CN115845849A - Ferrous ion doped black titanium dioxide nanosheet and preparation method thereof - Google Patents

Abstract

The invention relates to a ferrous ion doped black titanium dioxide material and a preparation method thereof. The ferrous ion doped black titanium dioxide (TiO) _2‑x ‑Fe ²⁺ The material has a nano-sheet structure, the particle size is 30-1000 nm ²⁺ The doping amount of (A) is 1-5 wt%. The preparation method comprises the following steps: 1) Tetrabutyl titanate, hydrogen fluoride and water are evenly mixed and subjected to hydrothermal reaction to obtain TiO ₂ A nanosheet; 2) Mixing the above TiO with a solvent ₂ Dispersing nanosheets, dopamine hydrochloride and ammonia water in a mixed solvent of water and ethanol by ultrasonic waves, and stirring at room temperature to obtain TiO ₂ -a polydopamine material; 3) Mixing the above TiO with a solvent ₂ -polydopamine material dispersed in FeCl ₃ Stirring overnight in the aqueous solution to obtain TiO ₂ poly-dopamine-Fe ³⁺ A material; 4) Mixing the above TiO with a solvent ₂ poly-dopamine-Fe ³⁺ Annealing the material in air to obtain TiO _2‑x ‑Fe ³⁺ A material; 5) Mixing the above TiO with a solvent ₂ ‑Fe ³⁺ Annealing the material in a mixed gas of hydrogen and argon to obtain TiO _2‑x ‑Fe ²⁺ A material. The TiO provided by the invention _2‑x ‑Fe ²⁺ The material can generate a large amount of active oxygen free radicals with cytotoxicity in cancer cells, and has the potential of being applied to the preparation of antitumor drugs.

Description

A kind of black titanium dioxide nanosheet doped with ferrous iron ion and preparation method thereof

technical field

The invention belongs to the technical field of nanometer materials, and relates to a black titanium dioxide nanosheet material doped with divalent iron ions and a preparation method thereof.

Background technique

Titanium dioxide (TiO ₂ ) nanoparticles are a typical inorganic semiconductor material, which can generate cytotoxic active oxygen radicals with the assistance of light/acoustics, and have important applications in biomedical fields such as tumor treatment. In recent years, scholars have discovered that a new type of nanomaterial TiO _2-x can be obtained after chemical reduction of TiO ₂ . The surface of TiO _2-x is rich in Ti ³⁺ and oxygen vacancies (O _V ), which can not only generate •OH through Fenton-like catalytic reactions, but also generate •OH and ¹ O ₂ with the aid of light/acoustic. TiO _2-x has attracted much attention in recent years due to its stronger catalytic activity and photo/acoustic response than TiO ₂ . At present, TiO _2-x is mainly used in photo/acoustic dynamic therapy in anti-tumor applications, because the Fenton-like catalytic performance of TiO _2-x alone is still not enough to kill cancer cells. In these treatment schemes, the antitumor effect of TiO _2-x is usually limited by many conditions such as excitation light penetration depth or insufficient oxygen content in the tumor site. Therefore, it is urgent and necessary to enhance the Fenton-like catalytic performance of TiO2 _-x , which is expected to make up for the deficiency of light/acoustic assisted therapy.

Metal doping is a common approach to enhance the performance of Fenton-like catalysts. For example, it has been reported in the literature that ferric ion (Fe ³⁺ ) metal salt is added to a titanium-containing precursor, and a Fe ³⁺ -doped white TiO ₂ is obtained through co-hydrolysis. Fe ³⁺ doping enables the formation of oxygen vacancies in the titania lattice. Both Fe ³⁺ and oxygen vacancies can be used as the catalytic active sites of H ₂ O ₂ , and jointly improve the catalytic performance. Therefore, the development of new technologies for preparing such materials is of great scientific significance for the application of non-light/acoustic-assisted tumor therapy.

Contents of the invention

The purpose of the present invention is to provide a black titanium dioxide nanosheet doped with ferrous ions and its preparation method. The nanosheet material has strong catalytic ability and can produce a large amount of active oxygen free radicals with cytotoxicity in cancer cells. Potential for preparing anticancer drugs.

The concrete technical scheme that realizes the object of the invention is:

The invention provides a black titanium dioxide nanosheet doped with divalent iron ions. The nanosheet component is TiO _2-x -Fe ²⁺ . In the nanosheet structure, the ferrous iron in the TiO _2-x lattice The doping amount of ions, that is, Fe ^{2+ ,} is 1-5 wt%; the diameter of the nanosheets is 30-1000 nm; wherein, X=0.01-0.07.

