Ternary Composite of Molybdenum Disulfide-Graphene Oxide-Polyaniline for Supercapacitor

Light Emitting Diode ◽

Rate Capability ◽

Energy Storage And Conversion ◽

Carbon Paper ◽

Power Sources ◽

X Ray

Abstract The ever-increasing need for small and lightweight power sources for use in portable or wearable electronic devices has spurred the development of supercapacitors as a promising energy storage and conversion system. In this work, a simple, facile and easy-to-practice method has been developed to employ carbon paper (CP) as the support to coat molybdenum disulfide (MoS2) and graphene oxide (GO), followed by electrodeposition of polyaniline (PANI) to render CP/MoS2-GO-PANI. The preparation parameters, such as amounts of MoS2, GO and number of aniline electropolymerization cycles, have been optimized to render CP/MoS2-GO-PANI the best capacitive performance. The as-prepared optimal CP/MoS2-GO-PANI is characterized by X-ray powder diffraction, scanning electron microscopy, energy-dispersive spectroscopy, and X-ray photoelectron spectroscopy. The supercapacitive properties of CP/MoS2-GO-PANI as an electrode have been evaluated electrochemically via cyclic voltammetry, galvanostatic charge/discharge, and electrochemical impedance spectroscopy testing. CP/MoS2-GO-PANI delivers a specific capacitance of 255.1 F/g at 1.0 A/g and exhibits excellent rate capability under larger current densities. Moreover, a symmetrical supercapacitor is assembled and three are connected in series to power a light-emitting diode for ~15 minutes, demonstrating the promising application potential of CP/MoS2-GO-PANI-based supercapacitor.

Enhancement of the Electrochemical Performance of LiNi1/3Co1/3Mn1/3O2 Cathode Material by Double-Layer Coating with Graphene Oxide and SnO2 for Lithium-Ion Batteries

Journal of Nanomaterials ◽

10.1155/2019/7586790 ◽

2019 ◽

Vol 2019 ◽

pp. 1-10

Author(s):

Yuxin Ma ◽

Ping Cui ◽

Dan Zhan ◽

Bing Gan ◽

Youliang Ma ◽

...

Keyword(s):

Electron Microscopy ◽

Graphene Oxide ◽

Cathode Material ◽

Coating Layer ◽

Rate Capability ◽

Electrode Polarization ◽

Transfer Resistance ◽

X Ray ◽

Double Coating

The graphene oxide-coated SnO2-Li1/3Co1/3Mn1/3O2 (GO-SnO2-NCM) cathode material was successfully synthesized via a facile wet chemical method. The pristine NCM and GO-SnO2-NCM were characterized by X-ray diffraction, scanning electron microscopy, energy-dispersive spectroscopy, transmission electron microscopy, and X-ray photoelectron spectroscopy. The results showed that the double-coating layer did not destroy the NCM crystal structure, with multiple nano-SnO2 particles and GO uniformly covering the NCM surface. Electrochemical tests indicated that GO-SnO2-NCM exhibited excellent cycling performance, with 90.7% capacity retention at 1 C after 100 cycles, which was higher than 74.3% for the pristine NCM at the same cycle. The rate capability showed that the double-coating layer enhanced surface electronic–ionic transport. Electrochemical impedance spectroscopy results confirmed that the GO-SnO2-coating layer effectively suppressed the increased electrode polarization and charge transfer resistance during cycling.

Electroanalytical characterization of F-doped MoS2 cathode material for rechargeable magnesium battery

Functional Materials Letters ◽

10.1142/s1793604719500413 ◽

2019 ◽

Vol 12 (03) ◽

pp. 1950041 ◽

Cited By ~ 2

Author(s):

Gundu Venkateswarlu ◽

Devarapaga Madhu ◽

Jetti Vatsala Rani

Keyword(s):

