Emerging investigator series: Local pH Effects on Carbon Oxidation in Capacitive Deionization Architectures

2021 ◽  
Author(s):  
James Landon ◽  
Xin Gao ◽  
Ayokunle Omosebi ◽  
Kunlei Liu
Keyword(s):  
Ph Effects ◽  
Carbon Cloth ◽  
Carbon Oxidation ◽  
Capacitive Deionization ◽  
Effect Of Ph ◽  
Degree Of Oxidation ◽  
Local Ph

In this work, the effect of pH and potential is examined for the oxidation of carbon cloth electrodes used in capacitive deionization (CDI) processes. The degree of oxidation of the...

Nanoporous MnO2 Nanoflakes Modified Carbon Cloth Material for Efficient Removal of Heavy Metal Ions in Water by Capacitive Deionization

2018 ◽  
Vol MA2018-01 (32) ◽  
pp. 1973-1973
Author(s):  
Ying Wang ◽  
Daniel J Blackwood
Keyword(s):  
Heavy Metal ◽  
Metal Ions ◽  
Heavy Metal Ions ◽  
Electronic Conductivity ◽  
Porous Electrodes ◽  
Carbon Cloth ◽  
List Type ◽  
Capacitive Deionization ◽  
Counter Electrodes ◽  
High Electronic Conductivity

Increasing demand for the limited resource of fresh water for the large urban populations and development of agriculture and industry draws public concern. Removal of heavy metals such as lead, cadmium, chromium and mercury is crucial in environmental improvement of water and industrial wastewater treatment. Great efforts have been made through chemical precipitation, adsorption, ion exchange, filtration and electrochemical treatment. However, a large volume of sludge residue, expensive and complex matrix materials and low efficiency are still problems that need to be improved. Capacitive deionization (CDI) is a promising energy-efficient technology for water desalination, which is easy to handle and environmentally friendly producing no secondary contaminants through the water purifying process [1]. In order to effectively remove ions, the porous electrodes with large surface area, good chemical stability, high electronic conductivity, and hydrophility are key factors in the selection of CDI materials. Highly porous carbon materials represent the typical electrodes to store the ions through surface ion adsorption/desorption, which is generally categorized as electrochemical double layer. By contrast, pseudocapacitors that consist of conducting polymers and transition metals, store more charge through redox reactions. Among the alternative candidates, the natural abundant and environmental benign MnO2 is of particular interest for research, due to its high theoretical specific capacitance and the ability to be use in mild aqueous electrolytes which expand its practical application [2-3]. MnO2 can be fabricated easily and its morphology can be controlled during simple hydrothermal growth processes. Direct growth on carbon cloth, which is an excellent flexible and conductive substrate, could enhance the regeneration and reuse property of MnO2 as an ideal CDI electrode. Porous MnO2@cabon cloth composites were prepared via a facile hydrothermal method (Figure a). The BET result showed that the average pore width is 18.2 nm. To investigate the CDI property of removing the heavy metal ions, one piece of MnO2@CC and one piece of activated carbon@graphite paper were assembled as working and counter electrodes respectively. This work confirmed the potential of using MnO2@CC as a good CDI electrode material for removal of heavy metal ions from water (Figure b). References S. Porada, R. Zhao, A. Wal, V. Presser, and P. M. Biesheuvel, Prog. Mater. Sci., 58, 1388 (2013). W. Wei, X. Cui, W. Chen, and D. G. Ivey, Chem. Soc. Rev., 40, 1697 (2011). J. Wang, F. Kang, and B. Wei, Prog. Mater. Sci., 74, 51 (2015). Figure 1

Influence of pore structure and cell voltage of activated carbon cloth as a versatile electrode material for capacitive deionization

Carbon ◽  
2017 ◽  
Vol 122 ◽  
pp. 329-335 ◽  
Author(s):  
Choonsoo Kim ◽  
Pattarachai Srimuk ◽  
Juhan Lee ◽  
Simon Fleischmann ◽  
Mesut Aslan ◽  
...  
Keyword(s):  
Activated Carbon ◽  
Pore Structure ◽  
Electrode Material ◽  
Cell Voltage ◽  
Carbon Cloth ◽  
Capacitive Deionization ◽  
Activated Carbon Cloth

scholarly journals Comprehensive study of buffer systems and local pH effects in electromembrane extraction

