Electrically Switched Ion Exchange Based on Carbon-Polypyrrole

ACS2GO © 2019. ← → → ←. loading. To add this web app to the home screen open the browser option menu and tap on Add to homescreen...
0 downloads 0 Views 732KB Size
Subscriber access provided by Gothenburg University Library

Remediation and Control Technologies

Electrically Switched Ion Exchange Based on Carbon-Polypyrrole Composite Smart Materials for the Removal of ReO4- from Aqueous Solutions Zizhang Guo, Mehnaz Shams, Chengzhou Zhu, Qiurong Shi, Yuhao Tian, Mark H. Engelhard, Dan Du, Indranil Chowdhury, and Yuehe Lin Environ. Sci. Technol., Just Accepted Manuscript • DOI: 10.1021/acs.est.8b04789 • Publication Date (Web): 23 Jan 2019 Downloaded from http://pubs.acs.org on January 24, 2019

Just Accepted “Just Accepted” manuscripts have been peer-reviewed and accepted for publication. They are posted online prior to technical editing, formatting for publication and author proofing. The American Chemical Society provides “Just Accepted” as a service to the research community to expedite the dissemination of scientific material as soon as possible after acceptance. “Just Accepted” manuscripts appear in full in PDF format accompanied by an HTML abstract. “Just Accepted” manuscripts have been fully peer reviewed, but should not be considered the official version of record. They are citable by the Digital Object Identifier (DOI®). “Just Accepted” is an optional service offered to authors. Therefore, the “Just Accepted” Web site may not include all articles that will be published in the journal. After a manuscript is technically edited and formatted, it will be removed from the “Just Accepted” Web site and published as an ASAP article. Note that technical editing may introduce minor changes to the manuscript text and/or graphics which could affect content, and all legal disclaimers and ethical guidelines that apply to the journal pertain. ACS cannot be held responsible for errors or consequences arising from the use of information contained in these “Just Accepted” manuscripts.

is published by the American Chemical Society. 1155 Sixteenth Street N.W., Washington, DC 20036 Published by American Chemical Society. Copyright © American Chemical Society. However, no copyright claim is made to original U.S. Government works, or works produced by employees of any Commonwealth realm Crown government in the course of their duties.

Page 1 of 21

Environmental Science & Technology

1

Electrically Switched Ion Exchange Based on Carbon-Polypyrrole

2

Composite Smart Materials for the Removal of ReO4- from Aqueous

3

Solutions

4

Zizhang Guoa,b, Mehnaz Shamsc, Chengzhou Zhua, Qiurong Shia, Yuhao Tianc, Mark

5

H. Engelhard d, Dan Dua, Indranil Chowdhuryc,Yuehe Lina,*

6

a

7

Pullman, WA 99164-2920, United States.

8

b

9

Water Pollution Control and Resource Reuse, Shandong University, Jinan 250100,

School of Mechanical and Materials Engineering, Washington State University,

School of Environmental Science and Engineering, Shandong Key Laboratory of

10

China

11

c

12

Pullman, Washington 99164, United States

13

d

14

Laboratory, Richland, WA 99352, United States

Department of Civil and Environmental Engineering, Washington State University,

Environmental Molecular Sciences Laboratory, Pacific Northwest National

15

1

ACS Paragon Plus Environment

Environmental Science & Technology

16

Abstract

17

A simple and rapid process of ReO4- (as a surrogate of TcO4-) removal from aqueous

18

solutions based on the electrically switched ion exchange (ESIX) method has been

19

demonstrated in this work. Activated carbon-Polypyrrole (AC-PPy) was synthesized

20

from activated carbon and pyrrole by electrodeposition method which was served as an

21

electrically switched ion exchanger for ReO4- removal. The characterization results

22

show that the AC-PPy composite exhibited an excellent loading capacity and a high

23

stability for ions uptake and release. Chronoamperometric studies show that the ESIX

24

treatment could be completed within 60 s, demonstrating the rapid uptake and release

25

of ions. Uptake and release of ReO4- was verified by electrochemical quartz crystal

26

microbalance with dissipation shift (EQCMD) studies. By modulating the

27

electrochemical potential of the AC-PPy, the uptake and release of ReO4- ions can be

28

controlled. Similar trends of uptake and release of ReO4- were observed in cyclic

29

voltammetry (-0.4 V to 0.8 V) for 5 cycles with the EQCMD. X-ray photoelectron

30

spectroscopy (XPS) confirmed the process of ReO4- removal in the AC-PPy composite.

