Excellent electromagnetic wave absorption of Co/Fe2O3 composites by additional activated carbon for tuning the optical and the magnetic properties

Tahir, Dahlang; Heryanto, Heryanto; Ilyas, Sultan; Fahri, Ahmad Nurul; Rahmat, Roni; Rahmi, Mufti Hatur; Taryana, Yana; Sukaryo, Sulistioso Giat

doi:10.1016/j.jallcom.2021.158780

Cited by 24 publications

(14 citation statements)

References 64 publications

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“…The detailed sample mixing method has been explained in our previous studies [29,30]. The calculation of the band gap using a UV-Vis spectrophotometer started by mixing the composites in 10-ml water.…”

Section: Methodsmentioning

confidence: 99%

Band gap of Fayalite for 5% Laterite Soil and Iron Sand Analysis from Theoretical Calculation of Kubelka–Munk equation, Taylor expansion, and Self-Consistent Field Method

Heryanto

Tahir

2022

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In this study, the fayalite structure is extracted from nickel slag and band gap modification is achieved by added with laterite soil and iron sand. We propose a precise estimation of the band gap using the Kubelka-Munk equation, aided by the Taylor expansion simulation, and show results for generalized gradient approximation and ab-initio. We successfully demonstrated that the combination of Tauc’s plots, Tauc’s plots with Taylor expansion, and self-consistent field methods is the most accurate way to measure the energy between the valence and conduction bands (band gap). In addition, we found an excellent correlation between an increase in the crystallinity index and a decrease in the crystallite size in relation to a decrease in the band gap.

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Section: Methodsmentioning

confidence: 99%

Band gap of Fayalite for 5% Laterite Soil and Iron Sand Analysis from Theoretical Calculation of Kubelka–Munk equation, Taylor expansion, and Self-Consistent Field Method

Heryanto

Tahir

2022

Preprint

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“…whereas, Fe 2 O 3 /activated carbon synthesized by Tahir et al, gave RL max = -69.39 dB at 4 mm thickness27 . The biomass-derived carbon/NiCo 2 S 4 synthesized by Hu et.…”

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confidence: 92%

“…The inclusion of cobalt in AC-based composites resulted in an improvement in their MW absorption properties, e.g., the banana peel-derived porous-activated carbon/Co 3 O 4 composite fabricated by Yusuf et al exhibited RL max = À51.5 dB and an EAB of 1.2 GHz at 2.5 mm thickness, 26 whereas the Co/Fe 2 O 3 / activated carbon synthesized by Tahir et al exhibited RL max = À69.39 dB at 4 mm thickness. 27 The biomass-derived carbon/ NiCo 2 S 4 synthesized by Hu et al achieved RL max = À62.74 dB at 2.24 mm and an excellent EAB of 7.62 GHz at 1.96 mm. 5 Thus, these results suggest the potential of activated carbon/magnetic material-based composites as MW absorbing materials.…”

Section: Introductionmentioning

confidence: 98%

Excellent microwave absorbing performance of biomass-derived activated carbon decorated with in situ-grown CoFe₂O₄ nanoparticles

et al. 2022

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“…The optical properties (refractive index (n and k)) and dielectric function (ε) of the semiconductor Fe 2 O 3 −carbon were determined from the quantitative analysis of the FTIR spectra using Kramers− Kronig (KK) relation. This method was successfully applied for the following materials: the composite cement/BaSO4/ Fe 3 O 4, 52 composite geopolymer fly ash−metal, 53 Co/Fe 2 O 3 − AC, 47 nanoparticle Zn(OH) 2 , 54 composite Fe/CNs/PVA, 55 bioplastics (SPF/starch/chitosan/polypropylene), 56 and composite nanocrystalline carbon−lignin/zinc oxide. 57 The magnetic properties are measured using a vibrating sample magnetometer (VSM) for various amount of carbon in Fe 2 O 3 .…”

Section: Introductionmentioning

confidence: 99%

“…By doping with high-band-gap materials, the optical absorption is enhanced in the visible regions . Activated carbon (AC) increases the band gaps of CuO and Fe 3 O 4 for absorbing EM wave interference. ,, AC is used to tune the structural, magnetic, and optical properties of the semiconductor by doping it with various materials ,,, depending on the application. ,− In our previous study, we successfully used Co/Fe 2 O 3 –AC for EM absorbers, but the physical phenomena between Fe 2 O 3 and AC are still not fully understood. Several questions exist regarding the relations between the optical, magnetic, electronic, and structural properties that support the applications of multifunctional materials.…”

