scholarly journals One-Step Multi-Doping Process for Producing Effective Zinc Oxide Nanofibers to Remove Industrial Pollutants Using Sunlight

Crystals ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 1268
Author(s):  
Osama Saber ◽  
Nagih M. Shaalan ◽  
Faheem Ahmed ◽  
Shalendra Kumar ◽  
Adil Alshoaibi
Keyword(s):  
Zinc Oxide ◽  
Band Gap ◽  
Driving Forces ◽  
Organic Dyes ◽  
Conventional Technique ◽  
Band Gap Energy ◽  
Gap Energy ◽  
Inorganic Species ◽  
One Step ◽  
Double Hydroxides

Doping processes for optical materials are one of the driving forces for developing efficient and clean technologies for decontamination of aquatic effluents through lowering their band gap energy to become effective in sunlight. The current study has used a non-conventional technique for doping zinc oxide by multi metals, non-metals and organic dyes through a one-step process. In this trend, Zn-Al nanolayered structures have been used as hosts for building host–guest interactions. Organic dyes that have inorganic species of iron, nitrogen and sulfur have been used as guests in the intercalation reactions of Zn-Al layered double hydroxides. By intercalating green dyes, organic–inorganic nanohybrids were formed as nanolayered structures with expanding interlayered spacing to 2.1 nm. By changing the concentration of green dyes and thermal treatment, series of nanofibers and nanoplates of zinc oxides were formed and doped by aluminum, iron and sulfur in addition to colored species. The optical properties of the multi-doped zinc oxide indicated that it became suitable for solar applications because its band gap energy decreased from 3.30 eV to 2.80 eV. The experimental and kinetic results of the multi-doped zinc oxide concluded that the colored pollutants were effectively removed during 50 min of sunlight irradiation.

scholarly journals Development of the Morphology and the Band Gap Energy of Co–Si Nanofibers by Inserting Zirconium and Titanium with Dual Anions Intercalation Process

2019 ◽  
Vol 9 (22) ◽  
pp. 4775 ◽  
Author(s):  
Osama Saber ◽  
Nagih M. Shaalan ◽  
Aya Osama ◽  
Adil Alshoaibi
Keyword(s):  
Optical Properties ◽  
Band Gap ◽  
Optical Materials ◽  
Band Gap Energy ◽  
Gap Energy ◽  
Intercalation Process ◽  
Trivalent Cations ◽  
Optical Applications ◽  
Double Hydroxides ◽  
First Time

The plate-like structure is the most familiar morphology for conventional layered double hydroxides (LDHs) in case their structures consist of divalent and trivalent cations in their layers. In this study, nanofibers and nanoneedles of Co–Si LDHs were prepared for the first time. By the inclusion of zirconium inside the nanolayers of LDH structures, their plates were formed and transformed to nanofibers. These nanofibers were modified by the insertion of titanium to build again plate-like morphology for the LDH structure. This morphology controlling was studied and explained by a dual anions intercalation process. The optical properties of Co–Si LDHs indicated that the incorporation of zirconium within their nanolayers decreased the band gap energy from 4.4 eV to 2.9 eV. Following the same behavior, the insertion of titanium besides zirconium within the nanolayers of Co–Si LDHs caused a further reduction in the band gap energy, which became 2.85 eV. Although there is no data for the optical properties of Co–Si LDHs in the literature, it is interesting to observe the low band gap energy for Co–Si LDHs to become more suitable for optical applications. These results concluded that the reduction of the band gap energy and the formation of nanofibers introduce new optical materials for developing and designing optical nanodevices.

Synthesis and characterization of a mixture of CoFe2O4 and MgFe2O4 from layered double hydroxides: Band gap energy and magnetic responses

2014 ◽  
Vol 369 ◽  
pp. 249-259 ◽  
Author(s):  
Ulises A. Agú ◽  
Marcos I. Oliva ◽  
Sergio G. Marchetti ◽  
Angélica C. Heredia ◽  
Sandra G. Casuscelli ◽  
...  
Keyword(s):  
Band Gap ◽  
Layered Double Hydroxides ◽  
Band Gap Energy ◽  
Synthesis And Characterization ◽  
Gap Energy ◽  
Double Hydroxides

scholarly journals The Influence of Calcination Temperature on the Formation of Zinc Oxide Nanoparticles by Thermal-Treatment

2013 ◽  
Vol 446-447 ◽  
pp. 181-184 ◽  
Author(s):  
Naif Mohammed Al-Hada ◽  
Elias Saion ◽  
A.H. Shaari ◽  
M.A. Kamarudin ◽  
Salahudeen A. Gene
Keyword(s):  
Particle Size ◽  
Zinc Oxide ◽  
Thermal Treatment ◽  
Band Gap ◽  
Calcination Temperature ◽  
Zinc Oxide Nanoparticles ◽  
Treatment Method ◽  
Band Gap Energy ◽  
Oxide Nanoparticles ◽  
Gap Energy

