From Thermal to Electroactive Graphene Nanofluids

Here, we describe selected work on the development and study of nanofluids based on graphene and reduced graphene oxide both in aqueous and organic electrolytes. A thorough study of thermal properties of graphene in amide organic solvents (N,N-dimethylformamide, N,N-dimethylacetamide, and N-methyl-2-pyrrolidone) showed a substantial increase of thermal conductivity and specific heat upon graphene integration in those solvents. In addition to these thermal studies, our group has also pioneered a distinct line of work on electroactive nanofluids for energy storage. In this case, reduced graphene oxide (rGO) nanofluids in aqueous electrolytes were studied and characterized by cyclic voltammetry and charge-discharge cycles (i.e., in new flow cells). In addition, hybrid configurations (both hybrid nanofluid materials and hybrid cells combining faradaic and capacitive activities) were studied and are summarized here.

Download Full-text

Thermohydraulic assessment of a novel hybrid nanofluid containing cobalt oxide-decorated reduced graphene oxide nanocomposite in a microchannel heat sink with sinusoidal cavities and rectangular ribs

International Communications in Heat and Mass Transfer ◽

10.1016/j.icheatmasstransfer.2021.105769 ◽

2022 ◽

Vol 131 ◽

pp. 105769

Author(s):

Mohammad Jamshidmofid ◽

Mehdi Bahiraei

Keyword(s):

Graphene Oxide ◽

Reduced Graphene Oxide ◽

Cobalt Oxide ◽

Heat Sink ◽

Hybrid Nanofluid ◽

Microchannel Heat Sink ◽

Reduced Graphene

Download Full-text

Assembly of Na3V2(PO4)2F3@C nanoparticles in reduced graphene oxide enabling superior Na+ storage for symmetric sodium batteries

RSC Advances ◽

10.1039/c7ra13441j ◽

2018 ◽

Vol 8 (6) ◽

pp. 2958-2962 ◽

Cited By ~ 18

Author(s):

Ye Yao ◽

Lu Zhang ◽

Yu Gao ◽

Gang Chen ◽

Chunzhong Wang ◽

...

Keyword(s):

Graphene Oxide ◽

Reduced Graphene Oxide ◽

Full Cell ◽

Discharge Cycle ◽

Reduced Graphene ◽

Sodium Batteries ◽

Charge Discharge

Symmetrical full cell of NVPF@C@rGO as both cathode and anode could light the LED lamp successfully after the 25th charge–discharge cycle at 1C.

Download Full-text

Synthesis of reduced graphene oxide/α-Bi2Mo3O12 @ β-Bi2O3 heterojunctions by organic electrolytes assisted UV-excited method

Chemical Engineering Journal ◽

10.1016/j.cej.2014.07.030 ◽

2014 ◽

Vol 257 ◽

pp. 309-316 ◽

Cited By ~ 19

Author(s):

Shiyi Cao ◽

Chuansheng Chen ◽

Tiangui Liu ◽

Yuenhong Tsang ◽

Xuming Zhang ◽

...

Keyword(s):

Graphene Oxide ◽

Reduced Graphene Oxide ◽

Organic Electrolytes ◽

Reduced Graphene

Download Full-text

The synergistic effect of nitrogen doping and para-phenylenediamine functionalization on the physicochemical properties of reduced graphene oxide for electric double layer supercapacitors in organic electrolytes

Journal of Materials Chemistry A ◽

10.1039/c7ta03194g ◽

2017 ◽

Vol 5 (24) ◽

pp. 12426-12434 ◽

Cited By ~ 14

Author(s):

Junghoon Yang ◽

Jeongyim Shin ◽

Mihui Park ◽

Gi-Hyeok Lee ◽

Mawuse Amedzo-Adore ◽

...

Keyword(s):

Graphene Oxide ◽

Synergistic Effect ◽

Physicochemical Properties ◽

Reduced Graphene Oxide ◽

Double Layer ◽

Electric Double Layer ◽

Nitrogen Doping ◽

Organic Electrolytes ◽

Reduced Graphene ◽

N Doping

This work studied the synergistic effect of N-doping and p-PDA functionalization on the properties of RGO for supercapacitors.

