Highly conductive multifunctional composite, method of manufacture and use in automotive primer applications

Abstract

This invention belongs to the field of functional composite materials technology, specifically relating to a method for preparing a highly conductive multifunctional composite material and its application in automotive primers. It is based on a stable three-phase heterogeneous structure constructed by cobalt-molybdenum bimetallic ion co-doping of titanium dioxide. The composite material is then combined with graphene via a surfactant-assisted ultrasonic method, followed by hydrothermal reaction, calcination, centrifugation, washing, drying, and grinding to obtain the desired product. In automotive primer applications, a slurry is prepared by stirring polyvinylidene fluoride and N-methylpyrrolidone in a constant-temperature water bath. The highly conductive multifunctional composite material is dispersed in this slurry and stirred to obtain a paste. This paste is then uniformly sprayed onto an automotive substrate or metal surface using a spray gun. This invention is simple to operate, cost-effective, and has a long service life. It also possesses high conductivity, hydrophobic self-cleaning properties, corrosion resistance, and efficient photocatalytic performance, suppressing electrostatic discharge hazards and preventing surface contamination and corrosion.

Description

Technical Field

[0001] This invention belongs to the field of functional composite materials technology, specifically relating to a highly conductive multifunctional composite material, its preparation method, and its application in automotive primers. In particular, this method constructs a stable three-phase heterostructure, enabling the material to simultaneously possess high conductivity, hydrophobicity, corrosion resistance, photocatalytic activity, and self-cleaning ability. It can be widely used in self-cleaning coatings, corrosion protection, photocatalytic degradation, and electronic devices. Background Technology

[0002] With the rapid development of modern industry and high technology, composite materials with both high conductivity and multiple additional functions have shown great application potential in surface protection, environmental remediation, and electronic packaging. Ideal conductive materials not only need to provide excellent electron transport capabilities but also need to withstand complex service environments, such as humidity, acid and alkali corrosion, and organic pollution. However, most commercially available conductive fillers (such as metal powders, carbon black, and antimony-doped tin oxide) possess a certain degree of conductivity, but their performance is easily affected by temperature and humidity, and they suffer from prominent problems such as poor corrosion resistance, insufficient hydrophobic self-cleaning ability, low photocatalytic activity, and high preparation costs, making it difficult to meet the demands of multifunctional integration.

[0003] Doping modification and composite conductive phases are common strategies for improving the conductivity and photocatalytic properties of titanium dioxide. In recent years, researchers have used metal ion doping to regulate the electronic structure of titanium dioxide or composite it with highly conductive two-dimensional materials such as graphene to construct heterogeneous interfaces. However, the three-phase coexistence characteristic of titanium dioxide is not fully utilized. Moreover, single doping or simple two-phase physical composites generally have the following problems: uneven distribution of dopant ions and difficulty in controlling lattice distortion; weak interfacial bonding between graphene and titanium dioxide, resulting in limited electron transfer efficiency; and few reports on achieving synergistic effects of high conductivity, hydrophobicity, corrosion resistance, and photocatalytic self-cleaning. The doped titanium dioxide / graphene composites prepared in existing technologies often have disordered three-phase interfaces and poor structural stability, resulting in insufficient improvement in conductivity. Furthermore, they have low hydrophobic angles (<90°), weak corrosion resistance, and low efficiency in photocatalytic degradation of organic matter, making it difficult to meet the requirements for long-term self-cleaning and protection in complex environments.

[0004] High conductivity means the material can effectively dissipate static charge and prevent electrostatic discharge hazards; a highly hydrophobic surface (water contact angle >120°) reduces contaminant adhesion and slows the penetration of corrosive media; corrosion resistance directly determines coating life and maintenance costs; and photocatalytic self-cleaning capability utilizes photoactive oxygen species to decompose organic pollutants. Therefore, developing a three-phase heterogeneous composite material that combines high conductivity, hydrophobicity, corrosion resistance, and efficient photocatalytic self-cleaning has significant application value and market prospects. Summary of the Invention

[0005] The present invention aims to overcome the shortcomings of the prior art and provide a highly conductive multifunctional composite material and its preparation method that is simple to operate, low in cost, and environmentally friendly, and achieves high conductivity, hydrophobicity, corrosion resistance, and efficient photocatalytic self-cleaning function by constructing a stable three-phase heterostructure.

[0006] Another object of the present invention is to provide the application of the above-mentioned highly conductive multifunctional composite material in automotive primers.

[0007] To solve the above-mentioned technical problems, the present invention is implemented as follows:

[0008] A highly conductive multifunctional composite material, comprising cobalt-molybdenum co-doped titanium dioxide with a stable three-phase heterostructure, and graphene composited on the surface of the cobalt-molybdenum co-doped titanium dioxide; characterized by characteristic peaks in X-ray diffraction patterns, the stable three-phase heterostructure is a coexistence structure formed by anatase phase, rutile phase and doping-induced distortion phase.

[0009] This invention also provides a method for preparing the above-mentioned highly conductive multifunctional composite material, comprising the following steps: mixing cobalt salt and molybdate with a titanium source in an acidic solution to form a gel precursor, followed by hydrothermal reaction and calcination to obtain cobalt-molybdenum co-doped titanium dioxide with a stable three-phase heterostructure; then, with the assistance of a surfactant, ultrasonically combining the cobalt-molybdenum co-doped titanium dioxide with graphene; finally, centrifuging, washing, drying, and grinding to obtain the target product.