The invention provides a method for preparing black titanium dioxide nanosheets doped with ferrous ions, the method specifically comprising the following steps:

Step 1: Mix tetrabutyl titanate, hydrogen fluoride, and water evenly, and after a hydrothermal reaction, collect the precipitate by centrifugation; then wash and dry to obtain white TiO ₂ nanosheets;

Step 2: ultrasonically disperse the _TiO2 nanosheets and dopamine hydrochloride obtained in step 1 in a mixed solvent of water and absolute ethanol, and add 25-28 wt% concentrated ammonia water dropwise under rapid stirring; after the reaction, collect the nanosheets by centrifugation ; followed by washing with water and absolute ethanol three times respectively, and drying to obtain a TiO ₂ -polydopamine composite material;

Step 3: ultrasonically disperse the TiO ₂ -polydopamine composite material and FeCl ₃ •6H ₂ O obtained in step 2 in water, and stir overnight; collect by centrifugation, wash with water and absolute ethanol for 3 times, and dry to obtain TiO ₂ -polydopamine - Fe ³⁺ composite material;

Step 4: Put the TiO ₂ -polydopamine-Fe ³⁺ obtained in Step 3 in a corundum porcelain boat, and anneal in air to obtain a TiO _2-x -Fe ³⁺ composite material;

Step 5: Put the TiO _2-x -Fe ³⁺ obtained in step 4 in a corundum porcelain boat, and anneal in a mixture of 5% volume hydrogen and 95% volume argon to obtain a TiO _2-x -Fe ²⁺ composite material , that is, the black titanium dioxide nanosheets doped with ferrous ions; wherein:

In step 1, the molar ratio of tetrabutyl titanate, hydrogen fluoride and water is 1:(0-5):(1-10), the hydrothermal temperature is 100-220°C, and the hydrothermal time is 6-24 h;

In step 2, the mass ratio of the _TiO2 nanosheets and dopamine hydrochloride is 1: (0.1-2), the volume ratio of water and ethanol mixed solvent is 1: (0.25-5), and the stirring time is 6-24 h;

In step 3, the mass ratio of the TiO ₂ -dopamine hydrochloride material to FeCl ₃ •6H ₂ O is 1: (50-150), and the stirring time is 6-24 h;

In step 4, the annealing conditions are as follows: the annealing temperature is 400-600 °C, the heating rate is 2-5 °C/min, and the annealing time is 1-5 h;

In step 5, the annealing conditions are as follows: the annealing temperature is 400-600 °C, the heating rate is 2-5 °C/min, and the annealing time is 1-5 h.

The main feature of the invention is that the TiO _2-x -Fe ²⁺ composite material is constructed by first modifying, then complexing, then oxidizing, and finally reducing. First, the abundant hydroxyl groups on the surface of _TiO2 nanosheets are favorable for polydopamine modification. After polydopamine modification, the phenolic hydroxyl group can complex Fe ³⁺ . Subsequently, the polydopamine was removed by annealing in air, while the complexed Fe ³⁺ migrated into the TiO ₂ lattice to form TiO _2-x -Fe ³⁺ . During the annealing process of 5% volume hydrogen and 95% volume argon gas mixture, Fe ³⁺ in the TiO _2-x lattice was reduced to Fe ²⁺ , and the degree of oxygen deficiency in TiO _2-x further increased. The focus of the preparation method provided by the invention is polydopamine modification and control of annealing conditions, so as to dope Fe ²⁺ in the TiO _2-x lattice. The TiO _2-x -Fe ²⁺ composite material constructed by the invention has good catalytic performance.

The beneficial effects of the invention include: the TiO _2-x -Fe ²⁺ composite material can be synthesized by first modifying, then complexing, then oxidizing, and finally reducing, and the synthesis conditions are controllable. At the same time, the invention solves the problem of poor catalytic performance of current TiO _2-x based catalysts. The TiO _2-x -Fe ²⁺ composite material in the invention has strong catalytic ability, can generate a large amount of active oxygen free radicals with cytotoxicity in cancer cells, and has the potential of being applied to the preparation of antitumor drugs.

