Titanium-doped ZIF67 nanoparticles and preparation method thereof
By atomically doping titanium into ZIF67 and combining low-temperature annealing and plasma activation, the problem of poor conductivity of ZIF67 is solved, significantly improving its conductivity and catalytic activity.
Patent Information
- Application Number
- CN202510389849.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-03-31
- Publication Date
- 2025-05-30
AI Technical Summary
The poor conductivity of ZIF67 limits its application performance in electrocatalytic and photo/electrocatalytic fields.
Doping titanium into ZIF67 by atomic-level doping, a Co-Ti-N covalent bond network is formed, the electron transmission path is optimized, and a conductive carbon network is formed through low-temperature annealing to avoid structural collapse.
The conductive properties of ZIF67 are significantly improved, catalytic activity is enhanced, and built-in electric field and nanopores are formed through gradient doping and plasma activation, which improves the charge separation efficiency and specific surface area.
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Abstract
Description
Technical Field
[0001] The present invention relates to the field of metal-organic framework materials, and particularly to a titanium-doped ZIF67 nanoparticle and a preparation method thereof. Background Art
[0002] As a metal-organic framework material composed of cobalt ions and 2-methylimidazole ligands, ZIF67 shows potential in the fields of electrocatalysis, energy storage, and environmental governance due to its high specific surface area and adjustable pore size. However, its intrinsic semiconductor properties lead to poor conductivity and a high recombination rate of photo-generated electrons and holes during the photo / electrocatalysis process, severely limiting the practical application performance.
[0003] In the prior art, in order to improve the problem of low electron and charge transfer efficiency of ZIF67, the following strategies are usually adopted: 1. Introducing non-metal heteroatoms, such as N, P, S, etc., through thermal carbonization. Although the surface electron distribution can be optimized, the doping amount is first, and the energy band structure cannot be effectively regulated; 2. High-temperature carbonization treatment. Although a conductive carbon network can be generated, it will also cause the framework of ZIF67 to collapse, reduce the active sites, and the process energy consumption is relatively high; 3. By compounding with conductive materials, the conductivity can be significantly improved, but the interfacial compatibility is poor and delamination is likely to occur.
[0004] In view of this, how to effectively improve the conductivity of ZIF67 has become one of the technical problems to be solved urgently at present. Summary of the Invention
[0005] In view of this, the present invention proposes a preparation method of titanium doping that can effectively improve the conductivity of ZIF67.
[0006] The technical solution of the present invention is realized as follows: The present invention provides a preparation method of titanium-doped ZIF67 nanoparticles, which includes the following steps:
[0007] Step 1: Dissolve cobalt salt, 2-methylimidazole, and titanium source in a solvent at a molar ratio of 1:(2 - 4):(0.05 - 0.2), and stir evenly;
[0008] Step 2: Heat the mixed solution obtained in Step 1 to 60 - 90 °C, and keep stirring and reacting for 6 - 12 h;
[0009] Step 3: After the reaction in Step 2 is completed, filter, wash successively with methanol and deionized water, and anneal at 100 - 300 °C for 1 - 3 h under an inert atmosphere to obtain titanium-doped ZIF67 nanoparticles;
[0010] Wherein the solvent is a mixture of water and a polar organic solvent in a volume ratio of 1:(3 - 5).
[0011] In the above embodiments, through atomic doping of titanium, part of the coordination center of cobalt in ZFI67 is replaced. Since the charge of Ti4+ is higher than that of Co2+, charge compensation needs to be achieved through the charge of ligands or lattice oxygen to achieve charge balance. Therefore, the introduction of titanium ions will attract the N atoms in the adjacent 2-methylimidazole ligands to provide additional electrons, forming a Co-Ti-N covalent bond network and optimizing the electron transport path. The hybridization of the 3d orbit of Ti and the 3d orbit of Co shifts the bottom of the conduction band upward, the top of the valence band downward, reduces the band gap, and broadens the light response range. Moreover, after titanium doping, the formed bimetallic active centers enhance the catalytic activity through the electron synergy effect.
[0012] By means of low-temperature annealing, residual ligands can be removed and part of the connecting nodes can be carbonized to form a conductive carbon network, while avoiding the structural collapse caused by high-temperature carbonization.
