Synthesis of high-quality Al-doped ZnO nanoink

International Journal of Modern Physics: Conference Series, 2013

Undoped and Al-doped ZnO (AZO) nanoparticles (NPs) have been successfully synthesized by the simple sol-gel method. The NPs have been characterized by a number of techniques as x-ray diffraction (XRD), UV-visible spectroscopy and scanning electron microscopy (SEM) at room temperature for 0%, 0.5%, 1% and 2% of Al concentration. The structural characteristics were examined using XRD and SEM with EDS. XRD analysis reveals that all samples crystallizes in polycrystalline nature with wurtzite lattice and exhibit no other impurity phase. The average crystallite size decreases with increase in Al concentration. The absorption spectra indicate increase in optical energy gap (Eg) with increase in Al ion doped into the ZnO lattice site.

Zinc oxide (ZnO) and Al doped zinc oxide (AZO) nanoparticles were synthesized by reflux method at 100 °C. X-ray diffraction results showed that Al doping decreases the average crystallite size of ZnO nanoparticles. Fourier transform infrared spectra were recorded to analyze the effect of Al doping on the vibrational frequencies of ZnO nanoparticles. Scanning electron microscopic investigation revealed that the surface morphology of ZnO nanoparticles is significantly modified by Al doping. Energy dispersive spectroscopy confirmed the presence of Al in AZO nanoparticles. The optical absorption measurement indicates that the absorption band edge is slightly shifted to higher wavelength region after Al doping. The calculated band gap value decreases from 3.37 to 3.36 eV. Photoluminescence spectra revealed that the emission peak intensity decreased by Al doping. Magnetic measurement demonstrates that the saturation magnetization of AZO nanoparticles decreased when compared with that of ZnO nanoparticles.

2011

Stable crystalline aluminum doped zinc oxide (AZO) nanopowders were synthesized using hydrothermal treatment processing. Three different aluminum precursors have been used. The Al-precursors were found to affect the morphology of the obtained nanopowders. AZO nanoparticles based on zinc acetate and aluminum nitrate have been prepared with different Al/Zn molar ratios. XRD investigations revealed that all the obtained powders have single phase zincite structure with purity of about 99%. The effect of aluminum doping ratio in AZO nanoparticles (based on Al-nitrate precursor) on structure, phase composition, and particle size has been investigated. The incorporation of Al in ZnO was confirmed by UV-Vis spectroscopy revealing a blue shift due to Burstein-Moss effect.

Ceramics International, 2014

This paper reports on the structural and optical properties of Al doped ZnO nanoparticles prepared through solgel method. Different atomic ratio percents of Al were doped into ZnO ranging from 1 at.% to 6 at.%. X-ray diffraction (XRD) results showed that ZnO crystallized into hexagonal wurtzite structure. The average crystallite size of ZnO nanoparticles decreased with increasing Al concentration. A compressive strain induced in ZnO upon Al doping was calculated using W-H plot analysis. The morphology of the samples is studied by using Field Emission Scanning Electron Microscope (FE-SEM). The Tauc relationship has been employed for calculating the band gap energy of Al doped ZnO samples based on UV-Vis data of the samples. The band gap increased monotonously as the Al concentration was increased from 1 at.% to 6 at.%. In addition to this, the photoluminescence (PL) properties of Al doped ZnO were studied.

Materials Letters, 2013

In this study, pure and Al-doped ZnO nanoparticles were successfully synthesized by the mechanochemical method. The effect of doping on structural and optical properties was studied. The structural investigations of products confirmed the hexagonal wurtzite structure for all products and also it was observed that doping caused a little change in lattice parameters. The results obtained by SEM revealed that the average particle size of products increases by doping and nanoparticles have almost spherical morphology. UV-visible absorption and PL spectra showed that the maximum ultraviolet absorption wavelength of products increases and the optical band gap shifts from 3.15 eV to 3.11 eV, with increasing the Al concentration.

Al-doped ZnO nanoparticle thin films were prepared on glass substrate at the optimum temperature of (410±10) °C by spray pyrolysis technique using zinc nitrate as a precursor solution and aluminium chloride as a dopant. The dopant concentration (Al/Zn at%) was varied from 0 to 2 at%. Structural analysis of the films shows that all the films are of polycrystalline zinc oxide in nature, possessing hexagonal wurtzite structure. The films exhibit variation in peak intensities corresponding to , and reflection planes on Aldoping. The crystallite size calculated by Scherrer formula has been found to be in the range of 35-65 nm. The optical absorption study shows that the optical band gap in the Al-doped films varies in the range of 3.11 -3.22 eV. The width of localized states in the band gap estimated by the Urbach tail analysis has been found to be minimum in case of the 1 at% Al-doped zinc oxide thin film.

