Patent Application
20250162901
The present application claims priority to Korean Patent Application No. 10-2023-0162336, filed Nov. 21, 2023, the entire contents of which is incorporated herein for all purposes by this reference.
The present invention relates to a method for manufacturing TiO2 powder and TiO2 powder prepared by the same.
Photocatalysts must be fundamentally stable, and, in order to function, they must have the ability to absorb light and oxidize other substances. Although mainly used as a white paint, TiO2 exhibits suitable properties as a photocatalyst, and, when mixed with other dyes or colored organic substances, it may also perform the photocatalytic function with light in the visible light range.
Meanwhile, NH3 and TiCl4 react on a wafer to form a Ti—N layer in a process of manufacturing a semiconductor forming a Ti—N layer. However, the amount of NH3 and TiCl4 used to form a Ti—N layer is actually only about 10% of the supply, and the remaining 90% is discharged and thrown away. Therefore, it is necessary to recover the residual NH3 and TiCl4 discharged in terms of resource recycling, but no technology has been proposed to solve such problem.
The present invention aims to solve the problems of the prior art as described above, and an object of the present invention is to provide a method for manufacturing TiO2 powder from a mixture discharged when NH3 and TiCl4 are reacted on a wafer to form a Ti—N layer.
In order to achieve the objectives, an aspect of a method for manufacturing TiO2 powder according to an embodiment of the present invention for achieving the above-described object is a method for manufacturing TiO2 powder comprising: capturing NH3 and TiCl4 from a residue after forming a Ti—N layer; dissolving the NH3 and TiCl4 in a solvent to prepare a mixture; obtaining TiO2 and NH4Cl from the mixture; and separating TiO2 powder from the obtained TiO2 and NH4Cl.
In an aspect of an embodiment of the present disclosure, wherein the TiO2 powder is nanoparticles.
In an aspect of an embodiment of the present disclosure, wherein the vanadium carbide is formed by refining vanadium oxide and a carbon compound, followed by mixing, to prepare a mixture of the vanadium oxide and the carbon compound, and subjecting the mixture to heat-treatment under vacuum and normal pressure.
In an aspect of an embodiment of the present disclosure, wherein the vanadium carbide has a molar ratio of vanadium to carbon of 2:1, 3:2, or 4:3.
In an aspect of an embodiment of the present disclosure, wherein the Max using vanadium carbide excludes the use of a vanadium metal.
In an aspect of an embodiment of the present disclosure, wherein the carbon content in the Max using vanadium carbide is 8 to 14 wt %.
In an aspect of an embodiment of the present disclosure, wherein the solvent is selected from the group consisting of nitric acid, ammonia, hydrogen peroxide, hydrochloric acid and combinations thereof.
In an aspect of an embodiment of the present disclosure, wherein, in the step of preparing the mixture, the NH3 and TiCl4 are dissolved in the solvent and reacted at a temperature of from 25° C. to 350° C.
In an aspect of an embodiment of the present disclosure, wherein, in the step of preparing the mixture, the NH3 and TiCl4 are dissolved in the solvent and reacted under a pressure of from 1 bar to 10 bar.
In an aspect of an embodiment of the present disclosure, wherein, in the step of obtaining the TiO2 and NH4Cl, the TiO2 and NH4Cl are obtained from the mixture at a temperature of 200° C. to 1,000° C.
In an aspect of an embodiment of the present disclosure, wherein the method further comprises additionally heat-treating the obtained TiO2 powder.
In an aspect of an embodiment of the present disclosure, wherein, in the step of additionally heat-treating the TiO2 powder, the obtained TiO2 powder is heat-treated at a temperature of from 200° C. to 1,000° C.
Another aspect of a method for manufacturing TiO2 powder according to an embodiment of the present invention is a method for manufacturing TiO2 powder being: wherein TiO2 and NH4Cl are obtained from a mixture prepared by dissolving NH3 and TiCl4 captured from a residue after forming a TiN layer in a solvent, and TiO2 powder is separated therefrom.
An aspect of a method for TiO2 powder according to an embodiment of the present invention prepared by the method of any one of claims 1 to 13.
