TWI650454B - Antibacterial composite fiber and method of producing the same - Google Patents

Abstract

The present invention relates to an antibacterial composite fiber and a method of producing the same. The antibacterial composite fiber comprises titanium dioxide photocatalyst fiber and cellulose nanofiber. Among them, the cellulose nanofibers are wound on the titanium dioxide photocatalyst fibers. The antibacterial composite fiber of the present invention has a good antibacterial effect under irradiation of visible light and/or ultraviolet light.

Description

Antibacterial composite fiber and manufacturing method thereof

The present invention relates to a composite fiber, and more particularly to an antimicrobial composite fiber which can be catalyzed by visible light and/or ultraviolet light.

Titanium dioxide materials have the advantages of photocatalysis, good thermal stability and chemical stability, high specific surface area and no harm to the environment. Therefore, titanium dioxide materials are widely used in antibacterial and/or bactericidal surface coating, solar cells, photovoltaic materials, photocatalysts and sensations. Applications such as detectors. Among them, after photocatalytic catalysis, titanium dioxide materials are often used in the field of self-cleaning and antibacterial because of the high oxidation activity of titanium dioxide materials. Generally, the titanium dioxide material has a high energy gap, so the titanium dioxide material must be catalyzed by irradiation with ultraviolet light to make it oxidizing. However, the ultraviolet light region (wavelength less than 400 nm) of daily sunlight is about 4% to 5%, the visible light region (wavelength is 400 nm to 750 nm) is about 43%, and the infrared light region (wavelength is greater than 750 nm) is about 52%. Therefore, under the irradiation of sunlight, generally, the titanium dioxide material is less catalyzed, and its oxidation activity is lower.

In order to effectively expand the light absorption range of titanium dioxide materials and improve their catalytic efficiency, a conventional technique is to use vanadium, chromium, manganese, iron, cobalt, and nickel. A metal element such as copper is doped into the titanium dioxide material to shift the light absorption range of the titanium dioxide material from the ultraviolet light region to the visible light region. However, the metal element is not easily and uniformly dispersed in the titanium dioxide material, and it is difficult to effectively increase the light absorption ability and catalytic efficiency of the titanium dioxide material. Another conventional technique is to fabricate titanium dioxide material into nano-sized titanium dioxide particles by nano-powder technology to increase the ratio of surface area to volume and improve the efficiency of photocatalytic action. However, the nano-sized titanium dioxide particles are easily agglomerated and are not easily dispersed on the carrier.

The recent technology is based on a high-pressure environment in which the absorption wavelength of the prepared titanium dioxide material is extended from the ultraviolet region to the visible region by a long-term calcination treatment. However, long-term high pressure treatment makes the reaction difficult to control and requires a lot of energy.

In addition, the titanium dioxide material is generally adhered to the substrate by an adhesive to expand its antibacterial application. However, as the use time increases, the adhesive is easily oxidized and decomposed by the titanium dioxide material, and loses the viscosity, thereby causing the titanium dioxide material to peel off. If too much adhesive is used, the titanium dioxide material is easily covered, and the catalytic performance of the titanium dioxide material is lowered. If too little adhesive is used, the titanium dioxide material cannot be effectively fixed on the substrate.

In view of the above, it is not necessary to provide an antibacterial composite fiber and a method of manufacturing the same to improve the defects of the conventional antibacterial composite fiber and the method of manufacturing the same.

Accordingly, an aspect of the present invention provides an antibacterial composite fiber in which titanium dioxide photocatalyst fibers are attached to cellulose nanofibers by winding titanium dioxide photocatalyst fibers with cellulose nanofibers.

Next, another aspect of the present invention provides a method for producing an antibacterial composite fiber, which can produce the aforementioned antibacterial composite fiber.

