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

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.

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

Journal of Environmental Chemical Engineering ◽

10.1016/j.jece.2019.103063 ◽

2020 ◽

Vol 8 (3) ◽

pp. 103063 ◽

Cited By ~ 3

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

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

Nanomaterials ◽

10.3390/nano8110934 ◽

2018 ◽

Vol 8 (11) ◽

pp. 934 ◽

Cited By ~ 15

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.

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Selective phosphate removal using layered double hydroxide/reduced graphene oxide (LDH/rGO) composite electrode in capacitive deionization

Journal of Colloid and Interface Science ◽

10.1016/j.jcis.2019.12.068 ◽

2020 ◽

Vol 564 ◽

pp. 1-7 ◽

Cited By ~ 5

Author(s):

Sung Pil Hong ◽

Hansun Yoon ◽

Jaehan Lee ◽

Choonsoo Kim ◽

Seoni Kim ◽

...

Keyword(s):

Graphene Oxide ◽

Reduced Graphene Oxide ◽

Layered Double Hydroxide ◽

Composite Electrode ◽

Phosphate Removal ◽

Capacitive Deionization ◽

Reduced Graphene ◽

Double Hydroxide

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Three-dimensional reduced graphene oxide decorated with iron oxide nanoparticles as efficient active material for high performance capacitive deionization electrodes

Chemical Engineering Journal Advances ◽

10.1016/j.ceja.2021.100094 ◽

2021 ◽

Vol 6 ◽

pp. 100094

Author(s):

Yolanda Belaustegui ◽

Inés Rincón ◽

Francisco Fernández-Carretero ◽

Patxi Azpiroz ◽

Alberto García-Luís ◽

...

Keyword(s):

Graphene Oxide ◽

Iron Oxide ◽

Reduced Graphene Oxide ◽

Iron Oxide Nanoparticles ◽

High Performance ◽

Active Material ◽

Three Dimensional ◽

Oxide Nanoparticles ◽

Capacitive Deionization ◽

Reduced Graphene

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Synthesis of Titanium Dioxide (TiO2)/Reduced Graphene Oxide (rGO) thin film composite by spray pyrolysis technique and its physical properties

Materials Science in Semiconductor Processing ◽

10.1016/j.mssp.2020.105140 ◽

2020 ◽

Vol 116 ◽

pp. 105140 ◽

Cited By ~ 1

Author(s):

A.S. AlShammari ◽

M.M. Halim ◽

F.K. Yam ◽

N.H. Mohd Kaus

Keyword(s):

Thin Film ◽

Titanium Dioxide ◽

Graphene Oxide ◽

Physical Properties ◽

Spray Pyrolysis ◽

Reduced Graphene Oxide ◽

Spray Pyrolysis Technique ◽

Film Composite ◽

Thin Film Composite ◽

Reduced Graphene

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Structural Applications of Thermal Insulation Alkali Activated Materials with Reduced Graphene Oxide

Materials ◽

10.3390/ma13051052 ◽

2020 ◽

Vol 13 (5) ◽

pp. 1052

Author(s):

Wu-Jian Long ◽

Can Lin ◽

Xiao-Wen Tan ◽

Jie-Lin Tao ◽

Tao-Hua Ye ◽

...

Keyword(s):

Thermal Conductivity ◽

Graphene Oxide ◽

Energy Consumption ◽

Reduced Graphene Oxide ◽

Thermal Insulation ◽

Expanded Polystyrene ◽

Information Modeling ◽

Reduced Graphene ◽

Structural Applications ◽

Alkali Activated

Development of low thermal conductivity and high strength building materials is an emerging strategy to solve the heavy energy consumption of buildings. This study develops sustainable alkali activated materials (AAMs) for structural members from waste expanded polystyrene (EPS) beads and reduced graphene oxide (rGO) to simultaneously meet the thermal insulation and mechanical requirements of building energy conservation. It was found that the thermal conductivity of AAMs with 80 vol.% EPS and 0.04 wt.% rGO (E8–G4) decreased by 74% compared to the AAMs without EPS and rGO (E0). The 28-day compressive and flexural strengths of E8–G4 increased by 29.8% and 26.5% with the addition of 80 vol.% EPS and 0.04 wt.% rGO, compared to the sample with 80 vol.% EPS without rGO (E8). In terms of compressive strength, thermal conductivity, and cost, the efficiency index of E8–G4 was higher than those of other materials. A building model made from AAMs was designed using building information modeling (BIM) tools to simulate energy consumption, and 31.78% of total energy consumption (including heating and cooling) was saved in the building operation period in Harbin City, China. Hence, AAMs made of waste EPS beads and rGO can realize the structural and functional integrated application in the future.

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