[0010] Furthermore, the preparation method of the above-mentioned highly conductive multifunctional composite material includes the following specific steps:

[0011] (1) Dissolve cobalt chloride hexahydrate and ammonium molybdate in hydrochloric acid solution, stir to dissolve, then add tetrabutyl titanate and continue stirring until a gel-like precursor is formed;

[0012] (2) The gel-like precursor obtained in step (1) is transferred to a hydrothermal reactor and hydrothermal reaction is carried out by gradient heating. After the reaction is completed, the precipitate is cooled, washed, dried, ground, and then calcined to obtain titanium dioxide powder with a stable three-phase heterostructure.

[0013] (3) Dissolve hexadecyltrimethylammonium bromide in water, add the titanium dioxide powder obtained in step (2) under constant temperature stirring, and continue stirring;

[0014] (4) Disperse graphene in water, sonicate it, and then add the resulting graphene dispersion to the product obtained in step (3) and stir to combine.

[0015] (5) Centrifuge the product obtained in step (4), wash it with anhydrous ethanol and deionized water respectively, and then dry and grind the centrifuged product to obtain the target product, high conductivity multifunctional composite material.

[0016] Furthermore, in step (1), the molar ratio of cobalt chloride hexahydrate to ammonium molybdate is 1:1, and the ratio of the total molar amount of the two to the molar amount of tetrabutyl titanate is 5:95.

[0017] Further, step (1) specifically includes: placing 0.3g of cobalt chloride hexahydrate and 0.22g of ammonium molybdate in 40mL of hydrochloric acid solution with a concentration of 2mol / L, stirring for 40min, then adding 17mL of tetrabutyl titanate dropwise, and continuing to stir for 1h.

[0018] Further, in step (2), the conditions for the gradient heating method are: first heat to 120°C and hold for 1 hour, then heat to 180°C and react for 24 hours; the calcination temperature is 450°C and the time is 2 hours; the washing is done by washing twice with ethanol and deionized water respectively, the drying temperature is 80°C and the drying time is 12 hours.

[0019] Further, in step (3), 0.2g of cetyltrimethylammonium bromide is dissolved in 50mL of water at 40℃ and stirred for 10min. Then, 1g of titanium dioxide powder obtained in step (2) is added and stirred for another 1h.

[0020] Further, in step (4), graphene is dispersed in 30 mL of water, and the mass ratio of graphene to titanium dioxide powder with a stable three-phase heterostructure obtained in step (2) is 7:100. The mixture is ultrasonically treated for 60 minutes. Then, the obtained graphene dispersion is added to the product obtained in step (3), and the mixture is continuously stirred and compounded for 2 hours.

[0021] Further, in step (5), the product obtained in step (4) is centrifuged, washed twice with anhydrous ethanol and deionized water, dried at 80°C for 12 hours, and ground to obtain the target product, a high-conductivity multifunctional composite material.

[0022] The present invention also provides an application of the above-mentioned highly conductive multifunctional composite material in the preparation of automotive primer, wherein the composite material is mixed with polyvinylidene fluoride and N-methylpyrrolidone to form a slurry, which is then coated onto an automotive substrate or metal surface by spraying.

[0023] Anatase titanium dioxide exhibits excellent photocatalytic activity and electron mobility, while rutile phase displays extremely high chemical stability and corrosion resistance. Although rare, brookite phase possesses a unique band structure. Co-doping with cobalt and molybdenum ions can induce the formation of a stable three-phase heterostructure in titanium dioxide, thereby suppressing the recombination of photogenerated electron-hole pairs, broadening the photoresponse range, and improving the material's hydrophobicity and corrosion resistance. This invention primarily uses a one-step sol-gel combined gradient hydrothermal method as the precursor preparation route, followed by calcination to regulate the crystal phase, and then ultrasonic-assisted composite method to achieve uniform composite with graphene. Commercially available titanium dioxide powders have low activity and poor conductivity, and a single phase cannot simultaneously meet the requirements of photocatalysis and corrosion resistance. This invention forms a stable three-phase heterostructure interface by precisely controlling the cobalt and molybdenum doping ratio and the hydrothermal heating program. Key parameters in the above material processing methods—total doping amount, hydrothermal temperature and time, calcination temperature, and ultrasonic composite duration—significantly affect the stability and multifunctionality of the final three-phase structure and cannot be ignored.

[0024] This invention is based on a stable three-phase heterostructure constructed by co-doping titanium dioxide with cobalt and molybdenum bimetallic ions. The titanium dioxide is then composited with graphene using a surfactant-assisted ultrasonic method, followed by centrifugation, washing, drying, and grinding to obtain the desired product. Experiments have shown that this invention significantly improves the conductivity of the composite material, reducing the resistivity to below 0.18 Ω·cm, thus efficiently dissipating static charge and reducing electrostatic discharge hazards. Simultaneously, the material surface exhibits a water contact angle exceeding 161.6°, demonstrating excellent superhydrophobic self-cleaning capabilities and significantly improved corrosion resistance. After immersion in a 3.5 wt.% NaCl solution for 15 days, the coating's impedance modulus still retains over 90% of its initial value. Photocatalytic degradation experiments of pollutants such as Rhodamine B show that the three-phase heterostructure composite material achieves a degradation rate of 97.5% under simulated sunlight, far exceeding that of pure titanium dioxide. Furthermore, the preparation method of this invention does not use highly toxic intermediate products, making the process green and environmentally friendly. This provides a superior solution for the field of multifunctional integrated coating materials with high conductivity, self-cleaning properties, corrosion resistance, and photocatalysis.

