scholarly journals Synthesis, characteristics, and photocatalytic activity of zinc oxide nanoparticles stabilized on the stone surface for degradation of metronidazole from aqueous solution

2021 ◽  
Vol 8 (1) ◽  
pp. 55-63
Author(s):  
Amir Nasser Alibeigi ◽  
Neda Javid ◽  
Majid Amiri Gharaghani ◽  
Zhila Honarmandrad ◽  
Fatemeh Parsaie
Keyword(s):  
Zinc Oxide ◽  
Removal Efficiency ◽  
Zno Nanoparticles ◽  
Advanced Oxidation Process ◽  
Degradation Kinetics ◽  
Hexagonal Wurtzite Structure ◽  
Sem Analysis ◽  
Thermal Method ◽  
Average Crystalline Size ◽  
Stone Surface

Background: The presence of antibiotics such as metronidazole in wastewater even at low concentrations requires searching for a suitable process such as advanced oxidation process (AOP) to reduce the level of pollutants to a standard level in water. Methods: In this study, zinc oxide (ZnO) nanoparticles were synthesized by thermal method using zinc sulfate (ZnSO4 ) as a precursor, then, stabilized on stone and was used as a catalyst, in order to degrade metronidazole by photocalytic process. Effective factors on the removal efficiency of metronidazole including the initial metronidazole concentration, contact time, pH, and 0.9 gL-1 ZnO stabilized on the stone surface were investigated. Results: The X-ray diffraction (XRD) studies showed that the synthesized nanomaterials have hexagonal Wurtzite structure. Also, scanning electron microscopy (SEM) analysis revealed that the average crystalline size of the synthesized ZnO particles was in the range of 1.9-3.2 nm. The spectra represented a sharp absorption edge at 390 nm for ZnO nanoparticles corresponding to band gap of 3.168 eV. The BET-BJH specific surface area of the synthesized ZnO nanoparticles was 25.504 m2 /g. The EDS spectrum of ZnO nanoparticles showed four peaks, which were identified as Zn and O. The maximum removal efficiency was 98.36% for the synthetic solution under a specific condition (pH = 11, reaction time = 90 minutes, ZnO concentration = 0.9 gL-1, and the initial concentration of metronidazole = 10 mgL-1). The photocatalytic degradation was found to follow pseudo-first-order degradation kinetics. Conclusion: Therefore, the ZnO nanoparticles synthesized by thermal decomposition are suitable and effective photocatalytic materials for degradation of pharmaceutical contaminants.

Effect of cobalt doping on microstructures and dielectric properties of ZnO

2019 ◽  
Vol 97 (3) ◽  
pp. 227-232 ◽  
Author(s):  
Ye Zhao ◽  
Fan Tong ◽  
Mao Hua Wang
Keyword(s):  
Zno Nanoparticles ◽  
Sol Gel ◽  
Hexagonal Wurtzite Structure ◽  
Sem Analysis ◽  
Co Doping ◽  
In Doping ◽  
Zno Powders ◽  
Doped Zno ◽  
Zno Crystal ◽  
Co Doped

Pure and cobalt-doped ZnO nanoparticles (2.5, 5, 7.5, and 10 atom % Co) are synthesized by sol–gel method. The as-synthesized nanoparticles are characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and field emission scanning electron microscopy (FE-SEM) analysis. The nanoparticles of 0, 2.5, and 5 atom % Co-doped ZnO exhibited hexagonal wurtzite structure and have no other phases. Moreover, the (101) diffraction peaks position of Co-doped ZnO shift toward a smaller value of diffraction angle compared with pure ZnO powders. The results confirm that Co ions were well incorporated into ZnO crystal lattice. Simultaneously, Co doping also inhibited the growth of particles, and the crystallite size decreased from 43.11 nm to 36.63 nm with the increase in doping concentration from 0 to 10 atom %. The values of the optical band gap of all Co-doped ZnO nanoparticles gradually decreased from 3.09 eV to 2.66 eV with increasing Co content. Particular, the dielectric constant of all Co-doped ZnO ceramics gradually increased from 1.62 × 103 to 20.52 × 103, and the dielectric loss decreased from 2.36 to 1.28 when Co content increased from 0 to 10 atom %.

