STRUCTURAL, OPTICAL AND MAGNETIC INVESTIGATIONS ON UNDOPED AND Mn-DOPED ZnO NANOPARTICLES

2010 ◽  
Vol 09 (05) ◽  
pp. 495-502 ◽  
Author(s):  
N. RAJKUMAR ◽  
K. RAMACHANDRAN
Keyword(s):  
Zno Nanoparticles ◽  
Photoelectron Spectroscopy ◽  
Spherical Particles ◽  
Precipitation Method ◽  
Chemical Compositions ◽  
Secondary Phases ◽  
X Ray ◽  
Doped Zno ◽  
Co Precipitation ◽  
Mn Doped

Undoped and Mn (1 and 3 at.%) doped ZnO nanoparticles were synthesized by a simple chemical co-precipitation method. Rietveld refinement of X-ray diffraction (XRD) data revealed that undoped and Mn doped ZnO nanoparticles crystallize in the monophasic wurtzite structure and monotonous expansion of the lattice constants with increasing Mn content, due to the effective Mn doping. TEM images of all the samples showed the monodispersive spherical particles with the size of ~7 nm. The quantum confinement of nanoparticles was tested from UV–Vis absorbance measurement and the particle sizes were calculated and compared with TEM and XRD. The chemical compositions were analyzed by energy dispersive spectroscopy (EDS). In order to investigate the origin of ferromagnetism, the electronic structures of the Zn , O , and Mn atoms were probed by X-ray photoelectron spectroscopy (XPS). XPS data revealed that most of the dopants (Mn) exists in +2 oxidation state for 3 at.% Mn doped ZnO sample. The magnetization curves of the Mn doped ZnO samples indicate the existence of room-temperature ferromagnetic (RTFM) behavior. Here the observed RTFM in Mn doped ZnO can be attributed to the substitutional incorporation of Mn at Zn sites rather than due to the formation of any secondary phases.

The Influence of Montmorillonite Incorporation in Mn-Doped ZnO Nanoparticles for Photocatalytic Degradation of Organic Dyes

2015 ◽  
Vol 1112 ◽  
pp. 194-200
Author(s):  
Nadia Febiana Djaja ◽  
Rosari Saleh
Keyword(s):  
Zno Nanoparticles ◽  
Diffuse Reflectance Spectroscopy ◽  
Organic Dyes ◽  
Uv Light ◽  
Precipitation Method ◽  
X Ray Diffraction ◽  
X Ray ◽  
Doped Zno ◽  
Co Precipitation ◽  
Mn Doped

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.

Magnetism in Mn-doped ZnO nanoparticles prepared by a co-precipitation method

2006 ◽  
Vol 17 (5) ◽  
pp. 1278-1285 ◽  
Author(s):  
O D Jayakumar ◽  
H G Salunke ◽  
R M Kadam ◽  
Manoj Mohapatra ◽  
G Yaswant ◽  
...  
Keyword(s):  
Zno Nanoparticles ◽  
Precipitation Method ◽  
Doped Zno ◽  
Co Precipitation ◽  
Mn Doped

Photocatalytic Activity of Zeolite Supported Transition Metal-(Co2+ and Cr2+) Doped ZnO: Comparative Study

2015 ◽  
Vol 827 ◽  
pp. 43-48
Author(s):  
Annisa Noorhidayati ◽  
Mia Putri Rahmawati ◽  
Nadia Febiana Djaja ◽  
Rosari Saleh
Keyword(s):  
Transition Metal ◽  
Zno Nanoparticles ◽  
Diffuse Reflectance Spectroscopy ◽  
Uv Light ◽  
Transition Metal Ions ◽  
Precipitation Method ◽  
X Ray Diffraction ◽  
X Ray ◽  
Doped Zno ◽  
Co Precipitation

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.

Effect of PEG on Structural and Magnetic Properties of Mn Doped ZnO Nanocrystals

2013 ◽  
Vol 678 ◽  
pp. 234-238 ◽  
Author(s):  
Vishwanath D. Mote ◽  
Babasaheb N. Dole
Keyword(s):  
Room Temperature ◽  
Magnetic Hysteresis ◽  
Lattice Parameters ◽  
Precipitation Method ◽  
Average Crystalline Size ◽  
X Ray ◽  
Zno Nanocrystals ◽  
Doped Zno ◽  
Co Precipitation ◽  
Mn Doped

Nanosized Mn doped ZnO samples were synthesized by co-precipitation method using Polyethylene glycol (PEG) as a capping agent. X- ray diffraction patterns confirm that the pure and Mn doped ZnO nanocrystals have wurtzite structure without any seconadary phases. Lattice parameters of pure and Mn doped ZnO nanocrystals increase slightly with increasing Mn concentration. The average crystalline size of pure and Mn doped ZnO nanocrystals are in the range of 14-18 nm. The X-ray density for pure and Mn doped ZnO sample is calculated using lattice parameters. It is found that almost static for Mn doped ZnO samples. In the Zn1-xMnx samples, room temperature magnetic hysteresis is observed and the saturation magnetization increases with increasing Mn content. However, these samples show room temperature ferromagnetic in nature. Result of the present investigation compared without PEG.

Transition Metal (Ni, Cr)-Doped ZnO Assisted CTAB Performance on Decolorization of Organic Dyes

2015 ◽  
Vol 1123 ◽  
pp. 289-294
Author(s):  
Annisa Noorhidayati ◽  
Raynaldi Philipus ◽  
Mia Putri Rachmawati ◽  
Rosari Saleh
Keyword(s):  
Transition Metal ◽  
Zno Nanoparticles ◽  
Organic Dyes ◽  
Uv Light ◽  
Precipitation Method ◽  
Ammonium Bromide ◽  
X Ray ◽  
Bet Method ◽  
Doped Zno ◽  
Co Precipitation

A series of semiconductor nanophotocatalyst based on transition metal (Ni and Cr) doped ZnO nanoparticles have been synthesized in the presence of cetril methyl ammonium bromide (CTAB) by co-precipitation method. Samples were characterized by X-Ray Diffraction (XRD), Energy Dispersive X-Ray (EDX), Field Emission Scanning Electron Microscope (FESEM), and Brunauer-Emmet-Teller (BET) method. The resulting materials were explored for the decolorization of 4 different organic dyes (methyl orange, methylene blue, malachite green, and congo red) under UV light irradiation. The resulting materials exhibited relatively higher photocatalytic decolorization than bare Ni- and Cr-doped ZnO nanoparticles with similar doping concentration

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