scholarly journals Synthesis and growth of spherical ZnO nanoparticles using different amount of plant extract

2021 ◽  
Vol 24 (12) ◽  
pp. 2147-2151
Author(s):  
Y.A. Dallatu ◽  
G.A. Shallangwa ◽  
S.N. Africa

The use of plant extracts has become an interesting ecofriendly method to synthesize and stabilize the different structures nanoparticles (NPs). This work investigated the effect of plant extract as a reducing and stabilizing agent on the growth and morphology of ZnO nanoparticles (ZnO-NPs). Green synthesis and growth of spherical ZnONPs was carried out by co-precipitation method using a Zinc acetate salt and various amounts of Azadirachta indica seed husk extract (20 ml and 40 ml). The synthesized ZnO-NPs were characterized by Fourier transform infrared (FTIR), scanning electron microscopy (SEM-EDX), and transmission electron microscopy (TEM). The FTIR analyses revealed the presence of Phenolic alcohol, amines and carboxylic acid groups and ZnO in synthesized NPs with more intense peaks at higher amount (40 ml) of A. indica extract. Also, structural morphology analyses using SEM revealed uniform spherical shaped particles with diameter from 25 to 60 nm (20 ml of extract) and 19 to 35 nm (40 ml of extract) for ZnO-NPs. The EDX spectral revealed that the required phase of Zn and O was present 69.54% (Zn) and 30.46% (O) at 20 ml of extract, also 73.71% (Zn), 26.26% (O) at 40 ml of extract respectively and confirmed high purity for the synthesized ZnO NPs. TEM revealed spherical shaped NPs with diameter ranging from 28 to 52 nm (20 ml of extract) and 8.2 to 11.9 nm (40 ml of extract) respectively, with a trend reduction in particle size of NPs at higher amount of A. indica seed extract (40 ml) and growth of more uniform particles with no agglomeration. The study showed successful growth of spherical ZnO-NPs with required properties at a higher amount of extract.

2020 ◽  
Vol 81 (6) ◽  
pp. 1296-1307
Author(s):  
R. Jeyachitra ◽  
S. Kalpana ◽  
T. S. Senthil ◽  
Misook Kang

Abstract Methylene blue (MB) dye is the most common harmful, toxic, and non-biodegradable effluent produced by the textile industries. The present study investigates the effect of zinc oxide (ZnO) nanoparticles (NPs) and Ag–Ni doped ZnO NPs on the performance of photocatalytic degradation of MB dye. Pure ZnO and Ag–Ni doped ZnO NPs are synthesized using the co-precipitation method. The crystalline nature and surface morphology of the synthesized pure ZnO and Ag–Ni doped ZnO NPs was characterized by powder X-ray diffraction, scanning electron microscopy (SEM), and high resolution transmission electron microscopy (HRTEM) analysis. The presence of spherical-like morphologies was confirmed from SEM and HRTEM analysis. The presence of Ni–O and Zn–O bands in the synthesized materials was found by Fourier transform infrared (FTIR) spectroscopy analysis. The MB dye was degraded under UV-light exposure in various pH conditions. The Ag (0.02%)–Ni doped ZnO NPs exhibits highest photocatalytic activity of 77% under pH 4.


2019 ◽  
Vol 17 (1) ◽  
pp. 865-873 ◽  
Author(s):  
Muhammad Ramzan Saeed Ashraf Janjua

AbstractThe nano aggregates of cobalt oxide (Co3O4) are synthesized successfully by adopting simple a co precipitation approach. The product obtained was further subjected to the calcination process that not only changed it morphology but also reduces the size of individual particles of aggregates. The prepared nano aggregates are subjected to different characterization techniques such as electron microscopies (scanning electron microscopy and transmission electron microscopy) and X-ray diffraction and results obtained by these instruments are analyzed by different software. The characterization results show that, although the arrangement of particles is compact, several intrinsic spaces and small holes/ pores can also be seen in any aggregate of the product. The as synthesized product is further tested for catalytic properties in thermal decomposition of ammonium perchlorate and proved to be an efficient catalyst.


