Structural Properties of Cu-Doped ZnO Prepared by Coprecipitation Method

2021 ◽  
Vol 1028 ◽  
pp. 90-95
Author(s):  
Kharisma Noor Afifah Supoyo ◽  
Mohammad Syaiful Anwar ◽  
Retno Asih ◽  
Malik Anjelh Baqiya ◽  
Prae Chirawatkul ◽  
...  

An experimental study to determine the effect of Cu doping on structural properties of ZnO nanoparticle has been conducted. Zn1-xCuxO (CZO) were prepared by co-precipitation method by varying Cu concentration with x = 0.00, 0.10, 0.11 and 0.12. The structural properties of the CZO sample were characterized by X-Ray diffraction (XRD) and X-ray Absorption Spectroscopy (XAS), which consist of XANES (X-ray Absorption Near-Edge Spectroscopy) and EXAFS (Extended X-ray Absorption Fine Structure). XAS measurements were performed in the energy of Cu K-edge and Zn K-edge using synchrotron radiation at SLRI (Synchrotron Light Research Institute) in Thailand. Both Cu K-edge and Zn K-edge XANES spectra indicate that the oxidation states of Cu and Zn ions are 2+. Analysis of XRD data with refinement method using Rietica software confirms the presence of Cu as doping in ZnO host lattice with the crystallite size ranging between 26 and 44 nm. Moreover, it shows that the obtained CZO samples are polycrystalline with (002) predominant reflection and exhibit a hexagonal wurtzite structure.

2014 ◽  
Vol 1025-1026 ◽  
pp. 645-650
Author(s):  
Supranee Foowut ◽  
Tawanrat Palothaisit ◽  
Natthadabhorn Boonlor ◽  
Panida Prompinit ◽  
Pinsuda Viravathana

In this work, the FexOy catalysts were prepared by the co-precipitation method. The catalysts were characterized by X-ray diffraction (XRD), X-ray absorption spectroscopy (XAS), and Brunauer-Emmett-Teller (BET) surface analysis. From XRD results, the FexOy with the wastewater to coagulant ratio of 1:2 catalyst (FexOy-1:2) calcined at 600 °C for 6 h showed the presence of the wustite (FeO) form. XANES analysis showed the phase of FeO in FexOy-1:2 calcined at 600 °C for 6 h which corresponded to the result from XRD. The FexOy 1:1 catalyst had higher specific surface area and larger total pore volume compared to the FexOy 1:2 catalyst.


2012 ◽  
Vol 18 (6) ◽  
pp. 1229-1238 ◽  
Author(s):  
Marion A. Stevens-Kalceff ◽  
Zhiqiang Liu ◽  
Hans Riesen

AbstractBaFCl:Sm3+ is an efficient photoluminescent storage phosphor for ionizing radiation. Cathodoluminescence (CL) microanalysis enables the Sm2+ and Sm3+ oxidation states of samarium doped BaFCl to be easily identified, provides information about electron-beam and X-ray induced modification of BaFCl:Sm, and enables the synthesis dependent spatial distribution of samarium dopants of <100 ppm concentration to be determined with sub-100 nm resolution at 295 K. CL spectroscopy of BaFCl:Sm particles reveals broad CL emissions at ∼360 and ∼500 nm associated with Vk(Cl−) and oxygen-vacancy defects in the BaFCl host lattice and fine structure CL emissions associated with major 4GJ → 6HJ (Sm3+) and 5DJ → 7FJ (Sm2+) transitions. CL microanalysis shows samarium dopants are uniformly distributed in conventional sintered microcrystalline BaFCl:Sm. In contrast, CL investigations reveal that for BaFCl:Sm nanoparticles, which have been prepared using a co-precipitation method, with greatly improved Sm3+ → Sm2+ conversion efficiency, the samarium dopants are concentrated near the particle surface resulting in a BaFCl:Sm3+ shell surrounding the BaFCl core, which is stable to energetic irradiation.


2017 ◽  
Vol 266 ◽  
pp. 117-121
Author(s):  
Piyasak Akcaboot ◽  
Napat Kanokpornwasin ◽  
Monthida Raoarun ◽  
Patraporn Saiwattanasuk ◽  
Pinsuda Viravathana

Co-promoted Cu/ZnO catalysts were studied for Fischer-Tropsch synthesis (FTS). All catalysts were prepared by the co-precipitation method, having the mass ratio of Co:Cu:Zn=0 (unpromoted), 0.05, 0.5:1:1, and characterized by X-ray diffraction (XRD), X-ray absorption spectroscopy (XAS), including X-ray absorption near edge structure (XANES) and extended X-ray absorption fine structure (EXAFS). From XRD and XAS, the results confirmed the phase transformation of CuO to Cu foil and Co3O4 to Co foil in Co-promoted catalysts after reduction. After FTS reaction testing, the Co-promoted catalysts showed the decrease in methanol selectivity of 15 and 1.6% for 0.05Co-Cu/ZnO and 0.5Co-Cu/ZnO, respectively, and the increase in C5-C15 selectivity during 30 h of reaction.