Description of drawings

Fig. 1 is the characterization picture of the TiO _2-x -Fe ²⁺ nanosheet prepared in Example 1 of the present invention;

Fig. 2 is an X-ray photoelectron spectrum (XPS) diagram of TiO _2-x -Fe ²⁺ nanosheets prepared in Example 1 of the present invention;

Fig. 3 is a laser scanning confocal microscope photo, which shows that the TiO _2-x -Fe ²⁺ nanosheets of the present invention enhance the level of active oxygen free radicals in mouse triple-negative breast cancer cells, namely 4T1 cells.

Detailed ways

The present invention will be further described in detail in conjunction with the following specific embodiments and accompanying drawings. The process, conditions, experimental methods, etc. for implementing the present invention, except for the content specifically mentioned below, are common knowledge and common knowledge in this field, and the present invention has no special limitation content.

Embodiment 1: Preparation of TiO _2-x -Fe ²⁺ composite material

Specifically include the following steps:

Step 1. Add 8.5ml of tetrabutyl titanate into a 20ml plastic vial, add 585μL of dilute hydrogen fluoride solution (32wt%) dropwise, and stir rapidly until the solution is clear. Transfer the solution to a reaction kettle, conduct a hydrothermal reaction at 180°C for 18 hours, wash with water and absolute ethanol three times, and dry to obtain TiO ₂ nanosheets;

Step 2: ultrasonically disperse 20 mg of TiO ₂ nanosheets in 50 ml of a mixed solvent of water and absolute ethanol (volume ratio 1:1). Add 20 mg of dopamine hydrochloride, mix well, add 1ml of concentrated ammonia water (25-28wt%) dropwise, and react for 4 hours. After being collected by centrifugation, wash with water and ethanol three times respectively, and dry to obtain TiO ₂ -polydopamine composite material;

Step 3: Disperse 10 mg of TiO ₂ -polydopamine composite material in 10 ml of 0.4mol/L FeCl ₃ aqueous solution, stir for 24 hours, centrifuge, wash with water and ethanol three times, and dry to obtain TiO ₂ -polydopamine-Fe ³⁺ composite material ;

Step 4: Put the TiO ₂ -polydopamine-Fe ³⁺ composite material in a corundum porcelain boat, and anneal in air at 550°C for 2 hours to obtain the TiO _2-x -Fe ³⁺ composite material;

Step 5. Put the TiO _2-x -Fe ³⁺ composite material obtained in Step 4 in a corundum porcelain boat, and anneal for 5 hours in a mixture of 5% volume hydrogen and 95% volume argon at 550°C to obtain TiO _{2 -x} -Fe ²⁺ composites.

The instruments used in the present invention to characterize TiO _2-x -Fe ²⁺ are: Zeiss Gemini SEM450 high-performance thermal field scanning electron microscope, JEOL JEM-2100F transmission electron microscope, Bruker D8 Advanced X-Ray Diffractometer, FV31-HSD laser scanning confocal Microscope and Axis Supra X-ray photoelectron spectrometer.

The characterization result of the TiO _2-x -Fe ²⁺ is:

Referring to Figure 1, it can be seen from the results of scanning electron microscopy (Figure 1a) that the appearance of TiO _2-x -Fe ²⁺ is nanosheets with a diameter of about 30-100nm. The TEM results (Fig. 1b, 1c) did not observe Fe ²⁺ nanoclusters, indicating that Fe ²⁺ should exist in the TiO _2-x lattice. From the results of X-ray diffraction (Fig. 1d), TiO _2-x -Fe ²⁺ still maintains the anatase crystal form, but the crystallinity becomes worse, which is attributed to the lattice distortion caused by Fe ²⁺ doping.

Referring to Figure 2, the XPS spectrum (Figure 2a) shows that the iron ions doped in TiO _2-x -Fe ²⁺ mainly exist in divalent form, and the doping amount of Fe ²⁺ is about 3.8%. The XPS spectrum (Fig. 2b) shows that the degree of oxygen deficiency in TiO _2-x -Fe ²⁺ is increased compared with TiO ₂ and TiO _2-x . It can be seen from the XPS spectrum (Fig. 2c) that the Ti2p peak position of TiO _2-x -Fe ²⁺ shifts to the direction of low binding energy, which also shows that there are oxygen vacancies in TiO _2-x -Fe ²⁺ .

Example 2: The application of TiO _2-x -Fe ²⁺ to increase the level of reactive oxygen free radicals in cancer cells

Specifically include the following steps:

Step 1: Plant 4T1 cells in a 96-well plate at a density of 5000 cells per well, and use 100 mL RPMI1640 medium for culture in each well. Incubate in a 5% CO ₂ , 37°C incubator for 24 h.

