scholarly journals High Photocatalytic Activity under Visible Light for a New Morphology of Bi2WO6 Microcrystals

Catalysts ◽  
2019 ◽  
Vol 9 (8) ◽  
pp. 667 ◽  
Author(s):  
Campos ◽  
Nobre ◽  
Filho ◽  
Ribeiro da Silva ◽  
Costa ◽  
...  
Keyword(s):  
Single Phase ◽  
High Surface ◽  
High Surface Area ◽  
Orthorhombic Phase ◽  
Xrd Analysis ◽  
High Photocatalytic Activity ◽  
Sem Images ◽  
Bismuth Tungstate ◽  
Adsorption Desorption ◽  
Dye Solutions

In this work, a new morphology was obtained for bismuth tungstate (Bi2WO6-glyc) using a hydrothermal method with the addition of glycerol as a surfactant. In order to compare, the bismuth tungstate without glycerol as the surfactant, i.e., Bi2WO6, was synthesized. Structural characterization by XRD and Rietveld refinement confirmed the orthorhombic structure as a single phase for all samples with high crystallinity. All active modes in Raman spectroscopy for the orthorhombic phase of bismuth tungstate were confirmed in agreement with XRD analysis. N2 adsorption/desorption and size pore distribution confirmed the high surface area (85.7 m2/g) for Bi2WO6-glyc when compared with Bi2WO6 (8.5 m2/g). The optical band gap by diffuse reflectance was 2.78 eV and 2.88 eV for Bi2WO6-glyc and Bi2WO6, respectively. SEM images confirmed the different morphology for these materials, and microstructures with cheese crisp were observed for Bi2WO6-glyc (cheese crisp). On the other hand, flower-like microcrystals were confirmed for Bi2WO6 sample. The photocatalytic performance of Bi2WO6-glyc (94.2%) in the photodegradation of rhodamine B (RhB) dye solutions at 60 min was more expressive than Bi2WO6 (81.3%) and photolysis (8.2%) at 90 min.

Functionalized Nano-graphene Oxide as Multi-modal Clinic for Effective Drug Delivery

2017 ◽  
Vol 10 (4) ◽  
pp. 3768-3771
Author(s):  
Soumitra Satapathi ◽  
Rutusmita Mishra ◽  
Manisha Chatterjee ◽  
Partha Roy ◽  
Somesh Mohapatra
Keyword(s):  
Drug Delivery ◽  
Graphene Oxide ◽  
Cancer Cell ◽  
High Surface ◽  
High Surface Area ◽  
Cancer Cell Line ◽  
Xrd Analysis ◽  
Graphene Derivatives ◽  
Nano Graphene

Nano-materials based drug delivery modalities to specific organs and tissues has become one of the critical endeavors in pharmaceutical research. Recently, two-dimensional graphene has elicited considerable research interest because of its potential application in drug delivery systems. Here we report, the drug delivery applications of PEGylated nano-graphene oxide (nGO-PEG), complexed with a multiphoton active and anti-cancerous diarylheptanoid drug curcumin. Specifically, graphene-derivatives were used as nanovectors for the delivery of the hydrophobic anticancer drug curcumin due to its high surface area and easy surface functionalization. nGO was synthesized by modified Hummer’s method and confirmed by XRD analysis. The formation of nGO, nGO-PEG and nGO-PEG-Curcumin complex were monitored through UV-vis, IR spectroscopy. MTT assay and AO/EB staining found that nGO-PEG-Curcumin complex afforded highly potent cancer cell killing in vitro with a human breast cancer cell line MCF7.

Texture Evaluation of Sol-Gel Derived Mesoporous Bioactive Glass

2013 ◽  
Vol 284-287 ◽  
pp. 230-234
Author(s):  
Yu Jen Chou ◽  
Chi Jen Shih ◽  
Shao Ju Shih
Keyword(s):  
Surface Area ◽  
Calcination Temperature ◽  
High Surface ◽  
Sol Gel ◽  
High Surface Area ◽  
Nitrogen Adsorption ◽  
Bioactive Glasses ◽  
Transmission Electron ◽  
Sol Gel Process ◽  
Adsorption Desorption

