Effects of Sn Concentration on Chemical Composition, Microstructure and Photocatalytic Activity of Nanoparticulate Sn-Doped TiO2 Powders Synthesized by Solution Combustion Technique

2018 ◽  
Vol 766 ◽  
pp. 191-196
Author(s):  
Oratai Jongprateep ◽  
Kornkamon Meesombad ◽  
Ratchatee Techapiesancharoenkij ◽  
Krissada Surawathanawises ◽  
Ratiporn Munprom
Keyword(s):  
Titanium Dioxide ◽  
Chemical Composition ◽  
Band Gap ◽  
Band Gap Energy ◽  
Solution Combustion ◽  
Gap Energy ◽  
Titanium Dioxide Powder ◽  
Dioxide Powder ◽  
Photocatalytic Activities ◽  
Combustion Technique

Utilization of photocatalytic properties of materials can be perceived through a wide range of applications, such as anti-bacterial, water treatment, and self-cleaning materials. It has been established that doping can result in alteration of photocatalytic activities. This study aimed at studying effects of tin concentration on chemical composition, microstructure, band gap energy, and photocatalytic activities of tin-doped titanium dioxide powder synthesized by solution combustion technique. Experimental results revealed that concentration of tin significantly influenced chemical composition of the powders. A semi-quantitative analysis indicated that tin oxide secondary phase increased from 11 to 23 wt%, as the Sn increased from 2.5 to 10 mol%, respectively. Tin concentration, nevertheless, did not significantly influence microstructure of the powders. All powders had average particle size ranging from 13.1 to 13.4 nm, which agglomerated into clusters with average sizes ranging from 103 to 140 nm. A slight increase of band gap energy was observed at higher tin concentration. The most prominent photocatalytic activities, determined from decomposition of methylene blue, was found in the titanium dioxide powder with 2.5 mol% Sn.

scholarly journals Synthesis and Characterization Titanium Dioxide (TiO2) Doped Vanadium(V) Using Solid State Method

ALCHEMY ◽  
2015 ◽  
Vol 4 (1) ◽  
Author(s):  
Khusnan Mustofa ◽  
Nur Aini ◽  
Susi Nurul Khalifah
Keyword(s):  
Titanium Dioxide ◽  
Solid State ◽  
Band Gap ◽  
Diffuse Reflectance Spectroscopy ◽  
Synthesis Method ◽  
Band Gap Energy ◽  
Solid State Method ◽  
Gap Energy ◽  
Wavelength Absorption ◽  
State Method

<p>TiO<sub>2</sub> Anatase activities should be increased from the UV to the visible light photocatalytic activity of TiO<sub>2</sub> to increase anatas. One efforts to optimize TiO<sub>2</sub> anatase activity is doping by using dopant vanadium(V). Synthesis method which is used in this research is a solid reaction method. The steps being taken in this methods include grinding and heating at high temperatures. Dopant concentrations of vanadium(V) which are used in the research was 0.3%, 0.5% and 0.7%. and the characterization used is X-ray diffraction and UV-Vis Diffuse Reflectance Spectroscopy. The result shows that there are a changing of particle size, band gap energy, and absorption of TiO<sub>2</sub> anatas wavelength because of dopan vanadium(V) addition. While TiO<sub>2</sub>’s structure does not change. The crystal sizes of each TiO<sub>2</sub> without doping, V-TiO<sub>2</sub> 0,3%, 0,5% and 0,7% are 53.21 nm, 47.67 nm, 79.65 nm dan 68.99 nm.  Band gap energy of each TiO<sub>2</sub> without doping, V-TiO<sub>2</sub> 0,3%, 0,5% dan 0,7% are 3.309 eV, 3.279 eV, 3.270 eV and 3.259 eV. While wavelength absorption of each TiO<sub>2</sub> without doping, V-TiO<sub>2</sub> 0,3%, 0,5% and 0,7% are 374.9 nm, 378.4 nm, 379.5 nm and 380.8 nm.<em> </em></p><p class="BodyAbstract"> </p><strong><em>Keywords</em>:</strong> <em>Synthesis, titanium dioxide, vanadium(V), solid state method</em>

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.

scholarly journals Polymer Thermal Treatment Production of Cerium Doped Willemite Nanoparticles: An Analysis of Structure, Energy Band Gap and Luminescence Properties

