scholarly journals Green Synthesis of High Temperature Stable Anatase Titanium Dioxide Nanoparticles Using Gum Kondagogu: Characterization and Solar Driven Photocatalytic Degradation of Organic Dye

Nanomaterials ◽  
2018 ◽  
Vol 8 (12) ◽  
pp. 1002 ◽  
Author(s):  
Kothaplamoottil Sivan Saranya ◽  
Vinod Vellora Thekkae Padil ◽  
Chandra Senan ◽  
Rajendra Pilankatta ◽  
Kunjumon Saranya ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Titanium Dioxide ◽  
Photocatalytic Activity ◽  
Green Synthesis ◽  
Organic Dye ◽  
Bet Surface Area ◽  
Tio2 Nps ◽  
X Ray ◽  
Transmission Electron

The present study reports a green and sustainable method for the synthesis of titanium dioxide (TiO2) nanoparticles (NPs) from titanium oxysulfate solution using Kondagogu gum (Cochlospermum gossypium), a carbohydrate polymer, as the NPs formation agent. The synthesized TiO2 NPs were categorized by techniques such as X-Ray Diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy analysis, Raman spectroscopy, scanning electron microscope- Energy-dispersive X-ray spectroscopy (SEM-EDX), Transmission electron microscopy (TEM), High-resolution transmission electron microscopy (HR-TEM), UV-visible spectroscopy, Brunauer-Emmett-Teller (BET) surface area and particle size analysis. Additionally, the photocatalytic actions of TiO2 NPs were assessed with regard to their ability to degrade an organic dye (methylene blue) from aqueous solution in the presence of solar light. Various parameters affecting the photocatalytic activity of the TiO2 NPs were examined, including catalyst loading, reaction time, pH value and calcination temperature of the aforementioned particles. This green synthesis method involving TiO2 NPs explores the advantages of inexpensive and non-toxic precursors, the TiO2 NPs themselves exhibiting excellent photocatalytic activity against dye molecules.

Optical and photocatalytic properties of photoactive paper with polycrystalline TiO2 nanopigment for optimal product design

TAPPI Journal ◽  
2012 ◽  
Vol 11 (5) ◽  
pp. 33-38 ◽  
Author(s):  
SEONGHYUK KO ◽  
PAUL D. FLEMING ◽  
MARGARET JOYCE ◽  
PNINA ARI-GUR
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Gas Chromatography ◽  
Titanium Dioxide ◽  
Optical Properties ◽  
Photocatalytic Activity ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Optimal Product Design

We investigated the effect of the crystalline phases of titanium dioxide nanopigment to optimize the optical properties and photocatalytic activity for synthesizing a photoactive paper. Six different ratios of anatase to rutile were prepared. Phase change and particle size were characterized using X-ray diffraction and transmission electron microscopy. Optical properties including opacity and brightness were tested. Photocatalytic activity was evaluated by measuring toluene decomposition, using gas chromatography. A specific ratio between two different crystallites of titanium dioxide showed relatively better optical and photoactive properties. The optimal anatase-to-rutile ratio was found to be 0.52:0.48.

scholarly journals Synchrotron Radiation Spectroscopy and Transmission Electron Microscopy Techniques to Evaluate TiO2 NPs Incorporation, Speciation, and Impact on Root Cells Ultrastructure of Pisum sativum L. Plants

Nanomaterials ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 921
Author(s):  
Simonetta Muccifora ◽  
Hiram Castillo-Michel ◽  
Francesco Barbieri ◽  
Lorenza Bellani ◽  
Monica Ruffini Castiglione ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Synchrotron Radiation ◽  
Pisum Sativum ◽  
Emission Spectrometry ◽  
Root Cells ◽  
Tio2 Nps ◽  
X Ray ◽  
Pisum Sativum L ◽  
Transmission Electron

