scholarly journals Synthesis of Reduced Graphene Oxide/Titanium Dioxide Nanotubes (rGO/TNT) Composites as an Electrical Double Layer Capacitor

Nanomaterials ◽  
2018 ◽  
Vol 8 (11) ◽  
pp. 934 ◽  
Author(s):  
John Lazarte ◽  
Regine Dipasupil ◽  
Gweneth Pasco ◽  
Ramon Eusebio ◽  
Aileen Orbecido ◽  
...  
Keyword(s):  
Titanium Dioxide ◽  
Graphene Oxide ◽  
Specific Capacitance ◽  
Reduced Graphene Oxide ◽  
Double Layer ◽  
Cyclic Voltammogram ◽  
Titanium Dioxide Nanotubes ◽  
Combination Methods ◽  
Double Layer Capacitor ◽  
Reduced Graphene

Composites of synthesized reduced graphene oxide (rGO) and titanium dioxide nanotubes (TNTs) were examined and combined at different mass proportions (3:1, 1:1, and 1:3) to develop an electrochemical double layer capacitor (EDLC) nanocomposite. Three different combination methods of synthesis—(1) TNT introduction during GO reduction, (2) rGO introduction during TNT formation, and (3) TNT introduction in rGO sheets using a microwave reactor—were used to produce nanocomposites. Among the three methods, method 3 yielded an EDLC nanomaterial with a highly rectangular cyclic voltammogram and steep electrochemical impedance spectroscopy plot. The specific capacitance for method 3 nanocomposites ranged from 47.26–165.22 F/g while that for methods 1 and 2 nanocomposites only ranged from 14.03–73.62 F/g and 41.93–84.36 F/g, respectively. Furthermore, in all combinations used, the 3:1 graphene/titanium dioxide-based samples consistently yielded the highest specific capacitance. The highest among these nanocomposites is 3:1 rGO/TNT. Characterization of this highly capacitive 3:1 rGO/TNT EDLC composite revealed the dominant presence of partially amorphous rGO as seen in its XRD and SEM with branching crystalline anatase TNTs as seen in its XRD and TEM. Such property showed great potential that is desirable for applications to capacitive deionization and energy storage.

scholarly journals Patching laser-reduced graphene oxide with carbon nanodots

Nanoscale ◽  
2019 ◽  
Vol 11 (26) ◽  
pp. 12712-12719 ◽  
Author(s):  
Volker Strauss ◽  
Mit Muni ◽  
Arie Borenstein ◽  
Bolortuya Badamdorj ◽  
Tobias Heil ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Reduced Graphene Oxide ◽  
Double Layer ◽  
Electric Double Layer ◽  
Carbon Nanodots ◽  
Electric Double Layer Capacitor ◽  
3D Graphene ◽  
Precursor Material ◽  
Double Layer Capacitor ◽  
Reduced Graphene

The performance of electric double layer capacitor (EDLC) electrodes based on 3D-graphene obtained by laser-assisted reduction of graphene oxide (GO) is improved by addition of carbon nanodots (CND) to the GO precursor material.

scholarly journals Sustainable Desalination by 3:1 Reduced Graphene Oxide/Titanium Dioxide Nanotubes (rGO/TiONTs) Composite via Capacitive Deionization at Different Sodium Chloride Concentrations

Nanomaterials ◽  
2019 ◽  
Vol 9 (9) ◽  
pp. 1319 ◽  
Author(s):  
John Paolo L. Lazarte ◽  
Liza Bautista-Patacsil ◽  
Ramon Christian P. Eusebio ◽  
Aileen H. Orbecido ◽  
Ruey-an Doong
Keyword(s):  
Titanium Dioxide ◽  
Graphene Oxide ◽  
Energy Consumption ◽  
Reduced Graphene Oxide ◽  
Contact Angles ◽  
Capacitive Deionization ◽  
Titanium Dioxide Nanotubes ◽  
Charging Time ◽  
Reduced Graphene ◽  
Charge Discharge

The capability of novel 3:1 reduced graphene oxide/titanium dioxide nanotubes (rGO/TiONTs) composite to desalinate using capacitive deionization (CDI) employing highly concentrated NaCl solutions was tested in this study. Parameters such as material wettability, electrosorption capacity, charge efficiency, energy consumption, and charge-discharge retention were tested at different NaCl initial concentrations—100 ppm, 2000 ppm, 15,000 ppm, and 30,000 ppm. The rGO/TiONTs composite showed good material wettability before and after CDI runs with its contact angles equal to 52.11° and 56.07°, respectively. Its two-hour electrosorption capacity during CDI at 30,000 ppm NaCl influent increased 1.34-fold compared to 100 ppm initial NaCl influent with energy consumption constant at 1.11 kWh per kg with NaCl removed. However, the percentage discharge (concentration-independent) at zero-voltage ranged from 4.9–7.27% only after 30 min of desorption. Repeated charge/discharge at different amperes showed that the slowest charging rate of 0.1 A·g−1 had the highest charging time retention at 60% after 100 cycles. Increased concentration likewise increases charging time retention. With this consistent performance of a CDI system utilizing rGO/TiONTs composite, even at 30,000 ppm and 100 cycles, it can be a sustainable alternative desalination technology, especially if a low charging current with reverse voltage discharge is set for a longer operation.

scholarly journals MoS2/Reduced Graphene Oxide-Based 2D Nancomposites for Boosting the Energy Density of Electric Double-Layer Capacitor