31

Conclusively, the smart material shows an excellent efficiency and selectivity for the

32

removal ReO4- from aqueous solutions.

33 34

Keywords: electrically switched ion exchange, activated carbon, polypyrrole,

35

composites, perrhenate removal.

36

2

ACS Paragon Plus Environment

Page 2 of 21

Page 3 of 21

Environmental Science & Technology

37

Introduction

38

Radioactive 99Tc occupy a significant proportion of the radioactive activity of nuclear

39

waste, which is a byproduct of the plutonium production process.1 They are present as

40

TcO4- in the environment and has a very long half-life (2.13×105 yrs) and mobility.2, 3

41

In addition, due to the high water solubility and a migrating ability in the earth's

42

environment, it has frequently caused water pollution. Accordingly, the removal of

43

TcO4- from radioactive-polluted water is a significant challenge. Generally, gravity

44

precipitation,4 solvent extraction5 and ion exchange6 were used to remove TcO4-.

45

Among these methods, the ion exchange method, with superiorities of high recovery

46

rate and facile operation, was usually used in TcO4- removal, with perrhenate ReO4-

47

anions typically being substituted for TcO4- in laboratory studies.7 Banerjee et al.8, 9

48

used functionalized hierarchically porous frameworks and a zirconium-based metal-

49

organic framework for removing TcO4- from wastewater; however, the ion exchange

50

equilibrium, which was reached in 10 to 20 h, is time-consuming and exhibits poor

51

efficiency. In this work, to improve the removal efficiency and effectiveness,

52

electrochemical techniques were introduced to assist ion exchange processing, and the

53

electrically switched ion exchange (ESIX) method was used for the removal of ReO4-

54

from aqueous solutions.

55

The ESIX technique was developed in our laboratory for selectively removal of Cs+

56

and ClO4-.10, 11 The main principles of this technique are that a smart material is used

57

as the electrically switched ion exchanger to control the ion uptake and release by the

58

modulation potential so that the adsorbed ions from the aqueous solution can be 3

ACS Paragon Plus Environment

Environmental Science & Technology

59

removed; in the meantime, the material can be reused. Thus, the smart materials with

60

switch functions can possess a lower cost and are more environmentally friendly. In

61

particular, the technique can reduce treatment costs and minimize secondary waste

62

generation with the advantages of selectivity, reversibility and controllability.12

63

The electrochemical active material plays a key role in the ESIX technique, which

64

usually uses a conducting polymer composite with a high surface area because it is

65

desirable for electrochemical charge and target ion storage.13 The porous composite,

66

due to the various sizes of the pores in its 3D structure, can provide the storage of

67

different electrolyte ions. The micropores serve as ion sites for energy storage, the

68

mesopores provide pathways for the energy transfer, while the macropores act as buffer

69

reservoirs in the electrochemical process.14,

70

carbon (AC) as the in the synthesis of the conducting polymer composite. It is well

71

established that AC possesses favorable conductivity,16 a particularly well-developed

72

pore structure17 and a low cost of preparation.18 Consequently, it is more suitable for

73

the synthesis of electrochemical active materials and for practical applications in water

74

treatment.

15

In this work, we introduce activated

75

The objectives of this work are (1) to study the feasibility of the electrosynthesized

76

AC-PPy composite to remove ReO4- by the ESIX method, (2) to investigate the

77

physicochemical and electrochemical properties of the AC-PPy composite, (3) and to

78

explain the behavior and mechanism of ReO4- removal from aqueous solution using the

79

smart material AC-PPy composite by electrochemical quartz crystal microbalance with

80

dissipation shift (EQCMD) and X-ray photoelectron spectroscopy (XPS) techniques. 4

ACS Paragon Plus Environment

Page 4 of 21

Page 5 of 21

Environmental Science & Technology

81

Materials and methods

82

Materials preparation and characterization

83

The AC derived from biomass waste Phragmites australis (PA) was activated using

84

potassium hydroxide at 750°C for 1 h.16 The PPy-functionalized AC was prepared by

85

the method of electrolytic deposition, as described in our previous work11, 19 and the

86

synthetic composite is referred to as AC-PPy. The morphological characteristics were

87

verified using a scanning electron microscope (SEM) (JSM 7600F, Japan Electron

88

Optics Lab.). The specific surface area and pore size distribution were calculated by the

89

Brunauer-Emmett-Teller (BET) equation and the density functional theory (DFT)

90

method according to nitrogen (N2) adsorption/desorption isotherms. The capacity of the

91

electroactive materials was evaluated by cyclic voltammetry (CV). Amperometric i-t

92

curves recorded the process of the ESIX for ReO4-. In this work, CV and i-t curves were

93

measured by a standard three-electrode system similar to that used in PPy electrolytic

94

deposition techniques. XPS was used to determine the changes in surface chemical

95

elements under different conditions.

