Template-free tuned light driven photocatalyst and method

Patent metadata

Field	Value
Publication number	US-2020338544-A1
Application number	US-202016855824-A
Country	US
Kind code	A1
Filing date	Apr 22, 2020
Priority date	Apr 26, 2019
Publication date	Oct 29, 2020
Grant date	—

Abstract

Described herein are methods of making the visible light photocatalysts without the use of templates that can comprise: (1) mixing a metal precursor, an alcohol, and a solvent to form a self assembled shapes at a temperature between the freezing point of the solvent and the boiling point of the solvent, (2) strengthening the shapes at a temperature of about 35° C. to about 300° C. for about 30 minutes to about 96 hours, and then (3) annealing the shapes at a temperature of between about 450° C. to about 750° C. for between about 4 hours to about 16 hours in a gaseous atmosphere. Also described are photocatalysts created by the described methods.

First claim

What is claimed is:

1 . A method of making a tuned, light-activated photocatalyst without the use of templates comprising: (1) mixing a metal precursor, an alcohol, and a solvent to form self-assembled shapes at a temperature between the freezing point of the solvent and the boiling point of the solvent, (2) strengthening the shapes at a temperature of about 35° C. to about 300° C. for about 30 minutes to about 96 hours, and then (3) annealing the shapes at a temperature of between about 450° C. to about 750° C. for between about 4 hours to about 16 hours in a gaseous atmosphere.

2 . The method of claim 1 , where step of mixing a metal precursor comprises mixing a metal salt, a metal alkoxide, a metal halide, or a combination thereof.

3 . The method of claim 2 , where the step of mixing a metal precursor comprises mixing a metal alkoxide.

4 . The method of claim 3 , where the step of mixing a metal alkoxide comprises mixing tantalum alkoxide.

5 . The method of claim 1 , where the step of mixing an alcohol comprises mixing in methanol, ethanol, n-propanol, isopropanol, n-butanol, sec-butanol, iso-butanol, or tent-butanol.

6 . The method of claim 5 , where the step of mixing an alcohol comprises mixing in ethanol.

7 . The method of claim 1 , where the step of mixing a solvent comprises mixing in water.

8 . The method of claim 7 , where the volume ratio of ethanol to water is from about 1:2 to about 1:40.

9 . The method of claim 8 , where the volume ratio of ethanol to water is 2:5.

10 . The method of claim 8 , where e ratio of ethanol to water is 1:20.

11 . The method of claim 1 , where the step of strengthening the shapes is done at a temperature of 200° C. from 12 hours to 72. hours.

12 . The method of claim 11 , where the step of strengthening the shapes is done at a temperature of 200° C. from 12 hours to 48 hours.

13 . The method of claim 1 , where the step of annealing the shapes is done at 625° C. for 8 hours.

14 . The method of claim 13 , where the step of annealing the shapes is done in a nitriding atmosphere.

15 . The method of claim 14 , where the step of annealing the shapes is done in an ammonia atmosphere.

16 . A method of making the visible light photocatalyst without the use of templates that can comprise: (1) mixing ethanol, water, and a tantalum ethoxide to form self-assembled, hollow spheres of tantalum oxide, (2) strengthening at a temperature of about 100° C. to about 300° C. for about 6 hours to about 96 hours to mechanically stiffen the spheres, and then (3) annealing the tantalum oxide to Ta 3 N 5 at a temperature of between about 450° C. to about 750° C. for between about 4 hours to about 16 hours in an ammonia atmosphere.

17 . A method of making a tuned, light-activated photocatalyst, comprising:
mixing a metal precursor and a solvent to form micelles in solution; heating the micelles and solution to strengthen the morphology of the micelles; rinsing the micelles and heating to remove the solvent; and annealing in a nitriding atmosphere to form hollow spheres of metal nitride.

Assignees

• Univ California

Inventors

• Kisailus David
• Wang Taifeng

Classifications

• B01J2235/00

  Indexing scheme associated with group B01J35/00, related to the analysis techniques used to determine the catalysts form or properties · CPC title

• B01J35/52

  Hollow spheres · CPC title

• B01J2235/15

  X-ray diffraction · CPC title

• B01J2235/30

  Scanning electron microscopy; Transmission electron microscopy · CPC title

• B01J35/77

  Compounds characterised by their crystallite size · CPC title