Effect of calcination temperature on phase transformation and crystallite size of copper oxide (CuO) powders

Ratnawulan, -; Fauzi, Ahmad; Hayati, Sukma

doi:10.1063/1.4995173

Cited by 18 publications

(11 citation statements)

References 5 publications

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“…Field Emission SEM images of the kaolinite clay and its calcined form show similar particle morphology (Figure A, F). Cu-doped nanocomposite material (Figure B) contains roughly spherical particles which are mostly aggregated . This is consistent with the presence of tenorite in the nanocomposite material which is in agreement with the X-ray diffractograms, (Figure B).…”

Section: Resultssupporting

confidence: 87%

“…The tenorite reflections are observed at 35.5, 38.7, and 66.2° 2θ in both Cu-doped and Cu/Zn-doped hybrid clay nanocomposites whereas other tenorite peaks were found at 61.4, and 65.9° (JCPDS 048–1548). Tenorite-like atacamite has a monoclinic crystal structure . The tenorite phase found in both Cu nanocomposites probably is a result of the reaction between NaOH and CuCl 2 in the reacting system which is presented in eq : The heating of the copper hydroxide produces CuO (tenorite) as shown in eq . Although the X-ray diffractogram of Cu-doped and Cu/Zn-doped nanocomposites show similarities (albeit with different reflection intensities) the reflection at 2θ 28.4° in the pattern of the Cu-doped nanocomposite suggests the presence of an additional crystalline phase called nantokite which is CuCl .…”

Section: Resultsmentioning

confidence: 94%

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Visible-Light-Mediated Photodynamic Water Disinfection @ Bimetallic-Doped Hybrid Clay Nanocomposites

Ugwuja

Adelowo

Ogunlaja

et al. 2019

ACS Appl. Mater. Interfaces

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This study reports a new class of photocatalytic hybrid clay nanocomposites prepared from low-cost sources (kaolinite clay and Carica papaya seeds) doped with Zn and Cu salts via a solvothermal process. X-ray diffraction analysis suggests that Cu-doping and Cu/Zn-doping introduce new phases into the crystalline structure of Kaolinite clay, which is linked to the reduced band gap of kaolinite from typically between 4.9 and 8.2 eV to 2.69 eV for Cu-doped and 1.5 eV for Cu/Zn hybrid clay nanocomposites (Nisar, J.; Århammar, C.; Jamstorp, E.; Ahuja, R. Phys. Rev. B 2011, 84, 075120). In the presence of solar light irradiation, Cu-and Cu/Zn-doped nanocomposites facilitate the electron−hole pair separation. This promotes the generation of singlet oxygen which in turn improves the water disinfection efficiencies of these novel nanocomposite materials. The nanocomposite materials were further characterized using high-resolution scanning electron microscopy, fluorimetry, thermogravimetric analysis, and Raman spectroscopy. The breakthrough times of the nanocomposites for a fixed bed mode of disinfection of water contaminated with 2.32 × 10 7 cfu/mL E. coli ATCC 25922 under solar light irradiation are 25 h for Zn-doped, 30 h for Cu-doped, and 35 h for Cu/Zn-doped nanocomposites. In the presence of multidrug and multimetal resistant strains of E. coli, the breakthrough time decreases significantly. Zn-only doped nanocomposites are not photocatalytically active. In the absence of light, the nanocomposites are still effective in decontaminating water, although less efficient than under solar light irradiation. Electrostatic interaction, metal toxicity, and release of singlet oxygen (only in the Cu-doped and Cu/Zn-doped nanocomposites) are the three disinfection mechanisms by which these nanocomposites disinfect water. A regrowth study indicates the absence of any living E. coli cells in treated water even after 4 days. These data and the long hydraulic times (under gravity) exhibited by these nanocomposites during photodisinfection of water indicate an unusually high potential of these nanocomposites as efficient, affordable, and sustainable point-of-use systems for the disinfection of water in developing countries.

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Section: Resultssupporting

confidence: 87%

Section: Resultsmentioning

confidence: 94%

Visible-Light-Mediated Photodynamic Water Disinfection @ Bimetallic-Doped Hybrid Clay Nanocomposites

Ugwuja

Adelowo

Ogunlaja

et al. 2019

ACS Appl. Mater. Interfaces

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“…Similar results have also been reported elsewhere [15,27]. As the sample is properly heated, the internal energy of the atoms will increase due to vibration which consequently changes the atomic distance or breaking some of the atomic bonds before diffuse to another atom to form new nuclei thus promoted a crystal growth with the same phase [28]. Since the Cacationmobilities are higher than Si atoms, then the phase formation of βwollastonite is more pronounced than the unreacted quartz at higher sintering temperature.…”

Section: Rietveld Refinement and Porositysupporting

confidence: 85%

Assessment of crystalline phase change and porosity by Rietveld refinement on lightweight cullet and paper ash glass-ceramic