96

EQCMD study

97

The uptake and release of ReO4- on the surfaces were investigated using an EQCMD

98

(Q-sense E4, Biolin Scientific, Inc.) by monitoring the changes in frequency and

99

dissipation shift. For an EQCMD, a negative frequency shift indicates uptake, and a

100

positive frequency shift indicates release. Here, shifts in frequency and dissipation were

101

monitored at the 3rd overtone. CV (-0.4 V to 0.8 V; Scan rate: 10 mV/s) measurement

102

with 5 cycles was used on an EQCMD to reach the equilibrium condition. The ion 5

ACS Paragon Plus Environment

Environmental Science & Technology

Page 6 of 21

103

exchange behavior between the conducting polymer and electrolyte can be verified

104

from CV curves, as the charging and discharging is associated with the redox process.20

105

To achieve a stable baseline, the sensor surface was rinsed with MilliQ (MQ) water for

106

approximately 50 min. An Au electrode was used because it has a 3 times faster uptake

107

rate than other electrodes.21, 22 The frequency shift is directly related to mass uptake, the

108

change in the frequency shift, the higher the mass uptake, following the Sauerbrey

109

equation:23

110

𝛥𝑚 = ―

𝐶𝛥𝑓𝑛

(1)

𝑛

111

where Δm is the deposited mass, Δfn is the shift in the overtone frequency, n is the

112

overtone number (1, 3, 5, 7, ...), and C is the crystal constant (17.7 ng/Hz cm2 for the 5

113

MHz crystal). Furthermore, mass uptake values can be obtained directly from the

114

EQCMD. The values obtained from both the EQCMD and equation 1 show negligible

115

difference. Using equation 1, the Sauerbrey equation is applicable to calculate the mass

116

of a rigid layer of the deposited material from the frequency shift.

117

Kinetics and selectivity study

118

A 10 mL 0.01 M NaReO4 solution was added into a 20 mL glass vial. Then, the porous

119

AC-PPy electrode was soaked in the solution for a desired time at room temperature.

120

Then, the solution was filtered through a 0.22 μm filter. The filtrates were analyzed

121

using ICP-MS to determine the concentration.

122

The fully oxidized AC-PPy was inserted into the given solutions mainly Cl-, NO3- and SO42- under +0.8 V for selectivity study24: (a) 0.01 M ReO4-

123

containing

124

+ 2 M Cl- (NaCl); (b) 0.01 M ReO4- + 2 M NO3- (NaNO3); (3) 0.01 M ReO4- + 2 M 6

ACS Paragon Plus Environment

Page 7 of 21

125 126

Environmental Science & Technology

SO42- (Na2SO4). The ReO4- relative amount adsorbed (%) was calculated as follows: 25 ReO4- relative amount adsorbed (%) = (𝐶0 ― 𝐶𝑒)/𝐶0 × 100

(2)

127

where C0 and Ce are the initial and equilibrium concentration of ReO4- (mg/L).

128

Results and Discussion

129

Physicochemical and electrochemical properties of AC-PPy

(b)

(a)

6 μm

(d)

750

600

450

300

0.04

BET Surface Area= 2,559.64 m²/g Langmuir Surface Area= 3,099.72 m²/g Pore Volume= 1.11 cm³/g

0.02

150 0.00 0

0

5

10

15

20

Pore width (nm)

0.0

130

AC AC-PPy

0.06

Volume (cm3/nm/g)

Volume adsorbed (cm3/g)

(c)

60 μm

0.2

0.4

0.6

0.8

392

1.0

P/P0

396

400

404

408

Binding energy (eV)

131

Figure 1. SEM images of (a) AC and (b) the AC-PPy composite. (c) N2

132

adsorption/desorption isotherm for the AC-PPy composite (the inset is the pore

133

distribution). (d) N 1s spectra for AC and the AC-PPy composite.