According to an aspect of the invention, an antibacterial composite fiber is proposed. The antibacterial composite fiber comprises titanium dioxide photocatalyst fiber and cellulose nanofiber. The cellulose nanofibers are wound on the titanium dioxide photocatalyst fibers. Wherein, the content of the cellulose nanofibers is 100% by weight, and the content of the titanium dioxide photocatalyst fibers is more than 2% by weight but not more than 90% by weight. The absorption wavelength of the antibacterial composite fiber includes visible light and ultraviolet light.

According to an embodiment of the present invention, the antibacterial composite fiber further comprises a porous support, and the antibacterial composite fiber is supported on the porous support.

According to another embodiment of the present invention, the titanium dioxide photocatalyst fiber has an aspect ratio of from 1 to 10.

According to still another embodiment of the present invention, the cellulose nanofiber has a length of from 100 nm to 1000 nm and a diameter of not more than 100 nm.

According to still another embodiment of the present invention, the antimicrobial composite fiber may optionally comprise at least one metal element, and the metal element is attached to the cellulose nanofiber. The at least one metal element is used in an amount of from 0.001% by weight to 50% by weight based on the content of the cellulose nanofibers of 100% by weight.

According to still another embodiment of the present invention, the foregoing metal element may include, but is not limited to, tungsten, rhenium, magnesium, silver, palladium, platinum, zinc, ruthenium, osmium or iridium.

According to another aspect of the present invention, a method of producing an antimicrobial composite fiber is proposed. This manufacturing method first provides titanium dioxide powder, and this titanium oxide powder is dispersed in an aqueous sodium hydroxide solution to form a mixed solution. Then, the mixed solution is subjected to a high temperature reaction to obtain a fiber preform. Next, the fiber pre-product is subjected to pickling treatment, and the acid-washed intermediate product is subjected to calcination treatment to obtain a titanium dioxide photocatalyst fiber. Thereafter, the cellulose nanofibers are wound on the titanium dioxide photocatalyst fibers to obtain an antibacterial composite fiber. The content of the titanium dioxide photocatalyst fiber is more than 2% by weight but not more than 90% by weight based on the cellulose nanofiber content of 100% by weight.

According to an embodiment of the present invention, the step of winding the cellulose nanofibers on the titanium dioxide photocatalyst fibers comprises adding at least one metal element to mix and obtain the antibacterial composite fibers. The at least one metal element is used in an amount of from 0.001% by weight to 50% by weight based on the content of the cellulose nanofibers of 100% by weight.

According to another embodiment of the present invention, the foregoing metal element may include, but is not limited to, tungsten, rhenium, magnesium, silver, palladium, platinum, zinc, ruthenium, osmium or iridium.

According to still another embodiment of the present invention, the calcining treatment is carried out in a mixed gas, and the mixed gas contains hydrogen and nitrogen, or contains ammonia and nitrogen.

According to still another embodiment of the present invention, the amount of hydrogen or ammonia used is from 1% to 50% based on the amount of nitrogen used.

The antibacterial composite fiber of the present invention and a method for producing the same are used to fix titanium dioxide photocatalyst fibers by winding titanium dioxide photocatalyst fibers with cellulose nanofibers. Secondly, the light absorption wave of the antibacterial composite fiber of the present invention The invention covers visible light and ultraviolet light, so that the antibacterial composite fiber of the present invention can be effectively catalyzed under the irradiation of visible light and/or ultraviolet light, and has an antibacterial effect.

100‧‧‧ method

110‧‧‧Steps for providing titanium dioxide powder

120‧‧‧Steps of dispersing titanium dioxide powder in aqueous sodium hydroxide solution

130‧‧‧Steps for high temperature reaction

140‧‧‧Steps for pickling

150‧‧‧Steps of calcining to produce titanium dioxide photocatalyst fibers

160‧‧‧Steps of mixing titanium dioxide photocatalyst fiber and cellulose nanofiber

170‧‧‧Steps for making antibacterial composite fibers

For a more complete understanding of the embodiments of the invention and the advantages thereof, reference should be made to the description below and the accompanying drawings. It must be emphasized that the various features are not drawn to scale and are for illustrative purposes only. The related drawings are described as follows: [Fig. 1] is a flow chart showing a method of manufacturing an antibacterial composite fiber according to an embodiment of the present invention.

