scholarly journals Aminolytic Depolymerisation of Polyethylene Terephthalate Wastes using Sn doped ZnO Nanoparticles

2021 ◽  
Author(s):  
Viswanathan Vinitha ◽  
Mani Preeyangha ◽  
Murugan Anbarasu ◽  
Gopal Jeya ◽  
Neppolian Bernaurdshaw ◽  
...  
Keyword(s):  
Zno Nanoparticles ◽  
Soft Drink ◽  
Research Work ◽  
Thermal Method ◽  
Chemical Recycling ◽  
Pet Waste ◽  
Global Environmental Issue ◽  
Vis Spectroscopy ◽  
Ft Ir ◽  
Doped Zno

Abstract Poly(ethylene terephthalate) (PET) is one of the most consumed polymers because of its excellent thermal and mechanical properties. By increasing in PET production and since the disposal of PET waste has growing to be a major global environmental issue each year. Chemical recycling is a most successful method to achieve circular economy in the PET utilizing industries. Current research work aims to complete depolymerization of waste PET from soft drink bottles by the aminolysis method to produce bis (2-hydroxy ethylene) terephthalamide (BHETA) in the presence of Sn doped ZnO. To evaluate catalytic activity, pure and Sn2+ doped ZnO nanoparticles prepared using different Sn2+ molar ratios at 0.5, 1.0 and 2.0 mol% and calcined at 500 0C for 1h. The synthesized catalysts characterised using FT-IR, XRD, and UV-vis spectroscopy. The surface morphology and percentage doping obtained from SEM and SEM-EDS, respectively. We have observed a reduction in optical band gap and crystallite size of ZnO due to tin doping. Aminolytic depolymerization of PET waste using ethanolamine promoted by Sn doped ZnO effectively under conventional thermal method. Increase in the yield of the BHETA observed with respect to increasing doping percentage of Sn and 1-2 mol% Sn doped ZnO nanoparticles afforded over 90% of BHETA. Structure and purity of BHETA, depolymerised product characterized by FT-IR, 1HNMR, 13C NMR, and MS.

scholarly journals Effects of aluminum (Al) incorporation on structural, optical and thermal properties of ZnO nanoparticles

2018 ◽  
Vol 36 (3) ◽  
pp. 419-426
Author(s):  
Nashiruddin Ahammed ◽  
Md Samim Hassan ◽  
Mehedi Hassan
Keyword(s):  
Thermal Properties ◽  
Electron Microscope ◽  
Zno Nanoparticles ◽  
Sol Gel ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Transmission Electron ◽  
Vis Spectroscopy ◽  
Ft Ir ◽  
Doped Zno

AbstractIn this research article, pure and 1 %, 3 % and 5 % aluminium doped zinc oxide nanoparticles (NPs) were prepared via sol-gel method and then calcined at 500 °C. X-ray diffraction (XRD), scanning electron microscope (SEM), Fourier transform infrared (FT-IR) spectroscopy, UV-Vis spectroscopy, thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) techniques were used to investigate the structural, optical and thermal properties of synthesized pure and Al doped ZnO nanoparticles. Energy dispersive X-ray spectroscopy (EDX) analysis revealed high purity of nanoparticles in the synthesized products without any impurity peaks. Mean dimension of the nanoparticles was ~28 nm and they were hexagonal in shape, according to the images analyzed by transmission electron microscope (TEM). The optical absorption spectra of pure and Al doped ZnO samples studied using UV-Vis spectrometry have been presented and we have observed that the band gap increases with increasing Al concentration. In FT-IR spectra, the broad absorption peaks around 485 cm−1 and 670 cm−1 were assigned to Zn–O vibration. Above 450 °C, the TG curve became flat what means there was no weight loss. In the DSC curve it is seen that the transition at 150 °C was highly exothermic because of structural relaxation and on doping the exothermic peaks became shifted to the lower value of temperature. These types of materials are very useful in optoelectronics applications.

