ZrO 2 nanocrystals were synthesized by the microwave combustion method (MCM) using urea as the fuel without using any template, catalyst or surfactant. For the purpose of comparison, it was also prepared using the conventional combustion method (CCM). The as-synthesized ZrO 2 was characterized by powder X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), high resolution scanning electron microscopy (HR-SEM), transmission electron microscopy (TEM), energy dispersive X-ray analysis (EDX), diffuse reflectance spectroscopy (DRS) and photoluminescence (PL) spectroscopy. The results indicated that the ZrO 2 nanocrystals obtained by MCM show high crystallinity and uniform size distribution than the ones prepared by CCM. Hence, the influence of the preparation methods on the structure, morphology and optical activity of ZrO 2 was investigated systematically. Photocatalytic degradation (PCD) of 4-Chlorophenol (4-CP), a potent endocrine disrupting chemical in aqueous medium was investigated by ZrO 2 nanocrystals obtained by MCM. The kinetics of PCD was found to follow pseudo first-order. Having established that ZrO 2 was photo catalytically active, the mixed oxide catalysts of ZrO 2-TiO 2 were also tested for the PCD of 4-CP. © 2012 Elsevier Inc.

John Kennedy L

Physics

School of Advanced Sciences

Chennai Campus

Selvam N.C.S

Manikandan A

Vijaya J.J.

Vellore Institute of Technology (VIT) is a private university located in&nbsp;Tamil Nadu, India. Founded in 1984, as Vellore Engineering College, the institution offers 20 undergraduate, 34 postgraduate, four integrated and four research programs. It has campuses in Vellore, Amravati, Bhopal and Chennai.

VIT is one of the top ranked private universities in India according to NIRF, THE and QS Rankings.&nbsp;Govt. of India has recognized&nbsp;VIT, Vellore as an&nbsp;Institution of Eminence. This has allowed VIT to take independent quality initiatives and move up in world ranking.

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VIT University

Journal of Colloid and Interface Science

Ce, Cu co-doped ZnO (Zn1-2xCexCuxO: x=0.00, 0.01, 0.02, 0.03, 0.04 and 0.05) nanocrystals were synthesized by a microwave combustion method. These nanocrystals were investigated by using X-ray diffraction (XRD), UV-visible diffuse reflectance spectroscopy (DRS), scanning electron microscopy (SEM), and vibrating sample magnetometer (VSM). The stability and magnetic properties of Ce and Cu co-doped ZnO were probed by first principle calculations. XRD results revealed that all the compositions are single crystalline. hexagonal wurtzite structure. The optical band gap of pure ZnO was found to be 3.22 eV, and it decreased from 3.15 to 3.10 eV with an increase in the concentration of Cu and Ce content. The morphologies of Ce and Cu co-doped ZnO samples confirmed the formation of nanocrystals with an average grain size ranging from 70 to 150 nm. The magnetization measurement results affirmed the antiferro and ferromagnetic state for Ce and Cu co-doped ZnO samples and this is in agreement with the first principles theoretical calculations. © 2014 Elsevier B.V. All rights reserved.

Physica E: Low-dimensional Systems and Nanostructures

Effect of Ce and Cu co-doping on the structural, morphological, and optical properties of ZnO nanocrystals and first principle investigation of their stability and magnetic properties

Zinc oxide (ZnO), zirconium oxide (ZrO2) and their coupled oxides in the molar ratio 1:1, 2:1 and 1:2 (labeled as ZnZr, Zn2Zr, and ZnZr2 respectively) were successfully prepared by a microwave assisted urea-nitrate combustion synthesis. The structure and morphology of the pure ZnO, ZrO2 and coupled ZnZr, Zn2Zr, and ZnZr 2 were characterized by powder X-ray diffraction (XRD), diffuse reflectance spectroscopy (DRS), photoluminescence spectroscopy (PL), high resolution scanning electron microscopy (HRSEM), energy dispersive X-ray spectrometry (EDX) and Brunauer-Emmett-Teller (BET) methods. The results of the photocatalytic degradation of 2,4-dichlorophenol (2,4-DCP) in aqueous solution indicated that the coupled metal oxide, Zn2Zr is more effective towards the degradation of 2,4-DCP when compared to ZnO, ZrO2, ZnZr and ZnZr2. © 2013 Elsevier Ltd and Techna Group S.r.l.

