Fabrication of mesoporous CdS nanorods by chemical etching

2003 ◽  
Vol 18 (2) ◽  
pp. 396-401 ◽  
Author(s):  
Lin Yang ◽  
Jian Yang ◽  
Zheng-Hua Wang ◽  
Jing-Hui Zeng ◽  
Li Yang ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
Room Temperature ◽  
Exchange Process ◽  
Mesoporous Structure ◽  
Visible Absorption ◽  
One Dimensional ◽  
X Ray ◽  
Ion Exchange Process ◽  
Cds Nanorods ◽  
Transmission Electron

One-dimensional CdS nanocrystallites were used as precursors for preparation of mesoporous CdS nanorods through an ion-exchange process at room temperature. The results from x-ray photoelectron spectroscopy, transmission electron microscopy, energy-dispersive x-ray analysis, and x-ray powder diffraction techniques showed that Ag+ did not affect the electronic structure of CdS or cause the disorder of crystal structure although the product contained a considerable amount of Ag2S. The visible absorption of Ag2S nanoparticles in the mesoporous structure led to the result that the intensities of Raman scattering peaks of the mesoporous nanorods were weaker than those of CdS initial nanorods.

Photoluminescence Enhancement of CdS Nanocrystals Fabricated on Dithiocarbamate Functionalized PET Substrates

2012 ◽  
Vol 512-515 ◽  
pp. 1511-1515
Author(s):  
Chun Lin Zhao ◽  
Li Xing ◽  
Xiao Hong Liang ◽  
Jun Hui Xiang ◽  
Fu Shi Zhang ◽  
...  
Keyword(s):  
Room Temperature ◽  
Hexagonal Structure ◽  
Diffraction Measurement ◽  
X Ray Diffraction ◽  
Visible Absorption ◽  
X Ray ◽  
Cds Nanocrystals ◽  
Morphological Studies ◽  
Transmission Electron

Cadmium sulfide (CdS) nanocrystals (NCs) were self-assembled and in-situ immobilized on the dithiocarbamate (DTCs)-functionalized polyethylene glycol terephthalate (PET) substrates between the organic (carbon disulfide diffused in n-hexane) –aqueous (ethylenediamine and Cd2+ dissolved in water) interface at room temperature. Powder X-ray diffraction measurement revealed the hexagonal structure of CdS nanocrystals. Morphological studies performed by scanning electron microscopy (SEM) and high-resolution transmission electron microscope (HRTEM) showed the island-like structure of CdS nanocrystals on PET substrates, as well as energy-dispersive X-ray spectroscopy (EDS) confirmed the stoichiometries of CdS nanocrystals. The optical properties of DTCs modified CdS nanocrystals were thoroughly investigated by ultraviolet-visible absorption spectroscopy (UV-vis) and fluorescence spectroscopy. The as-prepared DTCs present intrinsic hydrophobicity and strong affinity for CdS nanocrystals.

Low-temperature route to nanoscale P3N5 hollow spheres

2003 ◽  
Vol 18 (10) ◽  
pp. 2359-2363 ◽  
Author(s):  
Hongzhou Gu ◽  
Yunle Gu ◽  
Zhefeng Li ◽  
Yongcheng Ying ◽  
Yitai Qian
Keyword(s):  
Photoelectron Spectroscopy ◽  
Hollow Spheres ◽  
Molar Ratio ◽  
Visible Absorption ◽  
X Ray ◽  
Transmission Electron ◽  
Influence Of Temperature On ◽  
Wide Gap ◽  
20 Nm ◽  
High Degree

Nanoscale hollow spheres of amorphous phosphorus nitride (P3N5) were synthesized by reacting PCl3 with NaN3 at 150–250 °C. Transmission electron microscope images show that the hollow spheres have a diameter of 150–350 nm, and the thickness of the shell is 20 nm. A very small amount of curly films were also found in the sample prepared at 150 °C. The infrared spectrum indicates a high degree of purity. X-ray photoelectron spectroscopy indicates the presence of P and N, with a molar ratio of 1:1.62 for P:N. Ultraviolet-visible absorption spectroscopy shows an absorption band at 265–315 nm. Under photoluminescent excitation at 230 nm, the P3N5 emits ultraviolet light at 305 nm. With a band gap of 4.28 eV, the products may be a wide gap semiconductor. A possible mechanism and the influence of temperature on the formation of the hollow spheres are also discussed.

scholarly journals Characterization and Adsorption Behavior of Strontium from Aqueous Solutions onto Chitosan-Fuller’s Earth Beads