RSC Advances, 2013

Al-doped ZnO nanoparticles are synthesized by means of a heating up solution based thermal decomposition method. The synthesis involves a reaction of zinc acetylacetonate hydrate, aluminium acetylacetonate and 1,2-hexadecanediol in the presence of oleic acid and oleyl amine. A proposed reaction mechanism from reagents to monomers is corroborated by analysis of the evolving gases using headspace GC-MS analysis. The Al-doped ZnO nanoparticles synthesized are dynamically stabilized by adsorbed oleate ions, after deprotonation of oleic acid by oleyl amine, as was found by NOESY proton NMR and complementary FTIR spectroscopy. Precession electron diffraction shows a simultaneous increase in lattice parameters with Al concentration. This, together with HAADF-STEM and EDX maps, indicates the incorporation of Al into the ZnO nanoparticles. By the combination of complementary characterization methods during all stages of the synthesis, it is concluded that Al is incorporated into the ZnO wurtzite lattice as a dopant.

ZnO nanoparticles were synthesized by aqueous solution method.The synthesized particles were characterized by XRD, SEM and EDX .The X-ray diffraction studies reveals that the synthesized ZnO nanoparticles have wurtzite structure and the particle size varies from 11 to 13 nm. A change in morphology from hierarchical nanostructures in ZnO to nanorods after doping with aluminium has been observed. The Energy Dispersive X-Ray Diffraction Spectroscopy (EDX) reveals that the elemental composition of prepared samples and the incorporation of the Al ions into the ZnO lattice. The antibacterial activities of ZnO and Al doped ZnO nanoparticles were examined using the disc diffusion method against four pathogenic bacteria (Eschericia Coli , Klebsiella Pneumoniae , Bacillus Cereus, and Staphylococcus aureus).

Asian Journal of Nanoscience and Materials, 2019

Pure, Al doped, and (Co, Al) co-doped ZnO nano-powders were synthesized through chemical co-precipitation method at room temperature, using poly ethylene glycol (PEG) as stabilizing agent. The synthesized samples are characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) & energy-dispersive X-ray spectroscopy (EDS), transmission electron microscopy (TEM), high resolution transmission electron microscopy (HRTEM), the selected area electron diffraction (SAED) and vibrating sample magnetometer (VSM). XRD results revealed that all the samples had a hexagonal wurtzite crystal structure with no secondary phases and this indicates the absence of superfluous impurities. (Co, Al) co-doped samples reveals the lowest crystallite size comparing to pure and Al doped ZnO nano-particles, doping of aluminum and cobalt, aluminum could not disturb the Wurtzite structure of ZnO host lattice. SEM analysis demonstrated the morphology of the Pure, Al doped, and (Co, Al) co-doped ZnO nano-particles, morphology of the (Co, Al) co-doped samples shows high agglomeration compared to Pure and Al-doped ZnO nano-particles. EDS spectrum shows the incorporation of dopant elements, it reveals the nonexistence of impurities other than Zn, Al, and Co which is coincided by XRD results. TEM illustrations reveal the exact size of the crystallites, which are approximately confirmed by the XRD data, TEM images obviously shows that nano-particles are in heterogeneous spherical shape. HRTEM images of the Pure and Al-doped ZnO nano-particles shows clear lattice fringes about 5 nm and (Co, Al) co-doped images reveal lattice fringes are about 2 nm. VSM analysis of (Co, Al) co-doped samples reveals that all the three (1, 2, 3 mol% of cobalt by keeping Al-5 mol% at constant) concentrations showed the Ferromagnetic nature at room temperature. Among these 1 mol % of cobalt shows highest saturation magnetization (Ms) and Retentivity (Mr) values, while 2 mol % of cobalt shows highest coercitivity (Hc) value. GRAPHICAL ABSTRACT: 1. Introduction Zinc oxide (ZnO) is a semiconductor having wurtzite crystal structure, large direct band gap of 3.37 eV, and 60 meV exciton binding

Applied Surface Science, 2008