# US 11,896,957 B2 · Methods for producing photocatalyst, and uses of the photocatalyst in degrading NOx

> Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt

- Number: US 11,896,957 B2
- Document ID: US11896957B2
- Status: Granted
- Kind: B2
- Application number: 17/686,436
- Filed: 2022-03-04
- Published: 2023-09-07
- Granted: 2024-02-13
- Earliest claimed: 2022-03-04
- Assignees: Chung Yuan Christian University
- Applicants: Chung Yuan Christian University
- Inventors: Ya-Fen Wang; Sheng-Jie You; Christianson Raynard Sanito
- Web page: https://patentgrep.com/patent/US11896957B2

## CPC

- B01J 23/06: of zinc, cadmium or mercury
- B01D 53/8628: {Processes characterised by a specific catalyst}
- B01J 21/063: {Titanium; Oxides or hydroxides thereof}
- B01J 35/39: Photocatalytic properties
- B01J 37/0207: {Pretreatment of the support}
- B01J 37/04: Mixing {(B01J37/0009, B01J37/0018 take precedence)}
- B01J 37/082: {Decomposition and pyrolysis}
- B01D 2255/20707: Titanium
- B01D 2255/20792: Zinc
- B01D 2255/802: Photocatalytic
- B01D 2257/404: Nitrogen oxides other than dinitrogen oxide
- B01D 2259/802: Visible light
- B01J: CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- B01D: SEPARATION (separating solids from solids by wet methods B03B, B03D; by pneumatic jigs or tables B03B; by other dry methods B07; magnetic or electrostatic separation of solid materials from solid materials or fluids, separation by high-voltage electric fields B03C; centrifuges, vortex apparatus B04; presses per se for squeezing-out liquid from liquid-containing material B30B9/02; treatment of water C02F, e.g. softening by ion-exchange C02F1/42; {arrangements of air intake cleaners in gas turbine plants F02C7/05} ; arrangements or mounting of filters in air-conditioning, air-humidification or ventilation F24F13/28)

## Abstract

Disclosed herein are methods of producing photocatalysts for degrading NOx. According to some embodiments of the present disclosure, the method comprises mixing a transitional metal or its oxide with a bone powder or a shell powder, followed by heating the mixture for a least 12 hours to dehydrate the mixture, and calcinating the dehydrated product for 1-5 hours. Also disclosed herein are methods of degrading NOx by using the thus-produced photocatalysts. Materials used doped with the transitional metal or its oxide are bone powder and shell powder, which is derived from animals (a chicken, a cow, a pig, a duck, a sheep, a donkey, or a horse) and shells from different species of sea water (a shrimp, a crab, a clam, a barnacle, a snail, an abalone, or an oyster), respectively.

## Claims

### Claim 1

A method for degrading NOx in a sample, comprising,
(i) mixing the sample with a photocatalyst produced by a method comprising,
(a) mixing a transitional metal or an oxide thereof with a solvent at a ratio of 1:10 (w/v) to produce a first mixture;
(b) mixing a bone powder or a shell powder with the first mixture of step (a) to produce a second mixture, in which the bone powder or the shell powder and the transitional metal or the oxide thereof are present in the second mixture at a weight ratio of 0.1:1 to 10:1 (w/w);
(c) heating the second mixture of step (b) to produce a dehydrated product; and
(d) calcinating the dehydrated product of step (c) to produce the photocatalyst; and
(ii) irradiating the mixture of step (i) with solar light or visible light for at least 5 minutes;
wherein the step (ii) is carried out at a humidity of 40%.

### Claim 2 (depends on 1)

The method of claim 1, wherein after the step (ii), the NOx in the sample is degraded to a level of no more than 1.8 parts per million (ppm).

### Claim 3 (depends on 2)

The method of claim 2, wherein after the step (ii), the NOx in the sample is degraded to a level of more than 500 parts per billion (ppb).