Ultrahigh Desalinization Performance of Asymmetric Flow-Electrode

Research Article pubs.acs.org/journal/ascecg

Ultrahigh Desalinization Performance of Asymmetric Flow-Electrode Capacitive Deionization Device with an Improved Operation Voltage of 1.8 V Xingtao Xu, Miao Wang, Yong Liu, Ting Lu, and Likun Pan* Shanghai Key Laboratory of Magnetic Resonance, School of Physics and Materials Science, East China Normal University, 3663 N. Zhongshan Road, Shanghai 200062, China

Downloaded via UNIV OF SOUTH DAKOTA on July 1, 2018 at 11:10:10 (UTC). See https://pubs.acs.org/sharingguidelines for options on how to legitimately share published articles.

S Supporting Information *

ABSTRACT: Flow-electrode capacitive deionization (FCDI) is an emerging desalinization technology for high-concentration saline water treatment. However, in practical cases the operation voltage of FCDI is usually limited by the decomposition potential of water (1.23 V), which does harm the desalinization performance of FCDI. To address this issue, here for the first time we propose a novel asymmetric FCDI (AFCDI) device by using an activated carbon (AC)/MnO2 suspension as the positive electrode and AC suspension as the negative electrode. In AFCDI, the operation voltage can be improved to be 1.8 V, and a high salt removal efficiency of 78% is achieved in 0.1 M NaCl solution within 2 h, much higher than that for conventional FCDI (59%). To the best of knowledge, this value is also much higher than those for other FCDI devices reported previously. The present work may provide a promising high-performance desalinization device for high-concentration saline water treatment. KEYWORDS: Asymmetric flow-electrode capacitive deionization, Operation voltage, High-concentration saline water treatment, Desalinization

■

INTRODUCTION Nowadays, the shortage of clean water resources has become one of the most serious challenges with the increasing requirement of household, industry, and agriculture application.1−6 Capacitive deionization (CDI), also known as electrosorption, has been receiving great interest in the desalination field due to its lower energy consumption and environmental friendliness compared with conventional desalination technologies.7−11 This emerging technology is realized by adsorbing ions into the electric double layers (EDL) formed at the interface between the electrode and the solution when a low direct current (DC) potential (normally ≤1.2 V) is applied. Recent advances in CDI have been focused on the developments of CDI theory,12−16 experiment methods,17−22 system architectures,23−27 and electrode materials.6,28−36 Despite the progresses achieved by now, most of the works are restricted in the solution with a low or moderate ion concentration, which cannot meet the demand of practical applications. To solve this problem, Jeon et al. presented a new CDI system, called flow-electrode CDI (FCDI), which was operated by applying active material suspension as flowelectrode that had been explored in flowable supercapacitor by Gogotsi’s group.37 This approach realized continuous operation of single-pass CDI system and exhibited high salt removal efficiency (95%) in concentrated NaCl solution (32.1 g L−1). © 2016 American Chemical Society

Within the concept of FCDI, various techniques were developed, such as the exploration of new FCDI architecture and energy generation in FCDI.38−42 In these cases, the operation voltages are typically limited to below 1.23 V owing to water decomposition at higher voltages, resulting in poor desalinization performance. To address this issue, here for the first time we propose a novel asymmetric FCDI (AFCDI) device by using an activated carbon (AC)/MnO2 suspension as the positive electrode and AC suspension as the negative electrode (Figure 1). In this system, an improved operation voltage of 1.8 V is achieved due to the expanded potential window between the positively polarized AC/MnO2 electrode and the negatively polarized AC electrode.43,44 Benefiting from the improved operation voltage, the salt electrosorption of the AFCDI device reaches a high salt removal efficiency of 78% in 0.1 M NaCl solution within 2 h, much higher than that for conventional FCDI (59%).

■

EXPERIMENTAL SECTION

Material Synthesis. The AC/MnO2 used in this study was synthesized as reported previously.43 In brief, AC (Fuzhou Huanyi Carbon Company) was used as both the sacrificial reductant and matrix. Nanostructured MnO2 was deposited on the carbon matrix via Received: June 1, 2016 Revised: November 1, 2016 Published: November 23, 2016 189

DOI: 10.1021/acssuschemeng.6b01212 ACS Sustainable Chem. Eng. 2017, 5, 189−195

Research Article

ACS Sustainable Chemistry & Engineering Cs =

∫ i dV (1)

