Study of Bactericidal Properties of Mg-Doped ZnO Nanoparticles

2015 ◽  
Vol 1804 ◽  
pp. 31-36 ◽  
Author(s):  
Melina Perez-Altamar ◽  
Hilary Marrero ◽  
Milton Martínez Julca ◽  
Oscar Perales Perez

ABSTRACTThe present work focuses on the polyol-mediated synthesis of pure and Mg-doped ZnO nanoparticles. The synthesized samples were characterized via X-ray diffraction, Fourier transformed infrared spectroscopy, ultraviolet visible spectroscopy and photoluminescence techniques. The Standard Plate Count was used to assess the bactericidal properties of the nanoparticles against E. coli at 1000 ppm and 1500 ppm of concentration. The capacity of the Zn-Mg oxides to generate singlet oxygen (SO) species was also evaluated. X-ray diffraction information evidenced the formation of ZnO-wurtzite; no diffraction peaks corresponding to isolated Mg-phases were detected. The average crystallite size of the Zn-Mg oxide nanocrystals was estimated in the 6nm - 7nm range. Infrared spectroscopy measurements confirmed the formation of the oxide with a Metal-Oxygen band centered on 536 cm-1; other bands associated to the functional groups of polyol by product were also observed. The exciton peak of UV spectrum suggests similarity in the particle size with the dopant addition. The effect of particle composition (i.e. doping level) on the corresponding generation of SO and bactericidal capacity is presented and discussed.

2015 ◽  
Vol 827 ◽  
pp. 43-48
Author(s):  
Annisa Noorhidayati ◽  
Mia Putri Rahmawati ◽  
Nadia Febiana Djaja ◽  
Rosari Saleh

Transition metal ions (Co and Cr) doped ZnO nanoparticles supported on natural zeolite were synthesized using co-precipitation method. The synthesized samples were characterized by means of X-ray diffraction, energy dispersive X-ray, Fourier-transform infrared absorption, and UV-visible diffuse reflectance spectroscopy. The samples were further used as photocatalyst for degradation of methyl orange and methylene blue in aqueous solutions under UV light irradiation. The results showed that zeolite supported Cr-doped ZnO nanoparticles is more efficient compared with zeolite supported Co-doped ZnO nanoparticles. It is also revealed that zeolite supported samples possessed higher photocatalytic efficiency compared to bare samples.


2018 ◽  
Vol 2018 ◽  
pp. 1-7 ◽  
Author(s):  
Gebretinsae Yeabyo Nigussie ◽  
Gebrekidan Mebrahtu Tesfamariam ◽  
Berhanu Menasbo Tegegne ◽  
Yemane Araya Weldemichel ◽  
Tesfakiros Woldu Gebreab ◽  
...  

We report in this paper antibacterial activity of Ag-doped TiO2 and Ag-doped ZnO nanoparticles (NPs) under visible light irradiation synthesized by using a sol-gel method. Structural, morphological, and basic optical properties of these samples were investigated using X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray (EDX) spectrum, and UV-Vis reflectance. Room temperature X-ray diffraction analysis revealed that Ag-doped TiO2 has both rutile and anatase phases, but TiO2 NPs only have the anatase phase. In both ZnO and Ag-doped ZnO NPs, the hexagonal wurtzite structure was observed. The morphologies of TiO2 and ZnO were influenced by doping with Ag, as shown from the SEM images. EDX confirms that the samples are composed of Zn, Ti, Ag, and O elements. UV-Vis reflectance results show decreased band gap energy of Ag-doped TiO2 and Ag-doped ZnO NPs in comparison to that of TiO2 and ZnO. Pathogenic bacteria, such as Staphylococcus aureus, Pseudomonas aeruginosa, and Escherichia coli, were used to assess the antibacterial activity of the synthesized materials. The reduction in the viability of all the three bacteria to zero using Ag-doped ZnO occurred at 60 μg/mL of culture, while Ag-doped TiO2 showed zero viability at 80 μg/mL. Doping of Ag on ZnO and TiO2 plays a vital role in the increased antibacterial activity performance.


