scholarly journals Hydrothermal Synthesis, Characterization and Exploration of Photocatalytic Activities of Polyoxometalate: Ni-CoWO4 Nanoparticles

Crystals ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 456
Author(s):  
Fahad A. Alharthi ◽  
Hamdah S. Alanazi ◽  
Amjad Abdullah Alsyahi ◽  
Naushad Ahmad

This study demonstrated the hydrothermal synthesis of bimetallic nickel-cobalt tungstate nanostructures, Ni-CoWO4 (NCW-NPs), and their phase structure, morphology, porosity, and optical properties were examined using X-ray Diffraction (XRD), Fourier-transform infrared spectroscopy (FT-IR), Scanning electron microscopy- energy dispersive X-ray spectroscopy (SEM-EDS), high resolution Transmission electron microscopy (HR-TEM), Brunauer-Emmett-Teller (BET) and Raman instruments. It was found that as-calcined NCW-NPs have a monoclinic phase with crystal size ~50–60 nm and is mesoporous. It possessed smooth, spherical, and cubic shape microstructures with defined fringe distance (~0.342 nm). The photocatalytic degradation of methylene blue (MB) and rose bengal (RB) dye in the presence of NCW-NPs was evaluated, and about 49.85% of MB in 150 min and 92.28% of RB in 90 min degraded under visible light. In addition, based on the scavenger’s study, the mechanism for photocatalytic reactions is proposed.

2017 ◽  
Vol 50 ◽  
pp. 18-31 ◽  
Author(s):  
Rudzani Sigwadi ◽  
Simon Dhlamini ◽  
Touhami Mokrani ◽  
Patrick Nonjola

The paper presents the synthesis and investigation of zirconium oxide (ZrO2) nanoparticles that were synthesised by precipitation method with the effects of the temperatures of reaction on the particles size, morphology, crystallite sizes and stability at high temperature. The reaction temperature effect on the particle size, morphology, crystallite sizes and stabilized a higher temperature (tetragonal and cubic) phases was studied. Thermal decomposition, band structure and functional groups were analyzed by Brunauer-Emmett-Teller (BET), Scanning Electron Microscopy (SEM), Transmission electron microscopy (TEM), X-ray diffraction (XRD), Thermo-gravimetric analysis (TGA) and Fourier transform infrared (FT-IR). The crystal structure was determined using X-ray diffraction. The morphology and the particle size were studied using (SEM) and (TEM). The shaped particles were confirmed through the SEM analysis. The transmission electron microscopic analysis confirmed the formation of the nanoparticles with the particle size. The FT-IR spectra showed the strong presence of ZrO2 nanoparticles.


2021 ◽  
Vol 66 ◽  
pp. 61-71
Author(s):  
Tahereh Heidarzadeh ◽  
Navabeh Nami ◽  
Daryoush Zareyee

The principal aim of this research is using biosynthesized ZnO-CaO nanoparticles (NPs) for preparation of indole derivatives. ZnO-CaO NPs have been prepared using Zn(CH3COO)2 and eggshell waste powder in solvent-free conditions. Morphology and structure of NPs were determined by FT-IR, X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM), and energy dispersive spectra (EDS). It was used as a highly efficient catalyst for the synthesis of indole derivatives. Some indole derivatives were synthesized by the reaction of indole, formaldehyde, aromatic and aliphatic amines in the presence of ZnO-CaO NPs (5 mol%) in ethanol under reflux conditions. The assigned structure was further established by CHN analyses, NMR, and FT-IR spectra. Because of excellent capacity, the exceedingly simple workup and good yield, eco-friendly catalyst ZnO-CaO NPs were proved to be a good catalyst for this reaction.


2013 ◽  
Vol 750-752 ◽  
pp. 217-220
Author(s):  
Li Jin Feng ◽  
Rong Ma ◽  
Xiu Hua Li ◽  
Xu Chun Song

In the present paper, the WO3 nanoparticles were fabricated via a hydrothermal treatment. The products are characterized in detail by multiform techniques: transmission electron microscopy, X-ray diffraction. The results show that products are WO3 nanoparticles with diameter of about 100-150 nm. Electrochemistry properties of the prepared WO3 nanoparticles was characterized by cyclic voltammetry. Cyclic voltammetry results indicate that WO3 nanoparticles exhibits a remarkable electrochemical activity for hydrogen intercalation. The reason for electrochemical activity of WO3 nanoparticles is attributed to the formation of HxWO3 by hydrogen intercalation/de-intercalation into/out of the tungsten oxide.


2018 ◽  
Vol 281 ◽  
pp. 859-864
Author(s):  
Yan Xing ◽  
Meng Fei Zhang ◽  
Tian Jun Li ◽  
Wei Pan

La2NiO4+σ nanofibers exhibiting typical Ruddlesden–Popper structure (K2NiO4) were fabricated by a facile electrospinning method. X-ray diffraction, scanning electron microscopy and transmission electron microscopy were used to analyze the structure, morphology and crystal process of the La2NiO4+σ nanofibers. For electrical properties measurement, uniaxially aligned nanofibers were directly collected and assembled into electrode. In our research, La2NiO4+σ phase forms above 873K with no impurity phase emerges during the thermal treatments. The nanofibers are smooth and uniform throughout the entire length and the grain is growing as calcination temperature increases. Furthmore, the La2NiO4+σ nanofibers own high mixed conductivity at 773K, laying good foundation for intermediate temperature solid oxide fuel cells application.


