scholarly journals One-Pot Hydrothermal Preparation of Fe3O4 Decorated Graphene for Microwave Absorption

Materials ◽  
2020 ◽  
Vol 13 (14) ◽  
pp. 3065
Author(s):  
Zhonghe Du ◽  
Xibang Chen ◽  
Youwei Zhang ◽  
Xueyan Que ◽  
Pinggui Liu ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Microwave Absorption ◽  
Fe3o4 Nanoparticles ◽  
Average Particle Size ◽  
Average Particle ◽  
Hydrothermal Preparation ◽  
One Pot ◽  
Effective Bandwidths ◽  
Absorption Performance ◽  
Hydrothermal Approach

Fe3O4 decorated graphene was synthesized for electromagnetic wave absorption via a facile one-pot hydrothermal approach. The structure and morphology of the as-prepared nanomaterials were systematically investigated. The graphene oxide (GO) was reduced and Fe3O4 nanoparticles were evenly decorated on the surface of reduced graphene oxide (rGO) nanosheets. The average particle size of Fe3O4 nanoparticles is about 15.3 nm. The as-prepared rGO-Fe3O4 nanocomposites exhibited a good microwave absorption performance because of the combination of graphene and magnetic Fe3O4. When the thicknesses are 1.6 mm and 6.5 mm, the reflection loss (RL) values are up to −34.4 dB and −37.5 dB, respectively. The effective bandwidths are 3.8 and 1.9 GHz.

scholarly journals Facile Hydrothermal and Solvothermal Synthesis and Characterization of Nitrogen-Doped Carbon Dots from Palm Kernel Shell Precursor

2021 ◽  
Vol 11 (4) ◽  
pp. 1630
Author(s):  
Yakubu Newman Monday ◽  
Jaafar Abdullah ◽  
Nor Azah Yusof ◽  
Suraya Abdul Rashid ◽  
Rafidah Hanim Shueb
Keyword(s):  
Carbon Dots ◽  
Batch Reactor ◽  
Average Particle Size ◽  
Research Work ◽  
Palm Kernel ◽  
Average Particle ◽  
One Pot ◽  
Palm Kernel Shell ◽  
Doped Carbon Dots ◽  
Nitrogen Doped Carbon

Carbon dots (CDs), a nanomaterial synthesized from organic precursors rich in carbon content with excellent fluorescent property, are in high demand for many purposes, including sensing and biosensing applications. This research focused on preparing CDs from natural and abundant waste, palm kernel shells (PKS) obtained from palm oil biomass, aiming for sensing and biosensing applications. Ethylenediamine and L-phenylalanine doped CDs were produced via the hydrothermal and solvothermal methods using one-pot synthesis techniques in an autoclave batch reactor. The as-prepared N-CDs shows excellent photoluminescence (PL) property and a quantum yield (QY) of 13.7% for ethylenediamine (EDA) doped N-CDs (CDs-EDA) and 8.6% for L-phenylalanine (L-Ph) doped N-CDs (CDs-LPh) with an excitation/emission wavelength of 360 nm/450 nm. The transmission electron microscopy (TEM) images show the N-CDs have an average particle size of 2 nm for both CDs. UV-Visible spectrophotometric results showed C=C and C=O transition. FTIR results show and confirm the presence of functional groups, such as -OH, -C=O, -NH2 on the N-CDs, and the X-ray diffraction pattern showed that the N-CDs were crystalline, depicted with sharp peaks. This research work demonstrated that palm kernel shell biomass often thrown away as waste can produce CDs with excellent physicochemical properties.

scholarly journals Solvent-assisted thermal reduction of microcrystalline graphene oxide with excellent microwave absorption performance

RSC Advances ◽  
2018 ◽  
Vol 8 (28) ◽  
pp. 15315-15325 ◽  
Author(s):  
Chenbo Liao ◽  
Xukun Zhu ◽  
Wei Xie ◽  
Fangmei Zeng ◽  
Shihe Yi ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Absorption Band ◽  
Microwave Absorption ◽  
Reduction Method ◽  
Thermal Reduction ◽  
Wide Absorption Band ◽  
Absorption Performance ◽  
Microwave Absorption Performance ◽  
High Absorption

Reduced microcrystalline graphene oxide (rGO-M), a novel absorber with high absorption, low reflection and a wide absorption band, was prepared from NMGMs using a solvent-assisted thermal reduction method.

scholarly journals SiO2:MgMnO3: An Efficient Heterogeneous Catalyst for One Pot Synthesis of 1H-Pyrazolo[1,2-b]phthalazine-5,10-dione Derivatives

2020 ◽  
Vol 32 (10) ◽  
pp. 2489-2494
Author(s):  
S.S. Sagar ◽  
R.P. Chavan
Keyword(s):  
Surface Area ◽  
Average Particle Size ◽  
Bet Surface Area ◽  
High Yield ◽  
Average Particle ◽  
One Pot ◽  
Short Reaction Time ◽  
Investigative Techniques ◽  
Current Procedure ◽  
Efficient Heterogeneous Catalyst