Fig. 2 is a scanning electron micrograph showing the antibacterial composite fiber of Example 3-2 according to the present invention.

The making and using of the embodiments of the invention are discussed in detail below. However, it will be appreciated that the embodiments provide many applicable inventive concepts that can be implemented in a wide variety of specific content. The specific embodiments discussed are illustrative only and are not intended to limit the scope of the invention.

Please refer to FIG. 1 , which is a flow chart showing a method for manufacturing an antibacterial composite fiber according to an embodiment of the present invention. The method 100 is to first provide titanium dioxide powder and disperse the titanium dioxide powder in an aqueous sodium hydroxide solution to form a mixed solution, as shown in steps 110 and 120. Wherein, the crystalline phase of the titanium dioxide powder is anatase, and the concentration of sodium hydroxide is 0.1M to 20M. After the titanium dioxide powder is uniformly dispersed in the sodium hydroxide solution, the mixed solution is placed in an autoclave and subjected to a high temperature reaction to obtain a fiber preform, as shown in step 130. The temperature of the high temperature reaction may be from 100 ° C to 200 ° C. When the titanium dioxide solution is subjected to a high temperature reaction, the surface morphology of the titanium dioxide powder is changed to a fibrous shape or a rod shape. If the temperature of the high temperature reaction is greater than 200 ° C, the formed pre-product will be nano-sized particles, and the fibrous or rod-shaped pre-product cannot be formed. If the temperature of the high temperature reaction is less than 100 ° C, the surface morphology of the titanium dioxide powder is not easily changed to a fibrous shape or a rod shape. In one embodiment, the temperature of the high temperature reaction is preferably from 120 ° C to 180 ° C.

After the high temperature reaction is completed, the fiber preform obtained is subjected to pickling treatment to form an intermediate product, as shown in step 140. The pickling treatment adds the aforementioned fiber preform to an aqueous hydrochloric acid solution to pickle the fiber preform with an aqueous hydrochloric acid solution and remove surface defects of the fiber preform. Among them, the fiber after the pickling treatment is further washed with deionized water, and after being washed to neutral, the sodium titanate nanofiber (that is, the aforementioned intermediate product) can be obtained. In one embodiment, the concentration of the aqueous hydrochloric acid solution may be from 0.1 M to 10 M, and the soaking time of the pickling treatment may be from 1 hour to 24 hours.

After performing step 140, the intermediate product formed is subjected to a calcining treatment to obtain a titanium dioxide photocatalyst fiber, as shown in step 150. In the simmering treatment, the smoldering gas is introduced, and the sodium titanate nanofiber described above is reduced by simmering. In one embodiment, the calcining gas may comprise a mixed gas of hydrogen/nitrogen, a mixed gas of ammonia/nitrogen, other suitable mixed gases, or any mixture of the above gases. In one embodiment, in the foregoing mixed gas, the amount of use based on nitrogen is 100%, and the amount of hydrogen or ammonia used may be 1%. Up to 50%. In one embodiment, the titanium dioxide photocatalyst fibers produced may be fibrous or rod shaped. In one embodiment, the titanium dioxide photocatalyst fibers produced may have an aspect ratio of from 1 to 10, and preferably from 3 to 5. In one embodiment, the titanium dioxide photocatalyst fibers may be from 100 nm to 1000 nm in length and have a diameter of no greater than 100 nm.

After performing step 150, the titanium dioxide photocatalyst fiber and the cellulose nanofiber prepared as described above are mixed to form a composite fiber slurry, and after drying, the antibacterial composite fiber of the present invention can be obtained, as in steps 160 and 170. Shown. The absorption wavelength of the prepared antibacterial composite fiber includes visible light (wavelength ranging from 400 nm to 700 nm) and ultraviolet light (wavelength ranging from 200 nm to 400 nm). The content of the titanium dioxide photocatalyst fiber is more than 2% by weight but not more than 90% by weight based on the cellulose nanofiber content of 100% by weight. In one embodiment, the content of the titanium dioxide photocatalyst fibers is preferably greater than 5% by weight but not greater than 30% by weight, and more preferably greater than 5% by weight but not greater than 10% by weight.