Biosolids (Bs) for use in agriculture are an important way for introducing and transferring TiO2 nanoparticles (NPs) to plants and food chain. Roots of Pisum sativum L. plants grown in Bs-amended soils spiked with TiO2 800 mg/kg as rutile NPs, anatase NPs, mixture of both NPs and submicron particles (SMPs) were investigated by Transmission Electron Microscopy (TEM), synchrotron radiation based micro X-ray Fluorescence and micro X-ray Absorption Near-Edge Structure (µXRF/µXANES) and Inductively Coupled Plasma Optical Emission Spectrometry (ICP-OES). TEM analysis showed damages in cells ultrastructure of all treated samples, although a more evident effect was observed with single anatase or rutile NPs treatments. Micro-XRF and TEM evidenced the presence of nano and SMPs mainly in the cortex cells near the rhizodermis. Micro-XRF/micro-XANES analysis revealed anatase, rutile, and ilmenite as the main TiO2 polymorphs in the original soil and Bs, and the preferential anatase uptake by the roots. For all treatments Ti concentration in the roots increased by 38–56%, however plants translocation factor (TF) increased mostly with NPs treatment (261–315%) and less with SMPs (about 85%), with respect to control. In addition, all samples showed a limited transfer of TiO2 to the shoots (very low TF value). These findings evidenced a potential toxicity of TiO2 NPs present in Bs and accumulating in soil, suggesting the necessity of appropriate regulations for the occurrence of NPs in Bs used in agriculture.

The Influence of Introduction of Polyethylene Glycol on Synthesis of Bimodal Mesoporous γ-Al2O3

2013 ◽  
Vol 709 ◽  
pp. 89-92
Author(s):  
Xiang Li ◽  
Xin Mei Liu ◽  
Zi Feng Yan
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Polyethylene Glycol ◽  
Bet Surface Area ◽  
X Ray Diffraction ◽  
Relative Crystallinity ◽  
X Ray ◽  
Transmission Electron ◽  
Increasing Trend ◽  
Opposite Tendency

In the presence of polyethylene glycol (PEG2W),bimodal mesoporous γ-Al2O3 was successfully synthesized via hydrothermal method. The samples were respectively characterized by X-ray diffraction (XRD), N2 physisorption, transmission electron microscopy (TEM), thermogravimetric and differential scanning calorimeter (TG-DSC). Introduction of PEG2W can increase the relative crystallinity of AACH and γ-Al2O3. The BET surface area and pore volume of alumina shows an increasing trend with increasing of PEG2W content, while the pore size shows an opposite tendency. The PEG2W also plays an important role in inducing the formation of the nanorod-like alumina.

Hydrothermal Synthesis of Visible Light Active SnO2-SnS2 Nanocomposite Photocatalyst for the Reduction of Cr(VI) in Water

2013 ◽  
Vol 709 ◽  
pp. 7-10
Author(s):  
Jing Li ◽  
Xi Hua Du ◽  
Wei Min Dai ◽  
Yong Cai Zhang
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Photocatalytic Activity ◽  
Visible Light ◽  
Sno2 Nanoparticles ◽  
High Photocatalytic Activity ◽  
X Ray ◽  
Transmission Electron ◽  
Visible Light Active ◽  
Composition Structure

A low temperature (130 °C) hydrothermal method was proposed for the synthesis of SnO2-SnS2 nanocomposite. The composition, structure and optical property of the as-synthesized SnO2-SnS2 nanocomposite were characterized by X-ray diffraction, energy dispersive X-ray spectroscopy, transmission electron microscopy, high-resolution transmission electron microscopy and UV-vis diffuse reflectance spectra, and its photocatalytic activity was tested by the reduction of Cr(VI) in water under visible light (λ > 420 nm) irradiation. It was found that the as-synthesized SnO2-SnS2 nanocomposite exhibited high photocatalytic activity in the reduction of Cr(VI) in water under visible light (λ > 420 nm) irradiation, whereas SnO2 nanoparticles displayed no photocatalytic activity in the reduction of Cr(VI) in water under visible light (λ > 420 nm) irradiation.

TEM Study of Rutile-Phase TiO2 Nanosheets

2013 ◽  
Vol 850-851 ◽  
pp. 156-159
Author(s):  
Xin Yan Wu ◽  
Wei Xiong
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Photocatalytic Activity ◽  
Energy Dispersive Spectrometer ◽  
Sol Gel ◽  
Rutile Phase ◽  
High Photocatalytic Activity ◽  
X Ray ◽  
Transmission Electron ◽  
Sol Gel Process

