Study on Phase, Molecular Bonding, and Bandgap of Reduced Graphene Oxide Prepared by Heating Coconut Shell

The purpose of this work is to search reduced graphene oxide (RGO) phase by identifying the molecular bonding, energy band gap and phase of old coconut shell. The characterization was performed by using FTIR, Uv-Vis and XRD spectroscopy. The heating temperature used in this work was 400°C and 600°C.Furthermore, the type of heating atmosphere used in this research covers nitrogen, ambient air with and without rinsing step. The XRD analysis shows that the RGO phase is formed by turbostatic structure which is a pile of random arrangement of parallel layers that make up the graphite structure with cliftonite phase at temperature 400°C and 600°C. In the inert nitrogen gas treatment, there are two impurity phases such as potassium chlorate (KClO4) and sulfur (S11). The molecular bondings of C=C, C-C, C-O, C=O, C-H and O-H appeared on the FTIR spectra of the samples were indentified. Analysis by using linear regression and absorbance edge methods was conducted to result in energy gap in the range from 0.14 to 0.67 eV, indicating that the produced samples are semiconducting materials.

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Synthesis and Characterization of Reduced Graphene Oxide

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.678.56 ◽

2013 ◽

Vol 678 ◽

pp. 56-60 ◽

Cited By ~ 16

Author(s):

Cherukutty Ramakrishnan Minitha ◽

Ramasamy Thangavelu Rajendrakumar

Keyword(s):

Graphene Oxide ◽

Reduced Graphene Oxide ◽

Graphite Oxide ◽

High Performance ◽

Structural Changes ◽

Epoxy Group ◽

Xrd Analysis ◽

Si Substrates ◽

Reduced Graphene ◽

Reduced Graphite Oxide

Reduced graphene oxide is an excellent candidate for various electronic devices such as high performance gas sensors. In this work Graphene oxide was prepared by oxidizing graphite to form graphite oxide. From XRD analysis the peak around 11.5o confirmed that the oxygen was intercalated into graphite. By using hydrazine hydrate, the epoxy group in graphite oxide was reduced then the solution of reduced graphite oxide (rGO) is exfoliated. Raman spectrum of rGO contains both G band (1580 cm-1), D band (1350 cm-1). The remarkable structural changes reveals that reduction of graphene oxide from the values of ID/IG ratio that increase from 0.727 (GO) to 1.414 (rGO). The exfoliated reduced graphite oxide solution is spin coated on to the SiO2/Si substrates.

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Enhancing the Power Conversion Efficiency of Inverted Organic Photovoltaics with Gold Functionalized Reduced Graphene Oxide

MRS Proceedings ◽

10.1557/opl.2015.599 ◽

2015 ◽

Vol 1737 ◽

Author(s):

Rebecca Isseroff ◽

Zhenhua Yang ◽

Jessica Kim ◽

Andrew Chen ◽

Miriam Rafailovich

Keyword(s):

Graphene Oxide ◽

Fermi Level ◽

Reduced Graphene Oxide ◽

Active Layer ◽

Energy Gap ◽

Power Conversion ◽

Design Phase ◽

Reduced Graphene ◽

Exciton Recombination ◽

First Time

ABSTRACTIn this study, an “inverted” design, phase-separated morphology and gold-functionalized reduced graphene oxide (Au-rGO) were used to address exciton recombination and poor Fermi level alignment. To increase efficiencies, a unique methodology was used to coat Au-rGO on top of the active layer. When 0.05 Au-rGO was blended with the active layer, there were metal-thiolate bonds with P3HT and π-π stacking with PCBM. However, KPFM, measured for the first time for this material, showed that the while 0.05mM Au-rGO reduced the energy gap between P3HT and PBCM, this was offset by recombination. KPFM showed that Au-rGO may be better suited between the active layer and electrode. When 0.5mM Au-rGO was coated on top of the active layer, efficiency increased (p<0.002) nearly 600%, suggesting that Au-rGO is a more effective acceptor than a constituent of the active layer.

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Reduced Graphene Oxide Paper: Fabrication by a Green Thermal Reduction Method and Preliminary Study of its In Vitro Cytotoxicity

Journal of Nano Research ◽

10.4028/www.scientific.net/jnanor.45.199 ◽

2017 ◽

Vol 45 ◽

pp. 199-207 ◽

Cited By ~ 2

Author(s):

Xin Wang ◽

Peng Li ◽

Claudia Luedecke ◽

Qiang Zhang ◽

Zan Wang ◽

...