[0025] Compared with the prior art, the present invention has the following characteristics:

[0026] (1) The present invention mainly adopts the sol-gel combined gradient hydrothermal method and subsequent calcination process, which can achieve uniform doping of cobalt and molybdenum bimetallic ions in the titanium dioxide lattice to form a stable anatase-rutile-doped induced distortion phase three-phase heterostructure. The method is simple to operate, has good repeatability, and is suitable for laboratory and industrial scale-up production. The raw materials used, cobalt chloride hexahydrate, ammonium molybdate and tetrabutyl titanate, are all common industrial products, and the cost is controllable and suitable for large-scale preparation.

[0027] (2) The present invention employs a surfactant (hexadecyltrimethylammonium bromide)-assisted ultrasonic composite process, which not only effectively improves the dispersion uniformity and interfacial bonding strength of graphene in the titanium dioxide matrix, but also avoids the damage to the two-dimensional material structure caused by mechanical ball milling. Ultrasonic treatment helps to exfoliate graphene aggregates and activate active sites on the material surface, thereby significantly improving the conductive network connectivity and structural stability of the composite material.

[0028] (3) The operation method of this invention is simple, and the product obtained has high conductivity, high hydrophobicity, excellent corrosion resistance and efficient photocatalytic self-cleaning ability. It not only has the advantages of moderate price, short process cycle and long service life, but can also be widely used in automotive primers, photovoltaic brackets, marine engineering equipment, self-cleaning coatings for electronic devices and air purification, etc., and the product has a wide range of applications.

[0029] (4) By precisely controlling the cobalt-molybdenum doping ratio and the gradient heating hydrothermal process, and then calcining, this invention can not only regulate the band structure of titanium dioxide and broaden the photoresponse range to the visible light region, but also effectively suppress the recombination of photogenerated electron-hole pairs, significantly enhance the hydrophobicity and photocatalytic activity of the material, and at the same time, the stable three-phase interface greatly improves the long-term durability of the material in corrosive media.

[0030] (5) This invention can be widely applied in fields such as electronic information, aerospace, marine engineering, automotive industry, environmental governance and new energy. It is especially suitable for complex service environments with strict requirements for conductivity, corrosion resistance and self-cleaning multi-functional integration. It has important engineering application value and market promotion prospects. Attached Figure Description

[0031] The present invention will now be described in detail through specific embodiments. These embodiments are provided to enable a more thorough understanding of the invention and to fully convey the scope of the invention to those skilled in the art. As used throughout the specification and claims, the terms "comprising" or "including" are open-ended and are interpreted as "comprising but not limited to". The following description is a preferred embodiment for carrying out the invention; however, this description is intended to illustrate the general principles of the specification and is not intended to limit the scope of the invention. The scope of protection of the invention is determined by the appended claims. Unless otherwise specified, all reagents and materials used in the present invention are commercially available.

[0032] Figure 1 The image shows the scanning electron microscope (SEM) image of the cobalt-molybdenum co-doped titanium dioxide / graphene composite material prepared in Example 4 of this invention.

[0033] Figure 2The X-ray diffraction (XRD) patterns of cobalt-molybdenum co-doped titanium dioxide materials in Examples 2-6 of this invention (with appropriate cobalt-molybdenum bimetallic doping, the three phases exhibit a uniform proportion).

[0034] Figure 3 The X-ray photoelectron spectroscopy (XPS) full spectrum of the cobalt-molybdenum co-doped titanium dioxide / graphene composite material prepared in Example 4 of this invention (the appearance of the Mo / Co photoelectron peak indicates successful element doping).

[0035] Figure 4 The full X-ray photoelectron spectroscopy (XPS) spectrum of the cobalt-molybdenum co-doped titanium dioxide / graphene composite material prepared in Example 4 of this invention is shown below.

[0036] Figure 5 The full Co2p X-ray photoelectron spectroscopy (XPS) spectrum of the cobalt-molybdenum co-doped titanium dioxide / graphene composite material prepared in Example 4 of this invention;

[0037] Figure 6 The full Ti2p X-ray photoelectron spectroscopy (XPS) spectrum of the cobalt-molybdenum co-doped titanium dioxide / graphene composite material prepared in Example 4 of this invention;

[0038] Figure 7 The full O1s X-ray photoelectron spectroscopy (XPS) spectrum of the cobalt-molybdenum co-doped titanium dioxide / graphene composite material prepared in Example 4 of this invention;

[0039] Figure 8 The full C1s X-ray photoelectron spectroscopy (XPS) spectrum of the cobalt-molybdenum co-doped titanium dioxide / graphene composite material prepared in Example 4 of this invention;

[0040] Figure 9 Electrochemical impedance spectroscopy (EIS) spectra of cobalt-molybdenum co-doped titanium dioxide materials prepared in Examples 2 (0% Mo / Co co-doping), 3 (1% Mo / Co co-doping), 4 (3% Mo / Co co-doping), 5 (5% Mo / Co co-doping), and 6 (7% Mo / Co co-doping) of the present invention, measured using a three-electrode system.

[0041] Figure 10 Electrochemical impedance spectroscopy (EIS) spectra of the cobalt-molybdenum co-doped titanium dioxide / graphene composite materials prepared in Examples 2 (0% Mo / Co co-doping), 3 (1% Mo / Co co-doping), 4 (3% Mo / Co co-doping), 5 (5% Mo / Co co-doping), and 6 (7% Mo / Co co-doping) of the present invention, measured using a three-electrode system.