TiO2 nanosheets have been successfully synthesized via a simple sol-gel process. These nanostructures were characterized by transmission electron microscopy (TEM) and x-ray energy dispersive spectrometer (EDS). The sheet-shaped single-crystalline nanostructures are pure rutile-phase structure, with landscape dimension of 10-45 nm. EDS investigation confirms that the TiO2 nanosheets are only composed of Ti and O, and the atomic ration of Ti and O is close to 1:2. High photocatalytic activity might be expected for those TiO2 nanosheets due to their large surface area.

scholarly journals Cottonseed Oilcake Extract Mediated Green Synthesis of Silver Nanoparticles and Its Antibacterial and Cytotoxic Activity

2016 ◽  
Vol 2016 ◽  
pp. 1-6 ◽  
Author(s):  
Muthusamy Govarthanan ◽  
Min Cho ◽  
Jung-Hee Park ◽  
Jum-Suk Jang ◽  
Young-Joo Yi ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Silver Nanoparticles ◽  
Fourier Transform ◽  
Green Synthesis ◽  
Pseudomonas Syringae ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Xrd Techniques

Agroindustrial byproduct mediated green synthesis of silver nanoparticles was carried out using cottonseed oilcake (CSOC) extract. The aqueous silver nitrate formed stable silver nanoparticles with CSOC extract as a reducing agent for Ag+to Ag0. The synthesized nanoparticles were characterized using energy dispersive X-ray spectroscopy (EDS), transmission electron microscopy (TEM), Fourier transform infrared (FTIR) spectroscopy, and X-ray diffraction (XRD) techniques. The synthesized silver nanoparticles (AgNPs) (4 mM) significantly inhibited the growth of phytopathogens,Pseudomonas syringaepv.actinidiaeandRalstonia solanacearum. Further, cytotoxicity of AgNPs was evaluated using rat splenocyte cells. The splenocyte viability was decreased according to the increasing concentration of AgNPs and 90% of cell death was observed at 100 μg/mL.

Changing width bandgap of TiO2 nanoparticles incorporating GO

MRS Advances ◽  
2019 ◽  
Vol 4 (61-62) ◽  
pp. 3423-3431
Author(s):  
Daniela K. Calvo-Ramos ◽  
Marina Vega-González ◽  
José Santos-Cruz ◽  
Francisco Javier De Moure-Flores ◽  
Sandra A. Mayén-Hernández
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Methylene Blue ◽  
Photocatalytic Activity ◽  
Graphene Oxide ◽  
Nir Spectroscopy ◽  
Improved Method ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron

ABSTRACTNanoparticles of titanium dioxide (TiO2), synthesized by the sonochemical technique, were mixed with different amounts of graphene oxide (GO), obtained by the improved method of Hummer, in order to modify their bandwidth. The TiO2/OG compounds were characterized using different techniques: X-ray Diffraction (XRD), transmission electron microscopy (TEM), Raman and UV-Vis-NIR spectroscopy. TiO2 bandgap decreased, with GO incorporation, from 3.2 to 2.72 eV when GO was present at 20 weigh percentage (TiO2/GO-20%). Photodegradation experiments of methylene blue (MB) were performed with the materials to verify their photocatalytic activity. At 40 minutes, the pure TiO2 degraded 48% of MB, whereas the compound TiO2/GO-20% degraded 88%, showing a good incorporation of both compounds and the improvement of TiO2 photocatalitic properties.

scholarly journals In-Depth Structural and Optical Analysis of Ce-modified ZnO Nanopowders with Enhanced Photocatalytic Activity Prepared by Microwave-Assisted Hydrothermal Method

Catalysts ◽  
2020 ◽  
Vol 10 (5) ◽  
pp. 551 ◽  
Author(s):  
Otman Bazta ◽  
Ana Urbieta ◽  
Susana Trasobares ◽  
Javier Piqueras ◽  
Paloma Fernández ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Photocatalytic Activity ◽  
Scanning Transmission Electron Microscopy ◽  
Atomic Scale ◽  
X Ray ◽  
Microwave Assisted ◽  
Scanning Transmission Electron ◽  
Transmission Electron ◽  
Scanning Transmission

