Copolymer, a method of synthesizing thereof, and a method for producing hydrogen gas

Patent metadata

Field	Value
Publication number	US-2019270845-A1
Application number	US-201815910236-A
Country	US
Kind code	A1
Filing date	Mar 2, 2018
Priority date	Mar 2, 2018
Publication date	Sep 5, 2019
Grant date	—

Abstract

A copolymer containing carbazole-based and vinylene based moieties, a photoelectrode comprising a metal oxide substrate and the copolymer as a photoelectrocatalyst component to the photoelectrode, as well as a photoelectrochemical cell including the photoelectrode. Methods of producing the copolymers, and methods of using the photoelectrochemical cell to produce hydrogen gas are also provided.

First claim

1 : A copolymer of formula (I)

or a salt thereof, a solvate thereof, a tautomer thereof, a stereoisomer thereof, or a mixture thereof;
wherein:
R 1 is selected from the group consisting of a hydrogen, an optionally substituted alkyl, an optionally substituted cycloalkyl, an optionally substituted arylalkyl, an optionally substituted aryl, an optionally substituted alkanoyl, and an optionally substituted aroyl;
each R 2 is independently selected from the group consisting of an optionally substituted alkyl, an optionally substituted cycloalkyl, an optionally substituted aryl, and an optionally substituted arylalkyl;
each R 3 is independently selected from the group consisting of a hydrogen, an optionally substituted alkyl, an optionally substituted cycloalkyl, an optionally substituted arylalkyl, an optionally substituted aryl, an optionally substituted alkoxy, an optionally substituted alkanoyl, an optionally substituted aroyl, a halogen, a nitro, and a cyano;
each R 4 is independently selected from the group consisting of a hydrogen, an optionally substituted alkyl, an optionally substituted cycloalkyl, an optionally substituted arylalkyl, an optionally substituted aryl, an optionally substituted alkoxy, an optionally substituted alkanoyl, and an optionally substituted aroyl;
each R 5 is independently selected from the group consisting of a hydrogen, an optionally substituted alkyl, an optionally substituted cycloalkyl, an optionally substituted arylalkyl, an optionally substituted aryl, an optionally substituted alkoxy, an optionally substituted alkanoyl, an optionally substituted aroyl, a halogen, a nitro, and a cyano; and
n is a positive integer in a range of 2-10,000.

2 : The copolymer of claim 1 ,
wherein each R 3 , R 4 and R 5 are a hydrogen; R 1 is a hydrogen or an optionally substituted alkyl; and each R 2 is independently an optionally substituted alkyl.

3 : The copolymer of claim 2 ,
wherein R 1 is 2-ethylhexyl; and each R 2 is independently 2-ethylhexyl or dodecyl.

4 : The copolymer of claim 1 , which has a formula selected from the group consisting of

wherein n is a positive integer in the range of 2-10000 for each of formulae (P1) and (P2).

5 : The copolymer of claim 1 , which is in the form of microspheres having a diameter of 1-10 μm.

6 : The copolymer of claim 1 , which has a band gap energy of 2.0-2.8 eV.

7 : The copolymer of claim 1 , which has a fluorescence emission peak of 520-570 nm upon excitation at a wavelength of 380-400 nm.

8 : A method of producing the copolymer of claim 1 , the method comprising:
reacting a dialdehyde of formula (II)

or a salt, solvate, tautomer or stereoisomer thereof, with a diphosphonate of formula (III)

or a salt, solvate, tautomer or stereoisomer thereof in the presence of a base to form the copolymer, wherein:
R 1 is selected from the group consisting of a hydrogen, an optionally substituted alkyl, an optionally substituted cycloalkyl, an optionally substituted arylalkyl, an optionally substituted aryl, an optionally substituted alkanoyl, and an optionally substituted aroyl;
each R 2 is independently selected from the group consisting of an optionally substituted alkyl, an optionally substituted cycloalkyl, an optionally substituted aryl, and an optionally substituted arylalkyl;
each R 3 is independently selected from the group consisting of a hydrogen, an optionally substituted alkyl, an optionally substituted cycloalkyl, an optionally substituted arylalkyl, an optionally substituted aryl, an optionally substituted alkoxy, an optionally substituted alkanoyl, an optionally substituted aroyl, a halogen, a nitro, and a cyano;
each R 4 is independently selected from the group consisting of a hydrogen, an optionally substituted alkyl, an optionally substituted cycloalkyl, an optionally substituted arylalkyl, an optionally substituted aryl, an optionally substituted alkoxy, an optionally substituted alkanoyl, and an optionally substituted aroyl;
each R 5 is independently selected from the group consisting of a hydrogen, an optionally substituted alkyl, an optionally substituted cycloalkyl, an optionally substituted arylalkyl, an optionally substituted aryl, an optionally substituted alkoxy, an optionally substituted alkanoyl, an optionally substituted aroyl, a halogen, a nitro, and a cyano; and
each R 6 is an optionally substituted alkyl or an optionally substituted arylalkyl.

9 : The method of claim 8 , wherein a molar ratio of the dialdehyde of formula (II) to the diphosphonate of formula (III) is in a range of 1:2 to 2:1.

10 : A photoelectrode, comprising:
a metal oxide conducting substrate; and a layer comprising the copolymer of formula (I) of claim 1 deposited over the metal oxide conducting substrate; wherein the layer has a thickness in a range of 5-500 nm.

11 : The photoelectrode of claim 10 , which has an ultraviolet visible absorption with an absorption edge of 500-660 nm.

12 : The photoelectrode of claim 10 , wherein the metal oxide conducting substrate is fluorine doped tin oxide.

13 : A photoelectrochemical cell, comprising:
the photoelectrode of claim 10 ; a counter electrode; and an electrolyte solution comprising water and an inorganic salt in contact with both electrodes.

14 : The photoelectrochemical cell of claim 13 , wherein the electrolyte solution has an inorganic salt concentration of 0.05-1 M.

15 : The photoelectrochemical cell of claim 13 , wherein the electrolyte solution has a pH in a range of 5-9.

16 : The photoelectrochemical cell of claim 13 , wherein the photoelectrode has a photo-current density in a range from −1.0 to −100 μA/cm 2 when the electrodes are subjected to a potential of −0.25 to 0.05 V under visible light irradiation.

17 : The photoelectrochemical cell of claim 13 , wherein the photoelectrode has a photo-current density in a range from −0.25 to −2.5 mA/cm 2 when the electrodes are subjected to a potential of −0.5 to −2.0 V under visible light irradiation.

18 : The photoelectrochemical cell of claim 13 , further comprising a reference electrode in contact with the electrolyte solution.

19 : The photoelectrochemical cell of claim 16 , wherein the photo-current density decreases by less than 35% after subjecting the photoelectrode to a potential of −0.25 to 0.05 V under visible light irradiation for 1-9 hours.

20 : A method of forming hydrogen gas, the method comprising:
subjecting the electrodes of the photoelectrochemical cell of claim 13 to a potential of −2.0 to 0.05 V; and concurrently irradiating the photoelectrochemical cell with visible light, thereby forming hydrogen gas.

Assignees

• Univ King Fahd Pet & Minerals

Inventors

• Ullah Nisar
• Mansha Muhamad
• Khan Ibrahim
• Qurashi Ahsanulhaq

Classifications

• C08G2261/91

  Photovoltaic applications · CPC title

• C08G2261/1424

  containing ether groups, including alkoxy · CPC title

• C08G2261/3241

  containing one or more nitrogen atoms as the only heteroatom, e.g. carbazole · CPC title

• C08G2261/18

  conjugated · CPC title

• C08G2261/92

  TFT applications · CPC title