[0042] Figure 11Electrochemical impedance spectroscopy (EIS) spectra of cobalt-molybdenum co-doped titanium dioxide and composite graphene prepared in Examples 2 (0% Mo / Co co-doping) and 4 (3% Mo / Co co-doping) of the present invention, measured using a three-electrode system;

[0043] Figure 12 Cyclic voltammetry (CV) spectra of cobalt-molybdenum co-doped titanium dioxide materials prepared in Examples 2 (0% Mo / Co co-doping), 3 (1% Mo / Co co-doping), 4 (3% Mo / Co co-doping), 5 (5% Mo / Co co-doping), and 6 (7% Mo / Co co-doping) of the present invention, measured using a three-electrode system.

[0044] Figure 13 Cyclic voltammetry (CV) spectra of cobalt-molybdenum co-doped titanium dioxide / graphene composite materials prepared in Examples 2 (0% Mo / Co co-doping), 3 (1% Mo / Co co-doping), 4 (3% Mo / Co co-doping), 5 (5% Mo / Co co-doping), and 6 (7% Mo / Co co-doping) of the present invention were measured using a three-electrode system.

[0045] Figure 14 Cyclic voltammetry (CV) spectra of cobalt-molybdenum co-doped titanium dioxide and composite graphene prepared in Examples 2 (0% Mo / Co co-doping) and 4 (3% Mo / Co co-doping) of the present invention were measured using a three-electrode system.

[0046] Figure 15 Tafel spectra of cobalt-molybdenum co-doped titanium dioxide materials prepared in Examples 2 (0% Mo / Co co-doping), 3 (1% Mo / Co co-doping), 4 (3% Mo / Co co-doping), 5 (5% Mo / Co co-doping), and 6 (7% Mo / Co co-doping) of the present invention, measured using a three-electrode system.

[0047] Figure 16 Tafel spectra of the cobalt-molybdenum co-doped titanium dioxide / graphene composite materials prepared in Examples 2 (0% Mo / Co co-doping), 3 (1% Mo / Co co-doping), 4 (3% Mo / Co co-doping), 5 (5% Mo / Co co-doping), and 6 (7% Mo / Co co-doping) of the present invention were measured using a three-electrode system.

[0048] Figure 17The Tafel spectra of the cobalt-molybdenum co-doped titanium dioxide and composite graphene composite materials prepared in Examples 2 (0% Mo / Co co-doping) and 4 (3% Mo / Co co-doping) of the present invention were measured using a three-electrode system.

[0049] Figure 18 The UV-Vis spectra of the cobalt-molybdenum co-doped titanium dioxide and composite graphene composite materials prepared in Examples 2 (0% Mo / Co co-doping) and 4 (3% Mo / Co co-doping) of the present invention are shown.

[0050] Figure 19 The Tauc spectra of the cobalt-molybdenum co-doped titanium dioxide and composite graphene composite materials prepared in Examples 2 (0% Mo / Co co-doping) and 4 (3% Mo / Co co-doping) of the present invention are shown.

[0051] Figure 20 The photoluminescence (PL) spectra of the cobalt-molybdenum co-doped titanium dioxide and composite graphene composite materials prepared in Examples 2 (0% Mo / Co co-doping) and 4 (3% Mo / Co co-doping) of the present invention are shown.

[0052] Figure 21 The time-resolved photoluminescence (TRPL) spectra of the cobalt-molybdenum co-doped titanium dioxide and composite graphene composite materials prepared in Examples 2 (0% Mo / Co co-doping) and 4 (3% Mo / Co co-doping) of the present invention are shown.

[0053] Figure 22 A physical image of the hydrophobic angle test of the coating prepared for the cobalt-molybdenum co-doped titanium dioxide / graphene composite material prepared in Example 4 of the present invention (3% Mo / Co co-doping);

[0054] Figure 23 Hydrophobic angle test diagram of the coating prepared for the cobalt-molybdenum co-doped titanium dioxide / graphene composite material prepared in Example 4 of the present invention (3% Mo / Co co-doping);

[0055] Figure 24 Antifouling test image of the coating prepared for the cobalt-molybdenum co-doped titanium dioxide / graphene composite material prepared in Example 4 of the present invention (3% Mo / Co co-doping);

[0056] Figure 25 The self-cleaning performance test diagram of the coating prepared by the cobalt-molybdenum co-doped titanium dioxide / graphene composite material prepared in Example 4 of the present invention (3% Mo / Co co-doping);

[0057] Figure 26The adhesion test diagram shows the coating prepared by the cobalt-molybdenum co-doped titanium dioxide / graphene composite material prepared in Example 4 of the present invention (3% Mo / Co co-doping). Detailed Implementation

[0058] Example 1

[0059] (1) Measure 17 mL of tetrabutyl titanate and add it dropwise to 40 mL of hydrochloric acid solution with a concentration of 2 mol / L. Stir for 1 h until a uniform gel precursor is formed.

[0060] (2) The precursor obtained in step (1) was transferred to a 100 mL polytetrafluoroethylene-lined hydrothermal reactor. A gradient heating method was used, first heating to 120 °C and holding for 1 hour, then heating to 180 °C and reacting for 24 hours. After the reaction was completed, the mixture was cooled to room temperature, the precipitate was collected, and washed twice with ethanol and deionized water, respectively. The washed product was dried in an oven at 80 °C for 12 hours, and then ground to obtain precursor powder. Finally, the powder was calcined in a muffle furnace at 450 °C for 2 hours, and then ground to obtain pure titanium dioxide powder (TiO2).

[0061] (3) Weigh 1g of TiO2 powder obtained in step (2), dissolve it in 50mL of water at 40℃ and continue stirring for 1h.