Healthcare ◽  
2019 ◽  
Vol 7 (1) ◽  
pp. 52 ◽  
Author(s):  
Shameem Hasan ◽  
A. Iasir ◽  
Tushar Ghosh ◽  
Bhaskar Sen Gupta ◽  
Mark Prelas
Keyword(s):  
Electron Microscopy ◽  
Ion Exchange ◽  
Photoelectron Spectroscopy ◽  
Exchange Process ◽  
Equilibrium Concentration ◽  
Bet Surface Area ◽  
Ion Exchange Process ◽  
Adsorption Capacities ◽  
Transmission Electron ◽  
Fuller’S Earth

Fuller’s earth spherical beads using chitosan as a binder were prepared for the removal of strontium ions from aqueous solution. The adsorbents were characterized by scanning electron microscopy (SEM) and transmission electron microscopy (TEM), which revealed the porous nature of the beads. The Brunauer–Emmett–Teller (BET) surface area of the beads was found to be 48.5 m2/g. The adsorption capacities of the beads were evaluated under both batch and dynamic conditions. The adsorption capacity was found to be ~29 mg/g of adsorbent at 298 K when the equilibrium concentration of strontium in the solution was 925 mg/L at pH 6.5. The X-ray photoelectron spectroscopy (XPS) data suggest that strontium uptake by the beads occurs mainly through an ion-exchange process. Kinetic data indicate that the sorption of strontium onto the beads follows anomalous diffusion. Thermodynamic data suggest that the ion-exchange of Sr2+ on the bead surface was feasible, spontaneous and endothermic in nature.

Synthesis of Graphene Oxide Grafted with Epoxidized Natural Rubber via Aminosilane Linkage

2018 ◽  
Vol 940 ◽  
pp. 28-34
Author(s):  
Pollawat Charoeythornkhajhornchai ◽  
Anongnat Somwangthanaroj
Keyword(s):  
Graphene Oxide ◽  
Natural Rubber ◽  
Photoelectron Spectroscopy ◽  
Room Temperature ◽  
Interfacial Interaction ◽  
Epoxidized Natural Rubber ◽  
Rubber Matrix ◽  
Mixing Process ◽  
X Ray ◽  
Transmission Electron

Graphene oxide was synthesized from graphite by Hummer method and connected with (3-aminopropyl) triethoxysilane to form graphene oxide-aminosilane (GO-Si) linkage. The solution was centrifuged and washed with acetone to remove unreacted aminosilane before grafting with epoxidized natural rubber (ENR). ENR dissolved in toluene solution was mixed with GO-Si particle and dried at room temperature. Then, it was grafted to form graphene oxide grated with ENR via aminosilane linkage (GO-Si-ENR) by heat treatment. GO-Si-ENR was washed in toluene to remove unconnected ENR molecule. The synthesized GO particle in each step was characterized by Fourier transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS). The possible reaction mechanism was proposed in this research. The aim of this synthesis is to improve natural rubber - graphene interfacial interaction thus the dispersion of GO and GO-Si-ENR particle in natural rubber matrix by solvent mixing process was observed by transmission electron microscopy (TEM).

scholarly journals Bioimmobilization of lead by Bacillus subtilis X3 biomass isolated from lead mine soil under promotion of multiple adsorption mechanisms

2019 ◽  
Vol 6 (2) ◽  
pp. 181701 ◽  
Author(s):  
Weichuan Qiao ◽  
Yunhao Zhang ◽  
Hao Xia ◽  
Yang Luo ◽  
Si Liu ◽  
...  
Keyword(s):  
Bacillus Subtilis ◽  
Photoelectron Spectroscopy ◽  
Extracellular Polymeric Substances ◽  
Exchange Process ◽  
X Ray Diffraction ◽  
X Ray ◽  
Adsorption Mechanisms ◽  
Ion Exchange Process ◽  
Biosorption Process ◽  
Amine Groups

In this study, a lead-resistant bacterium, Bacillus subtilis X3, was used to prepare a lead bioadsorbent for immobilization and removal of lead in lead solution. The lead shot precipitate was analysed by scanning electron microscopy combined with energy dispersive X-ray fluorescence microscopy, Fourier transform infrared spectroscopy, X-ray diffraction and X-ray photoelectron spectroscopy. The adsorbed lead was mainly mineralized to form Pb 5 (PO 4 ) 3 OH, Pb 10 (PO 4 ) 6 (OH) 2 and Pb 5 (PO 4 ) 3 Cl; however, other mechanisms that can also promote the mineralization of lead should not be ignored. For example, Na + and Ca 2+ on the cell wall surface were exchanged with Pb 2+ in solution, which confirmed that the ion-exchange process occurred before mineralization. Moreover, adsorption bridging caused by extracellular polymeric substances also accelerated the further aggregation of lead, and the biomass was encapsulated by lead gradually. Hydroxyl, carbonyl, carboxyl and amine groups were not observed in lead mineral crystals, but the complexation between lead and these groups still benefited the mineralization of lead. The valence of Pb(II) was not changed after mineralization, which indicated that the biosorption process was not a redox reaction. Finally, biosorption occurred on the outer surface of the cell, but its specific surface area was relatively small, limiting the amount and efficiency of biosorption.

