Optical Properties of Zn-Doped CeO2 Nanoparticles as a Function of Zn Content

2014 ◽  
Vol 896 ◽  
pp. 108-111 ◽  
Author(s):  
Iis Nurhasanah ◽  
Heri Sutanto ◽  
Ririn Futikhaningtyas

CeO2 and Zn-doped CeO2 nanoparticles were synthesized by simple precipitation method in water/isopropanol mixed solvent from cerium nitrate and zinc nitrate with various mole ratios. The precipitates were then calcined at 300°C for 4 hours and characterized by X-ray diffraction (XRD) and uv-vis spectroscopy. Characterization by x-ray diffraction shows that high crystallinity of cubic fluorite structure of CeO2 with crystallite size in the range 6 12 nm depending on Zn content. CeO2 nanoparticles exhibits tranparent in the visible region and strong absorbance in the ultra-violet region. It was also found that significant effect of Zn content on transmittance and optical band gap. In addition, Zn substitution into Ce suppressing photocatalytic activity of pure CeO2 nanoparticle under sunlight irradiation. These results suggest that Zn-doped CeO2 nanoparticle is more prommising for safer optical UV-absorbers.

Polymers ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 1712
Author(s):  
Appusamy Muthukrishnaraj ◽  
Salma Ahmed Al-Zahrani ◽  
Ahmed Al Otaibi ◽  
Semmedu Selvaraj Kalaivani ◽  
Ayyar Manikandan ◽  
...  

Towards the utilization of Cu2O nanomaterial for the degradation of industrial dye pollutants such as methylene blue and methyl orange, the graphene-incorporated Cu2O nanocomposites (GCC) were developed via a precipitation method. Using Hummers method, the grapheme oxide (GO) was initially synthesized. The varying weight percentages (1–4 wt %) of GO was incorporated along with the precipitation of Cu2O catalyst. Various characterization techniques such as Fourier-transform infra-red (FT-IR), X-ray diffraction (XRD), UV–visible diffused reflectance (UV-DRS), Raman spectroscopy, thermo gravimetric analysis (TGA), energy-dispersive X-ray analysis (EDX), and electro chemical impedance (EIS) were followed for characterization. The cabbage-like morphology of the developed Cu2O and its composites were ascertained from field-emission scanning electron microscopy (FESEM) and high-resolution transmission electron microscopy (HR-TEM). In addition, the growth mechanism was also proposed. The results infer that 2 wt % GO-incorporated Cu2O composites shows the highest value of degradation efficiency (97.9% and 96.1%) for MB and MO at 160 and 220 min, respectively. Further, its catalytic performance over visible region (red shift) was also enhanced to an appreciable extent, when compared with that of other samples.


2014 ◽  
Vol 32 (4) ◽  
pp. 688-695 ◽  
Author(s):  
Munirah Munirah ◽  
Ziaul Khan ◽  
Mohd. Khan ◽  
Anver Aziz

AbstractThis paper describes the growth of Cd doped ZnO thin films on a glass substrate via sol-gel spin coating technique. The effect of Cd doping on ZnO thin films was investigated using X-ray diffraction (XRD), UV-Vis spectroscopy, photoluminescence spectroscopy, I–V characteristics and field emission scanning electron microscopy (FESEM). X-ray diffraction patterns showed that the films have preferred orientation along (002) plane with hexagonal wurtzite structure. The average crystallite sizes decreased from 24 nm to 9 nm, upon increasing of Cd doping. The films transmittance was found to be very high (92 to 95 %) in the visible region of solar spectrum. The optical band gap of ZnO and Cd doped ZnO thin films was calculated using the transmittance spectra and was found to be in the range of 3.30 to 2.77 eV. On increasing Cd concentration in ZnO binary system, the absorption edge of the films showed the red shifting. Photoluminescence spectra of the films showed the characteristic band edge emission centred over 377 to 448 nm. Electrical characterization revealed that the films had semiconducting and light sensitive behaviour.