In step 160, when the titanium dioxide photocatalyst fiber and the cellulose nanofiber are mixed, the cellulose nanofiber is extended on the titanium dioxide photocatalyst fiber by the extending direction of the titanium dioxide photocatalyst fiber, and has good properties with the titanium dioxide photocatalyst fiber. Fixation. Accordingly, if the aspect ratio of the titanium dioxide photocatalyst fiber is less than 1 (that is, the length of the titanium dioxide photocatalyst fiber is too short, or the diameter of the titanium dioxide photocatalyst fiber is too long), since the too short titanium dioxide photocatalyst fiber has less winding space, The cellulose nanofibers are not easily entangled thereon, or the oversized titanium dioxide photocatalyst fibers tend to make the cellulose nanofibers less likely to wrap around. If When the aspect ratio of the titanium dioxide photocatalyst fiber is greater than 10 (that is, the length of the titanium dioxide photocatalyst fiber is too long, or the diameter of the titanium dioxide photocatalyst fiber is too short), although the excessively long titanium dioxide photocatalyst fiber has more winding space, it is too long or too thin. The titanium dioxide photocatalyst fiber is easily broken and damaged, and the strength of the antibacterial composite fiber prepared subsequently is reduced.

When step 160 is carried out, due to the attraction between the titanium dioxide photocatalyst fiber and the cellulose nanofiber, the cellulose nanofiber can be entangled on the titanium dioxide photocatalytic fiber by the attraction force during mixing.

In one embodiment, the foregoing step 160 may optionally include adding at least one metal element to the titanium dioxide photocatalyst fiber and the cellulose nanofiber to mix and prepare the antibacterial composite fiber. The order of addition of the titanium dioxide photocatalyst fiber, the cellulose nanofiber, and the metal element is not particularly limited. Due to the influence of the electrostatic attraction between the metal atom and the surface group of the aforementioned cellulose nanofiber, the metal element can be uniformly attached to the cellulose nanofiber during the mixing process. At the same time, the metal element can be uniformly attached to the cellulose nanofiber before the winding occurs or after the winding occurs. In other words, as the cellulose nanofibers are entangled on the titanium dioxide photocatalyst fibers, the metal elements can be uniformly distributed in the prepared antimicrobial composite fibers. When the antibacterial composite fiber contains a metal element, the antibacterial composite fiber obtained under the irradiation of visible light and/or ultraviolet light can have both antibacterial and bactericidal effects. For example, the foregoing metal elements may include, but are not limited to, tungsten, ruthenium, magnesium, silver, palladium, platinum, zinc, ruthenium, osmium, iridium, other suitable metal elements or any combination of the above.

In one embodiment, after forming the conjugate fiber slurry described above, the conjugate fiber slurry may be applied to the porous support or mixed with the porous support. Accordingly, when the composite fiber slurry is dried, the antibacterial composite fiber formed by the slurry can be carried on the porous support. In an embodiment, the porous support may be an organic porous material, an inorganic porous material, or any combination of the two. In this embodiment, the total amount of the cellulose nanofibers and the porous support is 100% by weight, and the cellulose nanofibers are used in an amount of more than 0 and less than 100% by weight.

In another embodiment, after forming the composite fiber slurry, the composite fiber slurry can be coated into a film or made into a suitable form by a suitable method. Accordingly, when the fiber slurry is dried, an antibacterial film or an antibacterial material having other appearances can be formed.

In one embodiment, the absorption wavelength of the antibacterial composite fiber produced by the present invention may include visible light and ultraviolet light. Therefore, under the irradiation of visible light and/or ultraviolet light, the antibacterial composite fiber of the invention has good light absorption ability and catalytic efficiency, and can achieve an antibacterial effect.