Cathode Material ◽

Synergetic Effect ◽

Solution Process ◽

Rate Capability ◽

X Ray Diffraction ◽

X Ray ◽

Effective Performance

Fluorine (F)-doped MoS2 was prepared by F-doping into layered MoS2 via chemical solution process with fluoroboric acid. X-ray photoelectron spectroscopy, field emission scanning electron microscopy, energy dispersive X-ray spectroscopy, and X-ray diffraction were applied to conform the effect of F on the structure. The electrochemical performance was investigated by using cyclic voltammetry, electrochemical impedance spectroscopy, and galvanostatic charge/discharge studies. The F-doped MoS2 as cathode material for rechargeable Mg battery exhibited a good discharge capacity of 55[Formula: see text]mAhg[Formula: see text], with a good rate capability and good cycling stability when compared to pristine B-MoS2. The effective performance of F-doped MoS2 are attributed to the unique structure and synergetic effect between layered MoS2.

Preparation and Anti-Corrosive Properties of Waterborne Epoxy Composite Coating Containing Graphene Oxide Grafted with Sodium Tripolyphosphate

Coatings ◽

10.3390/coatings10040307 ◽

2020 ◽

Vol 10 (4) ◽

pp. 307 ◽

Cited By ~ 2

Author(s):

Na Wang ◽

Xu Yin ◽

Jing Zhang ◽

Huiying Gao ◽

Xinlin Diao ◽

...

Keyword(s):

Corrosion Resistance ◽

Graphene Oxide ◽

Sodium Tripolyphosphate ◽

Salt Spray ◽

Salt Spray Test ◽

Coated Sample ◽

X Ray ◽

Waterborne Epoxy

In this paper, graphene oxide (GO) was grafted with sodium tripolyphosphate (STP) to achieve a new anti-corrosive pigment (STG) with homogenous dispersion in waterborne epoxy (EP). The results obtained from Fourier transform infrared spectroscopy (FT-IR), X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM) and X-ray Diffraction (XRD) revealed that STP was successfully combined with GO by chemical bonding. The corrosion resistance of EP, GO/EP and STG/EP coatings on carbon steel substrates was investigated via electrochemical impedance spectroscopy (EIS) and salt spray test. The EIS results showed that the impedance value of coating with 0.7 wt.% STG reached 1.019 × 109 Ω∙cm2, which was considerably higher than that of neat waterborne EP coatings. Salt spray test results revealed once again that STG (0.7 wt.%)/EP coating had superior corrosion resistance. Besides, the STG (0.7 wt.%)/EP coated sample showed the highest adhesion strength between coating and substrate.

Ultrasound-assisted dispersive micro-solid phase extraction using molybdenum disulfide supported on reduced graphene oxide for energy dispersive X-ray fluorescence spectrometric determination of chromium species in water

Microchimica Acta ◽

10.1007/s00604-020-04476-4 ◽

2020 ◽

Vol 187 (9) ◽

Author(s):

Katarzyna Pytlakowska ◽

Karina Kocot ◽

Michał Pilch ◽

Maciej Zubko

Keyword(s):

Electron Microscopy ◽

Graphene Oxide ◽

Molybdenum Disulfide ◽

Solid Phase ◽

Sample Volume ◽

Aqueous Sample ◽

X Ray ◽

Chromium Vi ◽

Relative Standard

Abstract Molybdenum disulfide (MoS2) was supported on graphene oxide (GO) by hydrothermal method. The resulting nanocomposite (MoS2-rGO) was characterized by X-ray photoelectron spectroscopy, scanning electron microscopy, and transmission electron microscopy. The experiments show that at pH 2, MoS2-rGO has a great affinity for adsorption of hexavalent chromium ions while Cr(III) ions remain in aqueous sample. In the adsorption process, the dominant role plays chemisorption. The determined adsorption capacity is 583.5 mg g−1. Parameters affecting the extraction process, namely sample pH, sample volume, contact time, and matrix ions, were investigated by sequential batch tests. Under optimal conditions (pH 2, sample volume 50 mL, sonication time 10 min, adsorbent mass 1 mg), the calibration curve covers the 1–200 ng mL−1 range with a correlation coefficient (R2) of 0.998. The recovery of the method is 97 ± 3%. Other data of merit include a relative standard deviation of < 3.5%, enrichment factor of 3350, and detection limit of 0.050 ng mL−1. The accuracy of the method was confirmed by analysis of the reference materials QC1453 (chromium VI in drinking water) and QC3015 (chromium VI in seawater). The method was successfully applied to chromium speciation in water samples, including high salinity ones. The concentration of Cr(III) was calculated as the difference between the total concentration of chromium (after oxidation of Cr(III) to Cr(VI) with potassium permanganate) and the initial Cr(VI) content. Graphical abstract

