Electrochemical devices or systems comprising redox-functionalized electrodes and uses thereof

Patent metadata

Field	Value
Publication number	US-2017113951-A1
Application number	US-201615336637-A
Country	US
Kind code	A1
Filing date	Oct 27, 2016
Priority date	Oct 27, 2015
Publication date	Apr 27, 2017
Grant date	—

Abstract

Various aspects described herein relate to electrochemical devices, e.g., for separation of one or more target organic or inorganic molecules (e.g., charged or neutral molecules) from solution, and methods of using the same. In particular embodiments, the electrochemical devices and methods described herein involve at least one redox-functionalized electrode, wherein the electrode comprises an immobilized redox-species that is selective toward a target molecule (e.g., charged molecule such as ion or neutral molecule). The selectivity is based on a Faradaic/redox-activated chemical interaction (e.g., directional hydrogen binding) between the oxidized state of the redox species and a moiety of the target molecule (e.g., charged molecule such as ion or neutral molecule).

First claim

What is claimed is:

1 . An electrochemical system comprising:
a. a first electrode comprising a first conductive solid substrate and a first redox species immobilized to the first conductive solid substrate, wherein the first redox species is selective toward a target functional group of a target molecule; and b. a second electrode.

2 . The electrochemical system of claim 1 , wherein the first redox species in an oxidized state selectively binds to an electron-donating functional group of a target molecule.

3 . The electrochemical system of claim 2 , wherein the first redox species is an organometallic compound, an organic species, a crystalline solid, a cyclodextrin-based system, a metal-polypyrridyl system, metal dicarbamate, cryptand, redox-active arene, dendrimer comprising a redox-active center, or a redox-active organic macrocycle.

4 . The electrochemical system of claim 3 , wherein the first redox species is an organometallic compound, e.g., a ferrocene-based redox species.

5 . The electrochemical system of claim 4 , wherein the target functional group comprises a carboxylate moiety, a sulfonate moiety, or a phosphonate moiety.

6 . The electrochemical system of claim 1 , wherein the second electrode comprises a second solid substrate and a second redox species immobilized to the solid second substrate, wherein the second redox species undergoes a self-exchange reaction within the cathodic electrode during operation of the electrochemical system.

7 . The electrochemical system of claim 6 , wherein the second redox species is chemically different from the first redox species.

8 . The electrochemical system of claim 6 , wherein the second redox species is a charged species.

9 . The electrochemical system of claim 6 , wherein the second redox species is a molecule comprising an electron-accepting functional moiety.

10 . The electrochemical system of claim 6 , wherein the second redox species is a charged species of the first redox species, optionally wherein the first redox species is selected from the group consisting of quinone-containing polymers, cobaltocenium-containing polymers, polypyrrole, cyclodextrin-based systems, metal-polypyridyl systems, metal-dicarbamates, cryptands, dendrimers comprising redox-active centers, and redox-active organic macrocycles.

11 . The electrochemical system of claim 1 , further comprising an electrolyte disposed between the first electrode and the second electrode.

12 . The electrochemical system of claim 11 , wherein the electrolyte comprises an aqueous medium or an organic medium.

13 . A method of separating at least one target molecule from a fluid source comprising:
a. placing in a fluid source (i) a first electrode comprising a first solid substrate and a first redox species immobilized to the first solid substrate; and (ii) a second electrode; and b. applying an electrical potential across the first electrode and the second electrode such that the first redox species transforms to an oxidized state and selectively binds to a target electron-donating functional group of a target molecule present in the fluid source, thereby separating at least one target molecule comprising the target electron-donating functional group from the fluid source.

14 . The method of claim 13 , wherein the second electrode comprises a second solid substrate and a second redox species immobilized to the second solid substrate, wherein the second redox species is chemically different from the first redox species.

15 . The method of claim 14 , wherein the second redox species is selective toward a cationic species present in the fluid source.

16 . The method of claim 15 , wherein the cationic species is selected from the group consisting of heavy metals, transition metals, lanthanides, organic cations, inorganic cations, metal-organic cations, metal-inorganic cations, alkali metal ions, alkaline earth metal ions, and rare earth metal ions.

17 . The method of claim 13 , wherein the target molecule is an organic anion, an inorganic anion, a neutral molecule, or a oxygen-containing complex.

18 . The method of claim 13 , wherein the target molecule or cationic species is a micropollutant or a nanopollutant.

19 . The method of claim 15 , wherein the target molecule or cationic species is or is derived from a pharmaceutical compound, a personal healthcare product, a detergent, a pesticide, a herbicide, and/or an organic wastewater contaminant.

20 . The method of claim 15 , further comprising reversing the applied electrical potential to release the bound target molecule and/or captured cationic species from the electrodes.

21 . A method of increasing separation efficiency of a target molecule from a fluid source or increasing energy storage performance of an electrochemical device or system comprising:
a. placing in a fluid source (i) a first electrode comprising a first solid substrate and a first redox species immobilized to the first solid substrate; and (ii) a second electrode comprising a second solid substrate and a second redox species immobilized to the solid second substrate, wherein the second redox species is chemically different from the first redox species; and b. applying an electrical potential across the first electrode and the second electrode such that the first redox species transforms to an oxidized state and selectively binds to a target electron-donating functional group of a target molecule present in the fluid source and the second redox species undergoes a self-exchange reaction within the second electrode, thereby increasing the separation efficiency or energy storage performance of the electrochemical device or system by diverting at least a portion of electron transfer toward the self-exchange reaction of the second redox species and reducing electron transfer toward the fluid source.

22 . The method of claim 21 , wherein the fluid source is an aqueous fluid or an organic fluid.

Assignees

• Massachusetts Inst Technology

Inventors

• Su Xiao
• Achilleos Demetra S
• Hatton Trevor Alan

Classifications

• C02F2103/343

  from the pharmaceutical industry, e.g. containing antibiotics · CPC title

• C02F2101/301

  Detergents, surfactants · CPC title

• C02F2101/20

  Heavy metals or heavy metal compounds · CPC title

• C02F2101/306

  Pesticides · CPC title

• C02F1/4672

  by electrooxydation · CPC title