Method for hf-free facile and rapid synthesis of mxenes related compounds

Patent metadata

Field	Value
Publication number	US-2020399771-A1
Application number	US-202016946459-A
Country	US
Kind code	A1
Filing date	Jun 23, 2020
Priority date	Jun 24, 2019
Publication date	Dec 24, 2020
Grant date	—

Abstract

Provided herein is a method for preparing MXenes, such as Ti2CTx, Cr2CTx, and V2CTx, products prepared therefrom, and compositions and devices including the same.

First claim

What is claimed:

1 . A method for preparing a MXene, the method comprising:
providing a composite electrode comprising at least one MAX-phase composition and a carbonaceous material, wherein the at least one MAX-phase composition has an empirical formula of M n+1 AX n or M 2 M′ n X n+1 , wherein each of M and M′ is independently a Group IIIB, IVB, VB, or VIB metal; A is a Group IIB, IIIA, IVA, or VA element; and each X is C, N, or a combination thereof; and n is 1, 2, or 3; a counter electrode; and an electrolyte solution comprising an etchant between and in contact with the composite electrode and the counter electrode; and applying an electric current between the composite electrode and the counter electrode resulting in electrolytic reduction of the at least one MAX-phase composition thereby forming the MXene, wherein the electrolytic reduction is conducted at a temperature between 25 to 80° C.

2 . The method of claim 1 , wherein the electric current is applied at a voltage 2 V or less.

3 . The method of claim 1 , wherein the etchant is chloride.

4 . The method of claim 1 , wherein the carbonaceous material is carbon black (CB), carbon fiber cloth (CFC), or a mixture thereof.

5 . The method of claim 1 , wherein the composite electrode further comprises a binder.

6 . The method of claim 1 , wherein the at least one MAX-phase composition and the carbonaceous material are present in the composite electrode in a mass ratio of 80:20 to 99:1, respectively.

7 . The method of claim 6 , wherein the composite electrode further comprises a binder, wherein the binder is present in the composite electrode at 0.1 to 3% by weight.

8 . The method of claim 1 , wherein the electrolytic reduction is conducted at a temperature between 30 to 70° C.

9 . The method of claim 1 , wherein each of M and M′ is independently Hf, Cr, Mn, Mo, Nb, Sc Ta, Ti, V, W, or Zr; and A is Al.

10 . The method of claim 8 , wherein the electrolyte solution comprises 0.5 to 1.5 M HCl.

11 . The method of claim 10 , wherein each of M and M′ is independently Hf, Cr, Mn, Mo, Nb, Sc Ta, Ti, V, W, or Zr; and A is Al.

12 . The method of claim 1 , wherein the applying an electric current is maintained for 10 hours or less.

13 . The method of claim 1 , wherein the method comprises: providing a composite electrode comprising at least one MAX-phase composition, a carbonaceous material and a binder, wherein the at least one MAX-phase composition has an empirical formula of M n+1 AX n or M 2 M′ n X n+1 , wherein each of M and M′ is independently Hf, Cr, Mn, Mo, Nb, Sc Ta, Ti, V, W, or Zr; and A is Al; and each X is C, N, or a combination thereof; and n is 1, 2, or 3;
a counter electrode; and
an electrolyte solution between and in contact with the composite electrode and the counter electrode having a pH of 1 or less; and
applying an electric current between the composite electrode and the counter electrode at a voltage 2 V or less resulting in the electrolytic reduction of the at least one MAX-phase composition thereby forming the MXene, wherein the electrolytic reduction is conducted at a temperature between 30 to 70° C.

14 . The method of claim 12 , wherein the electrolytic reduction is conducted at a temperature between 40 to 60° C.

15 . The method of claim 12 , wherein the electrolyte solution comprises 0.5 to 1.5 M HCl.

16 . The method of claim 12 , wherein the at least one MAX-phase composition and the carbonaceous material are present in the composite electrode in a mass ratio of 80:20 to 99:1, respectively and the binder is present in the composite electrode 0.1 to 2% by weight.

17 . The method of claim 12 , wherein each of M and M′ is independently Hf, Cr, Mn, Mo, Nb, Sc Ta, Ti, V, W, or Zr; and A is Al.

18 . The method of claim 12 , wherein at least one MAX-phase composition has an empirical formula of M n+1 AX n and M is Cr, Ti, and V; A is Al.

19 . A method for preparing a MXene, the method comprising: providing a composite electrode comprising at least one MAX-phase composition; a carbonaceous material selected from the group consisting of CB, CFC, and combinations thereof; a binder, wherein the at least one MAX-phase composition has an empirical formula of M n+1 AX n , wherein each of M is Cr, Ti, and V; A is Al; and each X is C or N; and n is 1, 2, or 3; wherein the at least one MAX-phase composition and carbonaceous material are present in the composite electrode in a mass ratio of 90:10 to 99:1; and wherein the binder is present in the composite electrode in a weight ratio of 1.0-1.5% by mass;
a counter electrode; and an electrolyte solution comprising 0.5 to 1.5 M HCl between and in contact with the composite electrode and the counter electrode; and applying an electric current between the composite electrode and the counter electrode at a voltage 0.2 to 1.5 V for 8 to 10 hours resulting in the electrolytic reduction of the at least one MAX-phase composition thereby forming the MXene, wherein the electrolytic reduction is conducted at a temperature between 45 to 55° C.

20 . A MXene formed according to the method of claim 1 .

Assignees

• Univ Hong Kong Polytechnic

Inventors

• Hao Jianhua
• Pang Sin Yi

Classifications

• C25F5/00

  Electrolytic stripping of metallic layers or coatings · CPC title

• C01B21/076

  with titanium or zirconium {or hafnium} · CPC title

• C01B21/0617

  with vanadium, niobium or tantalum · CPC title

• C01B32/914 Primary

  Carbides of single elements · CPC title

• C01B32/921

  Titanium carbide · CPC title