Structural and Optical Properties of F-Doped ZnO Nanoparticles Synthesized by Co-Precipitation Process

2016 ◽  
Vol 675-676 ◽  
pp. 69-72
Author(s):  
Krisana Chongsri ◽  
Wanichaya Mekprasart ◽  
Wisanu Pecharapa
Keyword(s):  
Zno Nanoparticles ◽  
Fluoride Concentration ◽  
Precursor Solution ◽  
Hexagonal Wurtzite Structure ◽  
Ammonium Fluoride ◽  
Zinc Nitrate ◽  
Precipitation Process ◽  
Vis Spectroscopy ◽  
Doped Zno ◽  
Co Precipitation

In this work, we reported the preparation of F-doped ZnO nanoparticles by facile precipitation process using zinc nitrate and ammonium fluoride as starting precursors for Zn and F, respectively dissolved in deionized water. The precursor solution was prepared at various fluoride composition ranging from 1-5 wt%. The as-precipitated powders were calcined at different temperature from 500 °C to 700 °C for 2 h. Effect of calcination temperature and fluoride concentration on structural, morphologies, optical and electrical properties were investigated by X-ray diffraction (XRD), scanning electron microscope (SEM), UV-Vis spectroscopy, respectively. XRD results indicated the complete formation of hexagonal wurtzite structure of ZnO. SEM micrographs showed the agglomeration for each sample that noticeably influenced by fluoride content.

scholarly journals Synthesis of ZnO nanoparticles by a hybrid electrochemical-thermal method: influence of calcination temperature

2015 ◽  
Vol 50 (1) ◽  
pp. 21-28 ◽  
Author(s):  
F Hassan ◽  
MS Miran ◽  
HA Simol ◽  
MAB H Susan ◽  
MYA Mollah
Keyword(s):  
Calcination Temperature ◽  
Zno Nanoparticles ◽  
Zinc Salt ◽  
Thermal Method ◽  
Gravimetric Analysis ◽  
Zno Nps ◽  
X Ray ◽  
Calcination Temperatures ◽  
Ft Ir ◽  
Uv Visible

ZnO nanoparticles (NPs) with size less than 100 nm were successfully prepared by a hybrid electrochemical-thermal method using metallic zinc and NaHCO3 without the use of any zinc salt, template or surfactant. The NPs were characterized by Fourier transform infra-red (FT-IR) spectroscopy, UV-visible spectroscopy, photoluminescence spectroscopy (PL), thermo-gravimetric analysis (TGA), X-ray diffraction (XRD), scanning electron microscopy (SEM) and energy dispersive X-ray (EDX) spectroscopy. UV-visible spectral analysis indicated that the particle size increased with increasing calcination temperature. The band gap (3.91-3.83 eV) was higher for synthesized ZnO NPs than their bulk counterparts (3.37 eV). The FT-IR spectra at different calcination temperatures showed the characteristic band for ZnO at 450 cm-1 to be prominent with increasing temperature due to the conversion of precursor into ZnO. The wurtzite hexagonal phase was confirmed by XRD analyses for ZnO NPs calcined at 700oC. The green photoluminescent emission from ZnO NPs at different calcination temperatures is considered to be originated from the oxygen vacancy or interstitial related defects in ZnO. SEM images clearly showed that the NPs are granular and of almost uniform size when calcined at higher temperatures. EDX spectra further confirmed the elemental composition and purity of ZnO obtained on calcination at 700oC. The NPs are well dispersed near or above calcination temperature of 700oC.Bangladesh J. Sci. Ind. Res. 50(1), 21-28, 2015

scholarly journals Effect of silver doping on structural and photocatalytic circumstances of ZnO nanoparticles

2020 ◽  
pp. 13-20
Author(s):  
Luma Ahmed ◽  
Eitemad S. Fadhil ◽  
Ayad F. Mohammed
Keyword(s):  
Zno Nanoparticles ◽  
Precipitation Method ◽  
Methyl Green ◽  
Zno Nanoparticle ◽  
Zno Nps ◽  
Force Microscopy ◽  
Ft Ir ◽  
Doped Zno ◽  
Co Precipitation ◽  
Artificial Uv

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.

scholarly journals Effect of Ag Doping on Properties of Al–Doped ZnO Nanoparticles Varies as Zn1-X-YAgxALYO

2017 ◽  
Vol 14 (2) ◽  
pp. 146-152
Author(s):  
Neha Sharma ◽  
Sanjayay Kumar
Keyword(s):  
Zno Nanoparticles ◽  
Spherical Shape ◽  
Xrd Analysis ◽  
Crystalline Size ◽  
X Ray Diffraction ◽  
X Ray ◽  
In Doping ◽  
Vis Spectroscopy ◽  
Doped Zno

