Structural, Optical, and Electronic Characterization of Fe-Doped Alumina Nanoparticles

Heiba, Zein K.; Mohamed, Mohamed Bakr; Wahba, Adel Maher; Imam, N.G.

doi:10.1007/s11664-017-5830-0

Cited by 26 publications

(11 citation statements)

References 36 publications

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“…This result is in accordance with XRD data [19], which confirmed defect spinel structure of γ-alumina, characterized with the presence of cation vacancies. Extrapolation of linear part of the Tauc's plot for A10-1100 sample gave value of 1.74 eV, which is close to value reported previously for NiAl 2 O 4 [24], but also at 3.6 eV, which corresponds to band-gap energy of NiO [25] Tauc's plot of A20-1100 sample revealed presence of alumina (5.0eV), NiAl 2 O 4 (1.8eV) and NiO (3.6eV), with additional transition placed at 3.1 eV, which can be attributed to oxygen vacancy with one electron [26]. Tauc's plot of sample with the highest Ni loading (A40-1100) also revealed presence of NiAl 2 O 4 and NiO phases, but no alumina related transition is detected.…”

Section: Optical Characterizationsupporting

confidence: 89%

Application of Ni(II)-alumina composites for electrocatalytic reduction of 4-nitrophenol

et al. 2020

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Nickel-alumina composites with various content of nickel were synthetized by sol-gel method. The characterization of samples was performed by diffuse reflectance spectroscopy and electrochemical impedance spectroscopy using the Mott-Schottky analysis. Glassy carbon electrode modified by synthesized composites was investigated for reduction of 4-nitrophenol. Modification of glassy carbon electrode with composite sample led to the strong apparent electrocatalysis. Principal component analysis was used to establish correlation between structural, textural and electrochemical data of investigated composites.

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Section: Optical Characterizationsupporting

confidence: 89%

Application of Ni(II)-alumina composites for electrocatalytic reduction of 4-nitrophenol

et al. 2020

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“…As can be noted, the use of Al 2 O 3 as diluent (≤75 wt.%) has negligible effect in the DR spectrum. It is because multiple light reflections within the agglomerate give ZnO the opportunity to absorb the fraction of light reflected by Al 2 O 3 grains (Al 2 O 3 – E g ∼5 eV at 300 K) [20, 22, 23]. Oppositely, addition of CoO reduces significantly the reflectance of visible light.…”

Section: Resultsmentioning

confidence: 99%

Automated method for the determination of the band gap energy of pure and mixed powder samples using diffuse reflectance spectroscopy

Escobedo-Morales

Ruiz-López

Ruiz-Peralta

et al. 2019

Heliyon

166

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An automated method to determine the band gap energy ( E g ) of pure and mixed powder compounds using diffuse reflectance spectroscopy is presented. This method is based on a five-step algorithm that mimics the judgment made by an expert analyst in identifying the linear segments in Tauc plots and subsequent estimation of the E g value. It is demonstrated that the method to estimate E g by intersecting the straight-line fit of the Tauc segment with the photon energy axis is not appropriate for those samples containing more than one optical absorbing phase because systematic underestimation of the E g value results. The automated method accounts for such cases by introducing a base line function. The robustness of the implemented algorithm was tested using three model systems, ZnO-Al 2 O 3 , ZnO-CoO and ZnO-CdO. The estimated E g 's using the automated method differ in less than 1% than those obtained by its manual counterpart.

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“…However, above 973 K, all crystallite size values increase, reaching a maximum at the highest temperature of 1273 K. A possible explanation for the increase in crystallite size with temperature is sintering, which could be caused due to calcination temperature [29] . On the other hand, the content of iron can also affect the average crystallite size of the catalysts; however, while some works have described a decrease in the average crystallite size of the catalyst with increasing Fe content [30] . Our results showed otherwise.…”

Section: Resultsmentioning

confidence: 98%

Dry Reforming of Methane for Hydrogen Production Using Bimetallic Catalysts of Pt‐Fe Supported on γ‐Alumina

et al. 2021

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Biogas is a combustible composed mostly by methane (CH4) and carbon dioxide (CO2). Methane, the main component of biogas, is the responsible for the characteristics of the fuel itself. Greenhouse gases (GHG), including methane, along with global warming and depletion of fossil fuels have become issues of global concern. In the present work, Pt−Fe catalysts supported on γ‐Al2O3 varying the metal load were synthesized, characterized, and applied in the hydrogen production through dry reforming of methane. The synthesized catalysts were extensively characterized by analytical techniques such as X‐Ray diffraction (XRD), thermal gravimetric analysis coupled with differential thermal analysis (DTA/TGA), infrared spectroscopy with Fourier transform (FT‐IR), scanning electron microscopy (SEM), N2 physisorption, X‐ray photoelectron spectrometer (XPS) and high–resolution transmission electron microscopy (HR‐TEM). The results from the catalytic tests exhibited that methane conversion reached values up to 95 % for all studied catalysts. The maximum H2 selectivity was 68 % (973 K) and 55 % (1173 K), for the bimetallic catalysts 0.15 PFAc (0.5 % Pt‐0.15 % Fe wt/Al2O3) and 0.5 PFAc (0.5 % Pt–0.5 % Fe wt/Al2O3) respectively. XPS and HR‐TEM results confirmed the iron‐platinum phase (FePt). Catalyst characteristics such as specific surface area, average crystallite size and morphology showed to play a role in the methane reforming performance.

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Structural, Optical, and Electronic Characterization of Fe-Doped Alumina Nanoparticles

Cited by 26 publications

References 36 publications

Application of Ni(II)-alumina composites for electrocatalytic reduction of 4-nitrophenol

Application of Ni(II)-alumina composites for electrocatalytic reduction of 4-nitrophenol

Automated method for the determination of the band gap energy of pure and mixed powder samples using diffuse reflectance spectroscopy

Dry Reforming of Methane for Hydrogen Production Using Bimetallic Catalysts of Pt‐Fe Supported on γ‐Alumina

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