Recent years mesoporous bioactive glasses (MBGs) have become important biomaterials because of their high surface area and the superior bioactivity. Various studies have reported that when MBGs implanted in a human body, hydroxyl apatite layers, constituting the main inorganic components of human bones, will form on the MBG surfaces to increase the bioactivity. Therefore, MBGs have been widely applied in the fields of tissue regeneration and drug delivery. The sol-gel process has replaced the conventional glasses process for MBG synthesis because of the advantages of low contamination, chemical flexibility and lower calcination temperature. In the sol-gel process, several types of surfactants were mixed with MBG precursor solutions to generate micelle structures. Afterwards, these micelles decompose to form porous structures after calcination. Although calcination is significant for contamination, crystalline and surface area in MBG, to the best of the authors’ knowledge, only few systematic studies related to calcination were reported. This study correlated the calcination parameters and the microstructure of MBGs. Microstructure evaluation was characterized by transmission electron microscopy and nitrogen adsorption/desorption. The experimental results show that the surface area and the pore size of MBGs decreased with the increasing of the calcination temperature, and decreased dramatically at 800°C due to the formation of crystalline phases.

Synthesis and Application of Zn‑BTC/GO Nanocomposites as Highly Efficient Photocatalysts in the Dye Degradation

2021 ◽  
Vol 11 (1) ◽  
pp. 67-73
Author(s):  
Manh Nguyen Ba ◽  
Trang Pham Thi Thu ◽  
Hoa Tran Thi ◽  
Giang Le Ha
Keyword(s):  
Removal Efficiency ◽  
Dye Degradation ◽  
High Surface ◽  
High Surface Area ◽  
Reactive Dye ◽  
High Photocatalytic Activity ◽  
Microwave Method ◽  
Sem Image ◽  
High Initial Concentration ◽  
Reactive Red 195

Nanocomposite Zn-BTC/GO (BTC: benzene-1,3,5-tricarboxylic, GO: graphene oxide) was successfully synthesized by hydrothermal treatment with a microwave method. Samples were characterized by XRD, FTIR, EDS-mapping, BET, SEM, UV-vis DRS and XPS. SEM-image result showed nano Zn-BTC/GO particles size of 50-80 nm. Nanocomposite Zn-BTC/GO showed the a high surface area (1303 m2/g) and pore volume (1.08 cm3/g). The Zn-BTC/GO nanocomposite were tested for the photocatalytic degradation of reactive dye (Reactive Red 195) in an aqueous solution. The Zn-BTC/GO composites exhibited high photocatalytic activity. Thus, at the pH of 6.5 and the high initial concentration of 30 mg RR-195/L, removal efficiency reached the value of 96.16% after 60 min reaction. Moreover, nano Zn-BTC also showed high RR-195 removal efficiency after 3 catalytic regeneration. This contributes to sustainable development and green chemistry.

scholarly journals No detectable aerobic methane efflux from plant material, nor from adsorption/desorption processes

2008 ◽  
Vol 5 (6) ◽  
pp. 1551-1558 ◽  
Author(s):  
M. U. F. Kirschbaum ◽  
A. Walcroft
Keyword(s):  
Zea Mays ◽  
High Surface ◽  
High Surface Area ◽  
Atmospheric Methane ◽  
Plant Materials ◽  
Methane Fluxes ◽  
Detached Leaves ◽  
Filter Papers ◽  
Adsorption Desorption ◽  
Methane Efflux

Abstract. In early 2006, Keppler et al. (Nature, 439:187–191) reported a novel finding that plant leaves, and even simple organic materials, can release methane under aerobic conditions. We investigated here whether the reported methane release might simply arise from methane desorption from sample surfaces after prior exposure to higher methane concentrations. We exposed standard cellulose filter papers (i.e. organic material with a high surface area) to atmospheric methane concentration and then transferred them to a low-methane atmosphere. Our results suggest that any desorption flux was extremely small (−0.0001±0.0019 ngCH4 kgDW−1 s−1) and would play no quantitatively significant role in modifying any measured methane fluxes. We also incubated fresh detached leaves of several species and intact Zea mays seedlings under aerobic and low-light conditions. After correcting for a small measured methane influx into empty chambers, measured rates of methane emission by plant materials were zero or, at most, very small, ranging from −0.25±1.1 ngCH4 kgDW−1 s−1 for Zea mays seedlings to 0.10±0.08 ngCH4 kgDW−1 s−1 for a mixture of freshly detached grasses. These rates were much smaller than the rates originally reported by Keppler et al. (2006).