2 × m × ΔV × S

where ∫ idV is the integrated area of the CV curve (W), m is the active material mass of one electrode (g), ΔV is the window voltage (V), and S is the scan rate (mV s−1). 2.3. Desalinization Performance Test. Figure S1 (Supporting Information) shows the lab-scale setup of typical AFCDI structure. Flow-electrodes flow through the current and electrode compartments carved from graphite plates (10 mm, Qingdao Runhai Graphite Company) with a flow area in the dimensions (L × W × H) of 7 × 4 × 0.3 cm. Cation exchange membrane (CEM, Neosepta CMX, Japan) and anion exchange membrane (AEM, Neosepta AMX, Japan) were used with thicknesses of 170 and 140 μm, respectively. In a typical AFCDI system, flow-electrodes (50 mL in volume) composed of AC (negative electrode, 3.5 wt %) or AC/MnO2 (positive electrode, 4.13 wt %), carbon black (1.5 wt %), and NaCl aqueous solutions (0.1 M) were recycled at a flow rate of 100 mL min−1 using peristaltic pumps. The salt water made of NaCl (0.1 M, 50 mL) was recycled at a flow rate of 50 mL min−1. A constant voltage of 1.8 V was supplied using a DC power supply. The variation of NaCl concentration was monitored and measured at the outlet of the unit cell using a conductivity meter (DJS-10C, Precision & Scientific Instrument). For comparison, a conventional FCDI system with flowelectrodes (50 mL in volume) composed of AC (3.5 wt %), carbon black (1.5 wt %), and NaCl aqueous solutions (0.1 M) was conducted at a flow rate of 100 mL min−1 and a constant voltage of 1.2 V. The salt removal efficiency (η, %) and mean electrosorption rate (v, mg g−1 min−1) can be calculated as the following:

Figure 1. Schematic representation of AFCDI device.

the redox reaction between AC and KMnO4 in acid solution. Both the AC and AC/MnO2 were characterized by field emission scanning electron microscopy (FESEM, JEOL JSM-LV5610), X-ray powder diffraction (XRD, Rigaku D/Max2550, Cu Kα radiation) and N2 adsorption−desorption isotherm (Micromeritics Instrument Corporation, TriStar II 3020) without further pretreatment. The specific surface areas of the samples were evaluated based on the Brunauer− Emmett−Teller (BET) model by using the adsorption branches in the relative pressure (P/P0) range of 0.05−0.5. The pore volumes and pore size distributions were calculated from the adsorption branches of isotherms based on the density functional theory method. Electrochemical Characterization. To investigate the electrochemical performances of AC and AC/MnO2, film working electrodes were fabricated as follows. In detail, the active materials, carbon black and poly(vinyl alcohol), with a weight ratio of 80:10:10, were homogeneously mixed in deionized water at room temperature to get the electrode slurries. Then, the electrode slurries were uniformly coated on graphite papers through a casting method. Finally, the electrodes were dried at 80 °C under vacuum for 12 h. Cyclic voltammetry (CV) was carried out on an Autolab PGSTAT 302 N electrochemical workstation in 1 M NaCl solution. The platinum foil and saturated calomel electrode (SCE) were used as counter and reference electrodes, respectively. The specific capacitance (Cs, F g−1) was calculated from the CV curves according to the following equation:

η=

(C0 − C) × 100% C0

v=

(C0 − C) × V m×t

(2) (3) −1

where C0 and C is the initial and final NaCl concentration (mg L ), V is the volume of NaCl solution (L), m is the mass of the active materials (g), and t is the electrosorption time (min).

■

RESULTS AND DISCUSSION Characterization of Materials. Figure 2 shows the FESEM images of AC and AC/MnO2. It can be seen that

Figure 2. FESEM images of (a, b) AC and (c, d) AC/MnO2 particles. 190


Research Article

ACS Sustainable Chemistry & Engineering

Furthermore, the Barrett−Joyner−Halenda (BJH) pore size distributions of AC and AC/MnO2 are shown in Figure 4b,d. Obviously, AC exhibits a pore size distribution below 2 nm, whereas with the MnO2 depositing on AC surfaces, the resultant AC/MnO2 displays a broad pore size distribution ranging from micropores to mesopores. The specific surface areas and pore volumes of AC and AC/MnO2 are listed in Table 1. It can be seen that AC exhibits a specific surface area of

AC exhibits various sized particles with smooth surfaces (Figure 2a,b), whereas AC/MnO2 exhibits a flower-shape structure with sheet-like MnO2 attached on the surface of AC (Figure 2c,d). The diameter of AC/MnO2 is about 1 μm. The structures of AC and AC/MnO2 were further investigated by XRD measurements, as shown in Figure 3.

