Surface-modified spherical activated carbon for high carbon loading and its desalting performance in flow-electrode capacitive deionization

We have synthesized a new type of activated carbon (AC) containing ion-selective functional groups, trimethylammonium (AC-N) for anodes and sulfonate (AC-S) for cathodes, for high carbon loading of flow-electrodes. The AC-N and AC-S were partially covered with a 50 nm-thick polymer layer and their surfaces became more hydrophilic than that of bare AC. In the case of bare AC, the maximum carbon concentration in the flow electrodes was 10%, while in the case of the surface-modified AC (AC-N and AC-S), it increased to a maximum of 35% and decreased the viscosity due to the electrostatic repulsion. Moreover, with the increase in carbon concentration, the salt removal efficiencies were improved from 8.2% to 27.7%. This increase in efficiency was attributed to the formation of percolating networks, which occurred because of high carbon loading. The resulting improvement in electronic conductivity at higher loading led to a higher current, and thus an improved salt removal efficiency. Therefore, we expect that the surface-modified AC electrode can be used as a dispersant for hydrophobic AC particles in aqueous solution, as well as in flow electrodes to improve desalting performance in FCDI systems.

[1]  P. M. Biesheuvel,et al.  Membrane capacitive deionization , 2010 .

[2]  P. M. Biesheuvel,et al.  Theory of water desalination by porous electrodes with fixed chemical charge , 2015 .

[3]  Choonsoo Kim,et al.  Hybrid capacitive deionization to enhance the desalination performance of capacitive techniques , 2014 .

[4]  Y. Gogotsi,et al.  Graphene-containing flowable electrodes for capacitive energy storage , 2015 .

[5]  Ayokunle Omosebi,et al.  Enhanced Salt Removal in an Inverted Capacitive Deionization Cell Using Amine Modified Microporous Carbon Cathodes. , 2015, Environmental science & technology.

[6]  Jae-Hwan Choi,et al.  Selective removal of nitrate ion using a novel composite carbon electrode in capacitive deionization. , 2012, Water research.

[7]  C. R. Dennison,et al.  The Electrochemical Flow Capacitor: A New Concept for Rapid Energy Storage and Recovery , 2012 .

[8]  Lan Zhou,et al.  Binder-free phenyl sulfonated graphene/sulfur electrodes with excellent cyclability for lithium sulfur batteries , 2014 .

[9]  Karel J. Keesman,et al.  Direct prediction of the desalination performance of porous carbon electrodes for capacitive deionization , 2013 .

[10]  Xin Gao,et al.  Surface charge enhanced carbon electrodes for stable and efficient capacitive deionization using inverted adsorption–desorption behavior , 2015 .

[11]  Y. Oren,et al.  Capacitive deionization (CDI) for desalination and water treatment — past, present and future (a review) , 2008 .

[12]  Moon Hee Han,et al.  Desalination via a new membrane capacitive deionization process utilizing flow-electrodes , 2013 .

[13]  Linda Zou,et al.  Ion-selective carbon nanotube electrodes in capacitive deionisation , 2013 .

[14]  Volker Presser,et al.  Review on the science and technology of water desalination by capacitive deionization , 2013 .

[15]  B. Kastening,et al.  Design of a slurry electrode reactor system , 2013 .

[16]  D. Shaw,et al.  Introduction to colloid and surface chemistry , 1970 .

[17]  V. Presser,et al.  Investigation of carbon materials for use as a flowable electrode in electrochemical flow capacitors , 2013 .

[18]  R. Neumann,et al.  A facile route for the preparation of azide-terminated polymers. “Clicking” polyelectrolyte brushes on planar surfaces and nanochannels , 2010 .

[19]  Marc A. Anderson,et al.  Capacitive deionization as an electrochemical means of saving energy and delivering clean water. Comparison to present desalination practices: Will it compete? , 2010 .

[20]  D. Zhao,et al.  Carbon Materials for Chemical Capacitive Energy Storage , 2011, Advanced materials.

[21]  Sungil Jeon,et al.  Ion storage and energy recovery of a flow-electrode capacitive deionization process , 2014 .

[22]  Y. Gogotsi,et al.  Activated Carbon Spheres as a Flowable Electrode in Electrochemical Flow Capacitors , 2014 .

[23]  Volker Presser,et al.  Water desalination via capacitive deionization : What is it and what can we expect from it? , 2015 .

[24]  Linda Zou,et al.  Ion-exchange membrane capacitive deionization: A new strategy for brackish water desalination , 2011 .

[25]  Kelsey B. Hatzell,et al.  Flowable Conducting Particle Networks in Redox-Active Electrolytes for Grid Energy Storage , 2015 .

[26]  Kehe Su,et al.  Hierarchically porous silicon–carbon–nitrogen hybrid materials towards highly efficient and selective adsorption of organic dyes , 2015, Scientific Reports.

[27]  Volker Presser,et al.  Carbon flow electrodes for continuous operation of capacitive deionization and capacitive mixing energy generation , 2014 .

[28]  Ling Zhang,et al.  Preparation of polydopamine-functionalized graphene–Fe3O4 magnetic composites with high adsorption capacities , 2014 .

[29]  Chi-Woo Lee,et al.  Desalination of a thermal power plant wastewater by membrane capacitive deionization , 2006 .

[30]  W. Marsden.  I and J , 2012 .

[31]  Victor E. Brunini,et al.  Semi‐Solid Lithium Rechargeable Flow Battery , 2011 .

[32]  P. M. Biesheuvel,et al.  Optimization of salt adsorption rate in membrane capacitive deionization. , 2013, Water research.

[33]  P. M. Biesheuvel,et al.  Complementary surface charge for enhanced capacitive deionization. , 2016, Water research.

[34]  P. M. Biesheuvel,et al.  Fluidized bed electrodes with high carbon loading for water desalination by capacitive deionization , 2016 .

[35]  Brian J. Adzima,et al.  Multifunctional photo-crosslinked polymeric ionic hydrogel films , 2014 .

[36]  P. M. Biesheuvel,et al.  Theory of membrane capacitive deionization including the effect of the electrode pore space. , 2011, Journal of colloid and interface science.

[37]  P. M. Biesheuvel,et al.  Energy consumption and constant current operation in membrane capacitive deionization , 2012 .

[38]  Kelsey B. Hatzell,et al.  Effect of oxidation of carbon material on suspension electrodes for flow electrode capacitive deionization. , 2015, Environmental science & technology.

[39]  G. Yushin,et al.  Effect of Carbon Particle Size on Electrochemical Performance of EDLC , 2008 .