Pb(Zr0.52Ti0.48)O3 Ceramics Synthesized Using Planetary Ball Mill

2012 ◽  
Vol 620 ◽  
pp. 486-490
Author(s):  
Shafiza Afzan Sharif ◽  
Julie Juliewatty Mohamed ◽  
W.A.W. Yusoff
Keyword(s):  
Lead Zirconate Titanate ◽  
Ball Mill ◽  
Single Phase ◽  
Perovskite Phase ◽  
Xrd Analysis ◽  
Lead Zirconate ◽  
Planetary Ball Mill ◽  
X Ray Diffraction ◽  
Sem Images ◽  
Pzt Ceramics

Lead zirconate titanate Pb (Zr0.52Ti0.48)O3, (PZT) ceramic was successfully prepared from the mixture of commercial PbO, TiO2and ZrO2powders using planetary ball mill at room temperature. The phase formation and microstructure of the milled powders were characterized using X-ray diffraction (XRD) and Scanning Electron Microscope (SEM). XRD results indicated that the perovskite phase of PZT was formed from the mixture of starting materials after milling for 40 h. The grain sizes of the powders have been estimated from the SEM images to be ~200 nm. The compacted PZT samples were then sintered at 950 °C for 1 h. The samples were characterized by XRD and SEM, meanwhile the density was measured by Archimedes principle. XRD analysis on the sintered samples revealed the formation of single phase Pb (Zr0.52Ti0.48)O3ceramics while the SEM images estimated the grain size to be ~2 µm. The relative density of the obtained sintered PZT ceramics was measured to be approximately 99.93 % of the theoretical density. The results hence indicate that planetary ball mill is an effective preparatory technique to improve the sinterability of PZT ceramics.

Sol-Gel Precursors and the Oxygen Storage Capacity of PrOy-ZrO2 Materials

1997 ◽  
Vol 497 ◽  
Author(s):  
C. K. Narula ◽  
K. L. Taylor ◽  
L. P. Haack ◽  
L. F. Allard ◽  
A. Datye ◽  
...  
Keyword(s):  
Single Phase ◽  
High Surface ◽  
Sol Gel ◽  
High Surface Area ◽  
Fluorite Structure ◽  
Oxygen Storage Capacity ◽  
Oxygen Storage ◽  
Molar Ratio ◽  
Metal Nitrates ◽  
Temperature Programmed

ABSTRACTThe gels derived from mixtures of Pr(OiC3H7)3 and Zr(OiC3H7)4•iC3H7OH, upon hydrolysis and pyrolysis, furnish single-phase PrOy-ZrO2 materials crystallized in the fluorite structure. These materials can be coated onto high-surface-area γ-alumina powders or deposited onto dense α-alumina coupons in the form of thin films from a solution of parent alkoxides modified with 2,4-pentanedione in THF. The fluorite structure of the PrOy-ZrO2 in the films appears to be thermally stable in air up to 1200°C. Temperature-programmed-reduction (TPR) measurements show that the bulk PrOy-ZrO2 material with a Pr. Zr molar ratio of 1:1 can store and release oxygen while that with a molar ratio of 1:3 cannot.The precursors play an important role in determining phase composition of the resulting PrOy-ZrO2 material. A mixture of monoclinic and cubic or tetragonal phases was found in PrOy-ZrO2 prepared from a new single-source heterometallic alkoxide, Pr2Zr6(μ4-O)2(μ-OAc)6(μ-OiPr)10(OiPr)10, whereas a mixture of cubic and tetragonal phases was present in PrOy-ZrO2 made previously by coprecipitation from aqueous solutions of the metal nitrates.

Cr Doped TiO2 Supported on TUD-1 Photocatalyst for Dye Photodegradation

2014 ◽  
Vol 69 (5) ◽  
Author(s):  
Ooi Yee Khai ◽  
Leny Yuliati ◽  
Siew Ling Lee
Keyword(s):  
Photocatalytic Activity ◽  
Visible Light ◽  
High Surface ◽  
Sol Gel ◽  
High Surface Area ◽  
Xrd Analysis ◽  
Bandgap Energy ◽  
Doped Tio2 ◽  
Visible Light Driven ◽  
Synthesized Materials

