scholarly journals Akaganeite nanorices deposited muscovite mica surfaces as sunlight active green photocatalyst

2019 ◽  
Vol 6 (3) ◽  
pp. 182212 ◽  
Author(s):  
Anoja Senthilnathan ◽  
D. M. S. N. Dissanayake ◽  
G. T. D. Chandrakumara ◽  
M. M. M. G. P. G. Mantilaka ◽  
R. M. G. Rajapakse ◽  
...  
Keyword(s):  
Self Assembly ◽  
Uv Light ◽  
Average Particle ◽  
Efficient Treatment ◽  
X Ray ◽  
Force Microscopy ◽  
Highly Active ◽  
Muscovite Mica ◽  
Assembly Technique ◽  
Particle Length

Thin films of akaganeite [FeO(OH)] nanorices deposited muscovite mica (ANPM) surfaces are synthesized using the facile urea assisted controlled self-assembly technique. The synthesized materials are characterized using scanning electron microscopy (SEM) with energy-dispersive X-ray spectroscopy, atomic force microscopy, X-ray diffraction (XRD), Fourier transform infrared (FT-IR) spectroscopy and thermogravimetric analysis (TGA). The prepared nanorices on mica surfaces show average particle length and width of 200 and 50 nm, respectively. Synthesized material acts as an efficient photocatalyst under UV and sunlight conditions as demonstrated by the degradation of standard methylene blue (MB) solution. The MB degradation efficiencies of the catalyst under exposure to 180 min sunlight and UV are 89% and 87.5%, respectively, which shows that the catalyst is more highly active under sunlight than under UV light. Therefore, the synthesized material is a potential green photocatalyst in efficient treatment of industrial dye effluents under direct sunlight.

Observations of TiO2 Surfaces Using Totally Reflected X-ray In-plane Diffraction Under UV Irradiation

2002 ◽  
Vol 751 ◽  
Author(s):  
T. Horiuchi ◽  
H. Ochi ◽  
K. Kaisei ◽  
K. Ishida ◽  
K. Matsushige
Keyword(s):  
Uv Irradiation ◽  
Uv Light ◽  
Plane Surface ◽  
Signal To Noise Ratio ◽  
High Surface ◽  
Ultra Violet ◽  
High Signal ◽  
X Ray ◽  
Force Microscopy ◽  
Catalytic Activities

ABSTRACTSurface lattice displacements of titanium dioxide (TiO2: rutile) during ultra-violet (UV) light irradiation have been investigated using a total reflection x-ray diffraction, which provides a high signal to noise ratio (S/N) and superior in-plane surface diffraction. Under the environments in vapors of H2O, CH3OH, C2H5OH and C3H6OH, the photo-catalytic activities of TiO2 (110), (100) and (001) surfaces subject to UV irradiation have been measured. It is found that the diffraction peaks and their full width half maxima (FWHMs) show some peculiarities with respect to the photo-catalytic activities in both surface lattices and adsorbed molecules in vapors. Furthermore, Kelvin force microscopy (KFM) has showed that there exists a very high surface potential, probably due to surface atom displacements induced by UV irradiation. With regard to the origin of the photo-catalytic activities, the induced surface potentials are discussed.

scholarly journals Self-assembly of a terbium(III) 1D coordination polymer on mica

2019 ◽  
Vol 10 ◽  
pp. 2440-2448 ◽  
Author(s):  
Quentin Evrard ◽  
Giuseppe Cucinotta ◽  
Felix Houard ◽  
Guillaume Calvez ◽  
Yan Suffren ◽  
...  
Keyword(s):  
Self Assembly ◽  
Water Adsorption ◽  
Bulk Material ◽  
Molecular Organization ◽  
Suitable Candidate ◽  
Force Microscopy ◽  
Atomic Force ◽  
1D Coordination Polymer ◽  
Muscovite Mica ◽  
Intermediate Value

The terbium(III) ion is a particularly suitable candidate for the creation of surface-based magnetic and luminescent devices. In the present work, we report the epitaxial growth of needle-like objects composed of [Tb(hfac)3·2H2O] n (where hfac = hexafluoroacetylacetonate) polymeric units on muscovite mica, which is observed by atomic force microscopy. The needle-like shape mimics the structure observed in the crystalline bulk material. The growth of this molecular organization is assisted by water adsorption on the freshly air-cleaved muscovite mica. This deposition technique allows for the observation of a significant amount of nanochains grown along three preferential directions 60° apart from another. The magnetic properties and the luminescence of the nanochains can be detected without the need of surface-dedicated instrumentation. The intermediate value of the observed luminescence lifetime of the deposits (132 µs) compared to that of the bulk (375 µs) and the CHCl3 solution (13 µs) further reinforces the idea of water-induced growth.