134

Figure 1a and b show the SEM images of AC and the AC-PPy composite. AC shows a

135

morphology with a rough surface and an irregular porous structure, and typical PPy

136

structures are presented on the surface of the composite26. The PPy film residing on the

137

porous AC backbone to build the 3D porous structure will be highly beneficial for ion

138

diffusion.27 The N2 adsorption/desorption isotherms of the AC-PPy composite are used

139

to calculate the BET surface area and are shown in Figure 1c. The AC-PPy composite

140

reveals a high-surface-area value of 2559.64 m2/g with a pore volume of 1.11 cm3/g, as

7

ACS Paragon Plus Environment

Environmental Science & Technology

Page 8 of 21

141

well as a type I isotherm without a hysteresis loop. The result indicates that the

142

microporous structure inundates the AC-PPy composite smart material. 28, 29 In addition,

143

the pore-size distribution of the AC-PPy composite is shown in the inset of Figure 1c

144

and reveals microspores within the range below 2 nm. It is worth stating that the large

145

BET surface area and developed microporous structure provided an abundance of

146

storage sites for ReO4- ions.30 The N 1s spectra of AC and the AC-PPy composite were

147

analyzed via XPS and are shown in Figure 1d. The AC-PPy composite shows a clear

148

peak characteristic of nitrogen, further confirming the formation of PPy after

149

electrodeposition.

(b) GC electrode AC modified GC eletrode

Current (mA)

1.5

1.0

(c)

AC PPy AC-PPy

0.4

AC-PPy

0.4

0.2

Current (mA)

2.0

Current (mA)

(a)

0.0

0.2

0.0

0.5 -0.2

0.0

-0.4 0

150

-0.2

150

300

Times (s)

450

600

-0.4

-0.8

-0.6

-0.4

-0.2

0.0

0.2

0.4

Potential (V)

-0.8

-0.6

-0.4

-0.2

0.0

0.2

0.4

Potential (V)

151

Figure 2 (a) Amperometric i-t curves for the electrodeposition of the PPy film on a bare

152

glassy carbon (GC) electrode and AC-modified GC electrode. (b) CV curves (10 mV/s)

153

of AC, the PPy film and the AC-PPy composite in a 0.2 M NaCl solution. (c) 50

154

consecutive CV curves (10 mV/s) showing the effect of reduction-oxidation cycling on

155

the capacity of the AC-PPy-composite-modified GC electrode in a 0.2 M NaCl solution.

156

Amperometric i-t curves of the PPy film electrochemically deposited on the bare GC

157

electrode and AC-modified GC electrode are shown in Figure 2a. Different from the

158

bare GC electrode, a distinct current peak is observed at the beginning for the AC-

159

modified GC electrode. These two curves show completely different trends because of

160

the different nucleation processes early on in the electropolymerization.31 This finding

8

ACS Paragon Plus Environment

Page 9 of 21

Environmental Science & Technology

161

suggests that the high surface area and electronic conductivity of the AC-modified GC

162

electrode provided a larger number of nucleation sites for PPy deposition. Figure 2b

163

shows the CV curves of AC, the PPy film, and the AC-PPy composite in a 0.2 M NaCl

164

solution, which were used to evaluate the electrically switched ion exchange capacity

165

of the materials. In the potential range of -0.8 to +0.4 V, the oxidation and reduction

166

peaks in the CVs of AC, the PPy film, and the AC-PPy composite were gradually

167

enhanced, indicating that the capacities of the ions uptake and release were increasingly

168

powerful. The AC-PPy composite shows a higher oxidation peak and broader reduction

169

peak than does AC. The reason for this is the presence of the conductive polymer, which

170

can exchange the surface charge at the time of the potential transition between the

171

uptake and release of the ions in the aqueous solution. The same phenomenon also

172

occurs in the AC-PPy composite and PPy film; the possible reason is that the porous

173

structure of the AC-PPy composite facilitates ions to easily diffuse into or out of the

174

smart material.32 The effect of multiple voltammetric cycles on the AC-PPy composite

175

deposited on the GC electrode is shown in Figure 2c. In the NaCl electrolyte solution,

176

for 50 cycles, the AC-PPy composite retains the relatively sharp oxidation peak and

177

broad reduction peak, indicating that the AC-PPy composite possessed a good recycling

178

and regenerating capacity. The asymmetry characteristic of the peaks of the PPy film

179

was reported previously.33 However, the oxidative peak gradually shifted negatively

180

due to the amount of the potential scanning contribution to the structural relaxation of

181

the AC-PPy composite, which makes it easier for the ions to move in and out.19

182

Electrochemical uptake and release 9

ACS Paragon Plus Environment

Environmental Science & Technology

0.1

0.0

6

(c)

0.0

-0.5

Anodic treatment

4

Current (mA)

(b)

AC-PPy

Current (mA)

Current (mA)

(a) 0.2

Page 10 of 21

2

-1.0

Cathodic treatment -1.5

-2.0

-0.1 0

-2.5 -0.5

0.0

0.5

1.0

1.5

2.0

0

40

80

Potential (V)

183

120

160

Time (s)

200

0

50

100

150

200

250

Time (s)

184

Figure 3. (a) CV curves (10 mV/s) of the AC-PPy composite in a 0.1 M NaReO4

185

solution and i-t curves (b) during the anodic (1.8 V) and (c) cathodic (-0.4 V) treatments

186

in a 0.1 M NaReO4 solution.