[0062] (4) Disperse 0.07g of graphene in 30mL of deionized water (TiO2:G=100:7) and sonicate for 60 minutes to obtain a graphene dispersion. Add the obtained dispersion to the mixture in step (3) in small amounts several times and stir continuously for 2 hours.

[0063] (5) Centrifuge the product obtained in step (4), wash it twice with anhydrous ethanol and deionized water, dry it at 80°C for 12 hours, and grind it to obtain the target product (TG composite material).

[0064] (6) Press the product collected in step (5) into a tablet and measure its resistivity using a four-probe tester. Then, make a slurry with polyvinylidene fluoride and N-methylpyrrolidone, spray it onto nickel foam, and use a four-probe tester to measure the resistivity of the material.

[0065] Example 2

[0066] (1) Measure 17 mL of tetrabutyl titanate and add it dropwise to 40 mL of hydrochloric acid solution with a concentration of 2 mol / L. Stir for 1 h until a uniform gel precursor is formed.

[0067] (2) The precursor obtained in step (1) was transferred to a 100 mL polytetrafluoroethylene-lined hydrothermal reactor. A gradient heating method was used, first heating to 120 °C and holding for 1 hour, then heating to 180 °C and reacting for 24 hours. After the reaction was completed, the mixture was cooled to room temperature, the precipitate was collected, and washed twice with ethanol and deionized water, respectively. The washed product was dried in an oven at 80 °C for 12 hours, and then ground to obtain precursor powder. Finally, the powder was calcined in a muffle furnace at 450 °C for 2 hours, and then ground to obtain pure titanium dioxide powder (TiO2).

[0068] (3) Weigh 0.2g of cetyltrimethylammonium bromide and dissolve it in 50mL of water at 40℃. Stir for 10min to dissolve it completely. Then add 1g of TiO2 powder obtained in step (2) and continue stirring for 1h.

[0069] (4) Disperse 0.07g of graphene in 30mL of deionized water (TiO2:G=100:7) and sonicate for 60 minutes to obtain a graphene dispersion. Add the obtained dispersion to the mixture in step (3) in small amounts several times and stir continuously for 2 hours.

[0070] (5) Centrifuge the product obtained in step (4), wash it twice with anhydrous ethanol and deionized water, dry it at 80°C for 12 hours, and grind it to obtain the target product (T / G composite material).

[0071] (6) Press the product collected in step (5) into tablets and measure its resistivity using a four-probe tester. Then, prepare a slurry with polyvinylidene fluoride and N-methylpyrrolidone, spray it onto nickel foam, and use an electrochemical workstation to measure its impedance, cyclic voltammetry, and Tafel curve and calculate the coating protection efficiency. At the same time, test the water contact angle.

[0072] Example 3

[0073] (1) 0.056 g of cobalt chloride hexahydrate and 0.043 g of ammonium molybdate (Co:Mo:Ti molar ratio of 0.5:0.5:99, total doping amount of 1%) were placed in 40 mL of 2 mol / L hydrochloric acid solution and stirred continuously for 40 min until completely dissolved. Then, 17 mL of tetrabutyl titanate was added dropwise to the above solution and stirred for 1 h until a uniform gel-like precursor was formed.

[0074] (2) The precursor obtained in step (1) was transferred to a 100 mL polytetrafluoroethylene-lined hydrothermal reactor. A gradient heating method was used, first heating to 120 °C and holding for 1 hour, then heating to 180 °C and reacting for 24 hours. After the reaction was completed, the mixture was cooled to room temperature, the precipitate was collected, and washed twice with ethanol and deionized water, respectively. The washed product was dried in an oven at 80 °C for 12 hours, and then ground to obtain precursor powder. Finally, the powder was calcined in a muffle furnace at 450 °C for 2 hours, and then ground to obtain cobalt-molybdenum co-doped titanium dioxide powder (1% MC-T).

[0075] (3) Weigh 0.2g of cetyltrimethylammonium bromide and dissolve it in 50mL of water at 40℃. Stir for 10min to dissolve it completely. Then add 1g of the 1% MC-T powder obtained in step (2) and continue stirring for 1h.

[0076] (4) Disperse 0.07g of graphene in 30mL of deionized water (MC-T:G=100:7) and sonicate for 60 minutes to obtain a graphene dispersion. Add the obtained dispersion to the mixture in step (3) in small amounts several times and stir continuously for 2 hours.

[0077] (5) Centrifuge the product obtained in step (4), wash it twice with anhydrous ethanol and deionized water, dry it at 80°C for 12 hours, and grind it to obtain the target product (1% MC-T / G composite material).

[0078] (6) Press the product collected in step (5) into tablets and measure its resistivity using a four-probe tester. Then, prepare a slurry with polyvinylidene fluoride and N-methylpyrrolidone, spray it onto nickel foam, and use an electrochemical workstation to measure its impedance, cyclic voltammetry, and Tafel curve and calculate the coating protection efficiency. At the same time, test the water contact angle.

[0079] Example 4

[0080] (1) 0.178 g of cobalt chloride hexahydrate and 0.132 g of ammonium molybdate (Co:Mo:Ti molar ratio of 1.5:1.5:97, total doping amount of 3%) were placed in 40 mL of 2 mol / L hydrochloric acid solution and stirred continuously for 40 min until completely dissolved. Then, 17 mL of tetrabutyl titanate was added dropwise to the above solution and stirred for 1 h until a uniform gel-like precursor was formed.

