In this study,antimicrobial activity of zinc oxide(ZnO)nanoparticles(NPs)synthesized by different chemical,thermal and green routes were systematically investigated with an aim to determine which method yields the mos...In this study,antimicrobial activity of zinc oxide(ZnO)nanoparticles(NPs)synthesized by different chemical,thermal and green routes were systematically investigated with an aim to determine which method yields the most efficient antimicrobial property.The methodologies employed in this study were sol-gel,thermal decomposition,precipitation and green synthesis routes.The physical and optical properties of synthesized ZnO NPs were characterized by X-ray diffraction(XRD),scanning electron microscope(SEM),ultraviolet-visible spectroscopy(UV-Vis)and fluorescence spectroscopy.The results of the XRD and SEM analysis indicated the size and shape of the particles,depending on synthesis methodology and calcination temperature.The optical properties of the ZnO NPs investigated using UV-Vis absorption and photoluminescence spectra were also depending on the synthesized route.The antimicrobial activity of the ZnO NPs was tested against gram-negative bacteria(E.coli,P.aeruginosa and S.typhi),gram-positive bacteria(S.aureus and B.subtilis)and fungus(C.albicans)using agar-well diffusion method.Effects of size,shape of the crystal and concentration on the anti-microbial activity were investigated.The experimental results showed that the antimicrobial activity of ZnO NPs increased with decreasing size of the crystal.It was also found that the gram-positive bacteria were more sensitive to ZnO NPs than gram-negative bacteria and fungus.Interestingly,ZnO NPs synthesized using the green route showed more effective antimicrobial activity than those using the chemical or the thermal route.展开更多
Rare earth elements doped with zinc oxide nanoparticles(ZnO-NPs)have gathered a remarkable interest for their potential credence due to their high luminescent intensities.In this research,europium ion(Eu^(3+))doped an...Rare earth elements doped with zinc oxide nanoparticles(ZnO-NPs)have gathered a remarkable interest for their potential credence due to their high luminescent intensities.In this research,europium ion(Eu^(3+))doped and undoped zinc oxide nanoparticles(Eu_(1-x)Zn_(x)O)(x=0.03,0.06,0.09)were synthesized via co-precipitation method.The effects of varying the concentration of the europium ion(Eu^(3+))on the structure and optical properties were investigated.The structural and optical properties of europium ion(Eu^(3+))doped and un-doped zinc oxide nanoparticles(ZnO NPs)were characterized by XRD,UV-Vis,Photoluminescence,and FT-IR Spectroscopy.The XRD results reveal the Europium ion(Eu^(3+))was successfully incorporated into the zinc oxide host matrix and made highly crystalline.All the synthesized samples have a hexagonal wurtzite structure.UV-Vis absorption spectra measurements revealed increasing the dopant concentration increases the energy band compared to the undoped zinc oxide nanoparticles.Photoluminescence spectra confirmed doping europium ion(Eu^(3+))predominantly enhances the visible emission with various series characteristics of blue and green emission compared to undoped zinc oxide nanoparticles(ZnO NPs)which exhibits the near band emission.Fourier Transform Infra Red(FTIR)spectral analysis indicated the presence of functional groups attached to Europium ion(Eu^(3+))doped and undoped zinc oxide nanoparticles(ZnO NPs).In addition,the presence of an additional spectrum band with increasing the concentration of dopant amount demonstrates that europium ions(Eu^(3+))were successfully substituted into the zinc oxide host matrix.The photocatalytic activity response is investigated using organic methylene blue(MB)as a pollutant model and dopant played the role in enhancing the photocatalytic kinetics because Eu^(3+)ions act as an electron acceptor to promote charge separation and photocatalytic activity.The photocatalytic activity of europium ion(Eu^(3+))doped zinc oxide nanoparticles has higher performance than undoped zinc oxide nanoparticles(ZnO-NPs)since the dopant has the potential candidate in minimizing the recombination probability which in turn improves the performance of photocatalytic activities which makes it suitable for the local environment.展开更多
文摘In this study,antimicrobial activity of zinc oxide(ZnO)nanoparticles(NPs)synthesized by different chemical,thermal and green routes were systematically investigated with an aim to determine which method yields the most efficient antimicrobial property.The methodologies employed in this study were sol-gel,thermal decomposition,precipitation and green synthesis routes.The physical and optical properties of synthesized ZnO NPs were characterized by X-ray diffraction(XRD),scanning electron microscope(SEM),ultraviolet-visible spectroscopy(UV-Vis)and fluorescence spectroscopy.The results of the XRD and SEM analysis indicated the size and shape of the particles,depending on synthesis methodology and calcination temperature.The optical properties of the ZnO NPs investigated using UV-Vis absorption and photoluminescence spectra were also depending on the synthesized route.The antimicrobial activity of the ZnO NPs was tested against gram-negative bacteria(E.coli,P.aeruginosa and S.typhi),gram-positive bacteria(S.aureus and B.subtilis)and fungus(C.albicans)using agar-well diffusion method.Effects of size,shape of the crystal and concentration on the anti-microbial activity were investigated.The experimental results showed that the antimicrobial activity of ZnO NPs increased with decreasing size of the crystal.It was also found that the gram-positive bacteria were more sensitive to ZnO NPs than gram-negative bacteria and fungus.Interestingly,ZnO NPs synthesized using the green route showed more effective antimicrobial activity than those using the chemical or the thermal route.
基金financially supported by Adama Science and Technology University and the Ministry of Innovation and Technology of Ethiopia.
文摘Rare earth elements doped with zinc oxide nanoparticles(ZnO-NPs)have gathered a remarkable interest for their potential credence due to their high luminescent intensities.In this research,europium ion(Eu^(3+))doped and undoped zinc oxide nanoparticles(Eu_(1-x)Zn_(x)O)(x=0.03,0.06,0.09)were synthesized via co-precipitation method.The effects of varying the concentration of the europium ion(Eu^(3+))on the structure and optical properties were investigated.The structural and optical properties of europium ion(Eu^(3+))doped and un-doped zinc oxide nanoparticles(ZnO NPs)were characterized by XRD,UV-Vis,Photoluminescence,and FT-IR Spectroscopy.The XRD results reveal the Europium ion(Eu^(3+))was successfully incorporated into the zinc oxide host matrix and made highly crystalline.All the synthesized samples have a hexagonal wurtzite structure.UV-Vis absorption spectra measurements revealed increasing the dopant concentration increases the energy band compared to the undoped zinc oxide nanoparticles.Photoluminescence spectra confirmed doping europium ion(Eu^(3+))predominantly enhances the visible emission with various series characteristics of blue and green emission compared to undoped zinc oxide nanoparticles(ZnO NPs)which exhibits the near band emission.Fourier Transform Infra Red(FTIR)spectral analysis indicated the presence of functional groups attached to Europium ion(Eu^(3+))doped and undoped zinc oxide nanoparticles(ZnO NPs).In addition,the presence of an additional spectrum band with increasing the concentration of dopant amount demonstrates that europium ions(Eu^(3+))were successfully substituted into the zinc oxide host matrix.The photocatalytic activity response is investigated using organic methylene blue(MB)as a pollutant model and dopant played the role in enhancing the photocatalytic kinetics because Eu^(3+)ions act as an electron acceptor to promote charge separation and photocatalytic activity.The photocatalytic activity of europium ion(Eu^(3+))doped zinc oxide nanoparticles has higher performance than undoped zinc oxide nanoparticles(ZnO-NPs)since the dopant has the potential candidate in minimizing the recombination probability which in turn improves the performance of photocatalytic activities which makes it suitable for the local environment.