187

The CV experiment was performed to certify the uptake and release of ReO4- by the

188

controlled oxidation and reduction under electrochemical potential and is shown in

189

Figure 3a. The presence of an oxidative peak is evidence that the ReO4- ions were

190

uptaken into the AC-PPy composite; conversely, the ions were released when a negative

191

potential was applied. To maintain the charge balance, the charges during the oxidation

192

and reduction of PPy are compensated with the same amount of ReO4- into and out of

193

PPy. The electroactive ion exchange can efficiently uptake and release ReO4- rapidly,

194

which is confirmed in the current-time transient curves for recording the anodic and

195

cathodic treatments of ReO4- on the AC-PPy-composite-modified electrode (Figure 3b

196

and c). The uptake and release of ReO4- were nearly finished within 60 s. The required

197

time is significantly less than that of the pure ion exchange in references.8, 9

198

EQCMD study

199

The whole process includes electrochemical deposition, adsorption and desorption took

200

place onto a gold-coated sensor through the EQCMD machine. This was followed a

201

background electrolyte solution of 0.2 M NaCl (Figure S1, stage i) until again stabilized.

202

The PPy films were electrochemically deposited on a gold-coated sensor under a +0.7 10

ACS Paragon Plus Environment

Page 11 of 21

Environmental Science & Technology

203

V potential by flowing 0.2 M pyrrole dissolved in 0.2 M NaCl through the machine. A

204

sharp decrease in the frequency shift detected on the Q-Sense software indicated the

205

deposition of PPy on the gold sensor (Figure S1, stage ii). Then, 0.2 M NaCl was flown

206

again through the module to remove loosely attached PPy from the surface (Figure S1,

207

stage iii). Following this, MiliQ (MQ) water was flown to the module as it is the

208

background solution of ReO4- solution (Figure S1, stage iv). ReO4- was deposited on

209

the PPy-coated gold sensor by flowing 0.1 M ReO4- in MQ water through the flow

210

channels by applying cyclic voltammetry (Figure S1, stage v).

211

The changes in the frequency shift while depositing ReO4- are plotted in Figure S2a.

212

It is found that during the flow of ReO4-, the change in the frequency shift is in the order

213

of AC-PPy > PPy > AC. Using the Sauerbrey equation, this frequency shift was

214

converted to mass change during uptake. Compared to only PPy and only AC, the mass

215

change values (Figure 4) also indicate that the highest mass uptake of ReO4- was

216

achieved for the AC-PPy composite. This finding clearly indicates the advantage of

217

introducing AC as a porous backbone structure that with PPy can provide storage places

218

for ions. Similarly, the release of ReO4- (Figure S2b) indicates that the highest changes

219

in frequency were observed for the AC-PPy composite. These results clearly indicate

220

that the active ion exchange sites are from PPy functional groups, not from AC.

11

ACS Paragon Plus Environment

Environmental Science & Technology

AC PPy AC-PPy

ReO4 deposition

800 700

700 600 500 400 300 200

600 500 400 300 200 100

100

0

0

221

AC PPy AC-PPy

ReO4 release

Areal mass release (ng/cm2)

Areal mass deposition (ng/cm2)

800

Page 12 of 21

1st Cycle

2nd Cycle

3rd Cycle

4th Cycle

5th Cycle

1st Cycle

2nd Cycle

3rd Cycle

4th Cycle

5th Cycle

222

Figure 4. Change in areal mass during the deposition of ReO4- on material surfaces

223

(negative to positive voltage applied) and release of ReO4- from material surfaces

224

(positive to negative voltage applied) under CV measurement.

225

Figure 4 also shows that for the AC-PPy composite, up to 3rd cycle, the release of

226

ReO4- from the material surfaces was lower than the uptake, which means that the

227

uptake is partially reversible and the recovery ratio is 82% for 1st cycle, 90% for the

228

2nd cycle and nearly 100% for the 3rd cycle. After the 3rd cycle, the uptake and release

229

phenomenon began reaching equilibrium. However, for only PPy, even after the 5th

230

cycle, the recovery ratio is just 92%. This finding implies that AC-PPy provides good

231

storage sites for ReO4- ions, and the 3D porous structure of the AC-PPy film facilitates

232

ions to easily diffuse into or out of the composite film.

