nasibeh molahasani | East Tehran Branch, Islamic Azad Uni. (original) (raw)

Papers by nasibeh molahasani

Research paper thumbnail of Applying Taguchi method to optimize the synthesis conditions of ZrO2/TiO2/ZnO nanocomposite for high-performance photodegradation of Congo red

iranian journal of catalysis, Mar 1, 2021

Research paper thumbnail of Synthesis and Chracterization of Folic Acid conjugated ZnO/ Silica Core-shell as Cancer Therapeutic and Imaging Agent

Research journal of biotechnology

ABSTRACT

Research paper thumbnail of Effects of Mn doping on the structural, linear, and nonlinear optical properties of ZnO nanoparticles

Journal of the Optical Society of America B, 2018

In this study, the synthesis and characterization of undoped and Mn-doped ZnO nanoparticles with ... more In this study, the synthesis and characterization of undoped and Mn-doped ZnO nanoparticles with 2%, 5%, and 15% Mn/ZnO prepared using the hydrothermal method were reported. The structural, morphological, and chemical-bond properties of the Mn-doped ZnO nanoparticles were studied by using x-ray diffraction, field emission scanning electron microscopy (FESEM), energy dispersive x-ray analysis, and Fourier transform infrared spectroscopy analysis. X-ray diffraction patterns indicate that all of the samples have hexagonal wurtzite structures. The average diameters of the Mn-doped ZnO nanoparticles with different Mn/ZnO ratios were estimated to be about 20-38 nm from the FESEM images. The linear absorption coefficient and optical band gap energy of ZnO and Mn-doped ZnO nanoparticles were calculated using UV-Vis spectroscopy. A decrease in E g was observed by an increase in Mn concentration. The nonlinear optical measurements have been performed using a nanosecond Nd:YAG pulse laser by the Z-scan technique. Both the undoped and Mn-doped ZnO nanoparticles exhibited a negative nonlinear optical index of refraction at 532 nm relating to the self-defocusing phenomenon. The nonlinear optical absorption of ZnO and Mn-doped ZnO nanoparticles is attributed to two-photon absorption combined with free carrier absorption. Furthermore, the third-order nonlinear susceptibility values of the undoped and Mn-doped ZnO nanoparticles varied between 1.2 − 2.5 × 10 −9 esu, depending on the Mn contents. The results suggest that a Mn dopant can improve the nonlinear optical properties of ZnO nanoparticles, and Mn-doped ZnO nanoparticles synthesized through the hydrothermal method may be a promising candidate for nonlinear optical applications at 532 nm.

Research paper thumbnail of Correlation of Morphology and Luminescent Properties of Zno Nano Particles to Different Surfactants via Hydrothermal Method

international journal of nano dimension, 2013

Nanocrystalline Zinc Oxide (ZnO) powders with different morphology have been successfully synthes... more Nanocrystalline Zinc Oxide (ZnO) powders with different morphology have been successfully synthesized by using different surfactants such as Cetyl Trimethyl Ammonium Bromide (CTAB), Sodium Dodecyl Sulphate (SDS), and Tri Ethanol Amine (TEA) via hydrothermal method. The products were characterized by means of powder X-ray diffraction (XRD), Scanning electron microscopy (SEM), Transmission electron microscopy (TEM), UV-visible absorption and Photoluminescence (PL) spectroscopy. The sheets, rods, and spherical morphologies of the prepared SDS, CTAB, and TEA mediated ZnO were observed in the SEM micrographs..