Keyword(s):

Tissue Engineering ◽

Graphene Oxide ◽

Reduced Graphene Oxide ◽

Mammalian Cells ◽

Reduction Method ◽

Heating Temperature ◽

Synthesis Method ◽

Thermal Reduction ◽

Graphene Films ◽

Reduced Graphene

Graphene films have been intensively explored because of their unique mechanical and physicochemical properties for potential applications in field of tissue engineering and implants. However, for biomedical applications, it is necessary to fully understand the toxicity and biocompatibility of the prepared graphene films since different synthesis method might lead to different biological properties. Here we report a step-by-step thermal reduction method of preparing reduced graphene oxide (rGO) film directly on various substrates at low heating temperature (below about 200 °C) without requiring any chemical reduction agent like hydrazine or other reductants (therefore we call it green method). Slowly heating GO hydrosol that was coated on the surface of a glass cell-culture dish or inside of a polypropylene tube from room temperature to 60, 100, and 160 °C for 12 h, respectively, a shiny and flat surface without crumpled structure or tiny pores was formed. We peeled it off from the substrate to explore its cytotoxicity. The results exhibited that the rGO film was biocompatible with Cal-72 cell but against Escherichia coli bacteria. Our work confirmed that rGO film produced by the green reduction method is cytocompatible with mammalian cells, which makes this rGO film a promising material for tissue engineering scaffold or as a surface-modification coating of an implant.

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Low‐Thermal‐Budget Doping: Low‐Thermal‐Budget Doping of 2D Materials in Ambient Air Exemplified by Synthesis of Boron‐Doped Reduced Graphene Oxide (Adv. Sci. 7/2020)

Advanced Science ◽

10.1002/advs.202070039 ◽

2020 ◽

Vol 7 (7) ◽

pp. 2070039

Author(s):

Jun‐Hwe Cha ◽

Dong‐Ha Kim ◽

Cheolmin Park ◽

Seon‐Jin Choi ◽

Ji‐Soo Jang ◽

...

Keyword(s):

Graphene Oxide ◽

Reduced Graphene Oxide ◽

2D Materials ◽

Ambient Air ◽

Thermal Budget ◽

Boron Doped ◽

Reduced Graphene ◽

Low Thermal Budget

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The Effect of Reduced Graphene Oxide (rGO) Coating on Electrical Conductivity of Lithium Ferro Phosphate (LFP) as an Alternative Cathode for Li-Ion Battery

Materials Science Forum ◽

10.4028/www.scientific.net/msf.966.386 ◽

2019 ◽

Vol 966 ◽

pp. 386-391

Author(s):

Eka Suarso ◽

Anna Zakiyatul Laila ◽

Firsta Agung Setyawan ◽

Mochamad Zainuri ◽

Zaenal Arifin ◽

...

Keyword(s):

Electrical Conductivity ◽

Graphene Oxide ◽

Reduced Graphene Oxide ◽

Sol Gel ◽

Xrd Analysis ◽

Mass Ratio ◽

Good Crystallinity ◽

Reduced Graphene ◽

Phosphate Source

In this study an investigation has been conducted on the effect of reduced graphene oxide (rGO) coating on increasing the value of Lithium Ferro Phosphate (LFP) electrical conductivity. This coating process uses a variation of the mass ratio of LiFePO4/rGO by 90%:10%, 70%:20%, and 67%:33%. The LiFePO4 precursor was prepared using the sol-gel rute from the main commercial materials, namely Li2CO3 powder as a source of lithium ions, FeCl2.4H2O as a source of iron and NH4H2PO4 powder as a phosphate source. As for the coating used rGO extracted from coconut shell waste. The samples were calcined with temperature variations of 600°C, 650°C and 700°C in an argon environment for 10 hour. The phase purity and crystal structure of LiFePO4 were analyzed using XRD. The analysis of data from XRD was done using the the Match!, Rietica, and MAUD software. Based on the results of XRD analysis, LiFePO4 with high purity and good crystallinity was obtained when the sample was calcined at temperature of 700°C. The results of the MAUD analysis show that the best size of LiFePO4 crystal is 86,54 nm. LiFePO4/rGO nanocomposite was successfully synthesized by mechanical ultracentrifugation method. The characterization of the value of electrical conductivity, carried out using a four-point probe. The results show that the greater the percentage of rGO, the higher the value of electrical conductivity. The mass ratio of 67% LiFePO4 and 33% rGO shows an increment in good conductivity values, from the original order of 10-8 S/cm to the order of 10-4 S/cm.