scholarly journals Fabrication and Characterization of Antibacterial-active Multilayer Films Based on Keggin Polyoxometalates and Methylene Blue

2010 ◽  
Vol 65 (2) ◽  
pp. 140-146 ◽  
Author(s):  
Dan Chen ◽  
Jun Peng ◽  
Haijun Pang ◽  
Pengpeng Zhang ◽  
Yuan Chen ◽  
...  
Keyword(s):  
Methylene Blue ◽  
Self Assembly ◽  
Multilayer Films ◽  
Photoelectron Spectra ◽  
Layer By Layer ◽  
Force Microscopy ◽  
Atomic Force ◽  
Assembly Technique ◽  
Lbl Films ◽  
Cv Measurements

Two kinds of multilayer films based on Keggin polyoxometalates α-[SiW12O40]4−/α- [PMo12O40]3− and methylene blue have been prepared via the layer-by-layer (LBL) self-assembly technique. The multilayer films were characterized by UV/Vis spectra, atomic force microscopy (AFM) and X-ray photoelectron spectra (XPS). The cyclic voltammetry (CV) measurements have demonstrated that the electrochemical properties of POMs are maintained in the LBL films. The antibacterial activity of the LBL films has also been investigated, which shows a distinct antibacterial effect against Escherichia coli.

Orientation of Ferroelectric Liquid Crystals by Self-Assembled Bilayer Molecular Assembly

2001 ◽  
Vol 709 ◽  
Author(s):  
Sukhmal C. Jain ◽  
Vivechana Dixit ◽  
Vinod K. Tanwar ◽  
S. M. Shivaprasad
Keyword(s):  
Liquid Crystal ◽  
Indium Tin Oxide ◽  
Photoelectron Spectroscopy ◽  
Self Assembly ◽  
Uv Light ◽  
Uv Spectroscopy ◽  
Large Change ◽  
Molecular Assembly ◽  
Ferroelectric Liquid Crystal ◽  
Assembly Technique

ABSTRACTMolecular films of amino propyl triethoxy silane (APTES) attached with cinnamoyl moieties were deposited on indium tin oxide (ITO) coated glass and quartz substrates by self-assembly technique. The deposition of the monolayer films resulted in a large change in the wettability of the substrates. X-ray photoelectron spectroscopy (XPS) and UV-spectroscopy were used to study the structure and properties of the grown films. The molecular assembly was photodimerized by irradiating it with a linearly polarized UV-light. Thus created polymer-solid interface has been shown to produce good, stable planar orientation of ferroelectric liquid crystal mixtures. The electro-optical and switching properties of the ferroelectric liquid crystal cells have been investigated and found to be quite similar to those prepared in conventional manner.

Fabrication and Properties of Self-Assembled Nanosized Magnetic Particles

2001 ◽  
Vol 707 ◽  
Author(s):  
G. Salazar-Alvarez ◽  
M. Mikhailova ◽  
M. Toprak ◽  
Y. Zhang ◽  
M. Muhammed
Keyword(s):  
Self Assembly ◽  
Magnetic Particles ◽  
Average Particle Size ◽  
The Self ◽  
Average Particle ◽  
Shell Nanoparticles ◽  
Force Microscopy ◽  
Transmission Electron ◽  
Self Assembled ◽  
Core Shell Nanoparticles

ABSTRACTThe synthesis and characterisation of gold-coated cobalt nanoparticles, as well as their chemically- and magnetically-induced self-organisation have been studied. Metallic core-shell nanoparticles were prepared using two different experimental techniques: bulk reductive precipitation, with average particles size ∼15 nm, and microemulsion confining method, with average particle size of ∼6 nm. The self-assembly of prepared nanoparticles on flat substrates was achieved by derivatising the substrate and particle surfaces with bifunctional organic molecules that attaches to both particles and substrates. Examination of the self-assembled systems was carried out by a number of characterisation techniques including transmission electron microscopy (TEM), UV-visible spectrophotometry (UV-VIS), and atomic force microscopy (AFM).

