Synthesis,Surface Morphology, Optical Properties and Photocatalyst Activities of TiO2/ZnO/Fe2O3 Nanocomposites.

2020 ◽  
Author(s):  
Juliya Acha Parambil ◽  
Abdul Mujeeb V.M ◽  
S. Zh. Karazhanov ◽  
Jayaram Peediyekkal
Keyword(s):  
Methylene Blue ◽  
Optical Properties ◽  
Optical Band Gap ◽  
Band Gap Energy ◽  
Photoluminescence Intensity ◽  
Methylene Blue Degradation ◽  
Gap Energy ◽  
First Order ◽  
First Order Kinetics ◽  
Transition Surface

Abstract The photocatalytic degradation of methylene blue in aqueous solutions is enhanced significantly by formulating multiphase TiO2/ZnO/Fe2O3 nanocomposites. The photocatalytic activity of unary TiO2, binary TiO2/ZnO, and ternary TiO2/ZnO/Fe2O3 compounds are compared and reported. Using TiO2/ZnO/Fe2O3, methylene blue degradation became rapid and the reaction followed first-order kinetics. The consequences of the phase transition, surface features, and optical properties are compared and elucidated. The reduced photoluminescence intensity and decreased optical band gap energy in tertiary compounds impose higher degradation of methylene blue under irradiation.

Sol-gel growth of Ni doped CdS on glass substrates: effect of spin coating speed and dopant concentration

2020 ◽  
Vol 10 ◽  
Author(s):  
Atefeh Nazari Setayesh ◽  
Hassan Sedghi
Keyword(s):  
Thin Films ◽  
Optical Properties ◽  
Spin Coating ◽  
Optical Band Gap ◽  
Dopant Concentration ◽  
Rotation Speed ◽  
Sol Gel ◽  
Band Gap Energy ◽  
Gap Energy ◽  
Glass Substrates

Background: In this work, CdS thin films were synthesized by sol-gel method (spin coating technique) on glass substrates to investigate the optical behavior of the film. Methods: Different substrate spin coating speeds of 2400, 3000, 3600 rpm and different Ni dopant concentrations of 0 wt.%, 2.5 wt.%, 5 wt.%) were investigated. The optical properties of thin films such as refraction index, extinction coefficient, dielectric constant and optical band gap energy of the layers were discussed using spectroscopic ellipsometry method in the wavelength range of 300 to 900 nm. Results: It can be deduced that substrate rotation speed and dopant concentration has influenced the optical properties of thin films. By decreasing rotation speed of the substrate which results in films with more thicknesses, more optical interferences were appeared in the results. Conclusion: The samples doped with Ni comparing to pure ones have had more optical band gap energy.

Optical Properties of Nd Doped Lead Borotellurite Glass

2016 ◽  
Vol 846 ◽  
pp. 193-198 ◽  
Author(s):  
Azman Kasim ◽  
H. Azhan ◽  
S. Akmal Syamsyir ◽  
Mardhiah Abdullah ◽  
M.R.S. Nasuha
Keyword(s):  
Optical Properties ◽  
Room Temperature ◽  
Optical Band Gap ◽  
Band Gap Energy ◽  
Rare Earth Ions ◽  
Band Gaps ◽  
Refractive Indices ◽  
Excitation Wavelength ◽  
Gap Energy ◽  
Trivalent Rare Earth

Many trivalent rare earth ions such as Er3+, Tm3+, Ho3+, Pr3+ and Nd3+ were doped as absorption and emission centers in glass hosts. In this work, lead borotellurite (PBT) glass doped with neodymium ion (Nd3+) has been prepared and characterized by mean of their optical properties. The UV-Vis measurement has been carried out in order to determine the optical band gap energy, reflective indices and the polarizability. Optical absorption spectra of the glass samples are recorded in the range 400–900 nm at room temperature From the result, there are six significant absorption peaks that corresponds to 525 nm, 584 nm, 683 nm, 747 nm, 805 nm and 878 nm wavelength have been observed with the most predominant peak to be used as excitation wavelength is found centered at 584 nm. The energy band gaps as well as the refractive indices were found to vary from 2.50eV to 2.59eV and from 1.89 to 1.96 with mol% of Nd content respectively. Meanwhile, the polarizability shows a similar trend of results to refractive indices as it varies from 5.56 x 10-24 cm3 to 5.63 x 10-24 cm3. These results will be discussed further in details.