Research paper thumbnail of Study of Quantum Size Effects and Optical Characteristics in Colloidal CD1-XSNXTE Quantum Dotes

international journal of nano dimension, 2014

In this work, we report, optical properties of Cd1-xSnxTe quantum dots (x= 0.05, 0.10 and 0.15) s... more In this work, we report, optical properties of Cd1-xSnxTe quantum dots (x= 0.05, 0.10 and 0.15) synthesized in water using thioglycolic acid (TGA) as a modifier agent. The optical characterization of the samples was performed through absorption (UV) and photoluminescence spectra (PL). A red shift absorption and fluorescent emission peaks was observed which can be related to the increase of nanocrystals diameter with pass the reaction time. This size dependent phenomenon is concerned to the known “quantum confinement” effect and the highest quantum yield has been achieved under our experimental conditions (using thioglycolic acid (TGA) as a modifier agent) when the processing time reached to 150 min.

Research paper thumbnail of Enhanced Blue Green Emission of ZnO Nanorods Grown by Hydrothermal Method

Journal of Nano Research, 2012

In this paper, we report enhanced blue green emission of hexagonal shaped ZnO nanorods (NRS) grow... more In this paper, we report enhanced blue green emission of hexagonal shaped ZnO nanorods (NRS) grown via a simple hydrothermal method and silica coated then by using tetraethoxysilane (TEOS). The composition and structural characteristic of the prepared samples were studied by X-ray diffraction (XRD), Field Emission Scanning Electron Microscopy and Energy Dispersive X-ray analysis (FESEM-EDAX). The results revealed well crystallized hexagonal structure possessing a perfect and ideal growth habits of wurtzite zinc oxide grown along the [00 direction in preference in both the cases. Optical properties and quality of the prepared ZnO and silica coated ZnO nanorods were examined by UV-visible and FTIR spectroscopy. Photoluminescence (PL) spectra were used to study ZnO and silica coated ZnO nanorod electronic structure, which resulted in an obvious enhanced blue-green emission for ZnO nanorod and an intense red emission with a very low UV intensity for the silica coated nanorods. Appearanc...

Research paper thumbnail of Photocatalytic degradation of Congo red by ZnO nanoparticles with different morphology

Journal of Interfaces, Thin Films, and Low dimensional systems, Dec 1, 2019

In this study, ZnO nanoparticles in three shapes, spherical, rod, and sheet are synthesized by a ... more In this study, ZnO nanoparticles in three shapes, spherical, rod, and sheet are synthesized by a hydrothermal method using three different surfactants, namely three ethanol amine, cetyl three methyl ammonium bromide, and sodium dodecyl sulfate. In all cases, the chemical composition, powder identification, morphology. and particle size of the final product are characterized by Fourier transform infrared (FTIR), X-ray diffraction (XRD), field emission scanning electronic microscopy (FESEM), EDX elemental analysis, and UV-Vis spectroscopy. The photocatalytic activity of the nanoparticles are investigated for degradation of organic pollutants (Congo red dye). The removal tests of Congo red as a water organic pollutant indicates photocatalytic activity and absorption ability of synthesized zinc oxides. Finally, the comparison of the dye removal results show that the rod nanoparticle has more efficiency in the degradation of Congo red with 97% yield over 2 hours at pH=8.

Research paper thumbnail of Room Temperature Ferromagnetism in Cobalt Doped ZnO Nanoparticles

Research paper thumbnail of Room Temperature Ferromagnetism in Cobalt Doped ZnO Nanoparticles

In the field of spintronics, studying of semiconductors with ferromagnetically polarizable carrie... more In the field of spintronics, studying of semiconductors with ferromagnetically polarizable carriers at room temperature (RT) is a very interesting subject to study. In these kinds of materials, the spin and charge of the carriers can be coupled separately with an external magnetic field. While, electrons carry both charge and spin and processing of the information in conventional electronic devices is based only on the charge of the electrons. Whereas, spin electronics or spintronics, uses the spin of In this work we report synthesis and magnetic characterization of cobalt doped ZnO nanoparticles (with different percent of doped cobalt oxide). Synthesis of the materials was carried out at room temperature by polyacrylamide-gel method, using zink sulfate and cobalt nitrate as source materials, acrylamide as monomer and N,N-methylene bisacrylamide as a lattice reagent. Characterization of the samples were performed using XRD, SEM, TEM, UV and photoluminescence (PL) studies. The X-ray diffraction patterns obtained showed formation of wurtzite ZnO structure with no secondary Co phases. The EDS measurements were employed to investigate the composition of the samples and showed the presence of Zn and cobalt elements detected. The optical absorption spectra showed internal d-d transitions related to Co 2+ incorporated on the Zn lattice site of ZnO structure. The red-shift of the band-gap edge has been attributed to a merging of donor and conduction bands due to the Co doping. The magnetic behavior of prepared cobalt doped samples was finally investigated at room temperature using vibrating sample magnetometer (VSM). The results show that, the Co doped ZnO.nanopaticles with 2% CoO is ferromacnetic at RT. This magnetic property is greatly suppressed and replaced by a paramagnetism behavior at higher doping levels.