MRS Advances ◽  
2016 ◽  
Vol 1 (22) ◽  
pp. 1619-1624 ◽  
Author(s):  
Anishkumar Manoharan ◽  
Z. Ryan Tian ◽  
Simon S. Ang
Keyword(s):  
Graphene Oxide ◽  
Energy Density ◽  
Reduced Graphene Oxide ◽  
Double Layer ◽  
Electric Double Layer ◽  
Discharge Rate ◽  
Electric Double Layer Capacitor ◽  
Double Layer Capacitor ◽  
Reduced Graphene ◽  
Maximum Current

ABSTRACTA method for synthesizing and structuring 2D-MoS2/rGO (molybdenum disulfide/reduced graphene oxide) nanocomposite-based electric double layer capacitor (EDLC) that has a slower discharge rate and higher energy density than rGO-based EDLC (RG-EDLC) is reported. The rGO electrode and the nanocomposite were characterized using powder XRD and SEM for their physical and structural properties. Cyclic voltammetry (CV) was used to analyze the electrochemical behavior of the EDLCs. A maximum current density at which the MoS2/rGO nanocomposite-based EDLC (MRG-EDLC) can charge and discharge was 2.5 A/g, while it was 1A/g for the RG-EDLC. The specific capacitance of the MRG-EDLC was 14.52 F/g at 0.5 A/g with an energy density of 8.06 Wh/kg.

Deionization utilizing reduced graphene oxide-titanium dioxide nanotubes composite for the removal of Pb2+ and Cu2+

2020 ◽  
Vol 8 (3) ◽  
pp. 103063 ◽  
Author(s):  
L. Bautista-Patacsil ◽  
J.P.L. Lazarte ◽  
R.C. Dipasupil ◽  
G.Y. Pasco ◽  
R.C. Eusebio ◽  
...  
Keyword(s):  
Titanium Dioxide ◽  
Graphene Oxide ◽  
Reduced Graphene Oxide ◽  
Titanium Dioxide Nanotubes ◽  
Reduced Graphene

Concisely modularized assembling of graphene-based thin films with promising electrode performance

2019 ◽  
Vol 3 (7) ◽  
pp. 1462-1470 ◽  
Author(s):  
Weiwei Wei ◽  
Rohit L. Vekariy ◽  
Chuanting You ◽  
Yafei He ◽  
Ping Liu ◽  
...  
Keyword(s):  
Thin Films ◽  
Graphene Oxide ◽  
Reduced Graphene Oxide ◽  
Double Layer ◽  
Van Der Waals ◽  
Cellulose Nanofibers ◽  
Van Der Waals Interactions ◽  
Electrode Performance ◽  
Reduced Graphene

Highly dense thin films assembled from cellulose nanofibers and reduced graphene oxide via van der Waals interactions to realize ultrahigh volumetric double-layer capacitances.

Hybrid Supercapacitors Based on Self-Assembled Electrochemical Deposition of Reduced Graphene Oxide/Polypyrrole Composite Electrodes

2021 ◽  
Vol 16 (6) ◽  
pp. 949-956
Author(s):  
Jun Ma ◽  
Junaid Ali Syed ◽  
Dongyun Su
Keyword(s):  
Graphene Oxide ◽  
Specific Capacitance ◽  
Reduced Graphene Oxide ◽  
Electrochemical Deposition ◽  
High Energy ◽  
Carbon Cloth ◽  
Discharge Process ◽  
Rate Performance ◽  
Reduced Graphene ◽  
Self Assembled

Conductive polymers (CPs) have potential application to commercial energy storage because of their high electrochemical activity and low cost. However, an obstacle in developing CP-based supercapacitors is the degradation in their capacitance during the charge-discharge process that leads to poor rate performance. This study fabricates layers of a high-performance self-assembled polypyrrole/reduced graphene oxide (PPY/RGO) composite material on a carbon cloth through electrochemical deposition. The layered graphene improved the electrochemical properties of PPY. Carbon fiber rods were coated with the PPY/RGO composite layer, the thickness of which depends on the deposition time. Adequate capacitive behaviors were achieved by using 16 layers of polypyrrole/reduced graphene oxide, with a specific capacitance of 490 F g−1 (0.6 A g−1) and good rate performance. The results here provide a novel means of preparing graphene-based nanocomposites films for a variety of functions. A symmetric device was subsequently assembled by using electrodes featuring 16 layers of the polypyrrole/reduced graphene oxide composite. It yielded a specific capacitance of 205 F g−1 and a high energy density of 16.4 Wh kg−1. It also exhibited good cycle stability, with a capacitance retention rate of 85% for 5,000 cycles.

Modulation of oxygen functional groups and their influence on the supercapacitor performance of reduced graphene oxide

2020 ◽  
Vol 44 (44) ◽  
pp. 19022-19027
Author(s):  
Zegao Wang ◽  
Yuqing Wang ◽  
Xin Hao ◽  
Jingbo Liu ◽  
Yuanfu Chen ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Specific Capacitance ◽  
Reduced Graphene Oxide ◽  
Functional Groups ◽  
Oxygen Functional Groups ◽  
Reduced Graphene ◽  
Supercapacitor Performance

Through tuning the oxygen function groups, it was demonstrated that the specific capacitance of reduced graphene oxide can increase from 136 F g−1 to 182 F g−1.

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