233 234 235 236 237 238 12

ACS Paragon Plus Environment

Page 13 of 21

239

Environmental Science & Technology

XPS evidence

C 1s O1s

N 1s

Na 1s

a

Re 4f

b

c

0

200

400

600

800

1000

1200

Binding energy (eV)

240 241

Figure 5. XPS survey scans for (a) the AC-PPy composite, (b) after an anodic potential

242

of 1.8 V and the uptake of ReO4- and then (c) a cathodic potential of -0.4 V was applied

243

to the AC-PPy composite.

244

XPS evidence for the uptake and release of ReO4- is shown in Figure 5. As shown in

245

Figure 5a, the appearance of the peaks of N 1s indicates that the PPy film was deposited

246

on AC-modified GC electrode during the electropolymerization. Figure 5b shows the

247

XPS result of the AC-PPy composite after an anodic potential for removing ReO4-; the

248

peak of Re can be observed, indicating that the ReO4- was uptook and reflecting its high

249

affinity. When the potential was transformed to cathodic (Figure 5c), the peak of Re

250

disappeared, which means that the ReO4- ions were ejected out of composite. The result

251

is consistent with electrochemical testing and EQCMD results and reflects the

252

feasibility of ESIX for the removal of ReO4- from water.

253 254 255 13

ACS Paragon Plus Environment

Environmental Science & Technology

256

Kinetics and selectivity study

257 258

Figure 6. (a) The kinetics of AC-PPy and PPy for ReO4- removal and (b) selectivity of

259

AC-PPy composite.

260 261

From Figure 6a, the kinetics show that the adsorption equilibrium of PPy was reached

262

after 60 s. AC-PPy showed a slightly slower response due to the larger surface area and

263

more adsorptive sites. AC-PPy has the electrical conductivity of PPy and large surface

264

area of AC, resulting in the largest adsorption capacity. The results of Figure 6b show

265

good selectivity and adsorption capacities for ReO4- despite the high concentration of

266

competing ions in solutions.

267 268

Supporting Information Available

269

Additional information mentioned was listed in Supporting Information. This material

270

is available free of charge via the Internet at http://pubs.acs.org. The frequency shift of

271

uptake and release of ReO4- on the AC-PPy by EQCMD.

272 273

Author information 14

ACS Paragon Plus Environment

Page 14 of 21

Page 15 of 21

Environmental Science & Technology

274

Notes

275

The authors declare no competing financial interest

276

* Corresponding author:

277

Email: [email protected] (Y. Lin)

278

Acknowledgement

279

We thank EMSL, a national scientific user facility sponsored by the Department of

280

Energy’s Office of Biological and Environmental Research located at Pacific

281

Northwest National Laboratory, for providing the XPS measurement. Zizhang Guo

282

would like to acknowledge the fellowship from the China Scholarship Council

283

(201606220157). This work was also supported by US Geological Survey grant

284

(2016WA411B) via State of Washington Water Research Center.

15

ACS Paragon Plus Environment

Environmental Science & Technology

285

References

286

1.

287

W.; Leavy, I. I.; Riley, B. J.; Kim, D. S.; Schweiger, M. J. Reduction and simultaneous

288

removal of 99Tc and Cr by Fe(OH)2 (s) mineral transformation. Environ. Sci. Technol.

289

2017, 51 (15), 8635-8642.

290

2.

291

based adsorbent for Re adsorption as analogue to 99Tc. Nucl. Sci. Tech. 2017, 28 (3),

292

30-37.

293

3.

294

of technetium: a review of the behavior of an artificial element in the natural

295

environment. Am. J. Sci. 2010, 310 (8), 721-752.

296

4.

297

low-level radioactive waste vitrification. Chem. Mater. 1996, 8 (5), 1004-1021.

298

5.

299

pertechnetate and perrhenate. Chem. Soc. Rev. 2009, 38 (6), 1572-1586.

300

6.

301

Eur. J. Inorg. Chem. 2007, 2007 (10), 1321-1340.

302

7.

303

of TcO4− ions from solution: materials and future outlook. Chem. Soc. Rev. 2016, 45

304

(10), 2724-2739.

305

8.

