EFFECT OF pH ON ZnS NANOCRYSTALLINE THIN FILM EMBEDDED IN A POLYVINYL ALCOHOL MATRIX

2010 ◽  
Vol 24 (29) ◽  
pp. 5663-5673 ◽  
Author(s):  
J. P. BORAH ◽  
J. BARMAN ◽  
K. C. SARMA
Keyword(s):  
Electron Microscopy ◽  
Polyvinyl Alcohol ◽  
Ph Value ◽  
X Ray Diffraction ◽  
X Ray ◽  
Ph Values ◽  
Nanocrystalline Thin Film ◽  
Transmission Electron ◽  
Uv Visible ◽  
Compositional Characterization

Polyvinyl alcohol (PVA) has been used as a matrix to synthesize ZnS / PVA nanocomposite film on glass substrate by chemical method. Transmission electron microscopy (TEM), X-ray diffraction (XRD), Scanning electron microscopy (SEM) has been used for structural, morphological and compositional characterization. Optical properties have been studied by UV-Visible spectrophotometry and photoluminescence (PL) spectroscopy. Changing pH value from 4.8 to 0.8 decreases the particle size and correspondingly increases the band gap. The PL emission intensity also increases by decreasing the pH values.

Gelatin as an ecofriendly natural polymer for preparing colloidal silver@gold nanobranches

2016 ◽  
Vol 5 (5) ◽  
Author(s):  
Phuong Phong Nguyen Thi ◽  
Dai Hai Nguyen
Keyword(s):  
Ph Value ◽  
Component Ratio ◽  
X Ray Diffraction ◽  
Ag Nps ◽  
Au Nps ◽  
X Ray ◽  
Transmission Electron ◽  
Uv Visible ◽  
The Stability ◽  
Maximum Absorption Wavelength

AbstractWe report star-shaped silver@gold (Ag@Au) nanoparticles (NPs) in gelatin suspensions for the purpose of enhancing the stability of Ag@Au NPs. In this case, Ag NPs were designed as nucleating agents, whereas gelatin was used as a protecting agent for Au development. Especially, variable gelatin concentrations were also prepared to explore its ability to increase the stability of Ag@Au NPs. The obtained samples were then characterized by UV-visible spectroscopy, transmission electron spectroscopy (TEM), X-ray diffraction, and Fourier transform infrared spectroscopy. The maximum absorption wavelength of all samples (566–580 nm) indicated that branched Ag@Au@gelatin NPs were successfully synthesized. In addition, our TEM results revealed that the size of branched Ag@Au@gelatin NPs was found to be between 20 and 45 nm as influenced by the component ratio and the pH value. These results can provide valuable insights into the improvement of Ag@Au NP stability in the presence of gelatin.

Synthesis of ZnO Nanorods with Tunable Aspect Ratio

2012 ◽  
Vol 724 ◽  
pp. 205-208
Author(s):  
Li Yan Zhang ◽  
Fen Wang ◽  
Jian Feng Zhu
Keyword(s):  
Electron Microscopy ◽  
Aspect Ratio ◽  
Ph Value ◽  
Zno Nanorods ◽  
Heat Treating ◽  
X Ray Diffraction ◽  
X Ray ◽  
Preferred Direction ◽  
Transmission Electron ◽  
Scanning Electron

ZnO nanorods were prepared by heat treating of aqueous zinc acetate treated with organic of PVA. The products were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM) and transmission electron microscopy (TEM). The results indicate that the as synthesized ZnO are hexagonal wurtzite nanorods with the maximum aspect ratio of 10:1 (100 nm in diameter and about 1 μm in length). The morphology of nanorods was formed by the regulation of appropriate organic under a pH value of 8.5. The growth mechanism of ZnO is proposed that the nanocrystals grow along a preferred direction in a growth tunnel provided by organics.

Mixed-Solvothermal Preparation of Mace-Like CdS Nanocrystals

2012 ◽  
Vol 502 ◽  
pp. 164-168
Author(s):  
Ling Xu ◽  
Han Mei Hu ◽  
Hai Yan Xu
Keyword(s):  
Electron Microscopy ◽  
Large Scale ◽  
Volume Ratio ◽  
X Ray Diffraction ◽  
Visible Absorption ◽  
X Ray ◽  
Transmission Electron ◽  
Cds Nanostructures ◽  
Uv Visible ◽  
Solvothermal Preparation

Novel mace-like (wolf-teeth clubs) CdS nanostructures were successfully prepared on a large scale using CdCl2•2.5H2O and NH2CSNH2 as starting materials through a convenient mixed-solvothermal route. The as-synthesized products were characterized by X-ray diffraction (XRD), energy dispersive X-ray spectrometry (EDX), field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM) and UV-visible absorption spectroscopy. The experimental results reveal that the morphology of CdS products was greatly affected by the volume ratio of anhydrous ethanol and distilled water. The possible mechanism for the formation of mace-like CdS nanostructures is simply discussed.