Table 1. Specific Surface Areas and Pore Volumes of AC and AC/MnO2 sample

specific surface area (m2 g−1)

pore volume (cm3 g−1)

AC AC/MnO2

2152.8 325.8

1.30 0.72

2152.8 m2 g−1 and a pore volume of 1.30 cm3 g−1, much higher than those of AC/MnO2 (325.8 m2 g−1 and 0.72 cm3 g−1), which is consistent with a previous report.43 Electrochemical Characterization. Before desalinization tests, we first investigated the electrochemical performances of AC and AC/MnO2 film electrodes in 1 M NaCl solution by using CV measurements. As shown in Figure 5a, all CV curves display a relatively rectangular shape and no obvious redox peak can be observed. As calculated according to eq 1, the specific capacitances at a scan rate of 20 mV s−1 are 122.5 F g−1 for AC and 104.2 F g−1 for AC/MnO2, respectively. Additionally, the two materials display different potential stability windows (−0.8−0.2 V for AC and 0−1.0 V for AC/MnO2). As wellknown, limited by the decomposition potential of water (1.23 V), the potential window of symmetric capacitor in aqueous electrolyte is usually below 1.2 V. Once the potential window exceeds 1.2 V, the electrolyte will decompose. Fortunately, the asymmetric capacitor (ASC) is proposed as an effective method to improve the potential window. In this work, an ASC was

Figure 3. XRD patterns of AC and AC/MnO2 particles.

Clearly, AC exhibits a broad peak centered at ∼44°, indicating its amorphous structure. In contrast, AC/MnO2 exhibits sharp peaks centered at 37.5°, and 65.1°, which are assigned to the (310) and (002) planes of the tetragonal α-type MnO2 phase (JCPDS 44-0141), respectively. These results indicate that MnO2 is anchored on the surface of AC successfully via a simple redox reaction with a moderate preparation condition, which is beneficial for further studies and practical application. The porosity of AC and AC/MnO2 was investigated by N2 adsorption/desorption isotherms, as shown in Figure 4. As shown in Figure 4a, AC exhibits a I type isotherm, indicating its microporous structure. As for AC/MnO2, it displays a typical IV type isotherm, indicating the presence of mesopores.

Figure 4. N2 adsorption/desorption isotherms of (a) AC and (c) AC/MnO2 and corresponding BJH pore size distributions of (b) AC and (d) AC/ MnO2 obtained by using adsorption branch. 191


Research Article


Figure 5. (a) CV curves of AC and AC/MnO2 film electrodes at a scan rate of 20 mV s−1. (b) Optimization of the potential window of ASC measured by using CV tests at a scan rate of 20 mV s−1.

Figure 6. (a) Normalized concentration profiles, and (b) mean electrosorption rates for FCDI and AFCDI devices.

revealed in Figure 5b), its operation voltage can reach an improved value of 1.8 V without any unwanted electrochemical reactions (e.g., water decomposition). In practical cases, no obvious phenomenon of water decomposition has been observed. Figure 6a shows the variation of relative NaCl concentration (C/C0) for both FCDI and AFCDI devices within 2 h. It can be seen that AFCDI displays a higher salt removal efficiency of 78% than conventional FCDI (59%); moreover, this value is also higher than those for other FCDI devices reported previously (Table 2). This can be ascribed to

constructed by using AC as the negative electrode and AC/ MnO2 as the positive electrode in order to improve the potential window. The optimal mass ratio (m+/m− = 1.18) between positive and negative electrodes was estimated from the equation as follows:29

m+ C × V− = s− m− Cs+ × V+

(4)

where m+ and m− are the mass of the film electrode materials (g), Cs+ and Cs− are the specific capacitances (F g−1), V+ and V− are the potential windows of the positive and negative electrodes (mV s−1), respectively. Figure 5b shows the CV curves of the ASC device measured at 20 mV s−1 in 1.0 M NaCl solution with different potential windows. These curves exhibit quasi-rectangular shapes without noticeable redox peaks even when the potential window is increased up to 1.8 V, implying an ideal capacitive behavior in neutral aqueous medium for both electrodes. Considering the results of ASC, it should be postulated that when mass ratio of positive electrode (AC/ MnO2) to negative electrode (AC) is 1.18, a maximum operation voltage of 1.8 V can be achieved for the AFCDI device. Desalinization Performance Test. The desalinization performance of the AFCDI device was investigated in 0.1 M NaCl solution at a constant operation voltage of 1.8 V for 2 h. For comparison, conventional FCDI device was investigated in 0.1 M NaCl solution at a constant operation voltage of 1.2 V for 2 h. It should be noted that due to the limitation of decomposition potential of water (1.23 V), the maximum operation voltage of FCDI device can be only up to 1.2 V. However, for the AFCDI device, because of the expanded potential window between the positively polarized AC/MnO2 electrode and the negatively polarized AC electrode (as

