scholarly journals Carbon-Based Electric Double Layer Capacitors for Water Desalination

Author(s):  
Batya A. Fellman ◽  
Muataz Atieh ◽  
Evelyn N. Wang

In capacitive deionization (CDI), salt water is passed through two polarized electrodes, whereby the salt is adsorbed onto the electrode surface and removed from the water stream. This approach has received renewed interest for water desalination due to the development of new high-surface area carbon-based nanomaterials. However, there is currently limited understanding as to how electrode geometry, surface properties, and capacitance affect ion capture. In this work, we experimentally investigate various standard carbon-based electrode materials, including activated carbon and carbon cloths, as well as microfabricated silicon structures for CDI. Electrochemical characterization through cyclic voltammetry was used to determine the electrochemical properties of each material. In addition, a mini-channel test cell was fabricated to perform parametric studies on ion capture. By controlling electrode geometry and chemistry in these studies, the work helps elucidate transport mechanisms and provide insight into the design of optimal materials for capacitive deionization.

2020 ◽  
Vol 1 (1) ◽  
pp. 58-77
Author(s):  
Sumiya Adrita ◽  
Khandaker Tasnim ◽  
Ji Ryu ◽  
Shazid Sharker

Cancer remains one of the most deadly diseases globally, but carbon-based nanomaterials have the potential to revolutionize cancer diagnosis and therapy. Advances in nanotechnology and a better understanding of tumor microenvironments have contributed to novel nanotargeting routes that may bring new hope to cancer patients. Several low-dimensional carbon-based nanomaterials have shown promising preclinical results; as such, low-dimensional carbon dots (CDs) and their derivatives are considered up-and-coming candidates for cancer treatment. The unique properties of carbon-based nanomaterials are high surface area to volume ratio, chemical inertness, biocompatibility, and low cytotoxicity. It makes them well suited for delivering chemotherapeutics in cancer treatment and diagnosis. Recent studies have shown that the CDs are potential applicants in biomedical sciences, both as nanocarriers and nanotransducers. This review covers the most commonly used CD nanoparticles in nanomedicines intended for the early diagnosis and therapy of cancer.


2019 ◽  
Vol 9 (3) ◽  
pp. 282-291 ◽  
Author(s):  
T. Alfredy ◽  
Y. A. C. Jande ◽  
T. Pogrebnaya

Abstract Capacitive deionization (CDI) is a promising and rapidly growing technology for water treatment and the electrode materials play a key role in improving CDI performance. In this study, high surface area activated carbon was prepared from chicken feather (CF) bio-waste through pyrolysis and KOH activation; the KOH:CF ratio (R) and activation temperature (Ta) were variable parameters. The material was characterized by using the Brunauer, Emmett and Teller (BET) method, Fourier transform infrared (FTIR) spectroscopy and scanning electron microscopy (SEM). The lead (Pb2+) removal test was performed with a CDI cell containing the fabricated carbon electrode and 100 mg L−1 Pb(NO3)2 solution; the sample prepared with the ratio R of 1:1 and Ta = 800 °C exhibited higher Pb2+ removal efficiency of 81% and electro sorption capacity of 4.1 mg g−1 at the electrode potential 1.2 V and flow rate 5 mL min−1. Therefore, CF-derived carbon is considered as a promising CDI electrode material for removal of heavy metals from waste water.


Nanomaterials ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 1268 ◽  
Author(s):  
Álvaro Torrinha ◽  
Thiago M. B. F. Oliveira ◽  
Francisco W.P. Ribeiro ◽  
Adriana N. Correia ◽  
Pedro Lima-Neto ◽  
...  

Pharmaceuticals, as a contaminant of emergent concern, are being released uncontrollably into the environment potentially causing hazardous effects to aquatic ecosystems and consequently to human health. In the absence of well-established monitoring programs, one can only imagine the full extent of this problem and so there is an urgent need for the development of extremely sensitive, portable, and low-cost devices to perform analysis. Carbon-based nanomaterials are the most used nanostructures in (bio)sensors construction attributed to their facile and well-characterized production methods, commercial availability, reduced cost, high chemical stability, and low toxicity. However, most importantly, their relatively good conductivity enabling appropriate electron transfer rates—as well as their high surface area yielding attachment and extraordinary loading capacity for biomolecules—have been relevant and desirable features, justifying the key role that they have been playing, and will continue to play, in electrochemical (bio)sensor development. The present review outlines the contribution of carbon nanomaterials (carbon nanotubes, graphene, fullerene, carbon nanofibers, carbon black, carbon nanopowder, biochar nanoparticles, and graphite oxide), used alone or combined with other (nano)materials, to the field of environmental (bio)sensing, and more specifically, to pharmaceutical pollutants analysis in waters and aquatic species. The main trends of this field of research are also addressed.