2020 ◽  
Vol 10 (1) ◽  
Author(s):  
R. D. Ávila-Avilés ◽  
N. Torres-Gómez ◽  
M. A. Camacho-López ◽  
A. R. Vilchis-Nestor

Abstract Nature provides remarkable examples of mass-produced microscale particles with structures and chemistries optimized by evolution for particular functions. Synthetic chemical tailoring of such sustainable biogenic particles may be used to generate new multifunctional materials. Herein, we report a facile method for the synthesis of hybrid nano/microstructures Ag-Fe3O4 based on Dimorphotheca ecklonis pollen grains as bio-template. Silver nanoparticles was biosynthesized using pollen grains as a reduction and stabilization agent as well as a bio-template promoting the adhesion of silver nanoparticles to pollen surface. Fe3O4 nanoparticles were synthesized by co-precipitation method from FeSO4. Hybrid nano/microstructures Ag-Fe3O4 based on Dimorphotheca ecklonis pollen grains as bio-template were obtained and characterized using Scanning Electron Microscopy and Transmission Electron Microscopy to study the morphology and structure; Energy-Dispersive X-ray Spectroscopy to determine the chemical composition distribution; and Confocal Fluorescence Microscopy to demonstrate the fluorescence properties of hybrid nano-microstructures. Furthermore, these hybrid nano-microstructures have been studied by Surface-Enhanced Raman Scattering (SERS), using methylene blue as a target molecule; the hybrid nano-microstructures have shown 14 times signal amplification.


2020 ◽  
pp. 13-20
Author(s):  
Luma Ahmed ◽  
Eitemad S. Fadhil ◽  
Ayad F. Mohammed

This article describes the synthesis of ZnO nanoparticles (Nps) using the co-precipitation method and then calcinated at 500oC for 2 h. The photo activity of ZnO nanoparticles was examined in photo decolorization of methyl green dye under artificial UV -A light. This prepared photocatalyst (ZnO Np) was modified his surface by 2% Ag doped using the photo deposition method under inert gas for 3h. The characterization of undoped and 2% Ag doped ZnO Nps were estimated by Fourier-transform infrared spectroscopy (FT-IR), X-ray Diffraction (XRD), and Atomic force microscopy (AFM). In FT-IR analysis, the new peaks occurred around 624-778 cm-1 confirmed the Ag really is doped on prepared ZnO Np. Based on data from XRD, the mean crystal size was reduced with doped the 2% Ag. The AFM images for the prepared photocatalysts ensure that the shapes of all samples are semi-spherical with nanometer size. Series of kinetics experiments were performed for the photocatalytic decolourization of methyl green dye using undoped and 2% Ag doped ZnO nanoparticle and found to be pseudo-first-order kinetics.


Materials ◽  
2021 ◽  
Vol 14 (24) ◽  
pp. 7673
Author(s):  
Ziyang You ◽  
Jing Xu

The usage of nanoscale calcium silicate hydrate (nano C-S-H) proved to have an excellent promotion effect on the early performance of concrete as nano C-S-H with ultra-fine particle size can act as seeding for cement hydration. Therefore, it is of importance to tune the particle size during the synthesis process of nano C-S-H. In this paper, the influence of several variables of the particle size distribution (PSD) of nano C-S-H synthesized by chemical co-precipitation method with the aid of polycarboxylate (PCE) was studied by orthogonal experimental design. In addition, the composition, microstructure, and morphology of the C-S-H/PCE nanocomposites were analyzed by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and Raman spectrum. The results showed that the concentration of reactants had a significant impact on the PSD of C-S-H/PCE nanocomposites, followed by the dosage of dispersant. Ultrasonic treatment was effective in breaking the C-S-H/PCE aggregates with unstable agglomeration structures. The change in synthetic variables had a negligible effect on the composition of the C-S-H/PCE nanocomposites but had a significant influence on the crystallinity and morphology of the composites.


2021 ◽  
Author(s):  
Waseem Raza ◽  
Ghulam Nabi ◽  
Asim Shahzad ◽  
Nafisa Malik ◽  
Nadeem Raza

Abstract Lanthanum cerium ferrite nanoparticles has been synthesized for the first time via hydrothermal and co-precipitation method. The structural and morphological study of the nanoparticles have been examined by using X-ray powder diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and energy dispersive x-ray spectroscopy (EDX). The electrochemical study of J1 and J2 electrodes have been examined using three electrode system in 6 M KOH electrolyte using cyclic voltammetry (CV), galvanostatic charging-discharging (GCD) and electrochemical impendence spectroscopy (EIS). The highest specific capacitance of 1195 F/g has been obtained at a scan rate of 10 mV/s from hydrothermal synthesis nanomaterial electrode (J2) and long cycling life 92.3% retention after 2000th cycles. Furthermore, the energy density and power density of the J2 electrode at a current density of 5 A/g was 59 Wh/kg and 9234 W/kg respectively. Hence, the fabricated J2 electrode is a favorable candidate for super-capacitor applications.