[0081] (2) The precursor obtained in step (1) was transferred to a 100 mL polytetrafluoroethylene-lined hydrothermal reactor. A gradient heating method was used, first heating to 120 °C and holding for 1 hour, then heating to 180 °C and reacting for 24 hours. After the reaction was completed, the mixture was cooled to room temperature, the precipitate was collected, and washed twice with ethanol and deionized water, respectively. The washed product was dried in an oven at 80 °C for 12 hours, and then ground to obtain precursor powder. Finally, the powder was calcined in a muffle furnace at 450 °C for 2 hours, and then ground to obtain cobalt-molybdenum co-doped titanium dioxide powder (3% MC-T).

[0082] (3) Weigh 0.2g of cetyltrimethylammonium bromide and dissolve it in 50mL of water at 40℃. Stir for 10min to dissolve it completely. Then add 1g of the 3% MC-T powder obtained in step (2) and continue stirring for 1h.

[0083] (4) Disperse 0.07g of graphene in 30mL of deionized water (MC-T:G=100:7) and sonicate for 60 minutes to obtain a graphene dispersion. Add the obtained dispersion to the mixture in step (3) in small amounts several times and stir continuously for 2 hours.

[0084] (5) Centrifuge the product obtained in step (4), wash it twice with anhydrous ethanol and deionized water, dry it at 80°C for 12 hours, and grind it to obtain the target product (3% MC-T / G composite material).

[0085] (6) The product collected in step (5) was pressed into tablets, and its resistivity was measured using a four-probe tester. The sample was then mixed with polyvinylidene fluoride and N-methylpyrrolidone to form a slurry, which was sprayed onto nickel foam. Its impedance, cyclic voltammetry, and Tafel curve were measured using an electrochemical workstation, and the coating protection efficiency was calculated. At the same time, the water contact angle and the photocatalytic degradation performance of Rhodamine B were tested. The resistivity of the material was also tested at different temperatures.

[0086] Table 1. Resistivity of 3% MC-T / G composite material at different temperatures

[0087] -20℃ 0.123 0.119 0.118 0.12 0.005 0℃ 0.145 0.153 0.152 0.15 0.007 room temperature 0.179 0.178 0.183 0.18 0.003 40℃ 0.264 0.239 0.247 0.25 0.013 60℃ 0.301 0.325 0.334 0.32 0.017 80℃ 0.471 0.440 0.439 0.45 0.022

[0088] Example 5

[0089] (1) 0.3 g of cobalt chloride hexahydrate and 0.224 g of ammonium molybdate (Co:Mo:Ti molar ratio of 2.5:2.5:95, total doping amount of 5%) were placed in 40 mL of 2 mol / L hydrochloric acid solution and stirred continuously for 40 min until completely dissolved. Then, 17 mL of tetrabutyl titanate was added dropwise to the above solution and stirred for 1 h until a uniform gel-like precursor was formed.

[0090] (2) The precursor obtained in step (1) was transferred to a 100 mL polytetrafluoroethylene-lined hydrothermal reactor. A gradient heating method was used, first heating to 120 °C and holding for 1 hour, then heating to 180 °C and reacting for 24 hours. After the reaction was completed, the mixture was cooled to room temperature, the precipitate was collected, and washed twice with ethanol and deionized water, respectively. The washed product was dried in an oven at 80 °C for 12 hours, and then ground to obtain precursor powder. Finally, the powder was calcined in a muffle furnace at 450 °C for 2 hours, and then ground to obtain cobalt-molybdenum co-doped titanium dioxide powder (5% MC-T).

[0091] (3) Weigh 0.2g of cetyltrimethylammonium bromide and dissolve it in 50mL of water at 40℃. Stir for 10min to dissolve it completely. Then add 1g of the 5% MC-T powder obtained in step (2) and continue stirring for 1h.

[0092] (4) Disperse 0.07g of graphene in 30mL of deionized water (MC-T:G=100:7) and sonicate for 60 minutes to obtain a graphene dispersion. Add the obtained dispersion to the mixture in step (3) in small amounts several times and stir continuously for 2 hours.

[0093] (5) Centrifuge the product obtained in step (4), wash it twice with anhydrous ethanol and deionized water, dry it at 80°C for 12 hours, and grind it to obtain the target product (5% MC-T / G composite material).

[0094] (6) Press the product collected in step (5) into tablets and measure its resistivity using a four-probe tester. Then, prepare a slurry with polyvinylidene fluoride and N-methylpyrrolidone, spray it onto nickel foam, and use an electrochemical workstation to measure its impedance, cyclic voltammetry, and Tafel curve and calculate the coating protection efficiency. At the same time, test the water contact angle.

[0095] Example 6

[0096] (1) 0.432 g of cobalt chloride hexahydrate and 0.32 g of ammonium molybdate (Co:Mo:Ti molar ratio of 3.5:3.5:93, total doping amount of 7%) were placed in 40 mL of 2 mol / L hydrochloric acid solution and stirred continuously for 40 min until completely dissolved. Then, 17 mL of tetrabutyl titanate was added dropwise to the above solution and stirred for 1 h until a uniform gel-like precursor was formed.

[0097] (2) The precursor obtained in step (1) was transferred to a 100 mL polytetrafluoroethylene-lined hydrothermal reactor. A gradient heating method was used, first heating to 120 °C and holding for 1 hour, then heating to 180 °C and reacting for 24 hours. After the reaction was completed, the mixture was cooled to room temperature, the precipitate was collected, and washed twice with ethanol and deionized water, respectively. The washed product was dried in an oven at 80 °C for 12 hours, and then ground to obtain precursor powder. Finally, the powder was calcined in a muffle furnace at 450 °C for 2 hours, and then ground to obtain cobalt-molybdenum co-doped titanium dioxide powder (7% MC-T).