New visible light driven photocatalysts of 1 mol% Cr doped TiO2 supported on TUD-1 have been successfully synthesized. The Cr-TiO2/xTUD-1 (x = 10, 20, 30, 40 and 50) photocatalysts were prepared via surfactant-free sol-gel method followed by wet impregnation procedures. XRD analysis revealed that both TiO2 and Cr were incorporated in the highly porous siliceous matrix. FTIR analysis showed the existence of Si-O-Ti in all the materials. As observed, tetrahedral-coordinated Ti species were dominant in Cr-TiO2/10TUD-1, Cr-TiO2/20TUD-1 and Cr-TiO2/30TUD-1. Meanwhile, octahedral- coordinated Ti species were the dominant species in Cr-TiO2/40TUD-1 and Cr-TiO2/50TUD-1. It has been demonstrated that the amount of TUD-1 as photocatalyst support affected the wavelength response and the bandgap energy of the resulting materials. All the materials have bandgap energy of ~2.9 eV. The photocatalytic performance of the synthesized materials was tested out in dye photodegradation under visible light irradiation at 298 K for 5 hours. Results showed that all Cr-TiO2/TUD-1 materials had higher photocatalytic activity than that of Cr-TiO2. This could be explained by the high surface area and porosity provided by TUD-1 in enhancing the adsorption and diffusivities of the dye molecules, hence leading to the promising photocatalytic activity. Among the materials prepared, Cr-TiO2/30TUD-1 appeared as the most superior photocatalyst which gave the highest dye photodegradation.

scholarly journals Amorphous Mo5O14-Type/Carbon Nanocomposite with Enhanced Electrochemical Capability for Lithium-Ion Batteries

Nanomaterials ◽  
2019 ◽  
Vol 10 (1) ◽  
pp. 8 ◽  
Author(s):  
Ahmed M. Hashem ◽  
Ashraf E. Abdel-Ghany ◽  
Rasha S. El-Tawil ◽  
Sylvio Indris ◽  
Helmut Ehrenberg ◽  
...  
Keyword(s):  
Oxygen Deficiency ◽  
High Surface ◽  
High Surface Area ◽  
Lithium Ion ◽  
Carbon Matrix ◽  
X Ray Diffraction ◽  
Sem Images ◽  
Thermal Gravimetry ◽  
Type C ◽  
Carbon Nanocomposite

An amorphous MomO3m−1/carbon nanocomposite (m ≈ 5) is fabricated from a citrate–gel precursor heated at moderate temperature (500 °C) in inert (argon) atmosphere. The as-prepared Mo5O14-type/C material is compared to α-MoO3 synthesized from the same precursor in air. The morphology and microstructure of the as-prepared samples are characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), and Raman scattering (RS) spectroscopy. Thermal gravimetry and elemental analysis indicate the presence of 25.8 ± 0.2% of carbon in the composite. The SEM images show that Mo5O14 is immersed inside a honeycomb-like carbon matrix providing high surface area. The RS spectrum of Mo5O14/C demonstrates an oxygen deficiency in the molybdenum oxide and the presence of a partially graphitized carbon. Outstanding improvement in electrochemical performance is obtained for the Mo5O14 encapsulated by carbon in comparison with the carbon-free MoO3.

Efficient Removal of Cd2+ by the Mesoporous Silica Functionalized by APTES

2013 ◽  
Vol 726-731 ◽  
pp. 2409-2412
Author(s):  
Xiao Feng Cai ◽  
Kang Wei Ji ◽  
Wan Hao Wu ◽  
Jie Hou ◽  
Shi You Hao
Keyword(s):  
Aqueous Solution ◽  
Mesoporous Silica ◽  
Ph Value ◽  
High Surface ◽  
High Surface Area ◽  
Efficient Removal ◽  
Structure Directing Agent ◽  
Functionalized Mesoporous Silica ◽  
Adsorption Desorption ◽  
Large Pore Size

Amino-functionalized mesoporous silica (AFMS) with high amino loading, high surface area, and large pore size was synthesized using the anionic surfactant N-lauroylsarcosine sodium (Sar-Na) as template and 3-aminopropyltriethoxysilane (APTES) as co-structure directing agent (CSDA). The synthesized AFMS was characterized by N2adsorption-desorption, TEM and elemental analyzer. The results of the removal of Cd2+from aqueous solution showed that the pH value of aqueous solution affected the removal efficiency of Cd2+greatly, and that unary adsorption isotherm of Cd2+on the AFMS was well described by the Sips isotherm model, in which the adsorption capacity was 2.43 mmol/g for Cd2+, much higher than the literature data.

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