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The codoped nanoparticles by Aluminium and Nickel were prepared by sol-gel method and theirs different physical properties were studied. The obtained nanoparticles were undergoes a heat treatment in air at different temperatures ranging from 500 °C to 1000 °C in 2 hours. The structural results revealed that the structure is wurtzite with an average crystallite around 30nm, and the appearance of NiO second phase. The optical spectroscopy (UV-Vis) shows a red shift in band gap values with increasing of heat treatment temperature. Photoluminescence (PL) results indicate the effects of oxygen vacancies on emission spectra and confirms the shift of band gap energies. Magnetic measurements at 300K showed a superparamagnetic behaviors. [ABSTRACT FROM AUTHOR]

Pure and Mn+2-doped Zn2SiO4 nanocomposite materials were synthesized using a sol–gel method. The structural, optical, dielectric and magnetic properties of prepared samples were studied using different techniques. X-ray diffraction results show that the dominant phase is willemite (α-Zn2SiO4) with rhombohedral structure and average crystallite size varied from 70 to 90 nm. Photoluminescence spectra, PL of Zn2SiO4, have two broadband emissions centered at 375 nm and 760 nm. PL spectra of Zn2SiO4/Mn is characterized by one dominant peak at 525 and attributed to 4T1–6A1 transitions of Mn2+ ions. Photoluminescence excitation, PLE of Zn2SiO4/Mn at 78 K, has strong excitation band from 240 to 300 nm with maximum at about 255 nm (4.9 eV) compared to the bands in UV–Vis range. Dielectric constant, dielectric loss tangent and electrical conductivity of prepared samples are studied as a function of electric field frequency and indicated a strong dependent on Mn+2 ions. Zn2SiO4 and Zn2SiO4/Mn+2 have diamagnetic properties at room temperature at 300 K, while Zn2SiO4/Mn+2 has a ferromagnetic behavior at 5 K. [ABSTRACT FROM AUTHOR]

Nickel doped In2S3 films have been prepared by the chemical spray pyrolysis technique at 350 °C on glass substrates. The Ni doping level was changed by varying Ni:In molar ratio from 0 to 4% in solution. The structural studies reveal that the Ni-doped In2S3 films are polycrystalline and exhibit a cubic structure. As the Ni:In molar ratio increases, the crystallite size decreases from 27.5 to 23 nm and RMS roughness values increase from 12 to 18 nm, respectively. The presence of Ni in the deposited films was confirmed by energy dispersive spectroscopy. Raman studies show different peaks related to In2S3 phase and do not reveal any secondary phases of In-Ni and Ni-S. The transmission coefficient is about 70-55% in the visible region and 85-75% in near-infrared region. The band gap energy increases from 2.66 to 2.82 eV for direct transitions with the increase of Ni:In ratio from 0 to 4%. The refractive index values of In2S3:Ni thin films decrease from 2.46 to 2.40 and the extinction coefficient values are in the range 0.01-0.20. [ABSTRACT FROM AUTHOR]

Nanoparticles of willemite, α-Zn2SiO4 have been prepared by a sol–gel method. These samples were prepared by a simple solid-phase reaction under natural atmosphere at 1200 °C after the incorporation of ZnO:Mn and ZnO:V nanoparticles in silica monolith. The nanophosphors powder samples were characterized using X-ray diffraction, transmission electron microscopy (TEM) and photoluminescence (PL) spectroscopy. XRD analysis revealed that the α-Zn2SiO4 phase was at 1200 °C. In addition, the PL spectrum for the α-Zn2SiO4:Mn nanocomposite showed that a dominant peak at 525 nm which is due to4T1–6A1 transitions of Mn2+ ions. In the case of α-Zn2SiO4:V, the PL had shown a band centered around 540 nm. This band is due to the V in the interfaces between Zn2SiO4 particles and SiO2 host matrix. The findings of this work are very promising and can justify the use of these novel materials as a potential candidate in the field of photonic applications. [ABSTRACT FROM AUTHOR]