Zinc oxide nanoparticles were synthesized by the thermal-treatment method. Polyvinyl pyrrolidone was used as capping agent and Zinc nitrate was used as a precursor. The samples were calcined at 500 and 550°C for removal of the organic compounds. The structural characteristics of the calcined samples were examined by X-ray diffraction and transmission electron microscopy. The results show that the average particle size increases with increase in calcination temperature. The optical properties were characterized at room temperature using a UV–Vis spectrophotometer in the wavelength range between 200–800 nm and the band gap energy was calculated from reflectance spectra using kubalka munk function and the results indicated that the band gap energy decreased from 3.23 eV at 500 oC to 3.21 eV at 600 °C due to an increase of particle size. This simple thermal-treatment method has advantages of the pure nanoparticles formation as no additional chemicals were required, a lack of by-product effluents, and environmentally friendly process.

The calculation of band gap energy in zinc oxide films

2015 ◽  
Vol 36 (1) ◽  
pp. 013001 ◽  
Author(s):  
Ali Arif ◽  
Okba Belahssen ◽  
Salim Gareh ◽  
Said Benramache
Keyword(s):  
Zinc Oxide ◽  
Band Gap ◽  
Oxide Films ◽  
Band Gap Energy ◽  
Gap Energy ◽  
Zinc Oxide Films

scholarly journals Polarization-dependent optical band gap energy of aligned semiconducting titanium oxide nanowire deposits

Nanoscale ◽  
2021 ◽  
Author(s):  
Merve Taner ◽  
Matthias Pauly ◽  
Christophe Lefevre ◽  
Corinne Bouillet ◽  
mounir maaloum ◽  
...  
Keyword(s):  
Zinc Oxide ◽  
Band Gap ◽  
Titanium Oxide ◽  
Optical Band Gap ◽  
Polarized Light ◽  
Grazing Incidence ◽  
Band Gap Energy ◽  
Oxide Nanowires ◽  
Gap Energy ◽  
Linearly Polarized

Thin deposits of aligned semiconducting titanium oxide and of zinc oxide nanowires are prepared by grazing incidence spraying on transparent substrates. By measuring the transmittance of linearly polarized light of...

scholarly journals Effects of tin on the performance of ZnO photoanode for DSSC

2021 ◽  
Vol 26 (4) ◽  
Author(s):  
Vanja Fontenele Nunes ◽  
Francisco Marcone Lima ◽  
Edwalder Silva Teixeira ◽  
Paulo Herbert França Maia Júnior ◽  
Ana Fabíola Leite Almeida ◽  
...  
Keyword(s):  
Zinc Oxide ◽  
Band Gap ◽  
Current Density ◽  
Short Circuit ◽  
Short Circuit Current ◽  
Band Gap Energy ◽  
Short Circuit Current Density ◽  
Optical Measurements ◽  
X Ray ◽  
Gap Energy

ABSTRACT Tin Zinc Oxide thin films were deposited on transparent conductive oxide by chemical bath, at percentages of 5, 10 and 15% of tin (Sn) on the zinc oxide (ZnO) structure. All films were thermally treated to improve its crystallinity. The produced films with tin were characterized by x-ray diffraction and optical measurements, such as absorbance, transmittance and reflectance. The x-ray spectrum showed the formation of the ZnO wurtzite and the crystallite size of the films were calculated to be 53.74; 79.59 and 66.38 nm for the photoanodes at 5, 10 and 15% of tin (Sn), respectively, on the zinc oxide structure. The calculated band gap energy of the films revealed that the presence of tin can reduce the band gap energy to about 3.2 eV. Those films were used as photoanodes on dye sensitized solar cells (DSSC) to observe the effects of the tin (Sn) on the photovoltaic activity of the zinc oxide (ZnO) semiconductor. Parameters such as efficiency and short circuit current density were particularly affected by the presence of tin in the composition, with the 5% Sn ZnO film presenting the best results of 7.56 % efficiency and 34.35 mA/cm2, short circuit current density, the other films presented lower values for efficiency, which can be attributed to lower values of short-current density.

scholarly journals Effect of Annealing on Optical Properties of Zinc Oxide Thin Films Prepared by Homemade Spin Coater

2015 ◽  
Vol 15 (2) ◽  
pp. 111-116 ◽  
Author(s):  
Deependra Das Mulmi ◽  
Agni Dhakal ◽  
Buddha Ram Shah
Keyword(s):  
Thin Films ◽  
Zinc Oxide ◽  
Band Gap ◽  
Precursor Solution ◽  
Infrared Region ◽  
Band Gap Energy ◽  
Zno Thin Films ◽  
Gap Energy ◽  
Glass Substrates ◽  
Near Ultraviolet