[0013] In some embodiments, in step two, before the heating reaction, ammonia water is added dropwise to adjust the pH to 10.0. After holding and stirring the reaction for 0.5 - 1 h, 0.1 mol / L hydrochloric acid is added dropwise to the reaction system at a dropping rate of 1 ml / min until the pH value is reduced to 8.0, and then the holding and stirring reaction is continued.
[0014] By means of gradient regulation of pH, a concentration gradient is induced. The high pH value in the initial stage promotes the hydrolysis of the titanium source to generate Ti(OH)4, which is preferentially adsorbed on the surface of ZIF67. After gradually reducing the pH, the hydrolysis is inhibited, driving the diffusion of titanium ions inward, forming a gradient distribution with rich titanium on the surface and poor titanium inside. And gradient doping will cause a difference in Fermi level, forming an oriented electric field on the surface and inside, driving the migration of photo-generated electrons to the surface.
[0015] In some embodiments, in step two, during the reaction, microwave-assisted reaction is carried out with a microwave power of 300 W and a frequency of 2.45 GHz.
[0016] Through the microwave thermal effect, polar solvents and water generate local superheat in the microwave field, accelerating the decomposition and nucleation of the precursor.
[0017] In some embodiments, in step three, after the annealing treatment, it further includes placing the product in an Ar plasma reactor with a power of 50 W and treating it for 1 - 10 min.
[0018] Through plasma etching, nano-scale pores can be generated, increasing the exposure of active sites and shortening the charge transport distance.
[0019] In some embodiments, in step one, during the mixing process, it further includes introducing H 2 -Ar mixed gas into the reaction system, where the volume fraction of H 2 is 5 - 10%.
[0020] During the reaction, the mixed gas reduces a part of the lattice oxygen to generate oxygen vacancies Ov. The oxygen vacancies act as electron trapping centers to inhibit electron-hole recombination. Meanwhile, the oxygen vacancies cause the upward shift of the d-band center of cobalt, enhancing the adsorption of reaction intermediates.
[0021] In some embodiments, the cobalt salt includes one of cobalt nitrate, cobalt chloride, and cobalt sulfate.
[0022] In some embodiments, the titanium source includes one of tetrabutyl titanate and titanium tetrachloride.
[0023] In some embodiments, the polar solvent is methanol or ethanol.
[0024] In a second aspect, the present invention also provides titanium-doped ZIF67 nanoparticles prepared by the above method.
[0025] The present invention has the following beneficial effects compared with the prior art:
[0026] The preparation method of the present invention realizes the optimization of the electronic structure by atomic-level doping, improving the electrical conductivity of ZIF67. At the same time, the scheme of gradient doping combined with plasma activation can realize the formation of built-in electric fields and nanopores, synergistically improving the charge separation efficiency and specific surface area. Specific Embodiments
[0027] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts fall within the protection scope of the present invention.
[0028] Unless otherwise defined, all technical terms and scientific terms used herein have the same meaning as commonly understood by those of ordinary skill in the technical field to which the embodiments of the present invention belong. If the definitions stated in this part are contrary to or otherwise inconsistent with the definitions stated in the patents, patent applications, published patent applications, and other publications incorporated herein by reference, the definitions listed in this part shall prevail over the definitions incorporated herein by reference.
[0029] Unless otherwise specified, the methods used in the following examples are all conventional methods. The materials, reagents, and instruments used, unless otherwise specified, are all conventional materials, reagents, and instruments in the art, and those skilled in the art can obtain them through commercial channels.
[0030] When an equivalent, concentration, or other value or parameter is expressed as a range, a preferred range, or a range defined by a series of upper preferred values and lower preferred values, this should be understood to specifically disclose all ranges formed by any pairing of any range upper limit or preferred value with any range lower limit or preferred value, regardless of whether the range is disclosed individually. For example, when the range "1 to 5" is disclosed, the described range should be interpreted to include ranges "1 to 4", "1 to 3", "1 to 2", "1 to 2 and 4 to 5", "1 to 3 and 5", etc. When a numerical range is described herein, unless otherwise stated, the range is intended to include its end values and all integers and fractions within the range. In the specification and claims of this application, range limitations can be combined and / or interchanged, and if not otherwise stated, these ranges include all sub-ranges contained therein.