Research paper thumbnail of Room Temperature Ferromagnetism in Cobalt Doped ZnO Nanoparticles

Research paper thumbnail of Enhanced Blue Green Emission of ZnO Nanorods Grown by Hydrothermal Method

In this paper, we report enhanced blue green emission of hexagonal shaped ZnO nanorods (NRS) grow... more In this paper, we report enhanced blue green emission of hexagonal shaped ZnO nanorods (NRS) grown via a simple hydrothermal method and silica coated then by using tetraethoxysilane (TEOS). The composition and structural characteristic of the prepared samples were studied by X-ray diffraction (XRD), Field Emission Scanning Electron Microscopy and Energy Dispersive X-ray analysis (FESEM-EDAX). The results revealed well crystallized hexagonal structure possessing a perfect and ideal growth habits of wurtzite zinc oxide grown along the [001] direction in preference in both the cases. Optical properties and quality of the prepared ZnO and silica coated ZnO nanorods were examined by UV-visible and FTIR spectroscopy. Photoluminescence (PL) spectra were used to study ZnO and silica coated ZnO nanorod electronic structure, which resulted in an obvious enhanced blue-green emission for ZnO nanorod and an intense red emission with a very low UV intensity for the silica coated nanorods. Appearance of intense red emission seems to be very promising since and it could favor more reliable fluorescence sensing in drug delivery fluorescent detection with a minor UV emission.

Research paper thumbnail of Study of quantum size effects and optical characteristics in colloidal Cd 1-x Sn x Te quantum dotes

In this work, we report, optical properties of Cd 1-x Sn x Te quantum dots (x= 0.05, 0.10 and 0.1... more In this work, we report, optical properties of Cd 1-x Sn x Te quantum dots (x= 0.05, 0.10 and 0.15) synthesized in water using thioglycolic acid (TGA) as a modifier agent. The optical characterization of the samples was performed through absorption (UV) and photoluminescence spectra (PL). A red shift absorption and fluorescent emission peaks was observed which can be related to the increase of nanocrystals diameter with pass the reaction time. This size dependent phenomenon is concerned to the known "quantum confinement" effect and the highest quantum yield has been achieved under our experimental conditions (using thioglycolic acid (TGA) as a modifier agent) when the processing time reached to 150 min.

Research paper thumbnail of Correlation of morphology and luminescent properties of ZnO nano particles to different surfactants via hydrothermal method

Nanocrystalline Zinc Oxide (ZnO) powders with different morphology have been successfully synthes... more Nanocrystalline Zinc Oxide (ZnO) powders with different morphology have been successfully synthesized by using different surfactants such as Cetyl Trimethyl Ammonium Bromide (CTAB), Sodium Dodecyl Sulphate (SDS), and Tri Ethanol Amine (TEA) via hydrothermal method. The products were characterized by means of powder X-ray diffraction (XRD), Scanning electron microscopy (SEM), Transmission electron microscopy (TEM), UV-visible absorption and Photoluminescence (PL) spectroscopy. The sheets, rods, and spherical morphologies of the prepared SDS, CTAB, and TEA mediated ZnO were observed in the SEM micrographs..