Zinc oxide (ZnO) thin films were deposited on the ordinary glass substrates by spin coating method. The precursor solution was prepared by mixing zinc acetate dehydrate in appropriate proportions with ethanol and diethanolamine (DEA). The obtained thin films were dried at 200°C for 15 minutes in hot air oven. Crystalline ZnO thin films were achieved following annealing process at temperatures 300°, 400° and 500°C for 2 hours. Thin films as- prepared were studied by X-ray diffraction and UV-visible spectroscopy. The films were transparent from near ultraviolet to infrared region. Optical band gap energy of ZnO was obtained 3.22 eV at 300°C. On annealing at 400° and 500°C, band gap energy was shifted at 3.14 eV and 3.05 eV respectively.DOI: http://dx.doi.org/njst.v15i2.12126Nepal Journal of Science and Technology Vol. 15, No.2 (2014) 111-116

Modification of optical properties of PC-PBT/Cr2O3 and PC-PBT/CdS nanocomposites by gamma irradiation

2020 ◽  
Vol 92 (2) ◽  
pp. 20402
Author(s):  
Kaoutar Benthami ◽  
Mai ME. Barakat ◽  
Samir A. Nouh
Keyword(s):  
Refractive Index ◽  
Optical Properties ◽  
Band Gap ◽  
Color Difference ◽  
Band Gap Energy ◽  
Polybutylene Terephthalate ◽  
Γ Irradiation ◽  
Gap Energy ◽  
Vis Spectroscopy ◽  
Oxygen Atoms

Nanocomposite (NCP) films of polycarbonate-polybutylene terephthalate (PC-PBT) blend as a host material to Cr2O3 and CdS nanoparticles (NPs) were fabricated by both thermolysis and casting techniques. Samples from the PC-PBT/Cr2O3 and PC-PBT/CdS NCPs were irradiated using different doses (20–110 kGy) of γ radiation. The induced modifications in the optical properties of the γ irradiated NCPs have been studied as a function of γ dose using UV Vis spectroscopy and CIE color difference method. Optical dielectric loss and Tauc's model were used to estimate the optical band gaps of the NCP films and to identify the types of electronic transition. The value of optical band gap energy of PC-PBT/Cr2O3 NCP was reduced from 3.23 to 3.06 upon γ irradiation up to 110 kGy, while it decreased from 4.26 to 4.14 eV for PC-PBT/CdS NCP, indicating the growth of disordered phase in both NCPs. This was accompanied by a rise in the refractive index for both the PC-PBT/Cr2O3 and PC-PBT/CdS NCP films, leading to an enhancement in their isotropic nature. The Cr2O3 NPs were found to be more effective in changing the band gap energy and refractive index due to the presence of excess oxygen atoms that help with the oxygen atoms of the carbonyl group in increasing the chance of covalent bonds formation between the NPs and the PC-PBT blend. Moreover, the color intensity, ΔE has been computed; results show that both the two synthesized NCPs have a response to color alteration by γ irradiation, but the PC-PBT/Cr2O3 has a more response since the values of ΔE achieved a significant color difference >5 which is an acceptable match in commercial reproduction on printing presses. According to the resulting enhancement in the optical characteristics of the developed NCPs, they can be a suitable candidate as activate materials in optoelectronic devices, or shielding sheets for solar cells.

Stability Investigation in the Optical Properties of Thermally Evaporated Ge5Se95-x Znx Thin Films

2015 ◽  
Vol 7 (3) ◽  
pp. 1923-1930
Author(s):  
Austine Amukayia Mulama ◽  
Julius Mwakondo Mwabora ◽  
Andrew Odhiambo Oduor ◽  
Cosmas Mulwa Muiva ◽  
Boniface Muthoka ◽  
...  
Keyword(s):  
Thin Films ◽  
Band Gap ◽  
Optical Band Gap ◽  
Thermal Evaporation ◽  
Optical Transition ◽  
Bulk Material ◽  
Band Gap Energy ◽  
Optical Absorbance ◽  
Gap Energy ◽  
Constituent Elements

 Selenium-based chalcogenides are useful in telecommunication devices like infrared optics and threshold switching devices. The investigated system of Ge5Se95-xZnx (0.0 ≤ x ≤ 4 at.%) has been prepared from high purity constituent elements. Thin films from the bulk material were deposited by vacuum thermal evaporation. Optical absorbance measurements have been performed on the as-deposited thin films using transmission spectra. The allowed optical transition was found to be indirect and the corresponding band gap energy determined. The variation of optical band gap energy with the average coordination number has also been investigated based on the chemical bonding between the constituents and the rigidity behaviour of the system’s network.

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