Ceramics International

Microwave assisted combustion synthesis of coupled ZnO–ZrO2 nanoparticles and their role in the photocatalytic degradation of 2,4-dichlorophenol

In the present study, ZnO nanoparticles (ZNPs) and nanoflakes (ZNFs) were prepared by conventional combustion method and microwave combustion method, respectively. The structural phase and morphology were investigated by using X-ray diffraction (XRD), high resolution scanning electron microscopy (HR-SEM) and high resolution transmission electron microscopy (HR-TEM). The crystallite size was calculated using Scherrer formula, and it lies in the range of 20-21 nm for ZNFs and 23-28 nm for ZNPs. The elemental analysis was investigated by energy dispersive X-ray analysis (EDX). Also, absorbance and emission spectra were measured by using diffuse reflectance (DRS) and photoluminescence (PL) studies. The band gap was measured using Kubelka-Munk model and it shows 3.47 eV for ZNFs and 3.26 eV for ZNPs. A fill factor (FF) of 0.57, short-circuit current (J(sc)) of 8.02 mA/cm2, open-circuit voltage (V(oc)) of 0.70 V and an overall light to electricity conversion efficiency (eta) of 1.62% were obtained from the dye-sensitized solar cell (DSSCs) based on ZNFs.

Journal of Nanoscience and Nanotechnology

Optical Properties and Dye-Sensitized Solar Cell Applications of ZnO Nanostructures Prepared by Microwave Combustion Synthesis

Cu-Ni alloy nanoparticles were prepared by a microwave combustion method with the molar ratios of Cu2+ to Ni2+ as 3:7, 4:6, 5:5, 6:4 and 7:3. The as-prepared samples were characterized by XRD, HR-SEM, EDX and VSM. XRD and EDX analyses suggest the formation of pure alloy powders. The average crystallite sizes were found to be in the range of 21.56-33.25 nm. HR-SEM images show the clustered/agglomerated particle-like morphology structure. VSM results reveal that for low Ni content (Cu5Ni 5, Cu6Ni4 and Cu7Ni3), the system shows paramagnetic behaviors, whereas for high Ni content (Cu 3Ni7 and Cu4Ni6), it becomes ferromagnetic. © 2014 The Nonferrous Metals Society of China.

Transactions of Nonferrous Metals Society of China

Structure and magnetic properties of Cu-Ni alloy nanoparticles prepared by rapid microwave combustion method

Nickel oxide (NiO) nano- and microstructures were synthesized by the microwave combustion method (MCM) and the conventional combustion method (CCM) using urea as the fuel. The as-synthesized NiO powders were characterized by X-ray powder diffraction (XRD), high resolution scanning electron microscopy (HR-SEM), high resolution transmission electron microscopy (HR-TEM), energy dispersive X-ray analysis (EDX), diffuse reflectance spectroscopy (DRS), photoluminescence (PL) spectroscopy, Brunauer-Emmett-Teller (BET) analysis and vibrating sample magnetometer (VSM) analysis. The XRD results confirmed the formation of cubic phase NiO. The formation of NiO nano- and microstructures were confirmed by HR-SEM and HR-TEM and their possible formation mechanisms were also proposed. The optical absorption and photoluminescence emissions were determined by DRS and PL spectra respectively. The band gap was measured using the Kubelka-Munk model and it shows 3.36 eV for NiO (MCM) and 2.70 eV for NiO (CCM). The magnetic properties of the synthesized NiO nano- and microstructures were investigated with a vibrating sample magnetometer (VSM) and their hysteresis loops were obtained at room temperature. The relatively high saturation magnetization (21.22 emu/g) of NiO-MCM shows that it is ferromagnetic and low saturation magnetization (7.43 emu/g) of NiO-CCM confirms the superparamagnetic behavior. © 2013 Elsevier B.V.

Comparative investigation of NiO nano- and microstructures for structural, optical and magnetic properties

A simple and rapid microwave-assisted combustion method was developed to synthesize CdO nanospheres (CNS). The study suggested that the application of microwave heating to produce the homogenous CNS was achieved in a few minutes. The structure and morphology of the as-prepared CNS were investigated by means of X-ray diffraction (XRD), Fourier transforms infrared spectra (FT-IR), high resolution scanning electron microscopy (HR-SEM), Energy Dispersive X-ray analysis (EDX), transmission electron microscopy (TEM), diffused reflectance spectroscopy (DRS) and Photoluminescence (PL) spectroscopy. The XRD confirmed the formation of face centered cubic structure of CdO. The formation of CdO phase is also confirmed by FT-IR. The formation of spherical hollow nanospheres was confirmed by HR-SEM and TEM and their possible formation mechanisms were also tentatively proposed. The optical properties were determined by DRS and PL spectra. © 2011 Elsevier B.V.

Journal	Data powered by TypesetJournal of Colloid and Interface Science
Publisher	Data powered by TypesetElsevier BV
ISSN	0021-9797
Open Access	0