scholarly journals Graphene-Ionic Liquid Thin Film Nanolubricant

Nanomaterials ◽  
2020 ◽  
Vol 10 (3) ◽  
pp. 535 ◽  
Author(s):  
María-Dolores Avilés ◽  
Ramón Pamies ◽  
José Sanes ◽  
María-Dolores Bermúdez
Keyword(s):  
Ionic Liquid ◽  
Film Thickness ◽  
Photoelectron Spectroscopy ◽  
Room Temperature ◽  
Surface Damage ◽  
Thin Layers ◽  
Energy Dispersive Analysis ◽  
Lubricant Film Thickness ◽  
X Ray ◽  
Transmission Electron

Graphene (0.5 wt.%) was dispersed in the hydrophobic room-temperature ionic liquid 1-octyl-3-methylimidazolium bis(trifluoromethanesulfonyl) imide (IL) to obtain a new non-Newtonian (IL + G) nanolubricant. Thin layers of IL and (IL + G) lubricants were deposited on stainless steel disks by spin coating. The tribological performance of the new thin layers was compared with those of full fluid lubricants. Friction coefficients for neat IL were independent of lubricant film thickness. In contrast, for (IL + G) the reduction of film thickness not only afforded 40% reduction of the friction coefficient, but also prevented wear and surface damage. Results of surface profilometry, scanning and transmission electron microscopy (SEM and TEM), energy dispersive analysis (EDX), X-ray photoelectron spectroscopy (XPS) and Raman spectroscopy were discussed.

Characterization of Highly Luminescent LaPO4:Eu3+/LaPO4 One-Dimensional Core/Shell Heterostructures

2008 ◽  
Vol 8 (3) ◽  
pp. 1266-1271 ◽  
Author(s):  
Wenbo Bu ◽  
Jianlin Shi
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Photoelectron Spectroscopy ◽  
Core Shell ◽  
Trap States ◽  
Hydrothermal Conditions ◽  
One Dimensional ◽  
X Ray ◽  
Luminescence Efficiency ◽  
Transmission Electron

Highly luminescent LaPO4:Eu3+/LaPO4 one-dimensional (1D) core/shell heterostructures were successfully synthesized by a mild and simple self-aggregation process under refluxing or hydrothermal conditions. The resulting 1D core/shell heterostructures were characterized using a variety of techniques including X-ray diffraction (XRD), transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HRTEM), selected area electron diffraction (SAED), and X-ray photoelectron spectroscopy (XPS) to demonstrate successful coating by the crystalline LaPO4. In addition, a possible formation mechanism for this core/shell heterostructure was proposed. Finally, the photoluminescence property of the LaPO4:Eu3+/LaPO4 1D core/shell heterostructures was investigated in detail, which illustrates that the core/shell heterostructures remarkably increase the luminescence efficiency because the LaPO4 shells effectively eliminate surface trap-states and suppress the energy quenching in the energy-transfer processes.

scholarly journals Synthesis and Characterization of B/NaF and Silicon Phthalocyanine-Modified TiO2 and an Evaluation of Their Photocatalytic Removal of Carbamazepine

Separations ◽  
2020 ◽  
Vol 7 (4) ◽  
pp. 71
Author(s):  
Chukwuka B. Anucha ◽  
IIknur Altin ◽  
Debora Fabbri ◽  
Ismail Degirmencioglu ◽  
Paola Calza ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
Total Pore Volume ◽  
Pure Tio2 ◽  
Complete Disappearance ◽  
Visible Absorption ◽  
X Ray ◽  
Transmission Electron ◽  
Bet Analysis ◽  
Silicon Based ◽  
Adsorption Desorption