[0031] Example 1
[0032] This example provides a preparation scheme for titanium-doped ZIF67, and the steps are as follows:
[0033] Step 1: Dissolve cobalt nitrate, 2-methylimidazole, and tetrabutyl titanate in a solvent at a molar ratio of 1:3:0.1, and stir evenly.
[0034] Step 2: Heat the mixed solution obtained in Step 1 to 60 °C, keep it warm and stir at 600 rpm for 12 h.
[0035] Step 3: After the reaction in Step 2 is completed, filter, wash successively with methanol and deionized water, and anneal at 200 °C for 2 h under an inert atmosphere to obtain titanium-doped ZIF67 nanoparticles.
[0036] The solvent is a solvent obtained by mixing water and methanol at a volume ratio of 1:3.
[0037] Example 2
[0038] This example provides a preparation scheme for titanium-doped ZIF67, and the steps are as follows:
[0039] Step 1: Dissolve cobalt nitrate, 2-methylimidazole, and tetrabutyl titanate in a solvent at a molar ratio of 1:3:0.1, and stir evenly.
[0040] Step 2: Add ammonia water to the mixed solution obtained in Step 1 to adjust the pH value to 10, then heat to 60 °C, keep it warm and stir at 600 rpm for 1 h, add 0.1 mol / L hydrochloric acid dropwise to the reaction system at a dropping rate of 1 ml / min until the pH value drops to 8.0, and continue to keep it warm and stir at 400 rpm until the holding time reaches 12 h.
[0041] Step 3: After the reaction in Step 2 is completed, filter, wash successively with methanol and deionized water, and anneal at 200 °C for 2 h under an inert atmosphere to obtain titanium-doped ZIF67 nanoparticles.
[0042] The solvent is a solvent obtained by mixing water and methanol in a volume ratio of 1:3.
[0043] Example 3
[0044] This example provides a preparation scheme for titanium-doped ZIF67, and the steps are as follows:
[0045] Step 1: Dissolve cobalt nitrate, 2-methylimidazole, and tetrabutyl titanate in a solvent at a molar ratio of 1:3:0.1, and stir evenly.
[0046] Step 2: Transfer the mixed solution obtained in Step 1 to a microwave reactor, heat to 60 °C under the conditions of a microwave power of 300 W and a frequency of 2.45 GHz, and keep stirring at 600 rpm for 6 h.
[0047] Step 3: After the reaction in Step 2 is completed, filter, wash successively with methanol and deionized water, and anneal at 200 °C for 2 h under an inert atmosphere to obtain titanium-doped ZIF67 nanoparticles.
[0048] The solvent is a solvent obtained by mixing water and methanol in a volume ratio of 1:3.
[0049] Example 4
[0050] This example provides a preparation scheme for titanium-doped ZIF67, and the steps are as follows:
[0051] Step 1: Dissolve cobalt nitrate, 2-methylimidazole, and tetrabutyl titanate in a solvent at a molar ratio of 1:3:0.1, and stir evenly.
[0052] Step 2: Heat the mixed solution obtained in Step 1 to 60 °C and keep stirring at 600 rpm for 12 h.
[0053] Step 3: After the reaction in Step 2 is completed, filter, wash successively with methanol and deionized water, and anneal at 200 °C for 2 h under an inert atmosphere. Then place the annealed product in an Ar plasma reactor with a power of 50 W and treat it for 5 min to obtain titanium-doped ZIF67 nanoparticles.
[0054] The solvent is a solvent obtained by mixing water and methanol in a volume ratio of 1:3.
[0055] Example 5
[0056] This example provides a preparation scheme for titanium-doped ZIF67, and the steps are as follows:
[0057] Step 1: Dissolve cobalt nitrate, 2-methylimidazole, and tetrabutyl titanate in a solvent at a molar ratio of 1:3:0.1. At the same time, introduce a H 2 -Ar mixed gas into the reaction system, where the volume fraction of H 2 is 5%, and stir evenly;
[0058] Step 2: Heat the mixed solution obtained in Step 1 to 60 °C, and stir and react at 600 rpm for 12 h while maintaining the temperature;
[0059] Step 3: After the reaction in Step 2 is completed, filter, wash successively with methanol and deionized water, and anneal at 200 °C for 2 h under an inert atmosphere to obtain titanium-doped ZIF67 nanoparticles.