In a method for manufacturing TiO2 powder and TiO2 powder prepared thereby according to an embodiment of the present invention, TiO2 and NH4Cl are obtained from residual NH3 and TiCl4 that are discharged without reacting during the process of forming a Ti—N layer on a wafer, and TiO2 powder is separated therefrom. Therefore, according to an embodiment of the present invention, TiO2 powder can be produced by recycling the residual NH3 and TiCl4 that are discharged.
The patent or application file contains at least one drawing executed in color. Copies of this patent or patent application publication with color drawing(s) will be provided by the Office upon request and payment of the necessary fee.
Hereinafter, a method for manufacturing TiO2 powder according to an embodiment of the present invention will be described in more detail with reference to the drawings attached hereto.
The method for manufacturing TiO2 powder according to an embodiment of the present invention for achieving the above-described object comprises capturing NH3 and TiCl4 from a residue after forming a Ti—N layer; dissolving the NH3 and TiCl4 in a solvent to prepare a mixture; reacting the mixture to obtain TiO2 and NH4Cl; and separating the obtained TiO2 and NH4Cl to obtain TiO2 powder.
In a process of manufacturing a semiconductor forming a Ti—N layer, NH3 and TiCl4 are reacted on a wafer to form a Ti—N layer. The NH3 and TiCl4 discharged after forming the layer are captured to prepare TiO2 powder.
In the step of preparing the mixture, the solvent may be used to adjust the ratio of anatase or a mixed phase of anatase and rutile as the crystal structure of TiO2 prepared by dissolving the mixture of NH3 and TiCl4 by adjusting the acidity to be between-0.02 and 1. In particular, the color of the obtained TiO2 powder may be controlled by heat-treating the TiO2 having the rutile structure in a temperature range of from 200° C. to 800° C. When the temperature range is 1,000° C. or higher, the final obtained TiO2 powder structure may be changed to a rutile structure. In addition, the molar ratio of NH3 and TiCl4 to the solvent may be controlled to from 0.01:1 to 0.13:1, and the solvent comprises one selected from the group consisting of nitric acid, ammonia, hydrogen peroxide, hydrochloric acid, and combinations thereof.
The step of preparing the mixture may comprise using a hydration reaction or a high-pressure reaction for solid-liquid separation. The hydration reaction may be performed at a temperature of from 25° C. to 100° C. The size of the TiO2 particles generated in the room temperature range is in the range of from 2 nm to 10 nm. The size of the particles generated in a NH4Cl solution is actually very small, which is because NH4Cl inhibits the growth of the particles. When TiO2 is generated, the size of the crystal particles maintains a nano size. However, they may be produced to form aggregates and be filtered depending on the heating temperature. Therefore, if the aggregates are formed to a certain size and then filtered and crushed to form particles, the size of the particles may be formed to be about 10 nm. The ammonia generated in the present invention may inhibit the growth of TiO2 particles and, thus, is recovered as NH4Cl.
Meanwhile, since the size of the particles prepared in the hydration reaction is very small, a high-pressure reaction may be used as a method of coagulating them to facilitate filtering. The temperature range of the high-pressure reaction may be 25° C. to 350° C., and the pressure range may be 1 bar to 10 bar. The TiO2 powder prepared to have a large particle size by controlling the temperature and pressure conditions as described above may be filtered and separated into solid and liquid.
The particle size may be controlled to 10 nm to 500 nm by heat-treating a mixture that has undergone a hydration reaction or a high-pressure reaction at a temperature of from 300° C. to 1,100° C. for 10 to 120 minutes.
In addition, TiO2 having a 100% rutile crystal structure may be produced into a yellow dye by additionally heat-treating TiO2 at 300° C. to 1,000° C. In particular, yellow dyes at various concentrations may be obtained depending on the temperature range.
The TiO2 powder produced from the above-described preparation method may be obtained as nanoparticles, and the size of the nanoparticle powder may be in the range of from 10 nm to 20 nm.
Hereinafter, preparation examples and experimental examples of the present invention are described. However, these preparation examples and experimental examples are intended to explain the constitution and effect of the present invention more specifically, and the scope of the present invention is not limited thereto.
NH3 and TiCl4 discharged from a reaction device after forming a TiN layer were condensed in a trap and captured as a mixture. Ultrapure water was added as a solvent to the mixture of the condensed NH3 and TiCl4 in a molar ratio of from 1:0.01 to 0.13 and mixed. The mixture was dissolved by heating at 45° C. for 2 hours. The dissolved mixture was obtained by forming TiO2 and NH4Cl at room temperature and pressure. The formed TiO2 and NH4Cl were first separated by using a filter, and then the TiO2 powder and NH4Cl were subjected to a second solid-liquid separation.