Research paper thumbnail of nm

Research paper thumbnail of Applying Taguchi method to optimize the synthesis conditions of ZrO2/TiO2/ZnO nanocomposite for high-performance photodegradation of Congo red

iranian journal of catalysis, Mar 1, 2021

Research paper thumbnail of Synthesis and Chracterization of Folic Acid conjugated ZnO/ Silica Core-shell as Cancer Therapeutic and Imaging Agent

Research journal of biotechnology

ABSTRACT

Research paper thumbnail of Effects of Mn doping on the structural, linear, and nonlinear optical properties of ZnO nanoparticles

Journal of the Optical Society of America B, 2018

In this study, the synthesis and characterization of undoped and Mn-doped ZnO nanoparticles with ... more In this study, the synthesis and characterization of undoped and Mn-doped ZnO nanoparticles with 2%, 5%, and 15% Mn/ZnO prepared using the hydrothermal method were reported. The structural, morphological, and chemical-bond properties of the Mn-doped ZnO nanoparticles were studied by using x-ray diffraction, field emission scanning electron microscopy (FESEM), energy dispersive x-ray analysis, and Fourier transform infrared spectroscopy analysis. X-ray diffraction patterns indicate that all of the samples have hexagonal wurtzite structures. The average diameters of the Mn-doped ZnO nanoparticles with different Mn/ZnO ratios were estimated to be about 20-38 nm from the FESEM images. The linear absorption coefficient and optical band gap energy of ZnO and Mn-doped ZnO nanoparticles were calculated using UV-Vis spectroscopy. A decrease in E g was observed by an increase in Mn concentration. The nonlinear optical measurements have been performed using a nanosecond Nd:YAG pulse laser by the Z-scan technique. Both the undoped and Mn-doped ZnO nanoparticles exhibited a negative nonlinear optical index of refraction at 532 nm relating to the self-defocusing phenomenon. The nonlinear optical absorption of ZnO and Mn-doped ZnO nanoparticles is attributed to two-photon absorption combined with free carrier absorption. Furthermore, the third-order nonlinear susceptibility values of the undoped and Mn-doped ZnO nanoparticles varied between 1.2 − 2.5 × 10 −9 esu, depending on the Mn contents. The results suggest that a Mn dopant can improve the nonlinear optical properties of ZnO nanoparticles, and Mn-doped ZnO nanoparticles synthesized through the hydrothermal method may be a promising candidate for nonlinear optical applications at 532 nm.

Research paper thumbnail of Correlation of Morphology and Luminescent Properties of Zno Nano Particles to Different Surfactants via Hydrothermal Method

international journal of nano dimension, 2013

Nanocrystalline Zinc Oxide (ZnO) powders with different morphology have been successfully synthes... more Nanocrystalline Zinc Oxide (ZnO) powders with different morphology have been successfully synthesized by using different surfactants such as Cetyl Trimethyl Ammonium Bromide (CTAB), Sodium Dodecyl Sulphate (SDS), and Tri Ethanol Amine (TEA) via hydrothermal method. The products were characterized by means of powder X-ray diffraction (XRD), Scanning electron microscopy (SEM), Transmission electron microscopy (TEM), UV-visible absorption and Photoluminescence (PL) spectroscopy. The sheets, rods, and spherical morphologies of the prepared SDS, CTAB, and TEA mediated ZnO were observed in the SEM micrographs..

Research paper thumbnail of Study of Quantum Size Effects and Optical Characteristics in Colloidal CD1-XSNXTE Quantum Dotes

international journal of nano dimension, 2014

In this work, we report, optical properties of Cd1-xSnxTe quantum dots (x= 0.05, 0.10 and 0.15) s... more In this work, we report, optical properties of Cd1-xSnxTe quantum dots (x= 0.05, 0.10 and 0.15) synthesized in water using thioglycolic acid (TGA) as a modifier agent. The optical characterization of the samples was performed through absorption (UV) and photoluminescence spectra (PL). A red shift absorption and fluorescent emission peaks was observed which can be related to the increase of nanocrystals diameter with pass the reaction time. This size dependent phenomenon is concerned to the known “quantum confinement” effect and the highest quantum yield has been achieved under our experimental conditions (using thioglycolic acid (TGA) as a modifier agent) when the processing time reached to 150 min.