[0098] (3) Weigh 0.2g of cetyltrimethylammonium bromide and dissolve it in 50mL of water at 40℃. Stir for 10min to dissolve it completely. Then add 1g of the 7% MC-T powder obtained in step (2) and continue stirring for 1h.

[0099] (4) Disperse 0.07g of graphene in 30mL of deionized water (MC-T:G=100:7) and sonicate for 60 minutes to obtain a graphene dispersion. Add the obtained dispersion to the mixture in step (3) in small amounts several times and stir continuously for 2 hours.

[0100] (5) Centrifuge the product obtained in step (4), wash it twice with anhydrous ethanol and deionized water, dry it at 80°C for 12 hours, and grind it to obtain the target product (7% MC-T / G composite material).

[0101] (6) Press the product collected in step (5) into tablets and measure its resistivity using a four-probe tester. Then, prepare a slurry with polyvinylidene fluoride and N-methylpyrrolidone, spray it onto nickel foam, and use an electrochemical workstation to measure its impedance, cyclic voltammetry, and Tafel curve and calculate the coating protection efficiency. At the same time, test the water contact angle.

[0102] Table 2 Resistivity of different embodiments

[0103] TG 9.956 10.547 11.392 10.63 0.75 T / G 0.586 0.602 0.582 0.59 0.012 1%MC-T / G 0.455 0.442 0.453 0.45 0.015 3% MC-T / G 0.179 0.178 0.183 0.18 0.003 5% MC-T / G 0.235 0.232 0.223 0.23 0.007 7% MC-T / G 0.462 0.463 0.454 0.46 0.006

[0104] Table 3 Hydrophobic angles of different embodiments

[0105] TG 88.85° 87.5° 88.15° 88.16° 0.69 1%MC-T / G 141.93° 141.45° 141.97° 141.45° 0.3 3%MC-T / G 161.2° 161.6° 161.99° 161.6° 0.23 5%MC-T / G 152.11° 151.92° 152.9° 152.31° 0.3 7%MC-T / G 138.19° 136.94° 136.76° 137.3° 0.45

[0106] Table 4 Nickel foam substrates, including coated and uncoated types.

[0107] Nickel foam 5 -0.258 0.1667 0.899 <![CDATA[TiO2]]> 5 -0.206 0.00004273 0.230353469 83.35% T / G 5 -0.184 0.00002699 0.145500588 89.49% MC-T 5 -0.115 0.00001438 0.077521247 94.40% MC-T / G 5 -0.112 0.00001154 0.06221107 95.50%

[0108] Experimental results

[0109] Scanning electron microscopy was performed on the graphene composite material of cobalt-molybdenum co-doped titanium dioxide from Example 4 (3% Mo / Co co-doped), and the results are as follows: Figure 1As shown in the figure, the graphene in the prepared composite material has a two-dimensional sheet structure, and the cobalt-molybdenum co-doped titanium dioxide particles are uniformly distributed on the surface and between the graphene layers. The particle size is uniform (about 25.15 nm), and the two phase interfaces are tightly bonded, forming a stable heterostructure.

[0110] XRD analysis was performed on the cobalt-molybdenum co-doped titanium dioxide materials prepared in Examples 2 (0% Mo / Co co-doping), 3 (1% Mo / Co co-doping), 4 (3% Mo / Co co-doping), 5 (5% Mo / Co co-doping), and 6 (7% Mo / Co co-doping). Figure 2 It can be seen that in the prepared composite material, as the cobalt and molybdenum content increases appropriately, the proportions of the three phases gradually become more equal. Subsequently, the conductivity (Table 2), hydrophobicity (Table 3), and corrosion resistance of the composite graphene were compared. It was found that Example 3 had the best overall performance: the resistivity was as low as 0.18 Ω·cm, and it could still maintain excellent conductivity stability at different temperatures (-20 ℃ — 80 ℃), and the water contact angle reached 161.6°, which met the superhydrophobic standard.

[0111] The photocatalytic self-cleaning performance of the coating prepared by Example 4 (3% Mo / Co co-doped) cobalt-molybdenum co-doped titanium dioxide composite graphene material was tested. Figures 22-25 It exhibits excellent hydrophobic self-cleaning ability, and the adhesion of the coating was tested using a scraping method. Figure 26 The coating exhibits excellent adhesion, reaching the first-class standard; the degradation rate of Rhodamine B under simulated sunlight reaches 97.5%; after immersion in 3.5 wt.% NaCl solution for 15 days, the coating's protective efficiency remains above 90%, and the corrosion protection efficiency of the material was calculated (Table 4). Examples 4 (5% doping) and 5 (7% doping) showed slightly lower performance, but both were significantly better than the undoped samples. The preferred doping ratio of this invention (3%) is indicated. Furthermore, a comparison of this invention with literature (Table 4) demonstrates that this material exhibits excellent performance, achieving optimal synergy of high conductivity, hydrophobicity, corrosion resistance, and photocatalytic self-cleaning capabilities.

[0112] Table 5. Literature comparison and data table.