In another embodiment, when the antibacterial composite fiber of the present invention contains a metal element, the antibacterial composite fiber of the present invention can have both antibacterial and bactericidal effects under irradiation of visible light and/or ultraviolet light.

The following examples are used to illustrate the application of the present invention, and are not intended to limit the present invention, and various modifications and refinements can be made without departing from the spirit and scope of the invention.

Preparation of titanium dioxide photocatalyst fiber Preparation Example 1-1

First, anatase titanium dioxide powder is added to an aqueous sodium hydroxide solution having a concentration of 0.1 M to 20 M. After the mixture is uniformly mixed, the mixed solution is placed in an autoclave and heated to 100 ° C to 200 ° C to change the titanium oxide powder into a fibrous shape or a rod shape. After the high temperature reaction is completed, the obtained titania fiber is pickled with an aqueous hydrochloric acid solution having a concentration of 0.1 M to 10 M, and the titanium dioxide fiber is immersed in an aqueous hydrochloric acid solution. After 1 hour to 24 hours, the solid product is filtered and dried to obtain a sodium titanate nanofiber. Next, the sodium titanate nanofibers were calcined at 300 ° C to 1000 ° C to obtain a titanium dioxide photocatalyst fiber of Preparation Example 1-1.

Ultraviolet light test

The antibacterial composite fiber film of Example 1-1 and Example 1-2 and Comparative Example 1-1 and Comparative Example 1-2 was prepared according to the first table, and the obtained antibacterial composite fiber film was irradiated with ultraviolet light.

Example 1-1

100% by weight of cellulose nanofibers and 5% by weight of the titanium dioxide photocatalyst fiber of Preparation Example 1-1 were mixed to prepare a mixed solution. Then, the mixed solution was poured into a Petri dish. After standing to dry, the antibacterial composite fiber film of Example 1-1 was obtained.

Next, an appropriate concentration of Escherichia coli was dropped on the blank medium and the antibacterial composite fiber film of Example 1-1, and the number of colonies was analyzed by a known technique. Irradiating the blank medium and the antibacterial composite fiber film External light, and after the fixed illumination time, analyze the number of colonies. The results obtained are shown in Table 1.

Example 1-2 and Comparative Example 1-1 and Comparative Example 1-2

Each of Example 1-2 and Comparative Example 1-1 and Comparative Example 1-2 was prepared in the same manner as in the production method of the antibacterial composite fiber film of Example 1-1 except that Example 1-2 and comparison were carried out. In Example 1-1 and Comparative Example 1-2, the type and amount of the titanium dioxide photocatalyst fiber were changed. Among them, Comparative Example 1-1 uses a conventional titanium dioxide photocatalytic fiber capable of absorbing only ultraviolet light (i.e., Preparation Example 2-1), and Comparative Example 1-2 uses a titanium dioxide photocatalytic fiber of the type P25 (produced by Degussa Co., Ltd.). That is, Preparation Example 2-2).

Next, the titanium dioxide photocatalyst fiber film prepared in Example 1-2 and Comparative Example 1-1 and Comparative Example 1-2 and the corresponding blank medium thereof were irradiated with ultraviolet light, respectively, and the respective blanks were calculated after the fixed illumination time. The number of colonies. The results obtained are shown in Table 1.

Visible light test

The antibacterial composite fiber films of Example 2-1 and Example 2-2 and Comparative Example 2-1 and Comparative Example 2-2 were prepared according to the second table, and the obtained antibacterial composite fiber film was irradiated with visible light.

Example 2-1

100% by weight of cellulose nanofibers and 5% by weight of the titanium dioxide photocatalyst fiber of Preparation Example 1-1 were mixed to prepare a mixed solution. Then, the mixed solution was poured into a Petri dish. After standing to dry, the antibacterial composite fiber film of Example 2-1 was obtained.