Research paper thumbnail of Enhanced Blue Green Emission of ZnO Nanorods Grown by Hydrothermal Method

Journal of Nano Research, 2012

In this paper, we report enhanced blue green emission of hexagonal shaped ZnO nanorods (NRS) grow... more In this paper, we report enhanced blue green emission of hexagonal shaped ZnO nanorods (NRS) grown via a simple hydrothermal method and silica coated then by using tetraethoxysilane (TEOS). The composition and structural characteristic of the prepared samples were studied by X-ray diffraction (XRD), Field Emission Scanning Electron Microscopy and Energy Dispersive X-ray analysis (FESEM-EDAX). The results revealed well crystallized hexagonal structure possessing a perfect and ideal growth habits of wurtzite zinc oxide grown along the [00 direction in preference in both the cases. Optical properties and quality of the prepared ZnO and silica coated ZnO nanorods were examined by UV-visible and FTIR spectroscopy. Photoluminescence (PL) spectra were used to study ZnO and silica coated ZnO nanorod electronic structure, which resulted in an obvious enhanced blue-green emission for ZnO nanorod and an intense red emission with a very low UV intensity for the silica coated nanorods. Appearanc...

Research paper thumbnail of Photocatalytic degradation of Congo red by ZnO nanoparticles with different morphology

Journal of Interfaces, Thin Films, and Low dimensional systems, Dec 1, 2019

In this study, ZnO nanoparticles in three shapes, spherical, rod, and sheet are synthesized by a ... more In this study, ZnO nanoparticles in three shapes, spherical, rod, and sheet are synthesized by a hydrothermal method using three different surfactants, namely three ethanol amine, cetyl three methyl ammonium bromide, and sodium dodecyl sulfate. In all cases, the chemical composition, powder identification, morphology. and particle size of the final product are characterized by Fourier transform infrared (FTIR), X-ray diffraction (XRD), field emission scanning electronic microscopy (FESEM), EDX elemental analysis, and UV-Vis spectroscopy. The photocatalytic activity of the nanoparticles are investigated for degradation of organic pollutants (Congo red dye). The removal tests of Congo red as a water organic pollutant indicates photocatalytic activity and absorption ability of synthesized zinc oxides. Finally, the comparison of the dye removal results show that the rod nanoparticle has more efficiency in the degradation of Congo red with 97% yield over 2 hours at pH=8.

Research paper thumbnail of Room Temperature Ferromagnetism in Cobalt Doped ZnO Nanoparticles

Research paper thumbnail of Room Temperature Ferromagnetism in Cobalt Doped ZnO Nanoparticles

In the field of spintronics, studying of semiconductors with ferromagnetically polarizable carrie... more In the field of spintronics, studying of semiconductors with ferromagnetically polarizable carriers at room temperature (RT) is a very interesting subject to study. In these kinds of materials, the spin and charge of the carriers can be coupled separately with an external magnetic field. While, electrons carry both charge and spin and processing of the information in conventional electronic devices is based only on the charge of the electrons. Whereas, spin electronics or spintronics, uses the spin of In this work we report synthesis and magnetic characterization of cobalt doped ZnO nanoparticles (with different percent of doped cobalt oxide). Synthesis of the materials was carried out at room temperature by polyacrylamide-gel method, using zink sulfate and cobalt nitrate as source materials, acrylamide as monomer and N,N-methylene bisacrylamide as a lattice reagent. Characterization of the samples were performed using XRD, SEM, TEM, UV and photoluminescence (PL) studies. The X-ray diffraction patterns obtained showed formation of wurtzite ZnO structure with no secondary Co phases. The EDS measurements were employed to investigate the composition of the samples and showed the presence of Zn and cobalt elements detected. The optical absorption spectra showed internal d-d transitions related to Co 2+ incorporated on the Zn lattice site of ZnO structure. The red-shift of the band-gap edge has been attributed to a merging of donor and conduction bands due to the Co doping. The magnetic behavior of prepared cobalt doped samples was finally investigated at room temperature using vibrating sample magnetometer (VSM). The results show that, the Co doped ZnO.nanopaticles with 2% CoO is ferromacnetic at RT. This magnetic property is greatly suppressed and replaced by a paramagnetism behavior at higher doping levels.