scholarly journals Zinc oxide nanoparticles prepared by thermal decomposition of zinc benzenepolycarboxylato precursors: Photoluminescent, photocatalytic and antimicrobial properties

2020 ◽  
Vol 85 (11) ◽  
pp. 1475-1488
Author(s):  
Lidija Radovanovic ◽  
Jelena Zdravkovic ◽  
Bojana Simovic ◽  
Zeljko Radovanovic ◽  
Katarina Mihajlovski ◽  
...  
Keyword(s):  
Thermal Decomposition ◽  
Zinc Oxide ◽  
Zno Nanoparticles ◽  
Diffuse Reflectance Spectroscopy ◽  
Antimicrobial Properties ◽  
Average Crystallite Size ◽  
Hexagonal Wurtzite Structure ◽  
Inhibitory Effect ◽  
Reactive Orange 16 ◽  
Air Atmosphere

Zinc oxide (ZnO) nanoparticles were obtained by thermal decomposition of one-dimensional zinc?benzenepolycarboxylato complexes as single- -source precursors at 450 ?C in an air atmosphere. The mechanism and kinetics of thermal degradation of zinc?benzenepolycarboxylato complexes were analyzed under non-isothermal conditions in an air atmosphere. The results of X-ray powder diffraction and field emission scanning electron microscopy revealed hexagonal wurtzite structure of ZnO with an average crystallite size in the range of 39?47 nm and similar morphology. The band gap and the specific surface area of ZnO nanoparticles were determined using UV?Vis diffuse reflectance spectroscopy and the Brunauer, Emmett and Teller method, respectively. The photoluminescent, photocatalytic and antimicrobial properties of the ZnO nanoparticles were also examined. The best photocatalytic activity in the degradation of C. I. Reactive Orange 16 dye was observed for the ZnO powder where the crystallites form the smallest agglomerates. All ZnO nanoparticles showed excellent inhibitory effect against Gram-positive bacterium Staphylococcus aureus and Gram-negative bacterium Escherichia coli.

scholarly journals Synthesis of Chitosan/Zinc Oxide Nanoparticles Stabilized by Chitosan via Microwave Heating

2019 ◽  
Vol 14 (2) ◽  
pp. 450 ◽  
Author(s):  
Nurul Amira Ahmad Yusof ◽  
Norashikin Mat Zain ◽  
Norlin Pauzi
Keyword(s):  
Zinc Oxide ◽  
Microwave Heating ◽  
Zno Nanoparticles ◽  
Bacterial Infections ◽  
Pathogenic Bacteria ◽  
Antibacterial Properties ◽  
Inhibition Zone ◽  
Mean Value ◽  
Average Crystalline Size ◽  
Xrd Patterns

Nowadays, zinc oxide (ZnO) has attracted attention in research and development because of its remarkable antibacterial properties. Chitosan/ZnO nanoparticles were successfully synthesized via microwave heating. The objectives of this work were to investigate the effect of stabilizer, power heating and time heating on size of chitosan/ZnO nanoparticles and to determine antibacterial activity against pathogenic bacteria, where chitosan was used as a stabilizing agent. Chitosan/ZnO nanoparticles were analyzed  by Fourier Transform Infra Red (FTIR), X-ray Diffraction (XRD), Field Emission Scanning Electron Microscopy (FESEM), and Zetasizer instrument. The power heating and time heating were varied from 400 to 800 Watt and 4 to 8 minutes, respectively. The presence of chitosan has role on preventing the nanoparticles from agglomeration by producing a milky solution of chitosan/ZnO nanoparticles without any suspensions. The increase of power  and time heating improved the size of nanoparticles. The peak in FTIR spectrum at around 427 cm-1 was confirmed the existence of the ZnO phase. XRD patterns showed that the chitosan/ZnO nanoparticles materials were pure phase with average crystalline size is 130 nm. FESEM revealed that chitosan/ZnO nanoparticles were uniformly distributed with the mean value of size is 70 nm and spherical shaped. Further impact of power and time heating on the size of the chitosan/ZnO nanoparticles can be shown by a nanoparticles size distribution with the average of 30 to 90 nm. The results showed that chitosan/ZnO nanoparticles have displayed an antibacterial inhibition zone against Gram-positive S. aureus and Gram-negative E. coli which 16.0 and 13.3 mm, respectively. Chitosan/ZnO nanoparticles were synthesized in this work presented have potential application to prevent bacterial infections. Copyright © 2019 BCREC Group. All rights reserved 