Author(s):  
Tusekile Alfredy ◽  
Joyce Elisadiki ◽  
Yusufu Abeid Chande Jande

Abstract Capacitive deionization (CDI) is among the promising technologies employed for water purification. CDI has been studied for the removal of various ionic species from water including fluoride ion (F−) with promising results. However, there is no comprehensive literature that summarizes the use of CDI for water defluoridation applications. Therefore, this review paper critically analyzes different electrode materials that have been studied for water defluoridation, their electrosorption capacities and F− removal efficiencies. It further discussed the parameters that influence CDI efficiency during defluoridation and point out the issues of F− selectivity when coexisting with other ions in the solution. We can conclude that different electrode materials have shown different abilities in electrosorption of F−. The carbon-based materials possess high surface area and good electrical conductivity which is paramount for ion adsorption but lack selectivity for F− removal. Metal oxides and hydroxides have been reported with improved electrosorption capacity and high selectivity to F− due to the ion exchange between the F− and the hydroxyls surface of the metal oxides/hydroxides. Apart from the good performance of these materials for defluoridation, the discovery of actual practicability use of the electrode materials for defluoridation for commercial scale is still a need.


Nanomaterials ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 2091
Author(s):  
Ngo Minh Phuoc ◽  
Euiyeon Jung ◽  
Nguyen Anh Thu Tran ◽  
Young-Woo Lee ◽  
Chung-Yul Yoo ◽  
...  

Capacitive deionization (CDI) based on ion electrosorption has recently emerged as a promising desalination technology due to its low energy consumption and environmental friendliness compared to conventional purification technologies. Carbon-based materials, including activated carbon (AC), carbon aerogel, carbon cloth, and carbon fiber, have been mostly used in CDI electrodes due their high surface area, electrochemical stability, and abundance. However, the low electrical conductivity and non-regular pore shape and size distribution of carbon-based electrodes limits the maximization of the salt removal performance of a CDI desalination system using such electrodes. Metal-organic frameworks (MOFs) are novel porous materials with periodic three-dimensional structures consisting of metal center and organic ligands. MOFs have received substantial attention due to their high surface area, adjustable pore size, periodical unsaturated pores of metal center, and high thermal and chemical stabilities. In this study, we have synthesized ZIF-67 using CNTs as a substrate to fully utilize the unique advantages of both MOF and nanocarbon materials. Such synthesis of ZIF-67 carbon nanostructures was confirmed by TEM, SEM, and XRD. The results showed that the 3D-connected ZIF-67 nanostructures bridging by CNTs were successfully prepared. We applied this nanostructured ZIF-67@CNT to CDI electrodes for desalination. We found that the salt removal performance was significantly enhanced by 88% for 30% ZIF-67@CNTs-included electrodes as compared with pristine AC electrodes. This increase in salt removal behavior was analyzed by electrochemical analysis such as cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) measurements, and the results indicate reduced electrical impedance and enhanced electrode capacitance in the presence of ZIF-67@CNTs.


2016 ◽  
Vol 5 (1) ◽  
Author(s):  
Shu Wan ◽  
Hengchang Bi ◽  
Litao Sun

AbstractThis paper provides a comprehensive review of recent progress in the synthesis and performance of graphene and carbon-based nanomaterials as efficient adsorbents for oils and organic solvents. Several advantages of these adsorbents are emphasized, including adjustable three-dimensional networks, high surface area, high chemical/thermal stability, high flexibility and elasticity, and extremely high surface hydrophobicity/ oleophilicity. Technical challenges are discussed, and future research directions are proposed.


2019 ◽  
Vol 43 (48) ◽  
pp. 19372-19378 ◽  
Author(s):  
Jianyu Huang ◽  
Simin Liu ◽  
Zifang Peng ◽  
Zhuoxian Shao ◽  
Yuanyuan Zhang ◽  
...  

The synergistic effects of high surface area and abundant heteroatoms make porous carbons superior electrode materials.


2019 ◽  
Vol 31 (8) ◽  
pp. 1709-1718
Author(s):  
T. Veldevi ◽  
K. Thileep Kumar ◽  
R.A. Kalaivani ◽  
S. Raghu ◽  
A.M. Shanmugharaj

Hierarchical nanostructured graphene–manganese dioxide nanowire (G-MnO2-NW) composites have been prepared by hydrothermal synthesis route using water/1-decanol as the medium. Synthesized materials were analyzed using various characterization tools to corroborate their chemical compositions, structure/morphology and surface area. Electrochemical measurements of the synthesized G-MnO2-NW electrode materials delivered the highest specific capacity (255 Fg-1), high rate capability and improved cycling stability at 0.5 Ag–1 in 1M sodium sulfate solution and this fact may be attributed to its high surface area and porosity. Moreover, synthesized G-MnO2-NW electrodes displayed better energy and power density, when compared to the MnO2-NW based electrodes.


2020 ◽  
Vol 10 (3) ◽  
pp. 918 ◽  
Author(s):  
Jack Clohessy ◽  
Witold Kwapinski

In recent years, a new class of superior heterogeneous acid catalyst for biodiesel production has emerged. These catalysts offer advantages over their predecessors such as high surface area, elevated acid site density, enhanced catalyst activity, good operation stability and relevant economic affordability in an environmentally friendly frame. This review was concerned with carbon-based solid acid (CBAS) catalysts derived from both carbohydrate and pyrolysis products. A series of CBASs with various origins such as D-glucose, sucrose, starch, cellulose and vegetable oil asphalt, converted to char and sulphonated, have been explored as potential heterogeneous catalysts. Catalyst preparation and synthesis methods were briefly summarized. Catalyst characterization and performance for biofuels related reactions were elucidated, identifying potential research applications. Three catalysts in particular were identified as having potential for industrial application and requiring further research.


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