A Facile Method for the Synthesis of Silver Nanoparticles in the Presence of Sodium Phosphate

2011 ◽  
Vol 109 ◽  
pp. 174-177 ◽  
Author(s):  
Yu Li Shi ◽  
Qi Zhou ◽  
Li Yun Lv ◽  
Wang Hong
Keyword(s):  
Electron Microscopy ◽  
Silver Nanoparticles ◽  
Sodium Phosphate ◽  
X Ray Diffraction ◽  
Visible Spectroscopy ◽  
X Ray ◽  
Stabilizing Agents ◽  
Transmission Electron ◽  
Silver Nps ◽  
Uv Visible

A facile method for the synthesis of silver nanoparticles (NPs) has been developed by using sodium phosphate (Na3PO4) as stabilizing agents and glucose the reducing agent, respectively. The obtained silver NPs have been characterized by X-ray diffraction (XRD), UV-visible spectroscopy (UV-vis) and transmission electron microscopy (TEM). It was found that in the presence of sodium phosphate, silver NPs with different morphologies and sizes were obtained. The formation mechanism of diverse silver NPs was studied preliminarily.

Optical and Structural Properties of PVP/Bi2S3 Nanoparticles by Chemical Method

2013 ◽  
Vol 678 ◽  
pp. 248-252
Author(s):  
K. Kavi Rasu ◽  
Dhandapani Vishnushankar ◽  
V. Veeravazhuthi
Keyword(s):  
Electron Microscopy ◽  
Diffraction Spectrum ◽  
X Ray Diffraction ◽  
Sem Images ◽  
X Ray ◽  
Ir Studies ◽  
Transmission Electron ◽  
Ft Ir ◽  
Crystalline Nature ◽  
Uv Visible

Bismuth sulfide (Bi2S3) and Polyvinyl pyrrolidone (PVP) encapsulated Bi2S3 Nanoparticles are synthesized from aqueous solutions at room temperature. Synthesized samples are subjected to UV-Visible Spectroscopy, X-Ray Diffraction (XRD), Scanning electron microscopy (SEM), Energy Dispersive Analysis of X-ray (EDAX), Transmission Electron Microscopy (TEM) and FT-IR studies and their results are compared. X-ray diffraction spectrum reveals the crystalline nature of the synthesized samples. Grain size value of PVP/ Bi2S3 nanoparticles show a decrease when compared to Bi2S3 nanoparticles and this ensures the good encapsulant effect of PVP on Bi2S3 nanoparticles. SEM images show that all the particles in the synthesized sample are nearly equal in size. From the TEM image we conclude that the particle size lies between 30nm to 70nm. Finally the samples are subjected to EDAX studies for determining their composition.

Preparation of Polyaniline Supported TiO2 Photocatalyst and its Photocatalytic Property

2011 ◽  
Vol 356-360 ◽  
pp. 524-528 ◽  
Author(s):  
Chun Ling Yu ◽  
Rui Xue Wu ◽  
Ying Huan Fu ◽  
Xiao Li Dong ◽  
Hong Chao Ma
Keyword(s):  
Electron Microscopy ◽  
Hydrothermal Process ◽  
Photocatalytic Property ◽  
Visible Spectrum ◽  
X Ray Diffraction ◽  
Visible Spectroscopy ◽  
Anthraquinone Dye ◽  
X Ray ◽  
Transmission Electron ◽  
Uv Visible

A polyaniline supported titanium dioxide photocatalyst was prepared by an impregnation-hydrothermal process and characterized by powder X-ray diffraction, transmission electron microscopy and UV-visible spectroscopy. It was found that the TiO2 nanoparticles were well dispersed on the surface of the polyaniline and the photocatalyst has a stronger absorption compared with that of pure TiO2 over the whole of the visible spectrum. The photocatalyst exhibited higher photocatalytic activity than pure TiO2 for the photodegradation of solutions of the anthraquinone dye, reactive brilliant blue KN-R, under visible light irradiation.

scholarly journals Degradation of Acid Red B by Manganese doped iron oxychloride and Permonosulfate: Performance and Inhomogeneous Activation Mechanism

2021 ◽  
Author(s):  
Rong Chen ◽  
Dan Zhao ◽  
Yanmao Dong ◽  
Chengrun Cai ◽  
Yan Yuan ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Photoelectron Spectroscopy ◽  
Ph Value ◽  
Active Species ◽  
Ion Concentration ◽  
Activation Mechanism ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Initial Ph