Section: Introductionmentioning

confidence: 99%

Enhanced Visible-Light Absorption of Fe₂O₃ Covered by Activated Carbon for Multifunctional Purposes: Tuning the Structural, Electronic, Optical, and Magnetic Properties

et al. 2021

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Visible-light absorption is a critical factor for photocatalyst activity and absorption of electromagnetic (EM) interference application. The band gap of Fe 2 O 3 is 2 eV, which can be increased by doping with a high-band-gap material such as carbon from activated carbon (AC) with a band gap of 4.5 eV for increased visible-light absorption. The porosity decreases from 88 to 81.6%, and the band gap increases from 2.14 to 2.64 eV by increasing the AC from 10 to 25%, respectively. The photocatalytic activity takes 120 min to produce a harmless product for 10− 20% AC, but 25% AC shows 89.5% degradation in only 90 min and the potential to attenuate the EM wave up to 99% due to the RL being below −20 dB. The secondand third-cycle degradation achieved by the composite Fe 2 O 3 −AC having 25% AC is 88.2 and 86.5% in 90 min, respectively. The pore of the surface state of AC contains a trapped charge, and interaction occurs between the charge (electron/hole) and O 2 or H 2 O to produce OH and superoxide (O 2 − ) radicals. These radicals move inside the molecule of the pollutant (methylene blue (MB)) to break up the bond, with the final products being H 2 O and CO 2 . The X-ray photoelectron (XPS) spectra show that oxygen plays a key role in the interatomic bonding with Fe, C, and MB atoms. The best absorption of EM interference is −21.43 dB, with degradation reaching 89.51% in only 90 min for 25% AC due to its higher band gap and anisotropy constant. Fe 2 O 3 −carbon is a multifunctional material for the green environment because of its electromagnetic interference absorption and photodegradation of wastewater.

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Excellent electromagnetic wave absorption of Co/Fe2O3 composites by additional activated carbon for tuning the optical and the magnetic properties

Cited by 24 publications

References 64 publications

Band gap of Fayalite for 5% Laterite Soil and Iron Sand Analysis from Theoretical Calculation of Kubelka–Munk equation, Taylor expansion, and Self-Consistent Field Method

Band gap of Fayalite for 5% Laterite Soil and Iron Sand Analysis from Theoretical Calculation of Kubelka–Munk equation, Taylor expansion, and Self-Consistent Field Method

Excellent microwave absorbing performance of biomass-derived activated carbon decorated with in situ-grown CoFe₂O₄ nanoparticles

Enhanced Visible-Light Absorption of Fe₂O₃ Covered by Activated Carbon for Multifunctional Purposes: Tuning the Structural, Electronic, Optical, and Magnetic Properties

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Excellent electromagnetic wave absorption of Co/Fe2O3 composites by additional activated carbon for tuning the optical and the magnetic properties

Cited by 24 publications

References 64 publications

Band gap of Fayalite for 5% Laterite Soil and Iron Sand Analysis from Theoretical Calculation of Kubelka–Munk equation, Taylor expansion, and Self-Consistent Field Method

Band gap of Fayalite for 5% Laterite Soil and Iron Sand Analysis from Theoretical Calculation of Kubelka–Munk equation, Taylor expansion, and Self-Consistent Field Method

Excellent microwave absorbing performance of biomass-derived activated carbon decorated with in situ-grown CoFe2O4 nanoparticles

Enhanced Visible-Light Absorption of Fe2O3 Covered by Activated Carbon for Multifunctional Purposes: Tuning the Structural, Electronic, Optical, and Magnetic Properties

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Excellent microwave absorbing performance of biomass-derived activated carbon decorated with in situ-grown CoFe₂O₄ nanoparticles

Enhanced Visible-Light Absorption of Fe₂O₃ Covered by Activated Carbon for Multifunctional Purposes: Tuning the Structural, Electronic, Optical, and Magnetic Properties