This study investigated the synthesis of two different types of photocatalysts, namely, boron/sodium fluoride co-doped titanium dioxide (B/NaF-TiO2), and its analogue, a dye-sensitized form of silicon-based axial methoxy substituted phthalocyanine (B/NaF-TiO2SiPc). Structural and morphological characterizations were performed via X-ray diffraction (XRD); Fourier transform infra-red (FTIR); N2 adsorption–desorption at 77 K by Brunauer–Emmett–Teller (BET) and Barrett, Joyner, and Halenda (BJH) methods; transmission electron microscopy (TEM); X-ray photoelectron spectroscopy (XPS); and UV–visible absorption spectroscopy. The estimated crystallite size of pure TiO2 and pure B/NaF-TiO2 was 24 nm, and that of B/NaF-TiO2SiPc was 29 nm, whereas particle sizes determined by TEM were 25, 28, and 31 nm for pure TiO2, B/NaF-TiO2 and B/NaF-TiO2SiPc respectively. No significant differences between B/NaF-TiO2 and B/NaF-TiO2SiPc were observed for surface area by (BET) analysis (13 m2/g) or total pore volume by the BJH application model (0.05 cm3/g). Energy band gap values obtained for B/NaF-TiO2 and B/NaF-TiO2SiPc were 3.10 and 2.90 eV respectively, lower than pure TiO2 (3.17 eV). The photocatalytic activity of the synthesized materials was tested using carbamazepine (CBZ) as the model substrate. Carbamazepine removal after 4 h of irradiation was almost 100% for B/NaF-TiO2 and 70% for B/NaF-TiO2SiPc; however, the substrate mineralization proceeded slower, suggesting the presence of organic intermediates after the complete disappearance of the pollutant.

scholarly journals Novel Route to Obtain Carbon Self-Doped TiO2 Mesoporous Nanoparticles as Efficient Photocatalysts for Environmental Remediation Processes under Visible Light

Materials ◽  
2019 ◽  
Vol 12 (20) ◽  
pp. 3349 ◽  
Author(s):  
Pablo A. Ochoa Rodríguez ◽  
Tamara B. Benzaquén ◽  
Gina A. Pecchi ◽  
Sandra G. Casuscelli ◽  
Verónica R. Elías ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
Environmental Remediation ◽  
Synthesis Method ◽  
Mesoporous Structure ◽  
Acid Orange 7 ◽  
X Ray Diffraction ◽  
Visible Radiation ◽  
X Ray ◽  
Transmission Electron ◽  
Adsorption Desorption

Titanium dioxide materials were synthesized using two different methods. The samples were characterized by X-ray diffraction (XRD), UV–Visible diffusion reflectance spectroscopy (UV-Vis DR), Raman spectroscopy, N2 adsorption/desorption, scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), transmission electron spectroscopy (TEM) and X-ray photoelectron spectroscopy (XPS). Although both kind of materials were found to have mesoporous structure and anatase crystalline phase, one of them was obtained from a synthesis method that does not involve the use of surfactants, and therefore, does not require calcination at high temperatures. This implies that the synthesized solid was self-doped with carbon species, coming only from the same source used for titanium. Then, the relationship between the presence of these species, the final calcination temperature, and the photocatalytic activity of the solids was studied in terms of the degradation and mineralization of an Acid Orange 7 aqueous solution, under visible radiation. A photosensitizing effect caused by the non-metal presence, that allows the solid to extend its absorption range, was found. Hence, a novel route to prepare C-modified photoactive mesoporous TiO2, simpler and cheaper, where neither a template nor an external carbon source is used, could be performed.

PREPARATION OF Au-LOADED TiO2 BY PHOTOCHEMICAL DEPOSITION AND OZONE PHOTOCATALYTIC DECOMPOSITION

2006 ◽  
Vol 13 (01) ◽  
pp. 51-55 ◽  
Author(s):  
PANKE HE ◽  
MIN ZHANG ◽  
DONGMEI YANG ◽  
JIANJUN YANG
Keyword(s):  
Photoelectron Spectroscopy ◽  
Room Temperature ◽  
Au Nanoparticles ◽  
Diffuse Reflectance Spectroscopy ◽  
Removal Rate ◽  
Photocatalytic Decomposition ◽  
X Ray ◽  
Transmission Electron ◽  
Photocatalytic Removal ◽  
Photochemical Deposition

In this paper, Au -loaded TiO 2( Au/TiO 2) photocatalysts were prepared by photochemical deposition method and characterized by transmission electron microscopy, diffuse reflectance spectroscopy and X-ray photoelectron spectroscopy. The results indicated the metallic Au nanoparticles were deposited on the surface of TiO 2 after the high-pressure mercury irradiation and regarded as an electronegative center. The photocatalytic decomposition of gaseous ozone was investigated on TiO 2 and Au -loaded TiO 2 at room temperature. Results indicated that the photocatalytic conversion of ozone can be improved by Au/TiO 2 and photocatalytic activity increased with the increase of the photodeposition time. The photocatalytic removal rate of ozone remained above 96% on the surface of 1% Au/TiO 2 with photodeposition for 120 min under black lamp irradiation for 20 h. Au cluster deposited on the surface of TiO 2 functioned not only as the electron trap center but also as the adsorption site of O 3 in photocatalytic reaction.

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