Effects of Nitrogen Doping on Optical Properties of Tungsten Oxide Thin Films

2012 ◽  
Vol 616-618 ◽  
pp. 1773-1777
Author(s):  
Xi Lian Sun ◽  
Hong Tao Cao
Keyword(s):  
Thin Films ◽  
Refractive Index ◽  
Optical Properties ◽  
Band Gap ◽  
Tungsten Oxide ◽  
Nitrogen Doping ◽  
Optical Band Gap ◽  
Band Gap Energy ◽  
Gap Energy ◽  
Tungsten Oxide Thin Films

In depositing nitrogen doped tungsten oxide thin films by using reactive dc pulsed magnetron sputtering process, nitrous oxide gas (N2O) was employed instead of nitrogen (N2) as the nitrogen dopant source. The nitrogen doping effect on the structural and optical properties of WO3 thin films was investigated by X-ray diffraction, transmission electron microscopy and UV-Vis spectroscopy. The thickness, refractive index and optical band gap energy of these films have been determined by analyzing the SE spectra using parameterized dispersion model. Morphological images reveal that the films are characterized by a hybrid structure comprising nanoparticles embeded in amorphous matrix and open channels between the agglomerated nanoparticles. Increasing nitrogen doping concentration is found to decrease the optical band gap energy and the refractive index. The reduced band gaps are associated with the N 2p orbital in the N-doped tungsten oxide films.

scholarly journals Synthesis of Heterostructure of ZnO@MOF-46(Zn) to Improve the Photocatalytic Performance in Methylene Blue Degradation

Crystals ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 1379
Author(s):  
Jiraporn Buasakun ◽  
Phakinee Srilaoong ◽  
Ramida Rattanakam ◽  
Tanwawan Duangthongyou
Keyword(s):  
Methylene Blue ◽  
Band Gap ◽  
Photocatalytic Performance ◽  
Degradation Process ◽  
Band Gap Energy ◽  
Photocatalytic Efficiency ◽  
Electron Hole ◽  
Methylene Blue Degradation ◽  
Gap Energy ◽  
Hole Recombination

The heterostructure of ZnO and MOF-46(Zn) was synthesized to improve the photocatalytic performance of ZnO and prove the synergistic theory that presented the coexistence of ZnO and MOF-46(Zn), providing better efficiency than pure ZnO. The heterostructure material was synthesized by using prepared ZnO as a Zn2+ source, which was reacted with 2-aminoterephthalic acid (2-ATP) as a ligand to cover the surface of ZnO with MOF-46(Zn). The ZnO reactant materials were modified by pyrolysis of various morphologies of IRMOF-3 (Zn-MOF) prepared by using CTAB as a morphology controller. The octahedral ZnO obtained at 150 mg of CTAB shows better efficiency for photodegradation, with 85.79% within 3 h and a band gap energy of 3.11 eV. It acts as a starting material for synthesis of ZnO@MOF-46(Zn). The ZnO/MOF-46(Zn) composite was further used as a photocatalyst material in the dye (methylene blue: MB) degradation process, and the performance was compared with that of pure prepared ZnO. The results show that the photocatalytic efficiency with 61.20% in the MB degradation of the heterostructure is higher than that of pure ZnO within 60 min (90.09% within 180 min). The reason for this result may be that the coexistence of ZnO and MOF-46(Zn) can absorb a larger range of energy and reduce the possibility of the electron–hole recombination process.

scholarly journals Effect of Heat Treatment on the Optical Properties of Cobalt Doped Stannic Oxide

2014 ◽  
Vol 28 ◽  
pp. 59-70
Author(s):  
Saba Jameel Hasan
Keyword(s):  
Heat Treatment ◽  
Optical Properties ◽  
Substrate Temperature ◽  
Band Gap ◽  
Spray Pyrolysis ◽  
Glass Substrate ◽  
Optical Band Gap ◽  
Band Gap Energy ◽  
Stannic Oxide ◽  
Gap Energy

This study investigates the effect of annealing on The optical properties of (SnO2:Co) films prepared by spray pyrolysis (SP) technique at a glass substrate temperature (Ts = 773 K). The absorbance and transmittance spectra have been recorded in order to calculate the optical constant and the optical band gap energy of the films. It was found that the annealing affects all the parameters under investigations

Optical Properties of Erbium Doped Tellurite Glasses

2016 ◽  
Vol 864 ◽  
pp. 37-41 ◽  
Author(s):  
Mukhayyarotin Niswati Rodliyatul Jauhariyah ◽  
Cari ◽  
Ahmad Marzuki
Keyword(s):  
Refractive Index ◽  
Optical Properties ◽  
Room Temperature ◽  
Optical Band Gap ◽  
Band Gap Energy ◽  
Tellurite Glasses ◽  
Ion Content ◽  
Gap Energy ◽  
Erbium Doped ◽  
Angle Method

This paper presents the optical properties of erbium doped tellurite glasses with the composition of 55TeO2-2Bi2O3-35ZnO-5PbO-(3-x)Na2O-xEr2O3 where x = 0, 0.5, 1.0, 1.5, 2.0, 2.5, and 3.0 mol% . Refractive index of the glasses was measured using Brewster’s angle method and their optical absorption spectra were measured in spectral range 200 – 1100 nm recorded at room temperature. The results show that the glass refractive index increases with the increase of Er3+ ion content in the glass and the optical band gap energy decreases with the increase of erbium content in the glass.