2017 ◽  
Vol 984 ◽  
pp. 116-123 ◽  
Author(s):  
Magnus Saed Restan ◽  
Henrik Jensen ◽  
Xiantao Shen ◽  
Chuixiu Huang ◽  
Ørjan Grøttem Martinsen ◽  
...  
Keyword(s):  
Ph Effects ◽  
Electromembrane Extraction ◽  
Local Ph ◽  
Comprehensive Study

Effects of acid treatment on the improvement of specific capacitance and deionization efficiency of porous carbon electrodes

2009 ◽  
Vol 9 (2) ◽  
pp. 159-165 ◽  
Author(s):  
R. L. Machunda ◽  
H. Jeon ◽  
J. K. Lee ◽  
J. Lee
Keyword(s):  
Functional Groups ◽  
Porous Carbon ◽  
Acid Treatment ◽  
Carbon Cloth ◽  
Capacitive Deionization ◽  
Surface Functional Groups ◽  
Activated Carbon Cloth ◽  
Porous Carbon Electrodes ◽  
Solution Surface ◽  
A Current

We report the effect of acid treatment on porous carbon materials on their double layer capacitance and electrosorption of ions in capacitive deionization systems. The as-received activated carbon cloth (ACC) had the capacitance value of 210 F/g and was markedly (∼175%) improved when treated with acid solution. Surface functional groups such as hydroxyl, quinines, lactones and ethers on carbon after modification were increased by 40% and 29% with HNO3 and H2SO4 respectively. In capacitive deionization test of NaCl solution, the ACC treated with HNO3 had more than two times removal efficiency when charged with a 1.5 V current than the untreated one. This is attributed to activation and changes of surface functional groups when charged with a current.

Desalination and disinfection of inland brackish ground water in a capacitive deionization cell using nanoporous activated carbon cloth electrodes

Desalination ◽  
2015 ◽  
Vol 362 ◽  
pp. 126-132 ◽  
Author(s):  
Karthik Laxman ◽  
Myo Tay Zar Myint ◽  
Mohammed Al Abri ◽  
Priyanka Sathe ◽  
Sergey Dobretsov ◽  
...  
Keyword(s):  
Activated Carbon ◽  
Ground Water ◽  
Carbon Cloth ◽  
Capacitive Deionization ◽  
Activated Carbon Cloth ◽  
Nanoporous Activated Carbon

scholarly journals Efficient Desalination of Brackish Ground Water via a Novel Capacitive Deionization Cell Using Nanoporous Activated Carbon Cloth Electrodes

2015 ◽  
Vol 12 (2) ◽  
pp. 22 ◽  
Author(s):  
K. Laxman ◽  
M.T.Z Myint ◽  
M. Al Abri ◽  
L. Al-Gharibi ◽  
B. Al Namani ◽  
...  
Keyword(s):  
Activated Carbon ◽  
Ground Water ◽  
Brackish Water ◽  
Water Samples ◽  
Sea Water ◽  
Water Desalination ◽  
Carbon Cloth ◽  
Capacitive Deionization ◽  
Activated Carbon Cloth ◽  
Nanoporous Activated Carbon

Sea water intrusion in ground water sources has made brackish water desalination a necessity in Oman. The application of capacitive deionization (CDI) for the deionization of ground water samples from wells in Al-Musanaah Wilayat is proposed and demonstrated. A CDI cell is fabricated using nanoporous activated carbon cloth (ACC) as the electrodes and is shown to be power efficient for desalting ground water samples with total dissolved solids (TDS) of up to 4,000 mg/l. The CDI cell was able to remove up to 73% of the ionic scaling and fouling contaminants from brackish water samples. The power consumption for deionization of brackish water was estimated to be 1 kWh/m3 of desalinated water, which is much lower than the power required to process water with equivalent TDS by the reverse osmosis processes. The CDI process is elaborated, and observations and analysis of the ion adsorption characteristics and electrical properties of the capacitive cell are elucidated.  

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