Table 2. Comparison of Salt Removal Efficiency for AFCDI and FCDI Devices device FCDI37 single module FCDI39 neutralization FCDI45 AFCDI (this work)

initial NaCl concentration (mg L−1)

applied voltage (V)

salt removal efficiency (%)

5.9 1

1.2 1.2

39.9 70

5.8

1.2

72.2

5.8

1.8

78

two reasons: (i) Because of the expanded potential window between the negative AC electrode and the positive AC/MnO2 electrode, AFCDI displays an improved operation voltage of 1.8 V compared with FCDI (1.2 V). (ii) AC/MnO2 exhibits a hydrophilic feature, whereas AC displays high hydrophobicity, as revealed by the contact angel tests shown in Figure S2 (Supporting Information). In addition, the AFCDI device was also investigated in higher concentration NaCl solutions (e.g., 0.2, 0.3, and 0.5 M), as shown in Figure S3 (Supporting Information). The results indicate that AFCDI still remains 192


Research Article


Table 3. Comparison of Mean Electrosorption Rates for AFCDI, FCDI, MCDI, and CDI Devices in NaCl Solution device CDI

MCDI

FCDI

electrode 3D hierarchical carbons//3D hierarchical carbons46 3D graphene//3D graphene47

ordered mesoporous carbons//ordered mesoporous carbons48 3D nitrogen-doped graphene//3D nitrogen-doped graphene49 graphene//graphene50 hierarchical carbon fibers//hierarchical carbon fibers51 mesoporous carbons// mesoporous carbons52 3D graphene/TiO2//3D graphene/TiO253 mesoporous carbons//mesoporous carbons36 nitrogen-doped carbons//nitrogen-doped carbons29 AC//carbon nanotubes/MnO254 carbon nanotubes/carbon nanofibers//carbon nanotubes/carbon nanofibers55 Na4Mn9O18//AC56 carbon nanotubes/graphene//carbon nanotubes/ graphene57 AC//AC58 AC//AC/MnO2 (this work)

surface area (m2 g−1)

pore volume (cm3 g−1)

1036.8

2.62

339

(C0 − Ct ) × V m

v = Γt /t

applied voltage (V)

nean electrosorption rate (mg g−1 min−1)

∼30

2.0

0.027

∼50

0.039 0.071 0.098 0.008

844

0.90

∼25

1.2 1.6 2.0 1.2

526.7

3.13

∼500

1.2

0.53

51.01 0.138

∼25 ∼90

2.0 1.6

0.033 0.013

410 187.6 2535 778.0

1.50 0.502

∼4000 ∼500 ∼30 ∼580

1.2 1.2 1.2 1.2

0.20 1.89 1.08 0.16

134

0.664

30 25

1.8 1.2

0.27 0.080

391

0.49

∼5844 750

1.2 2.0

1.97 1.32

325.8

0.72

15000 ∼5844

1.2 1.8

3.71 9.67

488 428

excellent desalination performances in highly concentrated solution. Figure 6b shows the mean electrosorption rates of FCDI and AFCDI devices and corresponding error bars. It is worth nothing that the data shown in Figure 6b are obtained by repeating the fabrication of the AFCDI device for several times. The mean electrosorption rate of AFCDI is compared with the values in state-of-the-art CDI-based desalination field (Table 3). Clearly, AFCDI exhibits a much higher value than those achieved for CDI and membrane CDI (MCDI) devices reported. These results demonstrate the superiority of the novel AFCDI device in this work. Kim−Yoon Plot Analysis. The Kim−Yoon plot is an effective tool to evaluate the deionization performance of CDI electrode materials, which was first proposed by Yoon et al.12 In this work, we utilize the Kim−Yoon plot to evaluate the deionization performance of our AFCDI device. The electrosorption capacity at t min (Γt, mg g−1) and corresponding mean electrosorption rate (v, mg g−1 min−1) were calculated according to the following equations, respectively:

Γt =

initial NaCl concentration (mg L−1)

Figure 7. Kim−Yoon plots for FCDI and AFCDI devices.