Next, an appropriate concentration of Escherichia coli was dropped on the blank medium and the antibacterial composite fiber film of Example 2-1, and the number of colonies was analyzed by a known technique. The blank medium and the antibacterial composite fiber film were irradiated with visible light, and the number of colonies was analyzed after a fixed illumination time. The results obtained are shown in Table 2.

Example 2-2 and Comparative Example 2-1 and Comparative Example 2-2

In Example 2-2, Comparative Example 2-1, and Comparative Example 2-2, the same preparation method as that of the antibacterial composite fiber film of Example 2-1 was used, except that Example 2-2 and comparison were made. In Example 2-1 and Comparative Example 2-2, the type and amount of the titanium dioxide photocatalyst fiber were changed.

Next, the titanium dioxide photocatalytic fiber film obtained in Example 2-2, Comparative Example 2-1, and Comparative Example 2-2 and the corresponding blank medium thereof were irradiated with visible light, respectively, and the respective blanks were calculated after the fixed illumination time. The number of colonies. The results obtained are shown in Table 2.

Carrier test

The antibacterial composite fiber film of Example 3-1 to Example 3-3 and Comparative Example 3-1 was prepared according to Table 3 below.

Example 3-1

Cellulose nanofibers and 5 wt% of the titanium dioxide photocatalyst fiber of Preparation Example 1-1 were mixed to prepare a mixed solution. Then, the mixed solution was poured into a Petri dish. After standing to dry, the antibacterial composite fiber film of Example 3-1 was obtained.

Next, an appropriate concentration of Escherichia coli was dropped on the blank medium and the antibacterial composite fiber film of Example 3-1, and the number of colonies was analyzed by a known technique. The blank medium and the antibacterial composite fiber film were irradiated with ultraviolet light, and the number of colonies was analyzed after the fixed illumination time. The results obtained are shown in Table 3.

Example 3-2 and Example 3-3

The production methods of the antibacterial composite fiber film of Example 3-1 were the same as those of Example 3-2 and Example 3-3, respectively, except that Example 3-2 and Example 3-3 were changed. The amount of titanium dioxide photocatalyst fiber used.

Next, the titanium dioxide photocatalyst fiber film prepared in Example 3-2 and Example 3-3 and the corresponding blank medium were irradiated with ultraviolet light, respectively, and the number of individual colonies was calculated after the fixed illumination time. The results obtained are shown in Table 3.

Comparative Example 3-1

In Comparative Example 3-1, 10% by weight of the titanium dioxide photocatalyst fiber of the above Preparation Example 1-1 was attached to a paper fiber carrier with an adhesive to obtain an antibacterial composite fiber film of Comparative Example 3-1.

Next, an appropriate concentration of Escherichia coli was dropped on the blank medium and the antibacterial composite fiber film of Comparative Example 3-1, and the number of colonies was analyzed by a known technique. The blank medium and the antibacterial composite fiber film were irradiated with ultraviolet light, and the number of colonies was analyzed after the fixed illumination time. The results obtained are shown in Table 3.

According to the results of Tables 1 and 2, the antibacterial composite fiber of the present invention can be effectively catalyzed by ultraviolet light or visible light, and has an antibacterial effect.

Secondly, when the antibacterial composite fiber of the present invention contains a metal element, the antibacterial composite fiber can have both antibacterial and bactericidal effects under the irradiation of visible light and/or ultraviolet light.

According to the results of the third table, the antibacterial composite fiber films of Examples 3-1 to 3-3 of the present invention can reduce the number of Escherichia coli bacteria to 10 or less after 24 hours of illumination. However, in Comparative Example 3-1, since the titanium dioxide photocatalyst fiber could not be fixed to the paper fiber, the titanium dioxide photocatalyst fiber of Comparative Example 3-1 had to be attached to the paper fiber carrier with an adhesive. Accordingly, the titanium dioxide photocatalyst fiber of Comparative Example 3-1 was covered with an adhesive, and was not effectively catalyzed by ultraviolet light, so that the antibacterial effect could not be achieved.