Abu-Samah

Sahar

Yusop

et al. 2020

Journal of Asian Ceramic Societies

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Lightweight glass-ceramic from waste material consists of (x) paper ash-(80-x) cullet-20 Kaolin clay where (10 ≤ x ≤ 30 weight %) are sintered at 900°C, 1000°C and 1100°C using conventional solid-state reaction technique. The influence of composition and sintering temperature on density, crystalline phase, porosity and surface pore morphology was studied. The crystal symmetry, space group and unit cell dimensions which are executed from XRD data are analyzed using SmartLab Studio II Powder XRD software. Meanwhile, the lattice parameter, cell volume, theoretical densities and porosity were estimated by Rietveld refinement method. The results reveal that all parameters exhibit a temperature-dependent character, as the temperature is increased, the density decreases and porosity increases due to bloating effects. It is also found out that the glass-ceramic compose of 25 paper ash −55 cullet-20 Kaolin clay, sintered at 900°C exhibits an optimum characteristic of the sample density reached optimum because of vitrification between cullet glass, paper ash and kaolin clay to form liquid phase which promotes adhesion and polymerization. It is observed that the surface morphology of the sample is affected by the crystallization process during sintering.

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“…(4), another experimental batch adsorption process was carried out using SS-RH adsorbent prepared at a predicted optimum process condition. The percent BGD uptake was 97.78%, which shows good conformity between predicted and experimental results at optimum levels with an approximate relative error of 2.70%, as shown in the shown that preparation of adsorbents from raw materials by the calcination process at favorable conditions evacuates adsorbed gases that otherwise fill the existing pores (Ratnawulan, Fauzi, & Sukma Hayati, 2017;Yusuff, 2017). Exhibit 10b revealed that the BGD was completely adsorbed unto the pores of the calcined SS-RH prepared at optimum condition after the adsorption process.…”

Section: Prediction Of Adsorbent Process Variable For Optimum Bgd Uptakesupporting

confidence: 68%

“…This creates pores for adsorption of the BGD to take place on the surface of the composite SS‐RH adsorbent. Recent studies have shown that preparation of adsorbents from raw materials by the calcination process at favorable conditions evacuates adsorbed gases that otherwise fill the existing pores (Ratnawulan, Fauzi, & Sukma Hayati, ; Yusuff, ). Exhibit b revealed that the BGD was completely adsorbed unto the pores of the calcined SS‐RH prepared at optimum condition after the adsorption process.…”

Section: Resultsmentioning

confidence: 99%

Synthesis of composite snail shell‐rice husk adsorbent for brilliant green dye uptake from aqueous solution: Optimization and characterization

Popoola

Aderibigbe

Yusuff

2018

Environmental Quality Mgmt

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The optimum preparation conditions for composite snail shell‐rice husk (SS‐RH) adsorbent that gives the optimum brilliant green dye (BGD) uptake has been found at a calcination temperature of 681.10°C, a calcination time of 2.61 hours, and a mixing ratio of 2.61 snail shell‐rice husk, leading to a 97.78% BGD uptake using Central Composite Design. The SS‐RH adsorbent characterization was executed before and after adsorption using a scanning electron microscope (SEM), energy‐dispersive x‐ray spectroscopy (EDS), and Fourier‐transform infrared spectroscopy (FTIR). The SEM image before adsorption showed a highly porous, uniform matrix formation with wide cavities resulting from favorable preparation by calcination at optimum conditions, whereas the image revealed complete adsorption of the BGD onto the vacant pores of the calcined SS‐RH after adsorption. EDS analysis revealed formation of active metal oxides on the surface of the composite SS‐RH was enhanced by the calcination process before adsorption, while changes in their weight percent were noticed after adsorption, showing the influence of the active metal oxides on the process. FTIR revealed the existence of functional groups on the SS‐RH surface, which can interact with the BGD molecules to enhance effective adsorption and cause a shift in the values of the wavenumbers of broad peaks before and after adsorption, respectively. In conclusion, the results obtained have proven SS‐RH to be a valuable composite adsorbent for BGD adsorption.

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Effect of calcination temperature on phase transformation and crystallite size of copper oxide (CuO) powders

Cited by 18 publications

References 5 publications

Visible-Light-Mediated Photodynamic Water Disinfection @ Bimetallic-Doped Hybrid Clay Nanocomposites

Visible-Light-Mediated Photodynamic Water Disinfection @ Bimetallic-Doped Hybrid Clay Nanocomposites

Assessment of crystalline phase change and porosity by Rietveld refinement on lightweight cullet and paper ash glass-ceramic

Synthesis of composite snail shell‐rice husk adsorbent for brilliant green dye uptake from aqueous solution: Optimization and characterization

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