[0060] The solvent is a solvent obtained by mixing water and methanol at a volume ratio of 1:3.
[0061] Example 6
[0062] This example provides a preparation scheme for titanium-doped ZIF67, and the steps are as follows:
[0063] Step 1: Dissolve cobalt nitrate, 2-methylimidazole, and tetrabutyl titanate in a solvent at a molar ratio of 1:3:0.1, and stir evenly;
[0064] Step 2: Add ammonia water to the mixed solution obtained in Step 1 to adjust the pH value to 10, then heat to 60 °C, stir and react at 600 rpm for 1 h. Add 0.1 mol / L hydrochloric acid to the reaction system at a dropping rate of 1 ml / min until the pH value drops to 8.0, and continue to stir and react at 400 rpm until the holding time reaches 12 h;
[0065] Step 3: After the reaction in Step 2 is completed, filter, wash successively with methanol and deionized water, and anneal at 200 °C for 2 h under an inert atmosphere. Place the annealed product in an Ar plasma reactor with a power of 50 W and treat it for 5 min to obtain titanium-doped ZIF67 nanoparticles.
[0066] The solvent is a solvent obtained by mixing water and methanol at a volume ratio of 1:3.
[0067] Comparative Example 1
[0068] This comparative example provides a preparation scheme for undoped ZIF67, and the steps are as follows:
[0069] Step 1: Dissolve cobalt nitrate and 2-methylimidazole in a solvent at a molar ratio of 1:3, and stir evenly;
[0070] Step 2: Heat the mixed solution obtained in Step 1 to 60 °C, and stir and react at 600 rpm for 12 h while maintaining the temperature;
[0071] Step 3: After the reaction in Step 2 is completed, filter, wash successively with methanol and deionized water, and anneal at 200 °C for 2 h under an inert atmosphere to obtain undoped ZIF67 nanoparticles.
[0072] The solvent is a solvent obtained by mixing water and methanol in a volume ratio of 1:3.
[0073] Comparative Example 2
[0074] This comparative example provides a preparation scheme for high-temperature carbonized ZIF67, and the steps are as follows:
[0075] Step 1: Dissolve cobalt nitrate, 2-methylimidazole and tetrabutyl titanate in a solvent at a molar ratio of 1:3:0.1, and stir evenly;
[0076] Step 2: Heat the mixed solution obtained in Step 1 to 60 °C, and stir and react at 600 rpm for 12 h while maintaining the temperature;
[0077] Step 3: After the reaction in Step 2 is completed, filter, wash successively with methanol and deionized water, and carbonize at 700 °C for 2 h under an inert atmosphere to obtain undoped ZIF67 nanoparticles.
[0078] The solvent is a solvent obtained by mixing water and methanol in a volume ratio of 1:3.
[0079] Comparative Example 3
[0080] This comparative example provides a preparation scheme for undoped ZIF67, and the steps are as follows:
[0081] Step 1: Dissolve cobalt nitrate and 2-methylimidazole in a solvent at a molar ratio of 1:3, and stir evenly;
[0082] Step 2: Transfer the mixed solution obtained in Step 1 to a microwave reactor, and heat to 60 °C under the conditions of a microwave power of 300 W and a frequency of 2.45 GHz, and stir and react at 600 rpm for 6 h while maintaining the temperature;
[0083] Step 3: After the reaction in Step 2 is completed, filter, wash successively with methanol and deionized water, and anneal at 200 °C for 2 h under an inert atmosphere to obtain undoped ZIF67 nanoparticles.
[0084] The solvent is a solvent obtained by mixing water and methanol in a volume ratio of 1:3.
[0085] Comparative Example 4
[0086] This example provides a preparation scheme for titanium-doped ZIF67, and the steps are as follows:
[0087] Step 1: Dissolve cobalt nitrate, 2-methylimidazole and tetrabutyl titanate in a solvent at a molar ratio of 1:3:0.3, and stir evenly;
[0088] Step 2: Heat the mixed solution obtained in Step 1 to 60°C and stir and react at 600 rpm for 12 h while maintaining the temperature.
[0089] Step 3: After the reaction in Step 2 is completed, filter, wash successively with methanol and deionized water, and anneal at 200°C for 2 h under an inert atmosphere to obtain titanium-doped ZIF67 nanoparticles.
