scholarly journals Cu-ZnO Nanostructures Synthesis and Characterization

2021 ◽  
pp. 708-717
Author(s):  
Saif T. Abdulredha ◽  
Nadia A. Abdulrahman
Keyword(s):  
Zinc Oxide ◽  
Energy Gap ◽  
Uv Spectroscopy ◽  
Blue Shift ◽  
Synthesis And Characterization ◽  
Zno Nanostructures ◽  
Similar Increase ◽  
Structural Pattern ◽  
Hydrothermal Technique ◽  
Different Temperatures

5wt% copper doped zinc oxide (Cu-ZnO) nanostructures were prepared via the hydrothermal technique at different temperatures of 70, 100, 130, 160 and 190oC.  UV spectroscopy, FE-SEM microscopy, XRD crystallography, and EDS measurements were used for nanostructure characterization. UV spectroscopy indicated a red shift for the absorption peaks, and hence a blue shift for the energy gap values, as temperature increased from 70 to 190oC. FE-SEM microscopy showed an increase in the average lengths and diameters of the nanostructures following a similar increase in temperature. XRD crystallography indicated decent structural patterns for Cu-ZnO nanostructures with an increase in crystallite size upon temperature increase. Interestingly, three unprecedented extra indices appeared in the structural pattern at 190oC, which might indicate a configuration of hexagonal crystallite with three extra planes. EDS measurements indicated the sole presence of Cu, Zn and O.

scholarly journals Characterization of Zinc oxide Nanostructures prepared by hydrothermal method with Antibacterial property

2019 ◽  
Vol 17 (42) ◽  
pp. 108-124
Author(s):  
Ibrahim Abdulkareem Ali
Keyword(s):  
Zinc Oxide ◽  
Antibacterial Activity ◽  
Crystallite Size ◽  
Annealing Temperature ◽  
Energy Gap ◽  
Antibacterial Property ◽  
Zno Nanostructures ◽  
Zinc Oxide Nanostructures ◽  
Oxide Nanostructures ◽  
Uv Visible

        In this study, Zinc oxide nanostructures were synthesized via a hydrothermal method by using zinc nitrate hexahydrate and sodium hydroxide as a precursor. Three different annealing temperatures were used to study their effect on ZnO NSs properties. The synthesized nanostructure was characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), Atomic force microscope (AFM), and Fourier Transform Infrared Spectroscopy (FTIR). Their optical properties were studied by using UV -visible spectroscopy. The XRD analysis confirms that all ZnO nanostructures have the hexagonal wurtzite structure with average crystallite size within the range of (30.59 - 34.52) nm. The crystallite size increased due to the incensement of annealing temperature. FESEM analysis indicates that ZnO has hexagonal shape of cylindrical pores, plate-like nanocrystals and Nanorods. AFM analysis shows that the average surface roughness of ZnO Nanostructures increases from 3.96 to 19.1 nm with the increase of annealing temperature. The FTIR peaks indicate successful preparation of ZnO Nanostructures. The FTIR method was used to analyses the chemical bonds which conformed the present of the Zn-O group in the region between (400-500) cm-1. The UV-visible showed a red shift in the absorption spectra related to the shift in the energy gap related to increase in the particle size.  the band gap energy has been calculated from the optical absorption spectra. The annealing process has been fond more effective on the value of energy gap. As the annealing temperature increases, the value of energy gap, increases as well; from (3.12to 3.22) eV. The prepared Nanostructure is used for antibacterial property. It shows strong antibacterial activity against S. aureus and P.aeuruginosa bacteria by the agar disc diffusion method. The white precipitate of ZnO NSs has superior antibacterial activity on gram-positive (S. aureus) than the gram-negative (P.aeuruginosa) bacteria.

Photoreflectance Characterization of InGaAs Lattice Matched to InP

1993 ◽  
Vol 324 ◽  
Author(s):  
V. Bellani ◽  
M. Amiotti ◽  
M. Geddo ◽  
G. Guizzetti ◽  
G. Landgren
Keyword(s):  
Energy Gap ◽  
Lattice Mismatch ◽  
Blue Shift ◽  
X Ray Diffraction ◽  
X Ray ◽  
Different Temperatures ◽  
Interfacial Strain ◽  
Valence Bands ◽  
Lattice Matched

AbstractWe measured photoreflectance (PR) spectra at different temperatures between 80 and 300 K, and optical absorption (OA) at 3 K on MOVPE grown Inl-xGaxAs nearly lattice-matched to InP. x-ray diffraction measurements gave a lattice mismatch δa/ao = -0.9.10−3 between ternary alloy and InP, corresponding to × = 0.485. We obtained the energy gap dependence on T from PR spectra. The blue shift of the gap was accounted for in terms of compositional difference with respect to the perfectly lattice matched alloy (× = 0.472), and elastic strain; moreover PR and OA showed evidence of the valence bands splitting at k = 0 due to interfacial strain, in fine agreement with theory.