Step 2: Disperse the TiO _2-x -Fe ²⁺ nanosheet material prepared in Example 1 into RPMI1640 medium to obtain a nanomaterial suspension with a concentration of 20 μg/ml. The material suspension of the control group was configured in the same manner. Add 100 μL of the material suspension into the corresponding wells, and incubate in a 5% CO ₂ , 37°C incubator for 24 h.

Step 3: Aspirate the supernatant and wash with phosphate-buffered saline (PBS). Then add 100 μL active oxygen fluorescent probe (DCFH-DA) working solution (Beyond, 1:1000) to each well and incubate for 25 min. The positive control group (ROS+) was treated by adding 2 μL of ROSup solution (Beiyuntian, 50 mg/ml) to the cells loaded with fluorescent probes and incubating for 25 min. Observation was carried out with a laser scanning confocal microscope, and its parameters were excitation wavelength 488nm and emission wavelength 525nm.

Referring to Figure 3, the experimental results show that compared with TiO ₂ or TiO _2-x , TiO _2-x -Fe ²⁺ can significantly increase the ROS level in 4T1 cells.

The protection content of the present invention is not limited to the above embodiments. Without departing from the spirit and scope of the concept of the present invention, changes and advantages conceivable by those skilled in the art are all included in the present invention, and the appended claims are the protection scope.

Claims (2)

1. A ferrous ion doped black titanium dioxide nanosheet is characterized in that the nanosheet is TiO _2-x -Fe ²⁺ In the nanosheet structure, tiO _2-x Ferrous ions in the lattice, i.e. Fe ²⁺ The doping amount of (A) is 1-5 wt%; the diameter of the nano sheet is 30-1000 nm; wherein, X =0.01-0.07.

2. A method for preparing ferrous ion doped black titanium dioxide nanoplates as defined in claim 1, comprising the steps of:

step 1: tetrabutyl titanate, hydrogen fluoride and water are uniformly mixed, and precipitate is collected by centrifugation after hydrothermal reaction; then washing and drying to obtain white TiO ₂ Nanosheets;

and 2, step: the TiO obtained in the step 1 ₂ Ultrasonically dispersing the nanosheets and dopamine hydrochloride in a mixed solvent of water and absolute ethyl alcohol, and dropwise adding 25-28wt% of ammonia water under rapid stirring; after the reaction, collecting the nanosheets by centrifugation; then washing with water and ethanol for 3 times, and drying to obtain TiO ₂ -a polydopamine composite;

and step 3: tiO obtained in the step 2 ₂ Polydopamine composites and FeCl ₃ •6H ₂ Dispersing O in water by ultrasonic wave, and stirring overnight; centrifugally collecting, washing with water and ethanol for 3 times, and drying to obtain TiO ₂ poly-dopamine-Fe ³⁺ A composite material;

and 4, step 4: tiO obtained in the step 3 ₂ poly-dopamine-Fe ³⁺ Putting the mixture into a corundum porcelain boat, and annealing the corundum porcelain boat in air to obtain TiO _2-x -Fe ³⁺ A composite material;

and 5: tiO obtained in the step 4 _2-x -Fe ³⁺ Putting the mixture into a corundum porcelain boat, and annealing the corundum porcelain boat in a mixed gas of 5 percent by volume of hydrogen and 95 percent by volume of argon to obtain TiO _2-x -Fe ²⁺ A composite material, namely a ferrous ion doped black titanium dioxide nanosheet; wherein:

in the step 1, the molar ratio of tetrabutyl titanate to hydrogen fluoride to water is 1: 0-5: 1-10, the hydrothermal temperature is 100-220 ℃, and the hydrothermal time is 6-24 h;

in step 2, the TiO is ₂ The mass ratio of the nano-sheets to the dopamine hydrochloride is 1: 0.1-2, the volume ratio of water to absolute ethyl alcohol is 1: 0.25-5, and the stirring time is 6-24 h;

in step 3, the TiO is ₂ -dopamine hydrochloride material, feCl ₃ •6H ₂ The mass ratio of O is 1: 50-150, and the stirring time is 6-24 h;

in step 4, the annealing conditions are as follows: the annealing temperature is 400-600 ℃, the heating rate is 2-5 ℃/min, and the annealing time is 1-5 h;

in step 5, the annealing conditions are as follows: the annealing temperature is 400-600 ℃, the heating rate is 2-5 ℃/min, and the annealing time is 1-5 h.

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