The present study deals with hydrothermal synthesis of SiO2 composite MgMnO3 catalyst. The obtained polycrystalline product was analyzed by using physical investigative techniques including XRD, SEM, EDAX, TEM, SAED and BET surface area. The product corresponded to average particle size of 100 nm by TEM images. The BET surface area was found 234.38 cm2/g for SiO2 composite MgMnO3 catalyst which indicates a good catalytic property. The synthesized catalyst was applied for the synthesis of 1H-pyrazolo[1,2-b]-phthalazine-5,10-dione in presence of ethanol as a solvent at 80 ºC. The current procedure and catalyst offers the gains of clean reaction, short reaction time, high yield, easy purification and financial availability of the catalyst.

scholarly journals Reduced graphene oxide decorated with octahedral NiS2/NiS nanocrystals: facile synthesis and tunable high frequency attenuation

RSC Advances ◽  
2019 ◽  
Vol 9 (10) ◽  
pp. 5550-5556 ◽  
Author(s):  
Min Lu ◽  
Na Gao ◽  
Xiao-Juan Zhang ◽  
Guang-Sheng Wang
Keyword(s):  
Graphene Oxide ◽  
Reduced Graphene Oxide ◽  
Microwave Absorption ◽  
High Frequency ◽  
High Frequency Range ◽  
Frequency Range ◽  
Facile Synthesis ◽  
Reduced Graphene ◽  
Absorption Performance ◽  
Microwave Absorption Performance

Reduced graphene oxide (RGO) decorated with octahedral NiS2/NiS nanocrystals were fabricated and they possessed an excellent microwave absorption performance in the high frequency range.

Inducing the magnetic character in reduced graphene oxide through incorporation of Fe2O3 nanoparticles

2017 ◽  
Vol 31 (15) ◽  
pp. 1750118 ◽  
Author(s):  
Abdur Rauf ◽  
Syed Sohail Ahmad Shah ◽  
Sobia Allah Rakha ◽  
Munazza Gul ◽  
Ishaq Ahmad ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Graphene Oxide ◽  
Reduced Graphene Oxide ◽  
Average Particle Size ◽  
Hybrid Structures ◽  
Average Particle ◽  
Multilayer Graphene ◽  
Magnetic Devices ◽  
Reduced Graphene ◽  
20 Nm

A chemical two-step approach based on solvothermal technique has been adopted to synthesize the reduced graphene oxide (rGO)/Fe2O3 hybrid materials. The rGO was prepurified by acidic treatment, followed by sensitization to attach the desired functional groups. The structural, compositional, morphological and magnetic analyzes of the prepared samples were carried out using various characterization techniques. The fabricated rGO/Fe2O3 heterostructures were confirmed by X-ray diffraction analysis and Fourier transform infrared spectroscopy. Raman spectroscopy evidenced the fabrication of multilayer graphene and scanning electron microscopy was carried out to study the morphology of the prepared samples. The average particle size of Fe2O3 nanoparticles (NPs) loaded on rGO was found to be [Formula: see text]20 nm, as was observed during transmission electron microscopy. Thermogravimetric analysis of rGO/Fe2O3 hybrid structures was performed to investigate their thermal behaviors. It was evidenced that the incorporation of Fe2O3 NPs into rGO enhanced its thermal stability. Vibrating sample magnetometry showed that ferromagnetic character was induced in rGO due to involvement of Fe2O3 NPs. The rGO/Fe2O3 hybrid structures can be considered as a competent material for fabrication of various magnetic devices.

scholarly journals Isothermal models of Chromium (VI) adsorption by using Fe3O4 nanoparticles

10.30544/489 ◽  
2020 ◽  
Author(s):  
Dang Tan Hiep ◽  
Bui Thi Hoa ◽  
Ngo Thi My Thanh ◽  
Nguyen Viet Long ◽  
Le Hong Phuc ◽  
...  
Keyword(s):  
Fe3o4 Nanoparticles ◽  
Contact Time ◽  
Ph Value ◽  
Average Particle Size ◽  
Adsorption Kinetic ◽  
Average Particle ◽  
Suitable Model ◽  
Isothermal Adsorption ◽  
Adsorption Models ◽  
Chromium Vi

The ferromagnetic Fe3O4 nanoparticles with the average particle size of about 10 nm were used to adsorb chromium (VI) in aqueous solution. The equilibrium of Cr(VI) adsorption can be achieved at the pH value of 2.5, in the contact time of 120 minutes. The mechanisms of Cr(VI) adsorption were evaluated by 4 isothermal adsorption models Langmuir, Freundlich, Redlich-Peterson, and Temkin. The results showed that all four models are satisfied; especially, Redlich-Peterson is the most suitable model to describe the adsorption kinetic of Cr(VI) on ferromagnetic Fe3O4 nanoparticles.

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