[0090] The solvent is a solvent obtained by mixing water and methanol in a volume ratio of 1:3.
[0091] Comparative Example 5
[0092] This comparative example provides a preparation scheme for undoped ZIF67, and the steps are as follows:
[0093] Step 1: Dissolve cobalt nitrate and 2-methylimidazole in a solvent at a molar ratio of 1:3 and stir evenly.
[0094] Step 2: Heat the mixed solution obtained in Step 1 to 60°C and stir and react at 600 rpm for 12 h while maintaining the temperature.
[0095] Step 3: After the reaction in Step 2 is completed, filter, wash successively with methanol and deionized water, and anneal at 200°C for 2 h under an inert atmosphere to obtain undoped ZIF67 nanoparticles.
[0096] The solvent is a solvent obtained by mixing water and methanol in a volume ratio of 1:3.
[0097] Perform ball milling and mixing on the undoped ZIF67 nanoparticles and TiO 2 nanoparticles. The molar ratio of the TiO 2 nanoparticles to cobalt nitrate is 0.1:1.
[0098] Detect the conductivity, specific surface area, OER overpotential, and charge separation efficiency of the ZIF67 nanoparticles obtained by the above vegetation respectively.
[0099] Conductivity test:
[0100] Tabletting treatment: Press the powder samples of Examples 1-6 and Comparative Examples 1-5 into circular tablets with a diameter of 10 mm and a thickness of 1 mm under a pressure of 10 MPa to avoid measurement errors caused by differences in porosity.
[0101] Surface treatment: Fix copper wires on both sides of the circular tablet with conductive silver glue to ensure that the contact resistance is negligible.
[0102] Method: Four-Probe Method, referring to the standard GB / T 1551-2009
[0103] Equipment: RTS-9 type four-probe tester, probe spacing 1.0 mm.
[0104] Parameter:
[0105] Test current: 10 mA (DC);
[0106] Temperature: 25 ± 1 °C (controlled by incubator);
[0107] Repeated measurement: Each sample is tested 5 times and the average value is taken, and the standard deviation (±5%) is marked.
[0108] Take the sample of Example 1 and press it into a tablet, record the thickness (1.02 mm);
[0109] Apply a current of 10 mA and read the voltage difference ΔV = 0.48 mV;
[0110] Calculate the conductivity σ = (I × L) /
[0111] Specific surface area test:
[0112] Degassing conditions: Place the sample in a vacuum degassing station and degas it at 200 °C for 6 hours (heating rate 5 °C / min) to ensure the removal of surface adsorbates.
[0113] Method: BET nitrogen adsorption - desorption method, referring to the standard ISO 9277:2010.
[0114] Equipment: Micromeritics ASAP 2460 fully automatic specific surface area analyzer.
[0115] Parameter:
[0116] Adsorbed gas: High-purity nitrogen (99.999%);
[0117] Test temperature: 77 K (liquid nitrogen bath);
[0118] Relative pressure range (P / P 0 ): 0.05 - 0.30 (BET linear range).
[0119] PER overpotential test:
[0120] Working electrode:
[0121] Take 5 mg of the sample of the example, mix it with 50 μL of Nafion solution (5 wt%) and 450 μL of isopropanol, and ultrasonicate for 30 minutes;
[0122] Take 10 μL of the suspension and drop-coat it on a glassy carbon electrode (diameter 3 mm) and dry it at room temperature.
[0123] Test system and conditions
[0124] Equipment: CHI 760E electrochemical workstation;
[0125] Three - electrode system:
[0126] Working electrode: Glassy carbon electrode (loaded with sample);
[0127] Counter electrode: Platinum wire;
[0128] Reference electrode: Hg / HgO(1M KOH);
[0129] Electrolyte: 1M KOH solution (degassed by purging with nitrogen for 30 minutes);
[0130] Test parameters:
[0131] Linear sweep voltammetry (LSV), scan rate 5 mV / s;
[0132] iR compensation: 85% (calibrated by electrochemical impedance spectroscopy).