AFCDI device should be a promising desalinization device for high-concentration saline water treatment.

■

CONCLUSION In this work, we propose a novel AFCDI device by using an AC/MnO2 suspension as the positive electrode and AC suspension as the negative electrode. The desalinization performance of the AFCDI device was investigated in 0.1 M NaCl solution, and it displays a high salt removal efficiency of 78%, much higher than that of conventional FCDI (59%) and the current values reported for other FCDI devices. Additionally, Kim−Yoon plot model analysis reveals that the AFCDI device integrates the merits of both high deionization capacity and fast deionization rate, indicating the superiority of the AFCDI device. It is postulated that the AFCDI device should be a promising desalinization device for high-concentration saline water treatment.

(5) (6)

where C0 and Ct are the initial concentration and the concentration at t min (mg L−1), respectively. V is the volume of the NaCl aqueous solution (L), m represents the mass of the active materials (g), and t is the time of electrosorption process (min). As shown in Figure 7, the Kim−Yoon plot for AFCDI device shifts toward the upper and right region (i.e., higher deionization capacity and faster deionization rate) compared to conventional FCDI device, demonstrating that the AFCDI device integrates the merits of both high deionization capacity and fast deionization rate. Therefore, it is postulated that the 193


Research Article


■

(13) Dykstra, J.; Zhao, R.; Biesheuvel, P.; van der Wal, A. Resistance identification and rational process design in Capacitive Deionization. Water Res. 2016, 88, 358−370. (14) Hemmatifar, A.; Stadermann, M.; Santiago, J. G. TwoDimensional Porous Electrode Model for Capacitive Deionization. J. Phys. Chem. C 2015, 119 (44), 24681−24694. (15) Tang, W.; Kovalsky, P.; He, D.; Waite, T. D. Fluoride and nitrate removal from brackish groundwaters by batch-mode capacitive deionization. Water Res. 2015, 84, 342−349. (16) He, D.; Wong, C. E.; Tang, W.; Kovalsky, P.; Waite, T. D. Faradaic Reactions in Water Desalination by Batch-Mode Capacitive Deionization. Environ. Sci. Technol. Lett. 2016, 3, 222−226. (17) Suss, M. E.; Biesheuvel, P.; Baumann, T. F.; Stadermann, M.; Santiago, J. G. In situ spatially and temporally resolved measurements of salt concentration between charging porous electrodes for desalination by capacitive deionization. Environ. Sci. Technol. 2014, 48 (3), 2008−2015. (18) Gao, X.; Landon, J.; Neathery, J. K.; Liu, K. Modification of carbon xerogel electrodes for more efficient asymmetric capacitive deionization. J. Electrochem. Soc. 2013, 160 (9), E106−E112. (19) Qu, Y.; Baumann, T. F.; Santiago, J. G.; Stadermann, M. Characterization of resistances of a capacitive deionization system. Environ. Sci. Technol. 2015, 49 (16), 9699−9706. (20) Gao, X.; Omosebi, A.; Landon, J.; Liu, K. Surface charge enhanced carbon electrodes for stable and efficient capacitive deionization using inverted adsorption−desorption behavior. Energy Environ. Sci. 2015, 8 (3), 897−909. (21) Cohen, I.; Avraham, E.; Noked, M.; Soffer, A.; Aurbach, D. Enhanced charge efficiency in capacitive deionization achieved by surface-treated electrodes and by means of a third electrode. J. Phys. Chem. C 2011, 115 (40), 19856−19863. (22) Li, H.; Liang, S.; Gao, M.; Li, G.; Li, J.; He, L. The study of capacitive deionization behavior of a carbon nanotube electrode from the perspective of charge efficiency. Water Sci. Technol. 2015, 71 (1), 83−88. (23) Suss, M. E.; Baumann, T. F.; Bourcier, W. L.; Spadaccini, C. M.; Rose, K. A.; Santiago, J. G.; Stadermann, M. Capacitive desalination with flow-through electrodes. Energy Environ. Sci. 2012, 5 (11), 9511− 9519. (24) Bian, Y.; Yang, X.; Liang, P.; Jiang, Y.; Zhang, C.; Huang, X. Enhanced desalination performance of membrane capacitive deionization cells by packing the flow chamber with granular activated carbon. Water Res. 2015, 85, 371−376. (25) Liang, P.; Yuan, L.; Yang, X.; Zhou, S.; Huang, X. Coupling ionexchangers with inexpensive activated carbon fiber electrodes to enhance the performance of capacitive deionization cells for domestic wastewater desalination. Water Res. 2013, 47 (7), 2523−2530. (26) Lee, J.; Kim, S.; Kim, C.; Yoon, J. Hybrid capacitive deionization to enhance the desalination performance of capacitive techniques. Energy Environ. Sci. 2014, 7 (11), 3683−3689. (27) Li, H. B.; Gao, Y.; Pan, L. K.; Zhang, Y. P.; Chen, Y. W.; Sun, Z. Electrosorptive desalination by carbon nanotubes and nanofibres electrodes and ion-exchange membranes. Water Res. 2008, 42 (20), 4923−4928. (28) Xu, X.; Pan, L.; Liu, Y.; Lu, T.; Sun, Z. Enhanced capacitive deionization performance of graphene by nitrogen doping. J. Colloid Interface Sci. 2015, 445, 143−150. (29) Liu, N.-L.; Dutta, S.; Salunkhe, R. R.; Ahamad, T.; Alshehri, S. M.; Yamauchi, Y.; Hou, C.-H.; Wu, K. C.-W. ZIF-8 derived, nitrogendoped porous electrodes of carbon polyhedron particles for highperformance electrosorption of salt ions. Sci. Rep. 2016, 6, 28847. (30) Qian, B.; Wang, G.; Ling, Z.; Dong, Q.; Wu, T.; Zhang, X.; Qiu, J. Sulfonated Graphene as Cation-Selective Coating: A New Strategy for High-Performance Membrane Capacitive Deionization. Adv. Mater. Interfaces 2015, 2 (16), 1500372. (31) Xu, X.; Pan, L.; Liu, Y.; Lu, T.; Sun, Z.; Chua, D. H. Facile synthesis of novel graphene sponge for high performance capacitive deionization. Sci. Rep. 2015, 5, 8458.