In present study, undoped ZnO, Zn0.8Ag0.2O, Zn0.8Al0.2O and Zn0.6Al0.2Ag0.2O samples are synthesized by simple solution method. X-ray diffraction (XRD), Scanning Electron Microscopy (SEM), Energy-Dispersive X-ray spectroscopy (EDX) and UV-visible (UV-Vis) spectroscopy are used to perform the characterization of undoped, doped and codoped samples. XRD analysis is exposed that hexagonal wurtzite crystalline structure obtained for undoped, doped and codoped samples without any extra representation of impurity phases. The crystalline size is when evaluated by using Scherrer, It has 44, 49, 41and 37nm for undoped ZnO, Zn0.8Ag0.2O, Zn0.8Al0.2O and Zn0.6Al0.2Ag0.2O samples. Similarly, the crystalline size and strain are also evaluated by Williamson hall (W-H) and size strain plot (SSP) for the undoped, doped and codoped nanoparticles. The evaluated crystalline size by SSP is three times greater than the result of the scherrer method. The SEM exposes that surface morphology of nanoparticle samples, in this case is the formation of large agglomeration in spherical shape with nanocrystallites of undoped and doped ZnO with apparent and definite boundaries. EDX points out the replacement of Al2+ and Ag+ with Zn2+ in ZnO matrix and consequences in the development of single-phase Zn1−x−yAgxAlyO. The blueshift is shown in UV-Vis absorption spectra because the band gap value increases with the increase in doping, except Ag+ doped ZnO nanoparticles.

scholarly journals Facile Green Synthesis of LaCe Co-Doped ZnO Nanoparticles and Their Structural, Optical and Antibacterial Properties

2018 ◽  
Vol 4 (5) ◽  
pp. 552-554
Author(s):  
M. Karthikeyan ◽  
A. Jafar Ahamed ◽  
P. Vijaya Kumar
Keyword(s):  
Green Synthesis ◽  
Zno Nanoparticles ◽  
Synthesis Method ◽  
Antibacterial Properties ◽  
Inert Gases ◽  
Diffusion Method ◽  
Zno Nps ◽  
Vis Spectroscopy ◽  
Doped Zno ◽  
Co Doped

This present work describes the synthesis of LaCe co-doped zinc oxide (ZnO) nanoparticles (NPs) prepared by green method using Gymnema sylvestre (G. sylvestre) leaves as reducing as well as capping agent. Green synthesis method avoids inert gases, high pressure, laser radiation, high temperature, toxic chemicals etc. as compared to conventional method like sol-gel technique method, laser ablation method, solvothermal method, inert gas condensation method and chemical reduction method. The synthesized LaCe co-doped ZnO NPs was characterized by X-Ray diffraction (XRD), field emission scanning electron microscopy (FESEM), elemental analysis (EADX), Fourier transform infrared spectroscopy (FTIR), UV-vis spectroscopy and photoluminescence (PL). The LaCe co-doped ZnO NPs was tested against clinical pathogens such as gram positive G+ (Staphylococcus aureus and Streptococcus pneumoniae) and gram negative G- (Klebsiella pneumoniae, Shigella sydenteriae, Escherichia coli, Pseudomonas aeruginosa and Protus vulgaris) bacterial strains using agar well diffusion method.

scholarly journals Optical and Structural Investigation of Mg2+ doped ZnO Nanoparticles using Gymnema sylvestre and Mangifera indica Leaves Extracts

2019 ◽  
Vol 5 (1) ◽  
pp. 607-609
Author(s):  
M. Karthikeyan . ◽  
A. Jafar Ahamed . ◽  
P. Vijaya Kumar .
Keyword(s):  
Zno Nanoparticles ◽  
Structural Investigation ◽  
Mangifera Indica ◽  
Gymnema Sylvestre ◽  
X Ray Diffraction ◽  
Zno Nps ◽  
Synthesis Of Nanoparticles ◽  
Vis Spectroscopy ◽  
Doped Zno ◽  
Physical And Chemical