2019 ◽  
Vol 964 ◽  
pp. 40-44 ◽  
Author(s):  
Hariyanto Budi ◽  
Husain Husain ◽  
Lapboonruang Supanun ◽  
Pratapa Suminar

Investigation of Fe K-edge X-Ray Absorption Near Edge Spectroscopy (XANES) spectra of Fe3O4 (FeO.Fe2O3) from natural source compared with the Fe3O4 standard is presented. The natural Fe3O4 powder was prepared from ironstone of Tanah Laut, Kalimantan Selatan by co-precipitation method. XANES measurements in transmission mode were performed at the Synchrotron Light Research Institute (SLRI), Nakhon Ratchasima, Thailand. XRD phase analysis confirms that the synthesized Fe3O4 powder is a single phase, but it cannot determine the proportion of Fe2O3 and FeO in the structure. TEM measurement confirms that the particle size of natural Fe3O4 about 10 nm. Qualitative analysis of the pre-edge XANES data revealed that the absorbing atom in the XAS measurement is Fe3+. Meanwhile, the absorption edge (E0) values of natural and standard Fe3O4 powders were 7126.44 eV and 7125.02 eV, respectively. The proportion was then acquired using XANES data analysis through Linear Combination Fitting (LCF). It was found that the natural Fe3O4 sample consisted of 98 wt. % Fe2O3 and 2 wt.% FeO, while the standard Fe3O4 powder consisted of 96 wt. % Fe2O3 and 4 wt. % FeO. The mechanism of the absorption in both samples is also described and compared.


Author(s):  
Luciana Biazati ◽  
Lucas Lorenzini ◽  
Sandra Ferreira ◽  
Arilza Porto ◽  
Eustáquio de Castro ◽  
...  

The correlation between iron distribution in octahedral or tetrahedral sites in synthetic magnetite and zinc spinel ferrites and their catalytic properties were investigated in this work. The zinc‑doped nanomagnetites were prepared by co-precipitation method and annealed at 420 °C. X-ray diffraction, UV-Vis, X-ray absorption and 57Fe Mössbauer spectroscopies were used to identify iron sites. The obtained results showed that ZnII replaces the relatively smaller FeIII cation in the tetrahedral sites, increasing the cubic lattice dimension, and this replacement remarkably enhances the catalytic effectiveness of the Zn-spinel ferrite towards the indigo carmine degradation compared to undoped magnetite. The indigo carmine degradation experiments were carried out using photo-Fenton method in which 50 mL of indigo carmine dye aqueous solutions (20 mg L−1, pH 3.0), 20 mg ZnxFe(3-x)O4, and 2.0 mL H2O2 (aqueous solution at 0.028 mol L−1) were placed under UV light at 25 °C. Under these experimental conditions the degradation rate of indigo carmine was superior to 98%.


2021 ◽  
Vol 945 (1) ◽  
pp. 012017
Author(s):  
Chin Ying Hui ◽  
Sin Jin Chung ◽  
Lam Sze Mun

Abstract A facile co-precipitation method was employed to fabricate hierarchical ZnO structure and characterized by various analytical instruments. The images of ZnO from field-emission scanning electron microscopy exhibited spheroidal morphology which composed of numerous layers of nanosheets and formed a hierarchical structure. Energy dispersive X-ray spectrum validated the presence of Zn and O atoms and its purity. X-ray diffraction pattern of ZnO revealed the establishment of hexagonal wurtzite structure. Optical property analysis disclosed that the as-fabricated ZnO had strong absorbance of wavelength from 350-410 nm with an absorption band edge of 367 nm. In this paper, the photocatalytic activity of hierarchical ZnO structure was confirmed by degradation of endocrine disrupting chemical, namely dimethyl phthalate under UV lamp irradiation. The photodegradation of dimethyl phthalate in aqueous solution over as-fabricated ZnO reached 55.9% after 60 min irradiation. The photocatalytic degradation of DMP obeyed the pseudo first-order kinetic reaction with a rate constant of 0.0166 min−1.


Batteries ◽  
2021 ◽  
Vol 7 (1) ◽  
pp. 5
Author(s):  
Min Li ◽  
Angelo Mullaliu ◽  
Stefano Passerini ◽  
Marco Giorgetti

Sodium titanium hexacyanoferrate (TiHCF, Na0.86Ti0.73[Fe(CN)6]·3H2O) is synthesized by a simple co-precipitation method in this study. Its crystal structure, chemical composition, and geometric/electronic structural information are investigated by X-ray powder diffraction (XRPD), microwave plasma-atomic emission spectroscopy (MP-AES), and X-ray absorption spectroscopy (XAS). The electroactivity of TiHCF as a host for Li-ion and Na-ion batteries is studied in organic electrolytes. The results demonstrate that TiHCF is a good positive electrode material for both Li-ion and Na-ion batteries. Surprisingly, however, the material shows better electrochemical performance as a Na-ion host, offering a capacity of 74 mAh g−1 at C/20 and a 94.5% retention after 50 cycles. This is due to the activation of Ti towards the redox reaction, making TiHCF a good candidate electrode material for Na-ion batteries.


Crystals ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 832
Author(s):  
Edna X. Figueroa-Rosales ◽  
Javier Martínez-Juárez ◽  
Esmeralda García-Díaz ◽  
Daniel Hernández-Cruz ◽  
Sergio A. Sabinas-Hernández ◽  
...  

Hydroxyapatite (HAp) and hydroxyapatite/multi-walled carbon nanotube (MWCNT) composites were obtained by the co-precipitation method, followed by ultrasound-assisted and microwave radiation and thermal treatment at 250 °C. X-ray diffraction (XRD) confirmed the presence of a hexagonal phase in all the samples, while Fourier-transform infrared (FTIR) spectroscopy elucidated the interaction between HAp and MWCNTs. The photoluminescent technique revealed that HAp and the composite with non-functionalized MWCNTs present a blue luminescence, while the composite with functionalized MWCNTs, under UV-vis radiation shows an intense white emission. These findings allowed presentation of a proposal for the use of HAp and HAp with functionalized MWCNTs as potential materials for optoelectronic and medical applications.


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