Materials ◽  
2021 ◽  
Vol 14 (5) ◽  
pp. 1118
Author(s):  
Ibrahim Mustapha Alibe ◽  
Khamirul Amin Matori ◽  
Mohd Hafiz Mohd Zaid ◽  
Salisu Nasir ◽  
Ali Mustapha Alibe ◽  
...  
Keyword(s):  
Solid State ◽  
Thermal Treatment ◽  
Band Gap ◽  
Optical Band Gap ◽  
Dopant Concentration ◽  
Blue Emission ◽  
Green Emission ◽  
Band Gap Energy ◽  
Solid State Lighting ◽  
Gap Energy

The contemporary market needs for enhanced solid–state lighting devices has led to an increased demand for the production of willemite based phosphors using low-cost techniques. In this study, Ce3+ doped willemite nanoparticles were fabricated using polymer thermal treatment method. The special effects of the calcination temperatures and the dopant concentration on the structural and optical properties of the material were thoroughly studied. The XRD analysis of the samples treated at 900 °C revealed the development and or materialization of the willemite phase. The increase in the dopant concentration causes an expansion of the lattice owing to the replacement of larger Ce3+ ions for smaller Zn2+ ions. Based on the FESEM and TEM micrographs, the nanoparticles size increases with the increase in the cerium ions. The mean particles sizes were estimated to be 23.61 nm at 1 mol% to 34.02 nm at 5 mol% of the cerium dopant. The optical band gap energy of the doped samples formed at 900 °C decreased precisely by 0.21 eV (i.e., 5.21 to 5.00 eV). The PL analysis of the doped samples exhibits a strong emission at 400 nm which is ascribed to the transition of an electron from localized Ce2f state to the valence band of O2p. The energy level of the Ce3+ ions affects the willemite crystal lattice, thus causing a decrease in the intensity of the green emission at 530 nm and the blue emission at 485 nm. The wide optical band gap energy of the willemite produced is expected to pave the way for exciting innovations in solid–state lighting applications.

scholarly journals Population Balance Application in TiO2 Particle Deagglomeration Process Modeling

Energies ◽  
2021 ◽  
Vol 14 (12) ◽  
pp. 3523
Author(s):  
Radosław Krzosa ◽  
Łukasz Makowski ◽  
Wojciech Orciuch ◽  
Radosław Adamek
Keyword(s):  
Particle Size ◽  
Titanium Dioxide ◽  
Mechanistic Model ◽  
Population Balance ◽  
Tio2 Particle ◽  
Application Process ◽  
Titanium Dioxide Powder ◽  
Dioxide Powder ◽  
Computational Fluid Dynamics Cfd ◽  
Hydrodynamic Stresses

The deagglomeration of titanium-dioxide powder in water suspension performed in a stirring tank was investigated. Owing to the widespread applications of the deagglomeration process and titanium dioxide powder, new, more efficient devices and methods of predicting the process result are highly needed. A brief literature review of the application process, the device used, and process mechanism is presented herein. In the experiments, deagglomeration of the titanium dioxide suspension was performed. The change in particle size distribution in time was investigated for different impeller geometries and rotational speeds. The modification of impeller geometry allowed the improvement of the process of solid particle breakage. In the modelling part, numerical simulations of the chosen impeller geometries were performed using computational-fluid-dynamics (CFD) methods whereby the flow field, hydrodynamic stresses, and other useful parameters were calculated. Finally, based on the simulation results, the population-balance with a mechanistic model of suspension flow was developed. Model predictions of the change in particle size showed good agreement with the experimental data. Using the presented method in the process design allowed the prediction of the product size and the comparison of the efficiency of different impeller geometries.

Phase transformation and heterojunction construction of bismuth oxyiodides by grinding-assistant calcination in the presence of thiourea and its photoactivity

2021 ◽  
Author(s):  
Zichen Shen ◽  
Huanzhen Liu ◽  
Xuemei Jia ◽  
Qiaofeng Han ◽  
Huiping Bi
Keyword(s):  
Phase Transformation ◽  
Band Gap ◽  
Layered Structure ◽  
Band Gap Energy ◽  
Gap Energy

Bismuth-rich oxyhalides are promising photocatalysts due to their special layered structure and adjustable band gap energy. In this work, a series of bismuth oxyiodides were fabricated by grinding-assistant calcining in...

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