Papers by Keyword: Sonochemical Synthesis

Abstract: This study focuses on the preparation and characterization of Nickel oxide nanoparticles (NiONPs) supported on the reduced graphene oxide (r-GO) surface by a simple ultra-sonochemical method (r-GO-NiONPs). The formation of the r-GO was confirmed by FT-IR spectroscopy. The layer content of the r-GO was characterised by Raman spectroscopy. The crystalline nature and average particle size of the NiONPs were inferred by Powder-XRD spectroscopy. The surface morphology of the prepared nanoparticle was studied by the Scanning Electron Microscopy (SEM). The total surface area of the r-GO-NiONPs was ascertained by Nitrogen gas BET adsorption isotherm. Surface area of r-GO-NiONPs is 282 m²g^-1 which is little over twice of Graphene Oxide (GO) 132 m²g^-1. The magnetic properties of the prepared r-GO-NiONPs was studied using Vibrating Sample Magnetometer (VSM). Field dependent magnetization studies of r-GO-NiONPs delivers a very promising result.

Abstract: A sonochemical method has been applied to prepared PbWO4 crystals by using different precursors. The as-prepared samples were characterized by X-ray diffraction (XRD) and transmission electron microscopy (TEM). It was found that the precursor played an important role in the synthesis of PbWO4 crystals. PbWO4 nanostructures with different morphologies, such as flower-like, rod-like, and dendrite-like, have been successfully obtained via a mild sonochemical method corresponding to the precursor PbCO3, Pb(NO3)2, and Pb(Ac)2, respectively.

Abstract: Zn₃(PO₄)₂.4H₂O, which is an important component of biomedical zinc phosphate cement, was synthesized from an aqueous solution of zinc oxide and orthophosphoric acid by the sonochemical method. This synthesis method yielded best results with respect to high purity and crystallinity. Structural characteristics of the compound were investigated by X-ray diffraction (XRD), Fourier transform infrared (FT-IR) and scanning electron microscopy (SEM). FT-IR spectra indicated the presences of different crystallographic PO₄³ ion and H₂O molecules for the Zn₃(PO₄)₂.4H₂O and Zn₃(PO₄)₂ structures. The resulting XRD patterns showed the purity phases of orthorhombic Zn₃(PO₄)₂.4H₂O and the monoclinic for its final decomposed Zn₃(PO₄)₂ product. The thermal stability, crystallite size, and plate-like microparticles of Zn₃(PO₄)₂.4H₂O and Zn₃(PO₄)₂ are different in this work from those in previous reports, which may be caused by the starting reagents and reaction condition for the sonochemical method.

Abstract: Cauliflower-like ZnO superstructures composed of nanoparticles in large scale were successfully synthesized only using Zn(CH3COO)2•2H2O and triethanolamine (TEA) aqueous solution mixtures via a template-free sonochemical process at the ambient condition. A number of techniques, including X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), UV-visible absorption and photoluminescence (PL) were used to characterize the obtained ZnO products. It has been interestingly found that UV-Vis absorption spectrum shows not only a weak and sharp peak at 367 nm in ultraviolet region but also a strong and broad band centered at 564 nm in visible region. The possible formation mechanism of ZnO cauliflower-like structure is also proposed.

Abstract: Nanocrystalline hydroxyapatite was prepared by a precipitation method with add of ultrasonic irradiation. In this work the effect of H3PO4 addition rate during synthesis and the influence of the magnesium incorporation into apatite were studded. The results revealed that the morphology and cristalinity of synthesized nanopowders are significantly affected by ultrasonic irradiation. Monophase hydroxyapatite was obtained when magnesium was added into HA lattice during the synthesis with ultrasonic irradiation.

Abstract: The main purpose of the present work was to investigate the influence of urea concentration on hydroxyapatite (HAp) synthesis. Calcium nitrate and ammoniumdihydrogenphosphate were used as Ca and P sources. A homogeneous precipitation agent – urea - was applied in the field of ultrasonic irradiation. Different Ca : P : urea molar ratios were applied and the samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and infrared spectroscopy (IR). The results reveal the influence of the urea concentration on the phase composition of the system, crystallite size and the particle morphology. Different Ca : P : urea molar ratios led to various system formation: from biphasic OCP and HAp to monophasic HAp. The estimated HAp crystallite size was 24.4 nm. An explanation of the mechanism of the HAp synthesis is given, regarding the formation of the intermediate and final product during ultrasonic irradiation.