ZnO nanoparticles immobilized on the surface of stones to study the removal efficiency of 4-nitroaniline by the hybrid advanced oxidation process (UV/ZnO/O3)

2019 ◽  
Vol 1176 ◽  
pp. 766-776 ◽  
Author(s):  
Mohammad Malakootian ◽  
Majid Amiri Gharaghani ◽  
Abbas Dehdarirad ◽  
Mehrdad Khatami ◽  
Mohammad Ahmadian ◽  
...  
Keyword(s):  
Removal Efficiency ◽  
Zno Nanoparticles ◽  
Advanced Oxidation Process ◽  
Oxidation Process ◽  
Advanced Oxidation

scholarly journals Enhanced Photocatalytic and Antibacterial Performance of ZnO Nanoparticles Prepared by an Efficient Thermolysis Method

Catalysts ◽  
2019 ◽  
Vol 9 (7) ◽  
pp. 608 ◽  
Author(s):  
Md. Hanif ◽  
Insup Lee ◽  
Jeasmin Akter ◽  
Md. Islam ◽  
Ali Zahid ◽  
...  
Keyword(s):  
Photocatalytic Activity ◽  
Zno Nanoparticles ◽  
Zinc Acetate Dihydrate ◽  
Hexagonal Wurtzite Structure ◽  
Thermal Method ◽  
X Ray Diffraction ◽  
Zno Nps ◽  
E Coli ◽  
Antibacterial Performance ◽  
Short Time

ZnO nanoparticles (ZnO-NPs) were synthesized by a straightforward modified thermal method using only one chemical: zinc acetate dihydrate. The process is environmentally safer than other methods because it does not involve other chemicals or a catalyst, acid, or base source. X-ray diffraction analysis indicated that the ZnO-NPs crystallize in the hexagonal wurtzite structure. The UV–vis absorption spectra revealed a marked redshift, which is critical for enhanced photocatalytic activity. We used methylene blue for photocatalytic activity tests and found an excellent degradation percentage (99.7%) within a short time (80 min). The antibacterial activity of the synthesized ZnO-NPs was tested against Escherichia coli at different concentrations of ZnO-NPs. The analysis revealed that the minimum inhibitory concentration (MIC) of the ZnO-NPs against E. coli was 30–50 μg/mL. Our ZnO-NPs were found to be more effective than previously reported ZnO-NPs synthesized via other methods.

Structural and Photoluminescence Studies of Ni-doped ZnO Nanoparticles Synthesized by Solution Combustion Method

2014 ◽  
Vol 1584 ◽  
Author(s):  
Murugesan SILAMBARASAN ◽  
Shanmugam SARAVANAN ◽  
Naoki OHTANI ◽  
Tetsuo SOGA
Keyword(s):  
Zno Nanoparticles ◽  
Hexagonal Wurtzite Structure ◽  
Combustion Method ◽  
Near Band Edge ◽  
Average Crystalline Size ◽  
X Ray Diffraction ◽  
Solution Combustion ◽  
Solution Combustion Method ◽  
Xrd Pattern ◽  
Photoluminescence Studies