Graphene Oxide Decorated with Titanium Nanoparticles to Reinforce the Anti-Corrosion Performance of Epoxy Coating

Coatings ◽

10.3390/coatings10020129 ◽

2020 ◽

Vol 10 (2) ◽

pp. 129 ◽

Cited By ~ 9

Author(s):

Heng Yuan ◽

Fugang Qi ◽

Nie Zhao ◽

Pengying Wan ◽

Biao Zhang ◽

...

Keyword(s):

Electron Microscopy ◽

Corrosion Resistance ◽

Graphene Oxide ◽

Composite Materials ◽

Salt Spray ◽

Corrosion Mechanism ◽

X Ray ◽

Ti Particles

Graphene oxide–titanium (GO-Ti) composite materials were fabricated using GO as a precursor and then anchoring nano titanium (Nano-Ti) particles on GO sheets with the help of a silane coupling agent. Then, the coating samples were prepared by dispersing GO, Nano-Ti particles, and GO-Ti in an epoxy resin at a low weight fraction of 1 wt %. The GO-Ti composites were investigated by X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). The dispersibility and anti-corrosion mechanism of the coatings were studied by sedimentation experiments, electrochemical impedance spectroscopy (EIS), SEM, and salt spray tests. The mechanical properties of the coatings were analyzed by friction and wear tests. The results showed that the Nano-Ti particles were successfully loaded on the GO surface by chemical bonds, which made GO-Ti composites exhibit better dispersibility in the epoxy than GO. Compared with Nano-Ti particles and GO, the GO-Ti composite exhibited significant advantages in improving the corrosion resistance of epoxy coatings at the same contents, which was attributed to the excellent dispersibility, inherent corrosion resistance, and sheet structure. Among the different proportions of composite materials, the GO-Ti (2:1) material exhibited the best dispersibility and corrosion resistance. In addition, the composite material also greatly improved the wear resistance of the coating.

Hydrothermal Synthesis of Cobalt Ruthenium Sulfides as Promising Pseudocapacitor Electrode Materials

Coatings ◽

10.3390/coatings10030200 ◽

2020 ◽

Vol 10 (3) ◽

pp. 200 ◽

Cited By ~ 1

Author(s):

Ravi Bolagam ◽

Sukkee Um

Keyword(s):

High Performance ◽

Electrode Materials ◽

Rate Capability ◽

Metal Sulfide ◽

Energy Storage Devices ◽

X Ray ◽

Storage Devices ◽

Ternary Metal

In this paper, we report the successful synthesis of cobalt ruthenium sulfides by a facile hydrothermal method. The structural aspects of the as-prepared cobalt ruthenium sulfides were characterized using X-ray diffraction, X-ray photoelectron spectroscopy, and Raman spectroscopy. All the prepared materials exhibited nanocrystal morphology. The electrochemical performance of the ternary metal sulfides was investigated by cyclic voltammetry (CV), galvanostatic charge-discharge (GCD), and electrochemical impedance spectroscopy techniques. Noticeably, the optimized ternary metal sulfide electrode exhibited good specific capacitances of 95 F g−1 at 5 mV s−1 and 75 F g−1 at 1 A g−1, excellent rate capability (48 F g−1 at 5 A g−1), and superior cycling stability (81% capacitance retention after 1000 cycles). Moreover, this electrode demonstrated energy densities of 10.5 and 6.7 Wh kg−1 at power densities of 600 and 3001.5 W kg−1, respectively. These attractive properties endow proposed electrodes with significant potential for high-performance energy storage devices.