Research paper thumbnail of Room Temperature Ferromagnetism in Cobalt Doped ZnO Nanoparticles

Research paper thumbnail of Enhanced Blue Green Emission of ZnO Nanorods Grown by Hydrothermal Method

In this paper, we report enhanced blue green emission of hexagonal shaped ZnO nanorods (NRS) grow... more In this paper, we report enhanced blue green emission of hexagonal shaped ZnO nanorods (NRS) grown via a simple hydrothermal method and silica coated then by using tetraethoxysilane (TEOS). The composition and structural characteristic of the prepared samples were studied by X-ray diffraction (XRD), Field Emission Scanning Electron Microscopy and Energy Dispersive X-ray analysis (FESEM-EDAX). The results revealed well crystallized hexagonal structure possessing a perfect and ideal growth habits of wurtzite zinc oxide grown along the [001] direction in preference in both the cases. Optical properties and quality of the prepared ZnO and silica coated ZnO nanorods were examined by UV-visible and FTIR spectroscopy. Photoluminescence (PL) spectra were used to study ZnO and silica coated ZnO nanorod electronic structure, which resulted in an obvious enhanced blue-green emission for ZnO nanorod and an intense red emission with a very low UV intensity for the silica coated nanorods. Appearance of intense red emission seems to be very promising since and it could favor more reliable fluorescence sensing in drug delivery fluorescent detection with a minor UV emission.

Research paper thumbnail of Study of quantum size effects and optical characteristics in colloidal Cd 1-x Sn x Te quantum dotes

In this work, we report, optical properties of Cd 1-x Sn x Te quantum dots (x= 0.05, 0.10 and 0.1... more In this work, we report, optical properties of Cd 1-x Sn x Te quantum dots (x= 0.05, 0.10 and 0.15) synthesized in water using thioglycolic acid (TGA) as a modifier agent. The optical characterization of the samples was performed through absorption (UV) and photoluminescence spectra (PL). A red shift absorption and fluorescent emission peaks was observed which can be related to the increase of nanocrystals diameter with pass the reaction time. This size dependent phenomenon is concerned to the known "quantum confinement" effect and the highest quantum yield has been achieved under our experimental conditions (using thioglycolic acid (TGA) as a modifier agent) when the processing time reached to 150 min.

Research paper thumbnail of Correlation of morphology and luminescent properties of ZnO nano particles to different surfactants via hydrothermal method

Nanocrystalline Zinc Oxide (ZnO) powders with different morphology have been successfully synthes... more Nanocrystalline Zinc Oxide (ZnO) powders with different morphology have been successfully synthesized by using different surfactants such as Cetyl Trimethyl Ammonium Bromide (CTAB), Sodium Dodecyl Sulphate (SDS), and Tri Ethanol Amine (TEA) via hydrothermal method. The products were characterized by means of powder X-ray diffraction (XRD), Scanning electron microscopy (SEM), Transmission electron microscopy (TEM), UV-visible absorption and Photoluminescence (PL) spectroscopy. The sheets, rods, and spherical morphologies of the prepared SDS, CTAB, and TEA mediated ZnO were observed in the SEM micrographs..

Research paper thumbnail of nm