Author(s):  
San San Htwe

This In the research paper analyses structural, morphological, compositional properties, optical properties and energy band gap of ZnO nanoparticle synthesized using zinc acetate dehydrate and NaOH using precipitation method reported. The synthesized nanoparticles analyze using X-Ray Diffraction (XRD) and scanning electron microscopy (SEM), and UV- Vis Spectroscopy. Synthesized nanoparticles can be utilized as building materials in fabrication of various personal care products and optoelectronic devices including solar cells, LED’s etc.


2014 ◽  
Vol 879 ◽  
pp. 155-163 ◽  
Author(s):  
Rahizana Mohd Ibrahim ◽  
Markom Masturah ◽  
Huda Abdullah

Nanoparticles of Zn1-xFexS ( x=0.0,0.1,0.2 and 0.3) were prepared by chemical co-precipitation method from homogenous solution of zinc and ferum salt at room temperature with controlled parameter. These nanoparticles were sterically stabilized using Sodium Hexamethaphospate (SHMP). Here, a study of the effect of Fe doping on structure, morphological and optical properties of nanoparticles was undertaken. Elemental analysis, morphological and optical properties have been investigated by Fourier-Transform-Infrared spectroscopy (FT-IR), X-Ray Fluorescence (XRF), Field Emmision Scanning Electron Microscopy (FESEM), X-ray Diffraction (XRD), Transmission Electron Microscopy (TEM) and UV-Visible Spectroscopy. FTIR measurement confirmed the presence of SHMP in the nanoparticles structure with the FESEM images depicting considerable less agglomeration of particles with the presence of SHMP. While XRF results confirm the presence of Fe2+ ion as prepared in the experiment. The particles sizes of the nanoparticles lay in the range of 2-10 nm obtained from the TEM image were in agreement with the XRD results. The absorption edge shifted to lower wavelengths with an increase in Fe concentration shown in the UV-Vis spectroscopy. The band gap energy value was in the range of 4.95 5.15 eV. The blueshift is attributed to the quantum confinement effect.


2016 ◽  
Vol 3 (02) ◽  
pp. 158
Author(s):  
Iis Nurhasanah ◽  
Nurul Wahyu Puspaningrum ◽  
Ida Nursati

<span>Nanoceria has been proposed as inorganic material for sunscreen product because of its <span>excellent UV absorpsition ability. Fine particle nanoceria and non-aglomeration determines <span>comport and covering capability on human skin. Particle size and aglomeration could be <span>controlled by parameters and medium synthesis. In the present work, nanoceria powders were <span>synthesized using precipitation method in different pH of 7 and 10. Precipitation was caried<br /><span>out in water/isopropanol mixed solvent. Cerium nitrate and amonium hydroxide was used as <span>source of cerium and precipitation agent, respectively. Crystal structure of nanoceria was <span>examined using x-ray diffraction (XRD). Scanning electron microscope (SEM) was used to <span>observe morphology of nanoceria. Diffraction pattern analysis shows that the precipitates <span>were single phase of nanoceria with cubic fluorite structure and lattice contants of 0.5429 nm<br /><span>and 0.5419 nm. Crystallite size and lattice strain were obtained from Williamson-Hall method. <span>Precipitation in pH of 7 resulted in smaller crystallite size which correlated to the larger lattice <span>strain and lattice constant. SEM image shows spherical morphology with less agglomeration <span>occuring for nanoceria precipitated in pH 10.</span></span></span></span></span></span></span></span></span></span></span></span></span><br /></span>


2013 ◽  
Vol 678 ◽  
pp. 91-96
Author(s):  
Krishnan Sambath ◽  
Manickam Saroja ◽  
Muthusamy Venkatachalam ◽  
Krishnan Rajendran ◽  
Kumaravelu Jagatheeswaran

Flower-like ZnO nanostructures have been synthesized using zinc nitrate hexahydrate and hexamethylenetetramine (HMT) by a low-temperature hydrothermal technique. The prepared ZnO nanostructures exhibit hexagonal wurtzite structure, well-defined flower-like morphology, and a strong blue emission photoluminescence. Flower-like ZnO nanostructures consisting of multilayered petals are formed with the length of about 1 μm. All the flower petals exhibit the tapering feature with the root size of 300-500 nm and tip size of 50-100 nm. The prepared ZnO sample has been studied using x-ray diffraction technique, energy dispersive x-ray analysis, scanning electron microscope and FTIR spectroscopy. The photoluminescence spectrum demonstrated two emission bands, a near band edge (NBE) emission in the UV region centering at 386 nm and a high intensity deep band emission (DBE) in the visible region centering at 483 nm.