Using 3-Isocyanatopropyltrimethoxysilane to Decorate Graphene Oxide with Nano-Titanium Dioxide for Enhancing the Anti-Corrosion Properties of Epoxy Coating

Polymers ◽

10.3390/polym12040837 ◽

2020 ◽

Vol 12 (4) ◽

pp. 837 ◽

Cited By ~ 5

Author(s):

Weihang Li ◽

Bojun Song ◽

Shirui Zhang ◽

Fan Zhang ◽

Chang Liu ◽

...

Keyword(s):

Titanium Dioxide ◽

Graphene Oxide ◽

Corrosion Mechanism ◽

Corrosion Properties ◽

X Ray ◽

Dispersion Test ◽

Nano Titanium Dioxide ◽

The Impact

In this paper, the graphene oxide loaded with nano titanium dioxide (TiO2–GO) was synthesized through 3-isocyanatopropyltrimethoxysilane (IPTMS) and characterized by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction analysis (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), thermogravimetric analysis (TGA), and dispersion test. The results illustrated our modification was successful and TiO2–GO was transferred from hydrophilic to hydrophobic. That greatly enhanced the dispersity of TiO2–GO in epoxy through the observation of the coating morphology test. Moreover, the impact of TiO2–GO on anti-corrosion property in epoxy was investigated by Electrochemical Impedance Spectroscopy (EIS). Comparing to pristine particles including GO and TiO2, TiO2–GO could more significantly improve the resistance of corrosion with the help of IPTMS. Furthermore, the anti-corrosion mechanism of TiO2–GO in epoxy was tentatively proposed and discussed.

On the Tribological Properties of RGO-MoS2 Composites Surface Modified by Oleic Acid

10.21203/rs.3.rs-1042992/v1 ◽

2021 ◽

Author(s):

TianXia LIU ◽

jian Qin ◽

Jian Wang ◽

jing Li

Keyword(s):

Graphene Oxide ◽

Oleic Acid ◽

Electron Microscope ◽

Scanning Electron Microscope ◽

Molybdenum Disulfide ◽

Friction And Wear ◽

X Ray ◽

Surface Modified ◽

Scanning Electron

Abstract Purpose To study the effect of oleic acid surface modified RGO/MoS2 composite lubricating additives on the friction and wear properties of 10# White Oil (10# WO). Method The influence of different concentrations of reduction graphene oxide/molybdenum disulfide (RGO-MoS2) and oleic acid surface modified reduction graphene oxide/molybdenum disulfide (OA-RGO-MoS2) on the lubricating properties in 10# WO was investigated by using a four-ball long-term friction and wear tester. The microscopic morphology, lattice structure, composition and element valence of the prepared material were characterized by scanning electron microscope, Raman spectroscopy, X-ray diffractometer, X-ray photoelectron spectroscopy, element analyzer and other instruments. The diameter, structure, morphology, composition and element valence state of the wear scar were obtained by multifunctional universal tool microscope, scanning electron microscope and X-ray photoelectron spectroscopy. Result In the RGO-MoS2 white oil system, when 0.4 wt% RGO-MoS2 was added, the anti-friction effect was the best, and the average friction coefficient (AFC) reduced by 21.8%. When 0.2 wt% RGO-MoS2 was added, the anti-wear effect was the optimal, and the average wear scar diameter (AWSD) decreased by 12.4%. In the OA-RGO-MoS2 white oil system, when 0.2 wt% OA-RGO-MoS2 was added, the anti-friction and anti-wear effects were the best, and the AFC reduced by 33.3%, and AWSD reduced by 14.1%. Conclusion Compared with RGO-MoS2, OA-RGO-MoS2 has a higher degree of graphitization, larger interlayer spacing, lower degree of layered accumulation, higher MoS2 load, and weaker thermal stability. Both lubricating additives have good anti-friction and anti-wear effects at low concentrations, and the anti-friction and anti-wear effects are more prominent after being modified by oleic acid. Analysis of friction mechanism shows that a lubricating protective film containing iron, oxygen, molybdenum, carbon, and sulfur is formed through adsorption or tribochemical reaction during the friction process, which improves the lubrication state and plays a role in reducing friction and anti-wear.