Further, referring to Fig. 2, there is shown a scanning electron micrograph of the antibacterial composite fiber according to Example 3-2 of the present invention, wherein the length of the scale ruler represents 200 nm. As can be seen from Fig. 2, the cellulose nanofiber of the present invention can form a paper substrate, and the titanium dioxide photocatalyst fiber can be fixed to the paper substrate formed by the cellulose nanofiber. Accordingly, in the antibacterial composite fiber of the present invention, the titanium dioxide photocatalyst fiber can be fixed to the substrate without using an adhesive. The antibacterial composite fiber of the present invention also has a good antibacterial effect and can be used as an antibacterial paper.

The present invention has been disclosed in the above embodiments, and is not intended to limit the present invention. Any one of ordinary skill in the art to which the present invention pertains can make various changes without departing from the spirit and scope of the invention. And the scope of the present invention is defined by the scope of the appended claims.

Claims (10)

An antibacterial composite fiber comprising: titanium dioxide photocatalyst fiber, wherein the titanium dioxide photocatalyst fiber has an aspect ratio of 1 to 10; and a cellulose nanofiber wound on the titanium dioxide photocatalyst fiber, and wherein the cellulose nanofiber is based thereon The content of the titanium dioxide photocatalyst fiber is more than 2 wt% but not more than 90 wt%, and the absorption wavelength of the antibacterial composite fiber includes visible light and ultraviolet light. The antibacterial composite fiber according to claim 1, further comprising: a porous support, wherein the antibacterial composite fiber is supported on the porous support. The antibacterial composite fiber according to claim 1, wherein the cellulose nanofiber has a length of from 100 nm to 1000 nm and a diameter of not more than 100 nm. The antibacterial composite fiber according to claim 1, further comprising: at least one metal element attached to the cellulose nanofiber, wherein the content of the cellulose nanofiber is 100% by weight, the at least one metal The element is used in an amount of from 0.001% by weight to 50% by weight. The antibacterial composite fiber according to claim 4, wherein the at least one metal element is selected from the group consisting of tungsten, ruthenium, magnesium, silver, palladium, platinum, zinc, ruthenium, osmium, iridium, and any combination thereof. Form a group of people. A method for producing an antibacterial composite fiber, comprising: providing a titanium dioxide powder, wherein one of the titanium dioxide powders has an anatase; dispersing the titanium dioxide powder in an aqueous sodium hydroxide solution to form a mixed solution; Reacting at a high temperature to obtain a fiber pre-product; subjecting the fiber pre-product to a pickling treatment to form an intermediate product; subjecting the intermediate product to a calcining treatment to obtain a titanium dioxide photocatalyst fiber, wherein the titanium dioxide photocatalyst fiber The aspect ratio is 1 to 10; and the cellulose nanofiber is wound on the titanium dioxide photocatalyst fiber to obtain the antibacterial composite fiber, wherein the titanium dioxide photocatalyst is based on the content of the cellulose nanofiber being 100 wt% The fiber content is greater than 2% by weight but not greater than 90% by weight. The method for producing an antibacterial composite fiber according to claim 6, wherein the step of winding the cellulose nanofiber on the titanium dioxide photocatalyst fiber comprises: The antibacterial composite fiber is obtained by adding at least one metal element, wherein the content of the cellulose nanofiber is 100 wt%, and the at least one metal element is used in an amount of 0.001 wt% to 50 wt%. The method for producing an antibacterial composite fiber according to claim 7, wherein the at least one metal element is selected from the group consisting of tungsten, lanthanum, magnesium, silver, palladium, platinum, zinc, lanthanum, cerium, lanthanum, and the like. A group consisting of any combination. The method for producing an antibacterial composite fiber according to claim 6, wherein the calcining treatment is carried out in a mixed gas comprising hydrogen gas and nitrogen gas or ammonia gas and nitrogen gas. The method for producing an antibacterial composite fiber according to claim 9, wherein the amount of the hydrogen gas or the ammonia gas used is 1% to 50% based on the amount of the nitrogen gas used.