In this work, nickel (Ni) doped indium sulfide (InS) films have been prepared by the spray pyrolysis (CSP) technique on glass substrates at 350 °C. The Ni doping level was changed with Ni:In (0, 2 and 4% in solution). The structural studies reveal that the deposited films are polycrystalline in nature exhibiting cubic structure. The crystallite size decreases from 27.5 to 23 nm and the root mean square roughness values increase from 13 to 18 nm. The transmission coefficient is about 70-55% in the visible region and 85-75% in near-infrared region. The band gap energy increases with nickel content from 2.74 to 2.82 eV for direct transitions. The refractive index values of InS:Ni thin films decrease from 2.43 to 2.40 and the extinction coefficient values are in the range 0.01-0.20. Besides, the AC conductivity contribution is interpreted using the universal Jonscher's power law and it is found thermally activated and it can be described by the correlated barrier-hopping models. These studies help to form significant correlation between temperature and activation energy. Nyquist plots show that the electrical response is accurately fitted by the Cole-Cole model and represented by an equivalent electrical circuit which consists of a parallel combination of a resistance and a constant phase element. From this analysis, the evidence of grain boundary conduction has been observed. [ABSTRACT FROM AUTHOR]

We report in this study the synthesis of mixed matrix reverse osmosis membranes by interfacial polymerization (IP) of thin film nanocomposite (TFNC) on porous polysulfone supports (PS). This paper investigates the synthesis of ZnO nanoparticles (NPs) using the sol-gel processing technique and NPs enhanced membranes and evaluates the performance of mixed matrix membranes. Aqueous m-phenyl diamine (MPD) and organic trimesoyl chloride (TMC)-NPs mixture solutions were used in the IP process. The reaction of MPD and TMC at the interface of PS substrates resulted in the formation of the thin film composite (TFC). NPs of ZnO with a size of about 25 nm were used for the fabrication of the TFNC membranes. The TFNC membranes were characterized and evaluated in comparison with a (TFC) membrane. Their performances were evaluated based on the water permeability and salt rejection. Experimental results indicated that the NPs improved membrane performance under optimal weight NPs. By changing the content of the filler, better hydrophilicity was obtained; the contact angle was decreased from 94° to 18°. Also, the permeate water flux was increased from 26 to 48 L/m2.h when the weight of NPs is 0.007g with the maintaining of high salt rejection of 99%. [ABSTRACT FROM AUTHOR]

Here, we report the fabrication of mixed matrix reverse osmosis membranes by interfacial polymerization (IP) of nanocomposite on porous polysulfone supports. Nanocomposites elaborated for this study comprise magnesium titanium oxide (MgTiO3) nanoparticles dispersed in polyamide host matrix synthesized by thein situIP process on porous polysulfone commercial supports. Aqueous m-phenyl diamine and organic trimesoyl chloride nanoparticles mixture solutions were used in the IP process. Nanoparticles of MgTiO3with a size of about 80 nm were used as filler for the fabrication of the nanocomposite membranes with a concentrations varying from 0.0001 to 0.009 wt.%. The samples were characterized by X-ray diffraction, scanning electron microscopy, atomic force microscopy, and contact angle setup. Their performances were evaluated based on the water permeability and salt rejection. Results indicated that the nanoparticles are well dispersed in the host matrix of polyamide layer and improved membrane performance under optimal nanoparticle content. By changing the concentration of the filler, hydrophilicity and roughness of the nanocomposite membranes were increased. Notably, the permeate water flux increased from 26 to 44.6 L/m2 h at the nanoparticles concentration of 0.001% with the maintaining of high salt rejection of 98%. These results were obtained with initial NaCl concentration of 2,000 ppm and under pressure of 225 psi. Also better hydrophilicity was obtained; the contact angle was decreased from 73 to 24°. [ABSTRACT FROM PUBLISHER]

The synthesis of ZnVO nanoparticles by a sol-gel processing technique for x ranging from 0 to 0.08 was reported in this work. In our approach, the water for hydrolysis was slowly released by esterification reaction followed by a supercritical drying in ethyl alcohol. The obtained nanopowder was characterized by various techniques. The results of X-ray diffraction, X-ray photoelectron spectroscopy and transmission electron microscope indicated that the V ion was incorporated in to the crystal lattices of wurtzite ZnO nanparticles. Photolumunescence (PL) spectra consist of a very wide and strong emission band located in the visible range where the intensity and energy position depend on the PL measurement temperature. Magnetic measurements at room temperature showed a diamagnetic for undoped ZnO and ferromagnetic behavior after doping with vanadium. The mechanism of nanoparticles formation and the comparison with recent results are discussed. [ABSTRACT FROM AUTHOR]