Ni-Doped ZnO Thin Films: Deposition, Characterization and Photocatalytic Applications

2021 ◽  
Vol 21 (3) ◽  
pp. 1560-1569
Author(s):  
K. Moorthy ◽  
S. S. R. Inbanathan ◽  
C. Gopinathan ◽  
N. P. Lalla ◽  
Abdulaziz Ali Alghamdi ◽  
...  
Keyword(s):  
Thin Films ◽  
Uv Light ◽  
Characteristic Root ◽  
Film Surface ◽  
Hexagonal Wurtzite Structure ◽  
Zno Thin Films ◽  
X Ray ◽  
Force Microscopy ◽  
Atomic Force ◽  
Doped Zno

Root like structured Ni-doped zinc oxide [Zn(1-x)NixO (x = 0.09)] thin films were deposited on a non-conducting glass substrate by indigenously developed spray pyrolysis system at optimized substrate hotness of 573±5 K. Thus obtained Ni-doped ZnO thin films were characterized by UV-visible spectroscopy, X-ray diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), Atomic Force Microscopy (AFM). XRD result revealed that Ni-doped ZnO has a polycrystalline nature with a hexagonal wurtzite structure. For pure ZnO and Ni-doped ZnO thin films, the particle sizes were 60.9 and 53.3 nm while lattice strain values were 1.56×10−3 and 1.14×10−3, respectively. The film surface showed characteristic root-like structure as observed by the SEM. It was observed that the Ni-doped ZnO thin films were grown in high density along with more extent of branching as compared to pure ZnO thin films but retained the root-like morphologies, however, the branches were more-thinner and of shorter lengths. AFM analysis showed that the surface grains of the Ni-doped samples are homogeneous with less RMS roughness values compared with the undoped ZnO samples. The photocatalytic activity of the prepared thin films was evaluated by the degradation of methyl orange (MO) dye under UV light irradiation. Pure ZnO and Ni-doped ZnO thin films took 150 min and 100 min to degrade about 60% MO dye, respectively.

Morphological, Structural and Optical Characteristics of Porous GaN Fabricated by UV-Assisted Electrochemical Etching

2020 ◽  
Vol 301 ◽  
pp. 3-11
Author(s):  
Nurul Syuhadah Mohd Razali ◽  
Alhan Farhanah Abd Rahim ◽  
Rosfariza Radzali ◽  
Ainorkhilah Mahmood ◽  
Muhammad Faiz Bahrol Anuar
Keyword(s):  
Pore Structure ◽  
Current Density ◽  
Uv Light ◽  
Electrochemical Etching ◽  
Structural Characteristics ◽  
Peak Shift ◽  
High Porosity ◽  
Etching Technique ◽  
X Ray ◽  
Force Microscopy

The fabrication of porous GaN (PGaN) by UV-assisted electrochemical etching with a variations of current densities (40, 60, and 80 mA/cm2) for 60 min in electrolytes consisting of 4% KOH are reported. Field Emission Scanning Electron Microscopy (FESEM), Energy Dispersive X-Ray (EDX), Atomic Force Microscopy (AFM) and X-ray Diffraction (XRD) were used to characterize the morphological and structural characteristics of the PGaN. All PGaN sample prepared by electrochemical etching technique produced a hexagonal-like pore shape. FESEM images demonstrated that the pore uniformity and porosity are affected significantly by the current density. The PGaN sample fabricated with 80 mA/cm2 produces a uniform and high porosity structure compared to other PGaN sample. This shows that the morphology and structural characteristic of PGaN are increase with the increase of current density. The EDX result revealed significant Ga and N atom presence in all samples. However, the O atom only presence in sample etched with 80 mA/cm2 implying that the etching process is occur vigorously in this sample. The AFM verified that the surface roughness and the pore depth are increased as current density increased. There were relatively large variations of the peak intensities for 2Theta-scan patterns as exposed by XRD. The peak shift for PGaN sample relative to as-grown was inconsistent and the changed was relatively small. Raman intensity found to be enhanced with the increase in current density and among the PGaN sample, the E2(high) peak for sample prepared with 60mA/cm2 and 80mA/cm2 was observed to be slightly shifted to lower frequency. The PL spectra displayed that the porosity has high impact on the PL peak intensity. . Overall, this proved that with the usage of low power UV light, the pore structure still can be produced as good as pore structure fabricated with high power UV light.