2021 ◽  
Author(s):  
Santanu Maity ◽  
P.P Sahu ◽  
Tiju Thomas

Abstract ZnO nanostructures are promising for a wide range of applications, including gas sensors. Ethanol sensing using ZnO remains unexplored though. In this paper, we report ethanol-sensing using un-doped ZnO nano flowers and Mg doped ZnO nano flowers. These are grown using a rather simple chemo-thermal process, making this a plausibly scalable technology. To study the structural and morphological properties of undoped ZnO and Mg doped ZnO nanoflowers, Raman spectroscopy, Fourier Transform Infrared Spectroscopy (FTIR), x-ray diffraction and Field Emission Scanning Electron Microscopy (FESEM) are carried out. Ethanol sensing properties of undoped ZnO and Mg doped ZnO nanoflower devices are investigated toward different ethanol concentration (concentration range of 1–600 ppm at 100°C–200°C). Our findings show that 15% Mg doped ZnO nano flower is better than ZnO nano flower for ethanol gas-sensing applications.


2015 ◽  
Author(s):  
T. J. Castro ◽  
S. W. da Silva ◽  
F. Nakagomi ◽  
A. Franco Júnior ◽  
H. V. S. Pessoni ◽  
...  

2017 ◽  
Vol 14 (2) ◽  
pp. 146-152
Author(s):  
Neha Sharma ◽  
Sanjayay Kumar

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.


2015 ◽  
Vol 1112 ◽  
pp. 194-200
Author(s):  
Nadia Febiana Djaja ◽  
Rosari Saleh

The present study compares the photocatalytic decolorization ability of bare Mn-doped ZnO and montmorillonite modified Mn-doped ZnO nanoparticles towards aqueous solution of organic dyes (methylene blue and malachite green) under UV light irradiation. Both photocatalysts were synthesized using co-precipitation method and characterized by X-ray diffraction, energy dispersive X-ray spectroscopy, Fourier-transform infrared absorption, electron spin resonance, and diffuse reflectance spectroscopy. Comparison of degradation efficiency demonstrated that montmorillonite modified Mn-doped ZnO nanoparticles exhibited higher activity than bare Mn-doped ZnO nanoparticles.


2013 ◽  
Vol 770 ◽  
pp. 354-357
Author(s):  
Krisana Chongsri ◽  
N. Wongpisutpaisan ◽  
A. Sungthong ◽  
Naratip Vittayakorn ◽  
Wisanu Pecharapa

Al-doped ZnO nanoparticles were synthesized by sonochemical method from zinc acetate dehydrate and aluminum acetate as starting precursors. The deionized (DI) water was selected as the solvent. Sonication of the precursor was performed by a Sonics Model VCX 750 for 30 minutes until precipitated product was finally obtained. The as-precipitated powders were calcined at different temperature range of 550-1100 °C for 2 hr. For all samples, their crystal structures were investigated by X-ray diffraction (XRD) and surface morphologies were observed by scanning electron microscope (SEM). The XRD results revealed that, the purity of as-synthesized powders increases when the calcination temperature increases. Moreover, it is noticed that the AlZnO partial peaks will appear when the as-synthesized powders were calcined at 800 – 1000 °C. In addition, SEM micrographs show the increase of agglomeration and the particles when the calcination temperature increases.


2014 ◽  
Vol 1685 ◽  
Author(s):  
Melina Pérez-Altamar ◽  
Oscar Perales-Pérez

ABSTRACTThe present work focuses on the fabrication of environmental friendly ZnO nanocrystals and chitosan/cellulose films hosting ZnO nanoparticles (NPs) as an attempt to produce nanocomposites with enhanced bactericidal capacity. The solution casting method was used to fabricate the chitosan/cellulose blend films. Highly monodisperse ZnO nanoparticles were synthesized using Zinc acetate and Triethylene glycol (TEG) via a modified Polyol route. ZnO crystal size was controlled by the heterogeneous nucleation approach. Optical properties of ZnO nanoparticles were studied by UV–vis spectroscopy and Photoluminescence Spectroscopy (PL) techniques. The nanoparticles’ size and morphology were determined by Transmission Electron Microscopy (TEM) and X-ray diffraction (XRD), respectively. Obtained results confirmed the effectiveness of the size-controlled synthesis employed. The chitosan/cellulose/ZnO nanocomposites were characterized by Fourier Transform – Infrared spectroscopy (FTIR) and X-ray diffraction (XRD) methods. The mechanical properties of produced bare and ZnO-bearing composites were determined from stress-strain tests. The Standard Plate Count and the Halo Zone methods were used to evaluate the bactericidal properties of the ZnO nanoparticles, chitosan/cellulose blend films and chitosan/cellulose/ZnO nanocomposites againstEscherichia coli(ATCC 35218).


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