Capacitive deionization of NH4ClO4 solutions with carbon aerogel electrodes

Farmer, Joseph C.; Fix, David V.; Mack, G.V.; Pekala, R.W.; Poco, J.F.

doi:10.1007/bf00242195

Cited by 198 publications

(129 citation statements)

References 9 publications

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“…3 (b) have shown the reduction in the diameter of the carbon fibers due to the chemical treatment of HNO 3 acid. It was reported that the chemical treatment may enhance the electro-adsorption and electro-desorption characteristics of carbon cloth materials [8]. Therefore, the chemical treatment analysis has contributed significantly in the chemical modification of carbon cloth materials which may enhance their performance in the electrochemical studies.…”

Section: Sem Analysismentioning

confidence: 99%

“…This process operates at low cell voltages and hence it is more energy efficient than electrodialysis and even reverse osmosis when the low salt content feed is treated [4][5][6]. The expensive high surface area carbon aerogel electrodes are used at present in electrochemical treatment procedures and which is a major challenge to be tackled in order to make this process commercially viable [7][8].…”

Section: Introductionmentioning

confidence: 99%

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Effect of Chemically Treated / Untreated Carbon Cloth: Potential Use as Electrode Materials in the Capacitive Deionization Process of Desalination of Aqueous Salt Solution

Thamilselvan

Nesaraj

Noel

et al. 2015

Journal of Electrochemical Science and Technology

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Capacitive deionization (CDI) process is a novel approach for desalination of an aqueous salt solution. In the present study, an activated carbon cloth (ACC) is proposed as effective electrode material. Initially the carbon cloth was activated in 1 M and 8 M HNO 3 for 9 hours at room temperature. The untreated and chemically activated carbon cloth (ACC) electrode materials were subjected to BET surface area measurements in order to get information about their specific surface area, average pore size, total pore volume and micropore area. The above materials were characterized by X-ray diffraction (XRD) and scanning electron microscope (SEM) also. The electrochemical studies for the electrodes were done using cyclic voltammetry (CV) in 0.1 M Na 2 SO 4 medium. From the studies, it was found that resistivity of the activated carbon cloth electrodes (treated in 1 M and 8 M HNO 3 ) was decreased significantly by the chemical oxidation in nitric acid at room temperature and its capacitance was found to be 90 F/g (1 M HNO 3 ) and 154 F/g (8 M HNO 3 ) respectively in 0.1 M Na 2 SO 4 solution. The capacitive deionization behavior of a single cell CDI with activated carbon cloth electrodes was also studied and reported in this work.

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Section: Sem Analysismentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Effect of Chemically Treated / Untreated Carbon Cloth: Potential Use as Electrode Materials in the Capacitive Deionization Process of Desalination of Aqueous Salt Solution

Thamilselvan

Nesaraj

Noel

et al. 2015

Journal of Electrochemical Science and Technology

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“…In commercial desalination technologies, such as reverse osmosis and multistage flash distillation, freshwater is produced at relatively high energy cost and often requires re-mineralization for human consumption. For brackish water or wastewater it can be advantageous to use a different type of technology, namely techniques where ions are removed from the feed water under the influence of electrical field effects, such as in electrodialysis [8,9], capacitive deionization [10][11][12][13][14][15][16][17][18][19][20][21][22][23][24][25][26][27][28], membrane capacitive deionization [29][30][31][32][33][34], desalination using microchannels [35], batteries [36], microbial desalination cells [37] and wires [38]. Such techniques have the potential to be energy-efficient as they focus on the removal of the (often relatively few) ions in the water to obtain freshwater in this way.…”

Section: Introductionmentioning

confidence: 99%

Time-dependent ion selectivity in capacitive charging of porous electrodes

Zhao

Soestbergen

Rijnaarts

et al. 2012

Journal of Colloid and Interface Science

238

182

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In a combined experimental and theoretical study we show that capacitive charging of porous electrodes in multicomponent electrolytes may lead to the phenomenon of time-dependent ion selectivity of the electrical double layers (EDLs) in the electrodes. This effect is found in experiments on capacitive deionization of water containing NaCl/CaCl 2 mixtures, when the concentration of Na + ions in the water is 5 times higher than the Ca 2+ -ion concentration. In this experiment, after applying a voltage difference between two porous carbon electrodes, first the majority monovalent Na + cations are preferentially adsorbed in the EDLs, and later they are gradually replaced by the minority, divalent Ca 2+ cations. In a process where this ion adsorption step is followed by washing the electrode with freshwater under open-circuit conditions, and subsequent release of the ions while the cell is shortcircuited, a product stream is obtained which is significantly enriched in divalent ions. Repeating this process three times by taking the product concentrations of one run as the feed concentrations for the next, a final increase in the Ca 2+ /Na + -ratio of a factor of 300 is achieved. The phenomenon of timedependent ion selectivity of EDLs cannot be explained by linear response theory. Therefore, a nonlinear time-dependent analysis of capacitive charging is performed for both porous and flat electrodes. Both models attribute time-dependent ion selectivity to the interplay of the transport resistance for the ions in the aqueous solution outside the EDL, and the voltage-dependent ion adsorption capacity of the EDLs. Exact analytical expressions are presented for the excess ion adsorption in planar EDLs (Gouy-Chapman theory) for mixtures containing both monovalent and divalent cations.key-words: water desalination; porous electrode theory; capacitive (non-faradaic) electrochemical cells; electrostatic double layer theory.2

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“…The last decades, special high ion absorbing carbon has been developed for use in super capacitors [47][48][49][50] and in capacitive deionization (CDI) [51,52]. If this material is used as electrode in a RED stack, during a certain time an internal ionic current can persist.…”

Section: Capacitive Electrodesmentioning

confidence: 99%

Reverse electrodialysis: evaluation of suitable electrode systems

Veerman

Saakes²,

Metz³

et al. 2010

J Appl Electrochem

236

188

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Reverse electrodialysis (RED) is a method for directly extracting electrical energy from salinity gradients, especially from sea and river water. For the commercial implementation of RED, the electrode system is a key component. In this paper, novel electrode systems for RED were compared with existing systems on safety, health, environment, technical feasibility and economics. Systems with inert DSA-type electrodes and a NaCl-HCl supporting electrolyte with the reversible Fe 2? /Fe 3? redox couple or the [Fe(CN) 6 ] 4-/Fe(CN) 6 ] 3-couple achieved the highest ranking. Improvements of the electrode system are also discussed like the use of special stable metal electrodes, graphite electrodes, other reversible redox couples, capacitive electrodes and electrolytes with carbon particles.

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Capacitive deionization of NH4ClO4 solutions with carbon aerogel electrodes

Cited by 198 publications

References 9 publications

Effect of Chemically Treated / Untreated Carbon Cloth: Potential Use as Electrode Materials in the Capacitive Deionization Process of Desalination of Aqueous Salt Solution

Effect of Chemically Treated / Untreated Carbon Cloth: Potential Use as Electrode Materials in the Capacitive Deionization Process of Desalination of Aqueous Salt Solution

Time-dependent ion selectivity in capacitive charging of porous electrodes

Reverse electrodialysis: evaluation of suitable electrode systems

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