ABSTRACTIn this paper, the authors have reported the structural and photoluminescence (PL) studies of pure and nickel (Ni) doped zinc oxide (ZnO) nanoparticles synthesized by the solution combustion method. The structural, morphological and optical studies are carried out by powder x-ray diffraction (XRD), field emission-scanning electron microscopy (FE-SEM) and PL spectra, respectively. The XRD pattern indicates that the prepared particles are in hexagonal wurtzite structure with the average crystalline size is around 35-50nm. Room temperature PL shows the near band edge related emission and the results are related several intrinsic defects in the ZnO nanoparticles.

scholarly journals Effect of NaOH concentration on optical properties of zinc oxide nanoparticles

2016 ◽  
Vol 34 (4) ◽  
pp. 819-827 ◽  
Author(s):  
Vaibhav Koutu ◽  
Lokesh Shastri ◽  
M. M. Malik
Keyword(s):  
Raman Spectroscopy ◽  
Zinc Oxide ◽  
Optical Properties ◽  
Zno Nanoparticles ◽  
Visible Spectrum ◽  
Hexagonal Wurtzite Structure ◽  
Peak Shift ◽  
Precipitation Method ◽  
Synthesis Process ◽  
Co Precipitation

AbstractIn the present work, powder zinc oxide samples were prepared by varying NaOH concentration (0.1 M – 0.4 M) using wet-chemical co-precipitation method. As-synthesized ZnO was characterized using X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), photoluminescence (PL) and Raman spectroscopy. Formation of hexagonal wurtzite structure of the ZnO samples has been revealed from XRD studies. This study further suggests reduction in crystallite size from 40 nm to 23 nm with an increase in NaOH concentration which is confirmed by FESEM. PL and Raman spectroscopy studies of these samples show significant peak shift towards the higher and lower energy respectively, with maximum PL emission between 400 nm and 470 nm region of the visible spectrum. Noticeable inverse relationship between optical properties of ZnO nanoparticles and NaOH concentration may be attributed to the rapid nucleation during the synthesis process. With these remarkable properties, ZnO nanoparticles may find applications in nanoelectronic devices, sensors, nanomedicine, GATE dielectrics, photovoltaic devices, etc.

scholarly journals Estimation of Particle Size and Band Gap of Zinc Oxide Nanoparticle Synthesized by Chemical Precipitation Method

2020 ◽  
Vol 41 (1) ◽  
pp. 46-50
Author(s):  
Surendra K. Gautam ◽  
Bibek Sapkota ◽  
Arun Bhujel ◽  
Sitaram Bhattarai
Keyword(s):  
Particle Size ◽  
Zinc Oxide ◽  
Band Gap ◽  
Zno Nanoparticles ◽  
Hexagonal Wurtzite Structure ◽  
Chemical Precipitation ◽  
Chemical Precipitation Method ◽  
Precipitation Method ◽  
X Ray ◽  
Uv Visible

Zinc oxide (ZnO) nanoparticles were synthesized by chemical precipitation method using 0.1M and 0.3M [Zn(NO3)2.6H2O] and Na2CO3 solutions. The particle size and band gap of ZnO nanoparticles were estimated and effect of concentration on it was investigated. The synthesized nanoparticles were characterized by X-ray diffraction (XRD), Transmission electron microscopy (TEM), Energy dispersive X-ray spectroscopy (EDX), Fourier transform infrared spectroscopy (FTIR) and UV-visible spectroscopy. The XRD result revealed that synthesized ZnO nanoparticles have pure hexagonal wurtzite structure and the particle size varies from 27.0 nm to 29.9 nm estimated by using Debye-Scherrer’s equation. The TEM image also projected the average particle size in the range of 20-30 nm and selected area electron diffraction (SAED) further verified the formation of hexagonal wurtzite structure. The FTIR result showed a broad absorption band related to Zn-O vibration band. The UV-visible absorption showed a red shift in the absorption edge with increasing concentration of Zn(NO3)2.6H2O solution. The sizes and band gaps of ZnO nanoparticles increased and decreased, respectively with increasing concentration of Zn(NO3)2.6H2O solution from 0.1M to 0.3M.

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