ASSOCIATED CONTENT

S Supporting Information *

The Supporting Information is available free of charge on the ACS Publications website at DOI: 10.1021/acssuschemeng.6b01212. Lab-scale setup of typical AFCDI structure, contact angle images, and normalized concentration profiles in higher concentration NaCl solutions for AFCDI device (PDF)

■

AUTHOR INFORMATION

Corresponding Author

*L. Pan. E-mail: [email protected]. Tel.: +86 21 62234132. Fax: +86 21 62234321. ORCID

Likun Pan: 0000-0001-9294-1972 Notes

The authors declare no competing financial interest.

■

ACKNOWLEDGMENTS Financial support from National Natural Science Foundation of China (No. 21276087) and Outstanding Doctoral Dissertation Cultivation Plan (PY2015040) is gratefully acknowledged.

■

REFERENCES

(1) Humplik, T.; Lee, J.; O’hern, S.; Fellman, B.; Baig, M.; Hassan, S.; Atieh, M.; Rahman, F.; Laoui, T.; Karnik, R.; Wang, E. N. Nanostructured materials for water desalination. Nanotechnology 2011, 22 (29), 292001. (2) Elimelech, M.; Phillip, W. A. The future of seawater desalination: energy, technology, and the environment. Science 2011, 333 (6043), 712−717. (3) Kim, S. J.; Ko, S. H.; Kang, K. H.; Han, J. Direct seawater desalination by ion concentration polarization. Nat. Nanotechnol. 2010, 5 (4), 297−301. (4) Suss, M.; Porada, S.; Sun, X.; Biesheuvel, P.; Yoon, J.; Presser, V. Water desalination via capacitive deionization: what is it and what can we expect from it? Energy Environ. Sci. 2015, 8, 2296−2319. (5) Gohari, A.; Eslamian, S.; Mirchi, A.; Abedi-Koupaei, J.; Bavani, A. M.; Madani, K. Water transfer as a solution to water shortage: a fix that can backfire. J. Hydrol. 2013, 491, 23−39. (6) Lee, W. J.; Maiti, U. N.; Lee, J. M.; Lim, J.; Han, T. H.; Kim, S. O. Nitrogen-doped carbon nanotubes and graphene composite structures for energy and catalytic applications. Chem. Commun. 2014, 50 (52), 6818−6830. (7) Liu, Y.; Nie, C.; Liu, X.; Xu, X.; Sun, Z.; Pan, L. Review on carbon-based composite materials for capacitive deionization. RSC Adv. 2015, 5 (20), 15205−15225. (8) Anderson, M. A.; Cudero, A. L.; Palma, J. Capacitive deionization as an electrochemical means of saving energy and delivering clean water. Comparison to present desalination practices: Will it compete? Electrochim. Acta 2010, 55 (12), 3845−3856. (9) Porada, S.; Zhao, R.; Van Der Wal, A.; Presser, V.; Biesheuvel, P. M. Review on the science and technology of water desalination by capacitive deionization. Prog. Mater. Sci. 2013, 58 (8), 1388−1442. (10) Porada, S.; Feng, G.; Suss, M.; Presser, V. Capacitive deionization in organic solutions: case study using propylene carbonate. RSC Adv. 2016, 6 (7), 5865−5870. (11) Yeh, C.-L.; Hsi, H.-C.; Li, K.-C.; Hou, C.-H. Improved performance in capacitive deionization of activated carbon electrodes with a tunable mesopore and micropore ratio. Desalination 2015, 367, 60−68. (12) Kim, T.; Yoon, J. CDI ragone plot as a functional tool to evaluate desalination performance in capacitive deionization. RSC Adv. 2015, 5 (2), 1456−1461. 194


