized by techniques such as powder X-ray diffraction, transmission electron microscopy, high-resolution transmission electron microscopy, selected area electron diffraction, Brunauer–Emmett–Teller nitrogen adsorption and UV–Visible absorption spectroscopy. Analysis of the results showed that the products had uniform shape, narrow size distribution and displayed conspicuous quantum size effects.

Preparation of CdS and ZnS nanoparticles using microwave irradiation

Abstract Nanoparticles of CdS, ZnS have been prepared by a very simple fast reaction between CdCl 2 or Zn(Ac) 2 and thioacetamide in aqueous solution using microwave irradiation. The nanoparticles were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), reflectance and photoluminescence spectra. The sizes of the sample as prepared were calculated by Debye–Scherrer formula according to XRD spectra to be about 9 and 3 nm for CdS and ZnS, respectively. Similar results can also been obtained in the TEM images.

Preparation of Bi2S3 nanorods by microwave irradiation

Abstract Bi 2 S 3 nanorods, with a diameter of ca. 10 nm and a length of up to ca. 300 nm, have been successfully prepared from a formaldehyde solution of bismuth nitrate and thiourea by microwave irradiation. Powder X-ray diffraction (XRD) pattern indicates that the product is pure orthorhombic Bi 2 S 3 phase. The product is also characterized by the techniques of transmission electron microscopy (TEM) and X-ray photoelectron spectra (XPS).

Preparation of silver nanorods by electrochemical methods

Abstract Silver nanorods have been prepared by an electrochemical technique from an aqueous solution of AgNO 3 in the presence of polyethylene glycol (PEG). The silver nanorods were characterized by using transmission electron microscopy, X-ray diffraction, and absorption spectroscopy. It was found that the concentration of AgNO 3 and PEG affected the formation of the nanorods.

Microwave synthesis of nanocrystalline metal sulfides in formaldehyde solution

Nanocrystalline metal (Cu, Hg, Zn, Bi, Pb) sulfides with different shapes and different particle sizes have been successfully prepared in a formaldehyde solution of metal salt and thioacetamide by microwave irradiation. Powder X-ray diffraction patterns indicated that the products were pure orthorhombic Bi2S3 phase, cubic phase HgS, hexagonal phase CuS, cubic phase ZnS, cubic phase PbS, respectively. The products were also characterized by transmission electron microscopy. Ultraviolet reflection spectrum clearly indicates the presence of quantum size effects in ZnS.

Rapid synthesis of nanocrystalline SnO2 powders by microwave heating method

Abstract Nanocrystalline SnO2 powders of about 3 nm in size have been prepared by a microwave irradiation heating technique from an aqueous solution in the presence of SnCl4 and urea. The nanocrystalline SnO2 particles were characterized by transmission electron microscopy (TEM), X-ray diffraction (XRD), differential scanning calorimetric (DSC), thermogravimetric analysis (TG), and reflection spectrum. A bandgap is estimated to be 4.5 eV from the optical measurement of the nanoparticles.

Synthesis of amorphous Fe2O3 nanoparticles by microwave irradiation

Abstract Amorphous Fe 2 O 3 nanoparticles of about 3–5 nm in size have been synthesized by microwave irradiation heating of an aqueous solution, containing ferric chloride, polyethylene glycol-2000 and urea. The Fe 2 O 3 nanoparticles were characterized by the techniques of TEM, XRD, DSC, TGA and magnetization measurements.

Electrochemical preparation of silver dendrites in the presence of DNA

Silver dendrites have been prepared by an electrochemical technique in an aqueous solution of AgNO3 in the presence of DNA. An electrochemical cell was placed in an operating ulrasonic bath and carried out the electrolysis in the presence of an ultrasonic field. Silver dendrites were characterized with a transmission electron microscopy and X-ray diffraction. It was found that the concentration of AgNO3 and DNA affected the formation of the nanoparticles.

Photochemical synthesis and characterization of PbSe nanoparticles

PbSe nanoparticles have been prepared by a simple reaction between Pb(Ac)2 and Na2SeSO3 in the presence of complexating agent using photoirradiation. The nanoparticles were characterized by X-ray diffraction (XRD), energy-dispersive X-ray analysis (EDAX), transmission electron microscopy (TEM) and X-ray photoelectron spectra (XPS). The sizes of the sample as prepared were calculated by Debye-Scherrer formula according to XRD spectrum to be about 25 nm. Similar results can also been obtained in the TEM images.

Preparation of monodispersed nanocrystallineCeO2 powders by microwave irradiation

Monodispersed nanocrystalline CeO2 powders of size ca. 2.0 nm displaying quantum size effects have been prepared by microwave irradiation in an aqueous solution containing (NH4)2Ce(NO3)6, PEG and NaAc.