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A Study on Phase and Microstructure of Reduced Graphene Oxide Prepared by Heating Corncobs

JPSE (Journal of Physical Science and Engineering) ◽

10.17977/um024v5i22020p066 ◽

2020 ◽

Vol 5 (2) ◽

pp. 66-70

Author(s):

Kusuma Wardhani Mas'udah ◽

◽

Ahmad Taufiq ◽

Sunaryono Sunaryono ◽

◽

...

Keyword(s):

Graphene Oxide ◽

Reduced Graphene Oxide ◽

Oxide Phase ◽

Xrd Analysis ◽

Holding Time ◽

Layer Arrangement ◽

Three Samples ◽

Reduced Graphene

The purpose of this study was to find out reduced graphene oxide (RGO) phases by identifying the system, elemental system, and microstructure of corncobs. Characterization was carried out by XRD and SEM-EDX spectroscopy. The temperatures used in this work are 100, 200, and 250 ºC with a holding time of 1 hour. XRD analysis shows that the RGO phase is formed by the structure of the aromatic layer arrangement (graphite 002), and the widening comes from small-dimensional crystallites perpendicular to the aromatic layer (graphite 120). The elements contained in the three samples have a dominant proportion in the elements carbon and oxygen. From the SEM results obtained the morphology of corncobs powder that looks like sheets. The reduced graphene oxide phase is formed from the process of reducing corncobs powder.

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Paste electrode based on the thermally reduced graphene oxide in ambient air – Its characterization and analytical application for analysis of 4–chloro–3,5–dimethylphenol

Electrochimica Acta ◽

10.1016/j.electacta.2018.06.022 ◽

2018 ◽

Vol 282 ◽

pp. 233-241 ◽

Cited By ~ 3

Author(s):

Mariola Brycht ◽

Andrzej Leniart ◽

Janez Zavašnik ◽

Agnieszka Nosal–Wiercińska ◽

Krzysztof Wasiński ◽

...

Keyword(s):

Graphene Oxide ◽

Reduced Graphene Oxide ◽

Ambient Air ◽

Analytical Application ◽

Reduced Graphene ◽

Paste Electrode

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Localized SPR for Pb(II) ion sensing utilizing chitosan/reduced graphene oxide nanocomposite

Jurnal OptoElektronik ◽

10.53655/joe.z3238q ◽

2021 ◽

Author(s):

Suraya Abdullah ◽

Nur Hidayah Azeman ◽

Nur Hasiba Kamaruddin ◽

Nadhratun Naiim Mobarak ◽

Ahmad Ashrif A Bakar

Keyword(s):

Graphene Oxide ◽

Reduced Graphene Oxide ◽

Xrd Analysis ◽

Stability Study ◽

Localized Surface Plasmon ◽

Ion Sensing ◽

Sensing Material ◽

Reduced Graphene ◽

Relative Standard ◽

Oxygen Atoms

In this work, a simple and highly sensitive localized surface plasmon resonance (LSPR) technique had been developed for detection of Pb(II) utilizing chitosan/reduced graphene oxide (CS/rGO) nanocomposite as the sensing material. Gold nanoparticles (AuNP) had been incorporated with the nanocomposite material to induce strong LSPR responses. CS/rGO nanocomposite was coated on top of AuNP and had been utilized as active layer for Pb(II) ion sensing. The morphology and physical properties of gold nanoparticle-chitosan/reduced graphene oxide (AuNP-CS/rGO) nanocomposite was studied using field-emission scanning electron microscopy (FESEM), atomic force microscopy (AFM) and x-ray diffraction (XRD) analysis. FESEM exhibits a rough and wrinkle surface of AuNP-CS/rGO after the addition of rGO. AFM shows a higher surface roughness for AuNP-CS/rGO due to the presence of oxygen atoms in rGO where these oxygen atoms provide more sites for adsorption of Pb(II), hence enhance the sensitivity of the sensor. A good sensitivity of the LSPR sensor for detection of Pb(II) utilizing AuNP-CS/rGO was obtained which is 1.544 ppm-1 and the linearity of the sensor are 0.99 and 0.97. In stability study, AuNP-CS/rGO exhibits a good repeatability with relative standard deviation of 2% for 0.01 ppm.

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