Preparation of Poly(diallydimethyl ammonium chloride) (PDDA)/Au Nanocomposite Film by In Situ Electrochemical Reduction and its Electrocatalytic Properties

2010 ◽  
Vol 123-125 ◽  
pp. 189-192
Author(s):  
Hong Wei Shi ◽  
Li Zhang ◽  
Cong Wang ◽  
Ke Ying Zhang
Keyword(s):  
Electrochemical Reduction ◽  
Ammonium Chloride ◽  
Photoelectron Spectroscopy ◽  
Self Assembly ◽  
Composite Films ◽  
Nanocomposite Films ◽  
Layer By Layer ◽  
X Ray ◽  
Assembly Technique

Nanocomposite films containing Au nanoparticles were fabricated by alternating adsorption of poly(diallydimethyl ammonium chloride) (PDDA) and HAuCl4 using layer-by-layer self-assembly technique and subsequent in situ electrochemical reduction of the AuCl4- ions. The composition and properties of the composite films were characterized by ultraviolet-visible spectroscopy (UV-vis), X-ray photoelectron spectroscopy (XPS), and cyclic voltammetry (CV).The UV-vis characteristic absorbances of PDDA and Au increase almost linearly with the number of bilayers, which suggests a progressive deposition with almost an equal amount of the PDDA and Au in each cycle. X-ray photoelectron spectroscopy further confirms the presence of the main components (such as PDDA and Au) of the nanocomposite films. Furthermore, the nanocomposite films also exhibit good electrocatalytic activity for the oxidation of ascorbic acid (AA), which may be used in electrochemical biosensors.

Photocatalytic Activity of Pd Doped Tin Dioxide Inverse Opal Films

2012 ◽  
Vol 534 ◽  
pp. 135-140 ◽  
Author(s):  
Yang Liu ◽  
Bo Li ◽  
You Wei Yao ◽  
Jing Jing Gao ◽  
Zhen Dong Liu ◽  
...  
Keyword(s):  
Methylene Blue ◽  
Photocatalytic Activity ◽  
Self Assembly ◽  
Tin Dioxide ◽  
Uv Light ◽  
Sol Gel ◽  
The Self ◽  
Inverse Opal ◽  
Polystyrene Microsphere ◽  
Assembly Technique

Inverse opal films (IOFs) of SnO2 doped with Pd were prepared by the self-assembly technique using polystyrene microsphere (PS sphere) as template in combination with a sol-gel method. The photocatalysis properties of SnO2 IOFs were estimated through measuring the rate of the degradation of methylene blue (MB). The result shows that SnO2 IOFs have good photocatalytic activity, the solution of MB was degradated over 60% in 4 hours when it was dipped in SnO2 IOFs and exposed in the UV light. The addition of Pd in SnO2 IOFs improved the photocatalytic activity of the films and the degradation of MB can exceed 80% with the same condition. This sort of SnO2 IOFs doped with Pd indicated a potential application in photocatalysis field.

scholarly journals Fabrication and Characterization of Gas Sensor from ZrO2: MgO Nanostructure Thin Films by R.F. Magnetron Sputtering Technique

2019 ◽  
Vol 16 (1) ◽  
pp. 0199
Author(s):  
Khalil Et al.
Keyword(s):  
Thin Films ◽  
Gas Sensor ◽  
Spectral Response ◽  
Average Particle Size ◽  
Average Particle ◽  
X Ray ◽  
Sensing Properties ◽  
Force Microscopy ◽  
Plasma Sputtering ◽  
Atomic Force

Thin films ZrO2: MgO nanostructure have been synthesized by a radio frequency magnetron plasma sputtering technique at different ratios of MgO (0,6, 8 and  10)% percentage to be used as the gas sensor for nitrogen dioxide NO2. The samples were investigated by X-ray diffraction (XRD), atomic force microscopy (AFM), scanning electron microscopy (SEM), energy-dispersive X-ray (EDX) and sensing properties were also investigated. The average particle size of all prepared samples was found lower than 33.22nm and the structure was a monoclinic phase. The distribution of grain size was found lower than36.3 nm and uninformed particles on the surface. Finally, the data of sensing properties have been discussed, where they indicated that sensitivity reached 42.566% at 300 oC, spectral response time less than 52.2 s and recovery time 135.9 s.

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