306

A. A.; Doonan, C. J.; Ma, S.; Thallapally, P. K. Removal of Pertechnetate‐Related

Saslow, S. A.; Um, W.; Pearce, C. I.; Engelhard, M. H.; Bowden, M. E.; Lukens,

Wang, P. Y.; Zu, J. H.; Wei, Y. Z. Synthesis and characterization of porous 4VP-

Icenhower, J. P.; Qafoku, N. P.; Zachara, J. M.; Martin, W. J. The biogeochemistry

Darab, J. G.; Smith, P. A. Chemistry of technetium and rhenium species during

Katayev, E. A.; Kolesnikov, G. V.; Sessler, J. L. Molecular recognition of

Custelcean, R.; Moyer, B. A. Anion separation with metal–organic frameworks.

Banerjee, D.; Kim, D.; Schweiger, M. J.; Kruger, A. A.; Thallapally, P. K. Removal

Banerjee, D.; Elsaidi, S. K.; Aguila, B.; Li, B.; Kim, D.; Schweiger, M. J.; Kruger,

16

ACS Paragon Plus Environment

Page 16 of 21

Page 17 of 21

Environmental Science & Technology

307

Oxyanions from Solution Using Functionalized Hierarchical Porous Frameworks.

308

Chem. Eur. J. 2016, 22 (49), 17581-17584.

309

9.

310

D.; Schweiger, M. J.; Kruger, A. A.; Doonan, C. J. Zirconium-based metal–organic

311

framework for removal of perrhenate from water. Inorg. Chem. 2016, 55 (17), 8241-

312

8243.

313

10. Lin, Y.; Cui, X. Electrosynthesis, characterization, and application of novel hybrid

314

materials

315

nanocomposites. J. Mate. Chem. 2006, 16 (6), 585-592.

316

11. Zhang, S.; Shao, Y.; Liu, J.; Aksay, I. A.; Lin, Y. Graphene–polypyrrole

317

nanocomposite as a highly efficient and low cost electrically switched ion exchanger

318

for removing ClO4– from wastewater. ACS Appl. Mater. Interfaces 2011, 3 (9), 3633-

319

3637.

320

12. Cui, H.; Li, Q.; Qian, Y.; Tang, R.; An, H.; Zhai, J. Defluoridation of water via

321

electrically controlled anion exchange by polyaniline modified electrode reactor. Water

322

Res. 2011, 45 (17), 5736-5744.

323

13. Bello, A.; Barzegar, F.; Madito, M.; Momodu, D.; Khaleed, A.; Masikhwa, T.;

324

Dangbegnon, J.; Manyala, N. Electrochemical performance of polypyrrole derived

325

porous activated carbon-based symmetric supercapacitors in various electrolytes. RSC

326

Adv. 2016, 6 (72), 68141-68149.

327

14. Zhi, M.; Xiang, C.; Li, J.; Li, M.; Wu, N. Nanostructured carbon–metal oxide

328

composite electrodes for supercapacitors: a review. Nanoscale 2013, 5 (1), 72-88.

Banerjee, D.; Xu, W.; Nie, Z.; Johnson, L. E.; Coghlan, C.; Sushko, M. L.; Kim,

based

on

carbon

nanotube–polyaniline–nickel

17

ACS Paragon Plus Environment

hexacyanoferrate

Environmental Science & Technology

329

15. Zhi, M.; Yang, F.; Meng, F.; Li, M.; Manivannan, A.; Wu, N. Effects of pore

330

structure on performance of an activated-carbon supercapacitor electrode recycled from

331

scrap waste tires. ACS Sustain. Chem. Eng. 2014, 2 (7), 1592-1598.

332

16. Gao, Y.; Zhang, W.; Yue, Q.; Gao, B.; Sun, Y.; Kong, J.; Zhao, P. Simple synthesis

333

of hierarchical porous carbon from Enteromorpha prolifera by a self-template method

334

for supercapacitor electrodes. J. Power Sources 2014, 270 (4), 403-410.

335

17. Guo, Z.; Zhang, J.; Liu, H.; Kang, Y.; Yu, J.; Zhang, C. Optimization of the green

336

and low-cost ammoniation-activation method to produce biomass-based activated

337

carbon for Ni (II) removal from aqueous solutions. J.Clean. Prod. 2017, 159, 38-46.

338

18. Guo, Z.; Zhang, X.; Kang, Y.; Zhang, J. Biomass-derived carbon sorbents for Cd

339

(II) removal: activation and adsorption mechanism. ACS Sustain. Chem. Eng. 2017, 5

340

(5), 4103-4109.