Download Full-text

Battery and supercapacitor materials in flow cells. Electrochemical energy storage in a LiFePO4/reduced graphene oxide aqueous nanofluid

Electrochimica Acta ◽

10.1016/j.electacta.2018.05.151 ◽

2018 ◽

Vol 281 ◽

pp. 594-600 ◽

Cited By ~ 6

Author(s):

Daniel Rueda-Garcia ◽

Zahilia Cabán-Huertas ◽

Sergi Sánchez-Ribot ◽

Carlos Marchante ◽

Raul Benages ◽

...

Keyword(s):

Graphene Oxide ◽

Energy Storage ◽

Reduced Graphene Oxide ◽

Electrochemical Energy Storage ◽

Flow Cells ◽

Reduced Graphene ◽

Electrochemical Energy

Download Full-text

Novel Synthesis of Holey Reduced Graphene Oxide/Polystyrene (HRGO/PS) Nanocomposites by Microwave Irradiation as Anodes for High-Temperature Lithium-Ion Batteries

Materials ◽

10.3390/ma12142248 ◽

2019 ◽

Vol 12 (14) ◽

pp. 2248 ◽

Cited By ~ 2

Author(s):

Yazeed Aldawsari ◽

Yasmin Mussa ◽

Faheem Ahmed ◽

Muhammad Arsalan ◽

Edreese Alsharaeh

Keyword(s):

Electron Microscopy ◽

Graphene Oxide ◽

High Temperature ◽

Microwave Irradiation ◽

Reduced Graphene Oxide ◽

Coulombic Efficiency ◽

Lithium Ion ◽

Reduced Graphene ◽

Discharge Capacities ◽

Charge Discharge

To overcome the risk of exothermic lithium-ion battery overheating reactions, we fabricated a novel, high-temperature-stable anode material composed of holey reduced graphene oxide/polystyrene (HRGO/PS) nanocomposites synthesized through in situ bulk polymerization in the presence of HRGO via microwave irradiation. The HRGO/PS nanocomposites were characterized by Fourier transform infrared spectroscopy, X-ray diffraction, Raman spectroscopy, and electron microscopy analyses including field-emission scanning electron microscopy and transmission electron microscopy. All characterization studies demonstrated homogenous dispersion of HRGO in the PS matrix, which enhanced the thermal and electrical properties of the overall nanocomposites. These novel HRGO/PS nanocomposites exhibited excellent electrochemical responses, with reversible charge/discharge capacities of 92.1/92.78 mA·h/g at a current density of 500 mA/g with ~100% capacity retention and ~100% coulombic efficiency at room temperature. Furthermore, an examination of the electrochemical properties of these nanocomposites at 110 °C showed that HRGO/PS nanocomposites still displayed good charge/discharge capacities with stable cycle performances for 150 cycles.

Download Full-text

Simple synthesis of nanosheets of rGO and nitrogenated rGO

Beilstein Journal of Nanotechnology ◽

10.3762/bjnano.11.7 ◽

2020 ◽

Vol 11 ◽

pp. 68-75 ◽

Cited By ~ 3

Author(s):

Pallellappa Chithaiah ◽

Madhan Mohan Raju ◽

Giridhar U Kulkarni ◽

C N R Rao

Keyword(s):

Graphene Oxide ◽

Reduced Graphene Oxide ◽

Large Scale ◽

Cyclic Voltammograms ◽

Hydrogen Treatment ◽

High Nitrogen Content ◽

High Nitrogen ◽

Reduced Graphene ◽

High Yields ◽

Charge Discharge

A green and facile approach has been developed for the large-scale synthesis of nanosheets of reduced graphene oxide (rGO) and nitrogenated reduced graphene oxide (N-rGO). This has been achieved by direct thermal decomposition of sucrose and glycine at 475 °C in ca. 7 minutes, respectively. The present protocols for synthesizing rGO and N-rGO are simple and environmentally friendly as we do not use any harmful reagents, metal catalysts and solvents. Along with that, this method offers an inexpensive route with high yields to prepare rGO with a high nitrogen content (20–25 atom %). To further improve the properties of the synthesized rGO sheets, hydrogen treatment has been carried out to reduce the oxygen functional groups. Cyclic voltammograms and charge–discharge experiments have been carried out to understand the supercapacitor behavior of rGO and hydrogen treated (H-rGO) samples.

Download Full-text

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

Nanomaterials ◽

10.3390/nano9091319 ◽

2019 ◽

Vol 9 (9) ◽

pp. 1319 ◽

Cited By ~ 3

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.

Download Full-text