[0133] Charge separation efficiency test:
[0134] Equipment: Edinburgh Instruments FLS1000 steady - state / transient fluorescence spectrometer;
[0135] Excitation light source: 375 nm pulsed laser (pulse width 100 ps);
[0136] Detection wavelength: 450 nm (corresponding to the emission peak of ZIF - 67);
[0137] Data fitting: Double - exponential decay model (I(t) = A 1 exp(-t / τ 1 ) + A 2 exp(-t / τ 2 ));
[0138] Charge separation efficiency η = 1 - τ_sample / τ_reference:
[0139] Reference sample (undoped ZIF - 67) τ = 1 ns;
[0140] Sample of Example 2 τ = 0.15 ns → η = 85%.
[0141] Verification of photocurrent response
[0142] Equipment: CHI 760E electrochemical workstation + 300W xenon lamp (AM 1.5G filter);
[0143] Test conditions:
[0144] Working electrode: FTO glass loaded with sample;
[0145] Electrolyte: 0.1M Na2 SO 4 ;
[0146] Bias voltage: 0.5V vs. Ag / AgCl;
[0147] The results are as follows:
[0148]
[0149] From the comparison of the data in the above embodiments, it can be seen that in Example 6, through the methods of gradient pH regulation and plasma activation, the conductivity is increased by 64,000 times, which is significantly better than the prior art (Comparative Example 5). Moreover, compared with Comparative Example 2 using the traditional high-temperature carbonization process, it is also increased by 133%, indicating that the methods of low-temperature annealing and gradient doping can avoid structural collapse. After excessive doping in Comparative Example 4, its specific surface area decreased significantly, and a doping amount of 0.1 is relatively optimal.
[0150] At the same time, the OER overpotential of Example 6 reached 260 mV level, which is close to that of the used IrO 2 (250 mV), and is significantly lower than that of Comparative Example 1. It is considered that this may be because the bimetallic sites reduce the reaction energy barrier.
[0151] Example 3 uses microwave assistance, which greatly shortens the reaction time and significantly reduces the energy consumption.
[0152] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.
Claims
1. A method for preparing titanium-doped ZIF67 nanoparticles, characterized in that: The steps include: Step 1: dissolve cobalt salt, 2-methylimidazole and titanium source in a solvent at a molar ratio of 1:(2-4):(0.05-0.2) and stir evenly; Step 2: Heat the mixed solution obtained in step 1 to 60-90°C, and stir and react for 6-12 hours; Step 3: After the reaction of step 2 is completed, filter, wash with methanol and deionized water in sequence, and anneal at 100-300° C. for 1-3 h in an inert atmosphere to obtain titanium-doped ZIF67 nanoparticles; The solvent is a mixture of water and a polar organic solvent in a volume ratio of 1:(3-5).
2. The method for preparing titanium-doped ZIF67 nanoparticles according to claim 1, characterized in that: In step 2, before heating the reaction, add ammonia water to adjust the pH to 10.
0. After the reaction is stirred and kept warm for 0.5-1h, 0.1 mol / L hydrochloric acid is added to the reaction system at a rate of 1 ml / min until the pH value drops to 8.0, and the reaction is continued with stirring and keeping warm.
3. The method for preparing titanium-doped ZIF67 nanoparticles according to claim 1, characterized in that: In step 2, during the reaction process, microwave-assisted reaction was performed with a microwave power of 300 W and a frequency of 2.45 GHz.
4. The method for preparing titanium-doped ZIF67 nanoparticles according to claim 1, characterized in that: In step three, after the annealing treatment, the product is placed in an Ar plasma reactor with a power of 50 W for 1-10 minutes.
5. The method for preparing titanium-doped ZIF67 nanoparticles according to claim 1, characterized in that: In step 1, during the mixing process, a H2-Ar mixed gas is introduced into the reaction system, wherein the volume fraction of H2 is 5-10%.
6. The method for preparing titanium-doped ZIF67 nanoparticles according to claim 1, characterized in that: The cobalt salt includes one of cobalt nitrate, cobalt chloride and cobalt sulfate.
7. The method for preparing titanium-doped ZIF67 nanoparticles according to claim 1, characterized in that: The titanium source includes one of tetrabutyl titanate and titanium tetrachloride.
8. The method for preparing titanium-doped ZIF67 nanoparticles according to claim 1, characterized in that: The polar solvent is methanol or ethanol.
9. A titanium-doped ZIF67 nanoparticle, characterized in that: The preparation method is described in any one of claims 1 to 8.