2016 ◽  
Vol 697 ◽  
pp. 386-389 ◽  
Author(s):  
Jing Lin Shi ◽  
Zhi Xue Qu ◽  
Qun Wang

Chemical co-precipitation method was used to prepare Gd2Zr2O7 powders. The powders were then heated in air at 1500°C, 1510°C, 1525°C, 1530°C, 1550°C, 1575°C, 1600°C for 5 h, and 1575°C, 1600°C for 10 h, respectively. The samples after heat treatment were characterized by X-ray diffraction and Raman spectroscopy. X-ray diffraction patterns reveal that order-disorder transition of Gd2Zr2O7 occurs between 1550°C and 1575°C. Prior to the transition, the relative intensity of peaks corresponding to the super-lattice of pyrochlores increases with the increasing temperature. On the other hand, Raman spectra give an inconsistent result from the X-ray diffraction data. No appreciable difference can be observed for all the samples though with peaks broadening as temperature increases. The spectra of the samples indicated as fluorite structure in X-ray diffraction patterns appear with six resolvable peaks which is quite different from the spectrum of ideal fluorite structure.


Author(s):  
M Karthikeyan ◽  
A Jafar Ahamed ◽  
P Vijaya Kumar

The present investigation, the successful preparation of pure ZnO (Z1) NPs and SrBa dual doped ZnO (Z2) NPs by chemical co-precipitation technique without use of any capping agent. The structural and morphological properties of Z1 and Z2 NPs were analyzed using X-ray diffraction (XRD) studies, Field emission scanning electron microscopy (FESEM), Elemental analysis (EDAX), Fourier transform infrared spectroscopy (FTIR). An optical property was studied by UV–Vis spectroscopy and Photoluminescence (PL) spectra. The antimicrobial activity of Z1 and Z2 NPs has been investigated against Staphylococcus aureus and Klebsiella pneumoniae bacterial strains. It has been interestingly observed that Z2 NPs has enhanced the inhibitory activity than that of Z1 NPs against S. aureus and more efficiently than the K. pneumoniae bacterial strain.


2021 ◽  
Author(s):  
Senthilkumar M ◽  
C. Arunagiri

Abstract FexZn1-xO (x = 0, 0.05, 0.075, 0.1 M) nanoparticles based photocatalysts were synthesized by a chemical precipitation method and characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM) with energy dispersive X-ray emission (EDX) and UV–Vis spectroscopy. The photocatalytic efficiency of FexZn1-xO catalysts was assessed under visible light irradiation using the degradation of methylene blue (MB) and methyl orange (MO) dye in aqueous solution. The present investigation shows that the effect of optimized parameters (pH, catalyst dosage and initial dye concentration) and doping concentrations plays significant role in photocatalytic activity. The detailed photocatalytic mechanism for the enhancement of photocatalytic activity has also been proposed.


Author(s):  
NADI SHOJAEE ◽  
TOURADJ EBADZADEH ◽  
ALIREZA AGHAEI

In present study ZnO nanorods were synthesized in an aqueous solution using a domestic microwave oven for irradiation. The nanorods have been grown on substrates immersed in an aqueous solution which contains zinc nitrate and hexamethylenetetramine as precursors. Eventually, effect of some parameters such as precursor's concentration and heating time on growth mechanism was characterized. The product phase was detected using X-ray diffraction (XRD). Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) exhibited the resultant structure is uniform and single crystalline. Finally Uv-Vis spectroscopy was used to measure the nanorod's band gap.


Sign in / Sign up

Export Citation Format

Share Document