TiO2 powder was prepared in the same manner as in Preparation Example 1 above, but the heating conditions were changed to 70° C. for 1.5 hours.
TiO2 powder was prepared in the same manner as in Preparation Example 1 above, but the heating conditions were changed to 90° C. for 2 hours.
TiO2 powder was prepared in the same manner as in Preparation Example 1 above, but the conditions for first heating were 70° C. for 1 hour and 20 minutes, and the conditions for second heating were 90° C. for 2 hours.
TiO2 powder was prepared in the same manner as in Preparation Example 1 above, but the conditions for first heating were 50° C. for 1 hour and 20 minutes, and the conditions for second heating were 90° C. for 2 hours.
TiO2 powder was prepared in the same manner as in Preparation Example 1 above, but the heating conditions were changed to 800° C. for 0.5 hour.
TiO2 powder was prepared in the same manner as in Preparation Example 1 above, but the heating conditions were changed to 600° C. for 1 hour.
NH3 and TiCl4 discharged from a reaction device after forming a TiN layer were condensed in a trap and captured as a mixture. Ultrapure water was added as a solvent to the mixture of the condensed NH3 and TiCl4 in a molar ratio of from 1:0.01 to 0.13 and mixed. The mixture was dissolved by reaction at 150° C. and 4 bar. The dissolved mixture was heated at 150° C. and 4 bar for 180 minutes to form TiO2 and NH4Cl. The formed TiO2 and NH4Cl were first separated by using a filter, and then the TiO2 powder and NH4Cl were subjected to a second solid-liquid separation.
NH3 and TiCl4 discharged from a reaction device after forming a TiN layer were condensed in a trap and captured as a mixture. Ultrapure water was added as a solvent to the mixture of the condensed NH3 and TiCl4 in a molar ratio of from 1:0.01 to 0.13 and mixed. The conditions for obtaining TiO2 and NH4Cl were the same as those for Preparation Examples 1 to 3, 6 and 7. The TiO2 was obtained by controlling the particle size of TiO2 by heating the mixture for 20 to 180 minutes under the temperature conditions of Table 1 below.
NH3 and TiCl4 discharged from a reaction device after forming a TiN layer were condensed in a trap and captured as a mixture. Ultrapure water was added as a solvent to the mixture of the condensed NH3 and TiCl4 in a molar ratio of from 1:0.1 to 0.25, and mixed. The mixture was reacted at 25 to 130° C. and 1 to 4 bar for 30 to 180 minutes to obtain TiO2 and NH4Cl. Thereafter, NH4Cl was separated from the formed TiO2 by using a filter, and then the TiO2 powder was subjected to solid-liquid separation. The obtained TiO2 powder was additionally heat-treated at a temperature range of from 300° C. to 800° C. for 30 to 120 minutes to prepare yellow dyes having various concentrations.
NH3 and TiCl4 discharged from a reaction device after forming a TiN layer were condensed in a trap and captured as a mixture. Ultrapure water was added as a solvent to the mixture of the condensed NH3 and TiCl4 in a molar ratio of from 0.02:1 and mixed. The mixture was heated and reacted at 25 to 130° C. and 1 to 3 bar for 120 minutes to obtain TiO2 and NH4Cl. The TiO2 and NH4Cl formed at this time were first separated by using a filter, and then the TiO2 powder and NH4Cl were subjected to a second solid-liquid separation. The obtained TiO2 powder was additionally heat-treated at a temperature range of from 200° C. to 1,000° C. for 30 to 120 minutes to stabilize the crystal structure and control the crystal structures of anatase and a mixed phase of anatase and rutile to prepare TiO2 powder.
Table 2 below shows the results of analyzing the size (nm) of X-RD particles according to the Scherrer Equation of Preparation Examples 1 to 5.
The size of the particles prepared in a NH4Cl solution is actually very small, which is because NH4Cl inhibits the growth of particles. Therefore, aggregates were formed to a certain size, followed by crushing, to prepare particles such that the particle size was about 10 nm.
| Number | Date | Country | Kind |
|---|---|---|---|
| 10-2023-0162336 | Nov 2023 | KR | national |