Enhancing the Li+ diffusion in Li3VO4by coupling withreduced graphene oxide for lithium-ion batteries

Current Nanoscience ◽

10.2174/1573413717666210202115508 ◽

2021 ◽

Vol 17 ◽

Author(s):

Mingxuan Guo ◽

Haibo Li

Keyword(s):

Graphene Oxide ◽

Electronic Conductivity ◽

Specific Capacity ◽

Rate Capability ◽

Lithium Ion ◽

Reversible Capacity ◽

Ion Diffusion ◽

X Ray ◽

Host Materials

Background: Owing to the excellent theoretical specific capacity and safety intercalation potential, Li3VO4¬ (LVO) has been proposed as anadvanced anode material for lithium ions batteries (LIBs). However, the LVO suffers from low electronic conductivity that limits its commercialization. Objective: The reduced graphene oxide (rGO) is recommended to couple with micro-LVO particles aiming to enhance the conductivity of compositeelectrodes. Method: The LVO@rGO compositeis synthesized by a facile hydrothermal method. The morphology, crystallinity, valance state and electrochemical behavior of LVO@rGO are characterized by scanning electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy and electrochemical workstation, respectively. Further, the LIBs’ performance is explored by making a coins-type half-cell LIBs battery via battery system. Results: The Li+ diffusion rate of the optimized LVO@rGO electrode is 7.67×10-23 cm2 s-1, which improves two orders of magnitudesof pure LVO electrode. As a result, the LVO@rGO anode delivers a reversible capacity of 190.1 mAh/g at 0.1 A/g after 100 cycles, which is even twice higher than that of pure LVO anode (90.6 mAh/g). Besides,it exhibitssuperior rate capability, i.e.a reversible capability of 285.0, 220.2, 158.7, 105.2 and 71.7 mAh/g at 0.05, 0.1, 0.2, 0.5 and 1.0 A/g, respectively. Conclusion: The high conductivity and flexible texture enable rGO an idea building block to enhance the Li ion diffusion of whole electrode. On the other hand, it is instrumental in alleviating the aggregation of host materials, leading to high specific surface and specific capacity.

Transition Metal Oxides on Reduced Graphene Oxide Nanocomposites: Evaluation of Physicochemical Properties

Journal of Nanomaterials ◽

10.1155/2019/1703218 ◽

2019 ◽

Vol 2019 ◽

pp. 1-9 ◽

Cited By ~ 5

Author(s):

Vincenza Modafferi ◽

Saveria Santangelo ◽

Michele Fiore ◽

Enza Fazio ◽

Claudia Triolo ◽

...

Keyword(s):

Graphene Oxide ◽

Transition Metal ◽

Metal Oxides ◽

Reduced Graphene Oxide ◽

Transition Metal Oxides ◽

Rate Capability ◽

Thermal Reduction ◽

X Ray ◽

Reduced Graphene

Transition metal oxides on reduced graphene oxide (TMO@rGO) nanocomposites were successfully prepared via a very simple one-step solvothermal process, involving the simultaneous (thermal) reduction of graphene oxide to graphene and the deposition of TMO nanoparticles over its surface. Texture and morphology, microstructure, and chemical and surface compositions of the nanocomposites were investigated via scanning electron microscopy, X-ray diffraction, micro-Raman spectroscopy, and X-ray photoelectron spectroscopy, respectively. The results prove that Fe2O3@rGO, CoFe2O4@rGO, and CoO@rGO are obtained by using Fe and/or Co acetates as oxide precursors, with the TMO nanoparticles uniformly anchored onto the surface of graphene sheets. The electrochemical performance of the most promising nanocomposite was evaluated as anode material for sodium ion batteries. The preliminary results of galvanostatic cycling prove that Fe2O3@rGO nanocomposite exhibits better rate capability and stability than both bare Fe2O3 and Fe2O3+rGO physical mixture.