2010 ◽  
Vol 65 (8) ◽  
pp. 1033-1037 ◽  
Author(s):  
Sridhar Komarneni ◽  
Young Dong Noh ◽  
Joo Young Kim ◽  
Seok Han Kim ◽  
Hiroaki Katsuki

Anatase and Ca, Sr and Ca0.5Sr0.5 hydroxyapatites were synthesized by conventional-hydrothermal (C-H) as well asmicrowave-hydrothermal (M-H)methods.Microwave-assisted reactions led to accelerated syntheses of anatase but no such acceleration of reactions could be detected with the syntheses of hydroxyapatites because the crystallization of the latter materials occurred at very low temperature. Cu and Au metal powders were produced by using glucose, fructose or sucrose as reducing agents under C-H conditions at 160 ℃, where fructose and sucrose were found to be stronger reducing agents than glucose. The crystallinity of all the powders was characterized by powder X-ray diffraction, and morphology and particle sizes were determined by scanning or transmission electron microscopy


2010 ◽  
Vol 663-665 ◽  
pp. 100-103
Author(s):  
Zhen Ni Du ◽  
Yong Cai Zhang ◽  
Zhi You Xu ◽  
Ming Zhang

The synthesis of hexagonal phase Zn1-xMnxS (x = 0–0.05) nanorods was achieved by hydrothermal treatment of zinc manganese diethyldithiocarbamates (Zn1-xMnx-(DDTC)2, x=0–0.05) in 40 mass % hydrate hydrazine aqueous solution at 180 °C for 12 h. The structure, composition and optical property of the obtained products were characterized by X-ray diffraction, energy dispersive X-ray spectroscopy, transmission electron microscopy and UV-vis diffuse reflectance spectra.


2013 ◽  
Vol 32 (2) ◽  
pp. 157-162 ◽  
Author(s):  
Mahdiyeh Esmaeili-Zare ◽  
Masoud Salavati-Niasari ◽  
Davood Ghanbari

AbstractMercury selenide nanostructures were synthesized from the reaction of N, N′-bis(salicylidene)propane-1,3-diamine mercury complex, (Hg(Salpn)) as a novel precursor, via sonochemical method. The effect of different surfactant on the morphology and particle size of the products was investigated. Products were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier transform infrared (FT-IR) spectroscopy and X-ray energy dispersive spectroscopy (EDS).


2016 ◽  
Vol 2016 ◽  
pp. 1-8 ◽  
Author(s):  
Chaturbhuj K. Saurabh ◽  
Asniza Mustapha ◽  
M. Mohd. Masri ◽  
A. F. Owolabi ◽  
M. I. Syakir ◽  
...  

Cellulose nanofibers (CNF) were isolated fromGigantochloa scortechiniibamboo fibers using sulphuric acid hydrolysis. This method was compared with pulping and bleaching process for bamboo fiber. Scanning electron microscopy, transmission electron microscopy, Fourier transform infrared spectroscopy, X-ray diffraction, and thermogravimetric analysis were used to determine the properties of CNF. Structural analysis by FT-IR showed that lignin and hemicelluloses were effectively removed from pulp, bleached fibers, and CNF. It was found that CNF exhibited uniform and smooth morphological structures, with fiber diameter ranges from 5 to 10 nm. The percentage of crystallinity was significantly increased from raw fibers to cellulose nanofibers, microfibrillated, along with significant improvement in thermal stability. Further, obtained CNF were used as reinforcement material in epoxy based nanocomposites where tensile strength, flexural strength, and modulus of nanocomposites improved with the addition of CNF loading concentration ranges from 0 to 0.7%.


2013 ◽  
Vol 678 ◽  
pp. 248-252
Author(s):  
K. Kavi Rasu ◽  
Dhandapani Vishnushankar ◽  
V. Veeravazhuthi

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.


2015 ◽  
Vol 1786 ◽  
pp. 57-63
Author(s):  
Vasuda Bhatia ◽  
Bhawana Singh ◽  
Vinod K. Jain

ABSTRACTNano-graphite oxide has been synthesized from graphite flakes using modified Hummer’s method. Fourier transform infrared (FT-IR) data, x-ray diffraction (XRD) and transmission electron microscopy (TEM) revealed functionalization of the synthesised nano-graphitic platelets with oxygenated bonds. Using thermal embedding technique for the fabrication of self-assembled films, electrodes of nano-graphite oxide have been fabricated for enzyme free detection of cholesterol electrochemically. The electrodes provided a linear response for the enzyme less detection in the range of 50mg/dl to 500mg/dl with a correlation coefficient, R, of 0.99784 and sensitivity of 1.0587 µA/mg.


Sign in / Sign up

Export Citation Format

Share Document