2007 ◽  
Vol 280-283 ◽  
pp. 521-524
Author(s):  
Li Qiong An ◽  
Jian Zhang ◽  
Min Liu ◽  
Sheng Wu Wang

Yb3+ and Ho3+ co-doped Lu2O3 nanocrystalline powders were synthesized by a reversestrike co-precipitation method. The as-prepared powders were examined by the X-ray diffraction and transmission electron microscopy. The phase composition of the powders was cubic and the particle size was in the range of 30~50 nm. Emission and excitation spectra of the powders were measured by a spectrofluorometer and the possible upconversion luminescence mechanism was also discussed.


2006 ◽  
Vol 972 ◽  
Author(s):  
Vincenzo Esposito ◽  
Marco Fronzi ◽  
Enrico Traversa

AbstractNanometric 20% molar Sm-doped ceria (SDC20) powders were synthesized by tetrametylethylen ammine (TMDA) co-precipitation method. SDC20 was sintered in several conditions to control the final microstructure. Fast firing and conventional sintering were performed. LiNO3was used as an additive to promote liquid phase sintering of ceria at low temperatures (900-1200°C). Powders and dense pellets were analysed using X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), and transmission electron microscopy (TEM). Electrochemical impedance spectroscopy (EIS) measurements were performed on dense pellets in air to estimate the contribution of grain boundary and bulk to the electrical conductivity. Liquid phase sintering produced the densest samples with the highest conductivity.


2014 ◽  
Vol 879 ◽  
pp. 155-163 ◽  
Author(s):  
Rahizana Mohd Ibrahim ◽  
Markom Masturah ◽  
Huda Abdullah

Nanoparticles of Zn1-xFexS ( x=0.0,0.1,0.2 and 0.3) were prepared by chemical co-precipitation method from homogenous solution of zinc and ferum salt at room temperature with controlled parameter. These nanoparticles were sterically stabilized using Sodium Hexamethaphospate (SHMP). Here, a study of the effect of Fe doping on structure, morphological and optical properties of nanoparticles was undertaken. Elemental analysis, morphological and optical properties have been investigated by Fourier-Transform-Infrared spectroscopy (FT-IR), X-Ray Fluorescence (XRF), Field Emmision Scanning Electron Microscopy (FESEM), X-ray Diffraction (XRD), Transmission Electron Microscopy (TEM) and UV-Visible Spectroscopy. FTIR measurement confirmed the presence of SHMP in the nanoparticles structure with the FESEM images depicting considerable less agglomeration of particles with the presence of SHMP. While XRF results confirm the presence of Fe2+ ion as prepared in the experiment. The particles sizes of the nanoparticles lay in the range of 2-10 nm obtained from the TEM image were in agreement with the XRD results. The absorption edge shifted to lower wavelengths with an increase in Fe concentration shown in the UV-Vis spectroscopy. The band gap energy value was in the range of 4.95 5.15 eV. The blueshift is attributed to the quantum confinement effect.


Materials ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 3084
Author(s):  
Sajjad Mohsin I. Rayyif ◽  
Hamzah Basil Mohammed ◽  
Carmen Curuțiu ◽  
Alexandra Cătălina Bîrcă ◽  
Alexandru Mihai Grumezescu ◽  
...  

Zinc oxide (ZnO) nanoparticles (NPs) have been investigated for various skin therapies in recent years. These NPs can improve the healing and modulate inflammation in the wounds, but the mechanisms involved in such changes are yet to be known. In this study, we have designed a facile ZnO nano-coated dressing with improved antimicrobial efficiency against typical wound pathogens involved in biofilm and chronic infections. ZnO NPs were obtained by hydrothermal method and characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, and Fourier-transform infrared spectroscopy. Antibacterial and antibiofilm effects were evaluated against laboratory and clinical isolates of significant Gram-negative (Pseudomonas aeruginosa and Escherichia coli) and Gram-positive (Staphylococcus aureus and Enterococcus faecalis) opportunistic pathogens, by quantitative methods. Our results have shown that the developed dressings have a high antibacterial efficiency after 6–24 h of contact when containing 0.6 and 0.9% ZnO NPs and this effect is similar against reference and clinical isolates. Moreover, biofilm development is significantly impaired for up to three days of contact, depending on the NPs load and microbial species. These results show that ZnO-coated dressings prevent biofilm development of main wound pathogens and represent efficient candidates for developing bioactive dressings to fight chronic wounds.


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