341

19. Lin, Y.; Cui, X.; Bontha, J. Electrically controlled anion exchange based on

342

polypyrrole and carbon nanotubes nanocomposite for perchlorate removal. Environ. Sci.

343

Technol. 2006, 40 (12), 4004-4009.

344

20. Choi, D.; Zhu, C.; Fu, S.; Du, D.; Engelhard, M. H.; Lin, Y. Electrochemically

345

Controlled Ion‐exchange Property of Carbon Nanotubes/Polypyrrole Nanocomposite

346

in Various Electrolyte Solutions. Electroanalysis 2017, 29 (3), 929-936.

347

21. Serrano, P. N. Electrochemistry of technetium analogues rhenium and

348

molybdenum in room temperature ionic liquid. UNLV Theses, Dissertations,

349

Professional Papers, and Capstones, University of Nevada, Las Vegas, NV, 2011.

350

22. Hahn, B. P.; May, R. A.; Stevenson, K. J. Electrochemical deposition and 18

ACS Paragon Plus Environment

Page 18 of 21

Page 19 of 21

Environmental Science & Technology

351

characterization of mixed-valent rhenium oxide films prepared from a perrhenate

352

solution. Langmuir 2007, 23 (21), 10837-10845.

353

23. Kankare, J. Sauerbrey equation of quartz crystal microbalance in liquid medium.

354

Langmuir 2002, 18 (18), 7092-7094.

355

24. Dron, J.; Dodi, A. Comparison of adsorption equilibrium models for the study of

356

Cl−, NO3− and SO42− removal from aqueous solutions by an anion exchange resin. J.

357

Hazard. Mater. 2011, 190 (1-3), 300-307.

358

25. Zhang, B.; Xu, P.; Qiu, Y.; Yu, Q.; Ma, J.; Wu, H.; Luo, G.; Xu, M.; Yao, H.

359

Increasing oxygen functional groups of activated carbon with non-thermal plasma to

360

enhance mercury removal efficiency for flue gases. Chem. Eng. J. 2015, 263, 1-8.

361

26. Cysewska, K.; Karczewski, J.; Jasiński, P. Electrochemical synthesis of 3D nano-

362

/micro-structured porous polypyrrole. Mater. Lett. 2016, 183, 397-400.

363

27. Huang, C.; Young, N. P.; Zhang, J.; Snaith, H. J.; Grant, P. S. A two layer electrode

364

structure for improved Li Ion diffusion and volumetric capacity in Li Ion batteries.

365

Nano Energy 2017, 31, 377-385.

366

28. Li, X.; Chen, X.; Jiang, F.; Chen, L.; Lu, S.; Chen, Q.; Wu, M.; Yuan, D.; Hong,

367

M. The dynamic response of a flexible indium based metal–organic framework to gas

368

sorption. Chem. Commun. 2016, 52 (11), 2277-2280.

369

29. Vakifahmetoglu, C.; Presser, V.; Yeon, S. H.; Colombo, P.; Gogotsi, Y. Enhanced

370

hydrogen and methane gas storage of silicon oxycarbide derived carbon. Micropor.

371

Mesopor. Mat. 2011, 144 (1-3), 105-112.

372

30. Guo, Z.; Zhang, J.; Liu, H.; Kang, Y. Development of a nitrogen-functionalized 19

ACS Paragon Plus Environment

Environmental Science & Technology

373

carbon adsorbent derived from biomass waste by diammonium hydrogen phosphate

374

activation for Cr (VI) removal. Powder Technol. 2017, 318, 459-464.

375

31. Wang, D. W.; Li, F.; Zhao, J.; Ren, W.; Chen, Z. G.; Tan, J.; Wu, Z. S.; Gentle, I.;

376

Lu, G. Q.; Cheng, H. M. Fabrication of graphene/polyaniline composite paper via in

377

situ anodic electropolymerization for high-performance flexible electrode. ACS Nano

378

2009, 3 (7), 1745-1752.

379

32. Dubal, D. P.; Ayyad, O.; Ruiz, V.; Gomez-Romero, P. Hybrid energy storage: the

380

merging of battery and supercapacitor chemistries. Chem. Soc. Rev. 2015, 44 (7), 1777-

381

1790.

382

33. Wang, J.; Dai, J.; Yarlagadda, T. Carbon Nanotube− Conducting-Polymer

383

Composite Nanowires. Langmuir 2005, 21 (1), 9-12.

384

20

ACS Paragon Plus Environment

Page 20 of 21

Page 21 of 21

385

Environmental Science & Technology

TOC graphic

386

21

ACS Paragon Plus Environment