Pure and Ce-modified ZnO nanosheet-like polycrystalline samples were successfully synthesized by a simple and fast microwave-based process and tested as photocatalytic materials in environmental remediation processes. In an attempt to clarify the actual relationships between functionality and atomic scale structure, an in-depth characterization study of these materials using a battery of complementary techniques was performed. X-ray diffraction (XRD), field emission-scanning electron microscopy (FE-SEM), high-resolution transmission electron microscopy (HRTEM), high-angle annular dark field-scanning transmission electron microscopy (HAADF-STEM), energy-dispersive X-Ray spectroscopy-scanning transmission electron microscopy (STEM-XEDS), photoluminescence spectroscopy (PL) and UV–Visible absorption spectroscopy were used to evaluate the effect of Ce ions on the structural, morphological, optical and photocatalytic properties of the prepared ZnO nanostructures. The XRD results showed that the obtained photocatalysts were composed of hexagonal, wurtzite type crystallites in the 34–44 nm size range. The SEM and TEM showed nanosheet-shaped crystallites, a significant fraction of them in contact with bundles of randomly oriented and much smaller nanoparticles of a mixed cerium–zinc phase with a composition close to Ce0.68Zn0.32Ox. Importantly, in clear contrast to the prevailing proposals regarding this type of materials, the STEM-XEDS characterization of the photocatalyst samples revealed that Ce did not incorporate into the ZnO crystal lattice as a dopant but that a heterojunction formed between the ZnO nanosheets and the Ce–Zn mixed oxide phase nanoparticles instead. These two relevant compositional features could in fact be established thanks to the particular morphology obtained by the use of the microwave-assisted hydrothermal synthesis. The optical study revealed that in the ZnO:Ce samples optical band gap was found to decrease to 3.17 eV in the samples with the highest Ce content. It was also found that the ZnO:Ce (2 at.%) sample exhibited the highest photocatalytic activity for the degradation of methylene blue (MB), when compared to both the pure ZnO and commercial TiO2-P25 under simulated sunlight irradiation. The kinetics of MB photodegradation in the presence of the different photocatalysts could be properly described using a Langmuir–Hinshelwood (LH) model, for which the ZnO:Ce (2 at.%) sample exhibited the highest value of effective kinetic constant.

BiVO4/MIL-101 composite having the synergistically enhanced visible light photocatalytic activity

RSC Advances ◽  
2015 ◽  
Vol 5 (54) ◽  
pp. 43473-43479 ◽  
Author(s):  
Yanli Xu ◽  
Mengmeng Lv ◽  
Hanbiao Yang ◽  
Qi Chen ◽  
Xueting Liu ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Photocatalytic Activity ◽  
Thermogravimetric Analysis ◽  
Diffuse Reflectance ◽  
Emission Spectra ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Visible Light Photocatalytic

The BiVO4/MIL-101 composite and pure materials were characterized by X-ray diffraction, transmission electron microscopy, thermogravimetric analysis, UV-vis diffuse reflectance absorption spectra and photoluminescence emission spectra.

Characterization and Photocatalytic Activity of La1.6Ln0.4Zr2O7 (Ln= La, Nd, Dy, Er) Nanocrystals by Stearic Acid Method

2010 ◽  
Vol 123-125 ◽  
pp. 631-634 ◽  
Author(s):  
Yu Ping Tong ◽  
Shun Bo Zhao ◽  
Feng Lan Li ◽  
Chang Yong Li
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Photocatalytic Activity ◽  
Stearic Acid ◽  
Nitrogen Adsorption ◽  
Combustion Method ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Degradation Of Methyl Orange

La1.6Ln0.4Zr2O7 (Ln= La, Nd, Dy, Er) nanocrystals were prepared by stearic acid combustion method. The samples were characterized by powder X-ray diffraction (XRD), Brunauer-Emmett-Teller (BET) nitrogen adsorption, transmission electron microscopy (TEM) and high-resolution transmission electron microscopy (HRTEM). The photocatalytic activity of La1.6Ln0.4Zr2O7 was evaluated by the photocatalytic degradation of methyl orange. The order of the photocatalytic activity was as following: La1.6Er0.4Zr2O7>La1.6Dy0.4Zr2O7> La1.6Nd0.4Zr2O7> La2Zr2O7. La1.6Dy0.4Zr2O7 showed that the best photocatalytic activity and the reason may be related to the big magnetic moment of Er3+. It may be considered largely to be caused by the partly occupied Ln4f levels. Since the solid samples have the same structure, the reason that La1.6Er0.4Zr2O7 shows the highest reactivity may be related to lowest Ln4f level of Er3+.

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