Abstract manganese doped iron oxychloride (Mn-FeOCl) was synthesized by partial pyrolysis method. The Mn-FeOCl was used as heterogeneous catalyst to activate permonosulfate (PMS) for the degradation of azo dye acid red B(ARB) for the first time. The Mn-FeOCl was characterized by X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and X-ray diffraction spectroscopy (XRD). The effects of Mn-FeOCl dosage, PMS concentration, initial pH value, Cl ion concentration and humic acid (HA) dosage on the degradation of ARB by Mn-FeOCl/PMS were investigated. Results showed that the ARB was degraded effectively by Mn-FeOCl/PMS. The mineralization rate of ARB reached 42.5%. As the Mn-FeOCl dosage was 0.1g/L, PMS concentration was 1mmol/L, and ARB concentration was 0.05mmol/L, the degradation rate of ARB reached 99.4% in 30 minutes. With the increase of PMS dosage, Mn-FeOCl dosage, Cl− ion concentration and initial pH value, the decolorization effect of ARB increased. The reaction mechanism was analyzed by free radical quenching experiment and XPS. The main active species were determined as ·OH and SO4·− which generated by PMS activation. The SO4·−−was the main active species.

scholarly journals Oxalic Acid-Assisted Hydrothermal Synthesis and Luminescent of Hexagonal NaYF4:Ln3+ (Ln = Sm, Eu, Yb/Er) Micro/Nanoplates

2017 ◽  
Vol 2017 ◽  
pp. 1-10 ◽  
Author(s):  
Feng Tao ◽  
Zhishun Shen ◽  
Zhijun Wang ◽  
Da Shu ◽  
Qi Liu ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Oxalic Acid ◽  
Molar Ratio ◽  
Photoluminescence Properties ◽  
X Ray Diffraction ◽  
X Ray ◽  
Ph Values ◽  
Selected Area Electron Diffraction ◽  
Transmission Electron ◽  
Display Systems

Hexagonal NaYF4:Ln3+ micro/nanoplates were successfully synthesized via a hydrothermal method using oxalic acid as a shape modifier. X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), and selected area electron diffraction (SAED) have been used to study the morphologies and crystal structure of the products. The effects of the pH values and the molar ratio of oxalic acid to NaOH on the crystal growth have been investigated in detail. The time-dependent experiments have been conducted to investigate the morphology evolution process, and based on the results, a possible growth mechanism was proposed. The photoluminescence properties of 5 mol% Eu3+ and 3 mol% Sm3+ doped NaYF4 and 20 mol% Yb3+/2 mol% Er3+ codoped NaYF4 micro/nanoplates were investigated. The experimental results showed that NaYF4:Ln3+ micro/nanoplates have excellent luminescence and can be potential application in the field of light display systems, lasers, and optoelectronic devices.

scholarly journals Hydrothermal Synthesis of Ni/Al Layered Double Hydroxide Nanorods

2011 ◽  
Vol 2011 ◽  
pp. 1-6 ◽  
Author(s):  
Yun Zhao ◽  
Fenfei Xiao ◽  
Qingze Jiao
Keyword(s):  
Electron Microscopy ◽  
Reaction Time ◽  
Layered Double Hydroxide ◽  
Hydrothermal Reaction ◽  
Ph Value ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Double Hydroxide ◽  
Scanning Electron

Ni/Al layered double hydroxide (LDH) nanorods were successfully synthesized by the hydrothermal reaction. The crystal structure of the products was characterized by X-ray diffraction (XRD). The morphology of the products was observed using transmission electron microscopy (TEM) and field emission scanning electron microscopy (SEM). The influences of reaction time and pH value on the morphology of the Ni/Al LDHs were investigated. The result showed that the well-crystallized nanorods of Ni/Al LDHs could be obtained when the pH value was about 10.0 with a long reaction time (12–18 h) at 180°C.

scholarly journals Synthesis and application of pigments based on lanthanide orthoferrites

2020 ◽  
Vol 14 (2) ◽  
pp. 161-167
Author(s):  
Patrícia Pimentel ◽  
Jairo Dutra ◽  
Maria Câmara ◽  
Gerbeson Dantas ◽  
Osmar Bagnato ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Perovskite Phase ◽  
Visible Region ◽  
Ceramic Pigments ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Uv Visible ◽  
Cie Lab

In this work, we synthesized oxides with perovskite LnFeO3 type structure (where Ln = La, Pr and Nd), aiming their use as ceramic pigments. The as-synthesized powders, prepared by gelatin method, were thermally treated at 600 and 800 ?C to obtain the perovskite phase. The characterization was performed using X-ray diffraction technique, followed by Rietveld refinement, scanning and transmission electron microscopy, spectroscopy in the UV-Visible region and CIE Lab colorimetry. The calcined powders were also used for fabrication of ceramic pieces to evaluate the colour when 2 wt.% of the powders was added into a transparent glaze. The pigments presented shades ranging from pale brown for the powdered samples to yellowish when applied in the glazes.

Sign in / Sign up

Export Citation Format

Share Document