Research Article

ACS Sustainable Chemistry & Engineering (32) Pan, H.; Yang, J.; Wang, S.; Xiong, Z.; Cai, W.; Liu, J. Facile fabrication of porous carbon nanofibers by electrospun PAN/ dimethylsulfone for capacitive deionization. J. Mater. Chem. A 2015, 3, 13827−13834. (33) El-Deen, A. G.; Barakat, N. A.; Khalil, K. A.; Kim, H. Y. Hollow carbon nanofibers as an effective electrode for brackish water desalination using the capacitive deionization process. New J. Chem. 2014, 38 (1), 198−205. (34) Wen, X.; Zhang, D.; Yan, T.; Zhang, J.; Shi, L. Threedimensional graphene-based hierarchically porous carbon composites prepared by a dual-template strategy for capacitive deionization. J. Mater. Chem. A 2013, 1 (39), 12334−12344. (35) Wang, G.; Dong, Q.; Wu, T.; Zhan, F.; Zhou, M.; Qiu, J. Ultrasound-assisted preparation of electrospun carbon fiber/graphene electrodes for capacitive deionization: Importance and unique role of electrical conductivity. Carbon 2016, 103, 311−317. (36) Dutta, S.; Huang, S.-Y.; Chen, C.; Chen, J. E.; Alothman, Z. A.; Yamauchi, Y.; Hou, C.-H.; Wu, K. C.-W. Cellulose Framework Directed Construction of Hierarchically Porous Carbons Offering High-Performance Capacitive Deionization of Brackish Water. ACS Sustainable Chem. Eng. 2016, 4 (4), 1885−1893. (37) Jeon, S.-i.; Park, H.-r.; Yeo, J.-g.; Yang, S.; Cho, C. H.; Han, M. H.; Kim, D. K. Desalination via a new membrane capacitive deionization process utilizing flow-electrodes. Energy Environ. Sci. 2013, 6 (5), 1471−1475. (38) Porada, S.; Weingarth, D.; Hamelers, H. V.; Bryjak, M.; Presser, V.; Biesheuvel, P. Carbon flow electrodes for continuous operation of capacitive deionization and capacitive mixing energy generation. J. Mater. Chem. A 2014, 2 (24), 9313−9321. (39) Rommerskirchen, A.; Gendel, Y.; Wessling, M. Single module flow-electrode capacitive deionization for continuous water desalination. Electrochem. Commun. 2015, 60, 34−37. (40) Hatzell, K. B.; Hatzell, M. C.; Cook, K. M.; Boota, M.; Housel, G. M.; McBride, A.; Kumbur, E. C.; Gogotsi, Y. Effect of oxidation of carbon material on suspension electrodes for flow electrode capacitive deionization. Environ. Sci. Technol. 2015, 49 (5), 3040−3047. (41) Hatzell, K. B.; Iwama, E.; Ferris, A.; Daffos, B.; Urita, K.; Tzedakis, T.; Chauvet, F.; Taberna, P.-L.; Gogotsi, Y.; Simon, P. Capacitive deionization concept based on suspension electrodes without ion exchange membranes. Electrochem. Commun. 2014, 43, 18−21. (42) Jeon, S.-I.; Yeo, J.-G.; Yang, S.; Choi, J.; Kim, D. K. Ion storage and energy recovery of a flow-electrode capacitive deionization process. J. Mater. Chem. A 2014, 2 (18), 6378−6383. (43) Hatzell, K. B.; Fan, L.; Beidaghi, M.; Boota, M.; Pomerantseva, E.; Kumbur, E. C.; Gogotsi, Y. Composite manganese oxide percolating networks as a suspension electrode for an asymmetric flow capacitor. ACS Appl. Mater. Interfaces 2014, 6 (11), 8886−8893. (44) Khomenko, V.; Raymundo-Pinero, E.; Béguin, F. Optimisation of an asymmetric manganese oxide/activated carbon capacitor working at 2V in aqueous medium. J. Power Sources 2006, 153 (1), 183−190. (45) Wang, M.; Hou, S.; Liu, Y.; Xu, X.; Lu, T.; Zhao, R.; Pan, L. Capacitive neutralization deionization with flow electrodes. Electrochim. Acta 2016, 216, 211−218. (46) Wen, X.; Zhang, D.; Shi, L.; Yan, T.; Wang, H.; Zhang, J. Threedimensional hierarchical porous carbon with a bimodal pore arrangement for capacitive deionization. J. Mater. Chem. 2012, 22 (45), 23835−23844. (47) Wang, H.; Zhang, D.; Yan, T.; Wen, X.; Zhang, J.; Shi, L.; Zhong, Q. Three-dimensional macroporous graphene architectures as high performance electrodes for capacitive deionization. J. Mater. Chem. A 2013, 1 (38), 11778−11789. (48) Zou, L.; Li, L.; Song, H.; Morris, G. Using mesoporous carbon electrodes for brackish water desalination. Water Res. 2008, 42 (8), 2340−2348. (49) Xu, X.; Sun, Z.; Chua, D. H.; Pan, L. Novel nitrogen doped graphene sponge with ultrahigh capacitive deionization performance. Sci. Rep. 2015, 5, 11225.