Synthesis and characterization of zinc oxide (ZnO) nanostructures

2019 ◽  
Author(s):  
Smile Kataria ◽  
Saroj Bala ◽  
Subhash Chand ◽  
Suman Mahendia ◽  
O. P. Sinha ◽  
...  
Keyword(s):  
Zinc Oxide ◽  
Synthesis And Characterization ◽  
Zno Nanostructures

Synthesis and Characterization of Nanocrystalline ZnO Powders by a Direct Thermal Decomposition Route Using Zinc Nitrate Hexahydrate

2013 ◽  
Vol 770 ◽  
pp. 68-71 ◽  
Author(s):  
Supphadate Sujinnapram ◽  
Uraiphorn Termsuk ◽  
Atcharawan Charoentam ◽  
Sutthipoj Sutthana
Keyword(s):  
Thermal Decomposition ◽  
Crystallization Temperature ◽  
Zinc Nitrate ◽  
Zinc Nitrate Hexahydrate ◽  
Absorption Peak ◽  
Synthesis And Characterization ◽  
Nitrate Hexahydrate ◽  
Different Temperatures ◽  
Zno Powders

The nanocrystalline ZnO powders were synthesized by a direct thermal decomposition using zinc nitrate hexahydrate as starting materials. The precursor was characterized by TG-DTA to determine the thermal decomposition and crystallization temperature which was found to be at 325 oC. The precursors were calcined at different temperatures of 400, 500, and 600°C for 4 h. The structure of the prepared samples was studied by XRD, confirming the formation of wurtzite structure. The synthesized powders exhibited the UV absorption below 400 nm (3.10 eV) with a well defined absorption peak at around 285 nm (4.35 eV). The estimated direct bandgaps were obtained to be 3.19, 3.16, and 3.14 eV for the ZnO samples thermally decomposed at 400, 500, and 600°C, respectively.

Synthesis and characterization of coal fly ash supported zinc oxide catalyst for biodiesel production using used cooking oil as feed

2021 ◽  
Vol 170 ◽  
pp. 302-314
Author(s):  
Adeyinka S. Yusuff ◽  
Aman K. Bhonsle ◽  
Jayati Trivedi ◽  
Dinesh P. Bangwal ◽  
Lok P. Singh ◽  
...  
Keyword(s):  
Zinc Oxide ◽  
Fly Ash ◽  
Oxide Catalyst ◽  
Coal Fly Ash ◽  
Biodiesel Production ◽  
Synthesis And Characterization ◽  
Cooking Oil ◽  
Used Cooking Oil

The electron transport that occurs within wurtzite zinc oxide and the application of stress

MRS Advances ◽  
2017 ◽  
Vol 2 (48) ◽  
pp. 2627-2632 ◽  
Author(s):  
Poppy Siddiqua ◽  
Michael S. Shur ◽  
Stephen K. O’Leary
Keyword(s):  
Monte Carlo ◽  
Zinc Oxide ◽  
Electron Transport ◽  
Velocity Field ◽  
Monte Carlo Simulations ◽  
Significant Role ◽  
Energy Gap ◽  
Device Application ◽  
The Impact

ABSTRACTWe examine how stress has the potential to shape the character of the electron transport that occurs within ZnO. In order to narrow the scope of this analysis, we focus on a determination of the velocity-field characteristics associated with bulk wurtzite ZnO. Monte Carlo simulations of the electron transport are pursued for the purposes of this analysis. Rather than focusing on the impact of stress in of itself, instead we focus on the changes that occur to the energy gap through the application of stress, i.e., energy gap variations provide a proxy for the amount of stress. Our results demonstrate that stress plays a significant role in shaping the form of the velocity-field characteristics associated with ZnO. This dependence could potentially be exploited for device application purposes.

Sign in / Sign up

Export Citation Format

Share Document