In green nanotechnology, plant is used for the synthesis of nanoparticles which are gaining considerable interest among researchers as an eco-friendly alternative to conventional physical and chemical methods, as this approach eliminates the use of toxic chemicals. The present study describes the synthesis of Mg2+ (magnesium) doped zinc oxide (ZnO) nanoparticles (NPs) M1 using leaves extract of Gymnema sylvestre (G. sylvestre) belonging to Asclepiadaceae family and M2 using Mangifera indica (M. indica) belonging to Anacardiaceae family as reducing as well as capping agents. The obtained Mg2+ doped ZnO NPs (M1 and M2) were characterized by X-ray diffraction (XRD) studies, field emission scanning electron microscopy (FESEM), elemental analysis (EDAX), Fourier transform infrared spectroscopy (FTIR), UV-vis spectroscopy and photoluminescence (PL) spectra.

scholarly journals Structural, Optical, and Photocatalytic Activities of Ag-Doped and Mn-Doped ZnO Nanoparticles

2018 ◽  
Vol 2018 ◽  
pp. 1-9 ◽  
Author(s):  
Mengstu Etay Ashebir ◽  
Gebrekidan Mebrahtu Tesfamariam ◽  
Gebretinsae Yeabyo Nigussie ◽  
Tesfakiros Woldu Gebreab
Keyword(s):  
Zno Nanoparticles ◽  
Surface Defects ◽  
Visible Region ◽  
Methyl Violet ◽  
Secondary Phases ◽  
Photocatalytic Decolorization ◽  
Vis Spectroscopy ◽  
Photocatalytic Activities ◽  
Doped Zno ◽  
Mn Doped

We report the photocatalytic activities of ZnO, Ag-doped ZnO, and Mn-doped ZnO nanoparticles (NPs). Ag-doped and Mn-doped ZnO samples were synthesized using a coprecipitation method and calcined at 600°C. XRD, SEM, EDX, and UV-vis spectroscopy techniques were employed for characterization of the synthesized samples. The photocatalytic activities of the samples were evaluated by measuring the photocatalytic decolorization of methyl violet with sunlight being the source of energy. XRD patterns of the samples confirmed the wurtzite structure without change which was indicative of the absence of Mn- and Ag-related secondary phases for the doped ZnO. The UV-vis spectra indicated the band gap energy of ZnO, Ag-doped ZnO, and Mn-doped ZnO to be 2.98, 2.80, and 2.64 eV, respectively. Photocatalytic decolorization of methyl violet for the synthesized samples was found to be favorable at a pH of 9.0, catalyst dose of 1 g/L, and initial dye concentration of 4.5 × 10−4 g/L. Mn-doped ZnO and Ag-doped ZnO photocatalytic decolorization efficiency was significantly higher than undoped ZnO. Incorporation of Mn and Ag enhanced the visible-light photocatalytic activity of ZnO; this could be due to the ability of these metals to increase the surface defects of ZnO which in turn shift their optical absorption towards the visible region.

Fe-Doped ZnO Nanoparticles: Structural, Morphological, Antimicrobial and Photocatalytic Characterization

2017 ◽  
Vol 1143 ◽  
pp. 233-239 ◽  
Author(s):  
Viorica Mușat ◽  
Mariana Ibănescu ◽  
Dana Tutunaru ◽  
Florentina Potecaşu
Keyword(s):  
Zno Nanoparticles ◽  
Uv Light ◽  
Precipitation Method ◽  
X Ray Diffraction ◽  
Zno Nps ◽  
Oxide Semiconductors ◽  
Mueller Hinton ◽  
Vis Spectroscopy ◽  
Mueller Hinton Agar ◽  
Doped Zno

Oxide semiconductors have attracted increasing interest due to their potential in solving environmental problems. ZnO-based nanoparticles (NPs) are among the most investigated for efficient disinfection and microbial control.Iron-doped zinc oxide nanoparticles (Fe:ZnO NPs) were successfully fabricated through precipitation method at low temperature followed by thermal treatment. The obtained Fe:ZnO NPs were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and ultraviolet-visible (UV–Vis) spectroscopy. The effect of iron content on structural, morphological, antimicrobial and photocatalytic properties was investigated and discussed.The photocatalytic activity of the nanoparticles was tested by degradation of methylene blue (MB) solution under UV light for 60 min irradiation. The antibacterial activity was determined by paper disc method on Mueller-Hinton agar against the Gram-negative bacteria Escherichia coli (E. coli) and the Gram-positive bacteria Staphylococcus aureus (S. aureus) and compared to that of the undoped ZnO NPs. Consistent improvement on the photocatalytic and antimicrobial activity of Fe-doped ZnO nanoparticles was noticed.

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