(50) Li, H.; Zou, L.; Pan, L.; Sun, Z. Novel graphene-like electrodes for capacitive deionization. Environ. Sci. Technol. 2010, 44 (22), 8692− 8697. (51) Wang, G.; Dong, Q.; Ling, Z.; Pan, C.; Yu, C.; Qiu, J. Hierarchical activated carbon nanofiber webs with tuned structure fabricated by electrospinning for capacitive deionization. J. Mater. Chem. 2012, 22 (41), 21819−21823. (52) Mayes, R. T.; Tsouris, C.; Kiggans, J. O., Jr; Mahurin, S. M.; DePaoli, D. W.; Dai, S. Hierarchical ordered mesoporous carbon from phloroglucinol-glyoxal and its application in capacitive deionization of brackish water. J. Mater. Chem. 2010, 20 (39), 8674−8678. (53) Yin, H.; Zhao, S.; Wan, J.; Tang, H.; Chang, L.; He, L.; Zhao, H.; Gao, Y.; Tang, Z. Three-dimensional graphene/metal oxide nanoparticle hybrids for high-performance capacitive deionization of saline water. Adv. Mater. 2013, 25 (43), 6270−6276. (54) Chen, B.; Wang, Y.; Chang, Z.; Wang, X.; Li, M.; Liu, X.; Zhang, L.; Wu, Y. Enhanced capacitive desalination of MnO 2 by forming composite with multi-walled carbon nanotubes. RSC Adv. 2016, 6 (8), 6730−6736. (55) Li, H.; Gao, Y.; Pan, L.; Zhang, Y.; Chen, Y.; Sun, Z. Electrosorptive desalination by carbon nanotubes and nanofibres electrodes and ion-exchange membranes. Water Res. 2008, 42 (20), 4923−4928. (56) Lee, J.; Kim, S.; Kim, C.; Yoon, J. Hybrid capacitive deionization to enhance the desalination performance of capacitive techniques. Energy Environ. Sci. 2014, 7 (11), 3683−3689. (57) Wimalasiri, Y.; Zou, L. Carbon nanotube/graphene composite for enhanced capacitive deionization performance. Carbon 2013, 59, 464−471. (58) Gendel, Y.; Rommerskirchen, A. K. E.; David, O.; Wessling, M. Batch mode and continuous desalination of water using flowing carbon deionization (FCDI) technology. Electrochem. Commun. 2014, 46, 152−156.

195


Ultrahigh Desalinization Performance of Asymmetric Flow-Electrode

Recommend Documents