Optical Properties of Undoped and Dy3+-Doped Boro-Tellurite Glass

2014 ◽  
Vol 895 ◽  
pp. 194-199 ◽  
Author(s):  
Atiqah Ab Rasid ◽  
Husin Wagiran ◽  
Suhairul Hashim ◽  
Rosli Hussin ◽  
Zuhairi Ibrahim
Keyword(s):  
Optical Properties ◽  
Band Gap ◽  
Tellurite Glass ◽  
Optical Band Gap ◽  
Band Gap Energy ◽  
Excitation Wavelength ◽  
Absorption Bands ◽  
Gap Energy ◽  
Vis Spectroscopy ◽  
Doped Glasses

A series of undoped and Dy3+-doped boro-tellurite glasses were prepared, and their optical properties have been studied through XRD, absorption, optical band gap energy and photoluminescence. The XRD pattern has been used to confirm the amorphous nature of the prepared glass. The optical absorption spectra showed eight absorption bands which corresponded to 4I15/2, 4F9/2, 6F3/2, 6F5/2, 6F7/2, 6F9/2, 6F11/2 and 6H11/2 transitions from the ground state, 6H15/2. The optical band gap energy, Eopt for undoped glass was 3.08 eV and the Dy3+-doped glasses Eopt values varied from 3.16 3.24 eV. The emission spectra from photoluminescence spectroscopy showed two dominant emission peaks at 483 nm and 574 nm with an excitation wavelength of 325 nm (3.82 eV). Keywords: X-ray diffraction, boro-tellurite glass, photoluminescence, absorption spectrum, UV-Vis spectroscopy, energy band gap.

scholarly journals Effect of Stepwise Replacement of LiF by Bi2O3 and of Annealing on Optical Properties of LiF⋅B2O3 Glasses

ISRN Optics ◽  
2012 ◽  
Vol 2012 ◽  
pp. 1-7 ◽  
Author(s):  
Susheel Arora ◽  
Virender Kundu ◽  
D. R. Goyal ◽  
A. S. Maan
Keyword(s):  
Optical Properties ◽  
Band Gap ◽  
Optical Band Gap ◽  
Urbach Energy ◽  
Optical Characterization ◽  
Band Gap Energy ◽  
Gap Energy ◽  
Different Temperatures ◽  
Quench Method

Bismuth fluoroborate glasses with compositions xBi2O3⋅(40-x)LiF⋅60  B2O3  (x=0,5,10,15,  and  20) are synthesized by melt-quench method. Optical characterization was carried out to examine variation of optical band gap energy (Eg) and Urbach energy (EU) with respect to the concentration. It reflects the effect of stepwise replacement of non-oxide and less polarizable LiF by an oxide and more polarizable (Bi2O3) group on the optical properties of the samples. The value of Eg decreases with increase in concentration of Bi2O3. The samples were subjected to annealing at different temperatures (300°C, 350°C, and 400°C), and the effect of annealing on the optical properties of various samples was again studied. Annealing affects remarkably the values of Eg and EU in the samples with x=0.

scholarly journals Facile Synthesis of Flower-Like TiO2-Based Composite for Adsorption–Photocatalytic Degradation of High-Chroma Methylene Blue

Catalysts ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 515
Author(s):  
Mengqi Tian ◽  
Jingjing Wang ◽  
Runjun Sun ◽  
Mu Yao ◽  
Lianbi Li
Keyword(s):  
Methylene Blue ◽  
Photocatalytic Degradation ◽  
Photoluminescence Intensity ◽  
Facile Synthesis ◽  
First Order ◽  
Degradation Data ◽  
First Order Kinetics ◽  
Hydrochloric Acid Treatment ◽  
Pseudo Second Order ◽  
Facile Fabrication

A flower-like TiO2-based composite (denoted as Zn-Ti-6) was prepared using a flower-like zinc oxide template for adsorption–photocatalytic degradation of high-chroma methylene blue. The reaction took place in an alkaline environment following hydrochloric acid treatment to remove the template and form TiO2-based composite. Sodium hydroxide played both roles of morphology-directing agent and reactive etchant. The possible mechanism for the formation of flower-like Zn-Ti-6 was proposed. The adsorption and photocatalytic degradation behavior of Zn-Ti-6 on methylene blue (MB) removal was also investigated. The results revealed that Zn-Ti-6 showed better adsorption and photocatalytic degradation performance than TiO2 nanoparticles owing to its much larger specific surface area, more abundant hydroxyls, and lower photoluminescence intensity. The adsorption and photocatalytic degradation data of Zn-Ti-6 were well fitted to the pseudo-second-order and pseudo-first-order kinetics models, respectively. The excellent adsorption performance of Zn-Ti-6 is largely beneficial to the subsequent photocatalytic degradation performance for high-chroma wastewater treatment. Overall, this study contributes a facile fabrication strategy for flower-like TiO2-based composite to achieve the adsorption–photocatalytic degradation of high-chroma wastewater.

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.

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