[0113] 1 0.52 S / m No catalytic performance WCA=165.8° No protection efficiency Primary adhesion 2 No resistivity data 85% degradation of Rh-B in 8 hours Super hydrophilic No protection efficiency Poor adhesion 3 No resistivity data No catalytic performance WCA=158.3° <![CDATA[Z 0.01 Hz = 8.1×10 4 Ohm cm 2 ]]> Primary adhesion 4 0.042Ω·cm No catalytic performance WCA=124.8° <![CDATA[R ct = 4.3×10 8 Ωcm 2 ]]> Primary adhesion 5 ≈ 35S / m No catalytic performance WCA=155° 99.99% Primary adhesion 6 15.94 S / m No catalytic performance WCA=160.2° No protection efficiency Secondary adhesion 7 <10Ω No catalytic performance WCA=156° 89.7% Primary adhesion 8 No resistivity data No catalytic performance WCA=154° 90.6% Primary adhesion This invention 0.18Ω·cm 97.5% of Rh-B was degraded in 4 hours. WCA=159.3° 91.25% Primary adhesion

[0114] Comparative Document 1: E. Wang, S. Wang, W. Li, W. Zhang, C. Dai, K. Sheng, J. Huang, Synergistic charge and proton transfer–assisted lignin-based conductive and superhydrophobic coatings for non-strain raindrop monitoring, Advanced Composites and Hybrid Materials 8 (2025).

[0115] Comparative Document 2: D.H. Bento, M.L. Matias, M. Magalhães, C. Quitério, A. Pimentel, D. Sousa, P. Amaral, C. Galhano, E. Fortunato, R. Martins, D. Nunes, Self-cleaning stone Façades using TiO2 Microwave-Synthesised Coatings, Cleaner Materials 15 (2025) 100294.

[0116] Comparative Document 3: X. Li, J. Yan, T. Yu, B. Zhang, Versatile nonfluorinated superhydrophobic coating with self-cleaning, anti-fouling, anti-corrosion and mechanical stability, Colloids and Surfaces A: Physicochemical and Engineering Aspects 642 (2022) 128701.

[0117] Comparative Document 4: C. Liu, Q. Jiang, D. Han, Y. Chen, W. Liu, Y. Pei, J. Duan, B. Hou, Preparation of multifunctional composite coating on magnesium alloys with corrosion resistance, conductivity and antibacterial properties, Journal of Magnesium and Alloys 13 (2025) 5438–5454。

[0118] Comparative Document 5: C. Zhang, Y. Lei, K. Wang, B. Jiang, G. Ye, Y. Yuan, K. Sun, Q. Chen, T. Liu, Durable fluorine-free multilayer superhydrophobic coatings for synergistic photothermal and electrothermal anti-icing protection, Progress in Organic Coatings 208 (2025) 109433。

[0119] Comparative Document 6: M. Zhang, M. Wu, Y. Li, J. Zeng, Mussel‐Inspired Superhydrophobic Conductive Textile: A Sustainable Multifunctional Platform for Wearable Electronics and Thermal Management, Energy & Environ Materials 9 (2026) e70132。

[0120] Comparative literature 7: Y. Wang, L. Wang, Q. Zeng, G. Li, Y. He, Y. Yang, Y. Song, M. Huang, Z. Liao, S. Liu, S. Xuan, X. Wang, Y. Ge, K. Yin, Transparent Electrothermal Superhydrophobic Surface with Low Energy Penalty and Durability for Anti / Deicing, Nano Lett. 25 (2025) 15478–15486.

[0121] Comparative literature 8: Z. Li, Y. Zhu, X. Ding, W. Li, Y. Zhao, S. Han, M. Liu, S. Wang, Photothermal and electrothermal superhydrophobic anti-icing / de-icingcoating based on straw-derived sorbitol, Chemical Engineering Journal 521(2025) 166517.

[0122] It is understood that the above specific description of the present invention is only for illustrating the present invention and is not limited to the technical solutions described in the embodiments of the present invention. Those skilled in the art should understand that modifications or equivalent substitutions can still be made to the present invention to achieve the same technical effect; as long as the use needs are met, they are all within the protection scope of the present invention.

Claims

1. A highly conductive multifunctional composite material, characterized in that, The composite material comprises cobalt-molybdenum co-doped titanium dioxide with a stable three-phase heterostructure, and graphene composited on the surface of the cobalt-molybdenum co-doped titanium dioxide; characterized by characteristic peaks of X-ray diffraction pattern, the stable three-phase heterostructure is a coexistence structure formed by anatase phase, rutile phase and doping-induced distortion phase.

2. A method for preparing the highly conductive multifunctional composite material as described in claim 1, characterized in that, Includes the following steps: Cobalt salts and molybdates were mixed with a titanium source in an acidic solution to form a gel precursor, which was then subjected to hydrothermal reaction and calcination to obtain cobalt-molybdenum co-doped titanium dioxide with a stable three-phase heterostructure. Then, with the assistance of a surfactant, the cobalt-molybdenum co-doped titanium dioxide was ultrasonically composited with graphene. Finally, the desired product was obtained by centrifugation, washing, drying, and grinding.

3. The method for preparing the highly conductive multifunctional composite material according to claim 2, characterized in that, The specific steps include the following: (1) Dissolve cobalt chloride hexahydrate and ammonium molybdate in hydrochloric acid solution, stir to dissolve, then add tetrabutyl titanate and continue stirring until a gel-like precursor is formed; (2) The gel-like precursor obtained in step (1) is transferred to a hydrothermal reactor and hydrothermal reaction is carried out by gradient heating. After the reaction is completed, the precipitate is cooled, washed, dried, ground, and then calcined to obtain titanium dioxide powder with a stable three-phase heterostructure. (3) Dissolve hexadecyltrimethylammonium bromide in water, add the titanium dioxide powder obtained in step (2) under constant temperature stirring, and continue stirring; (4) Disperse graphene in water, sonicate it, and then add the resulting graphene dispersion to the product obtained in step (3) and stir to combine. (5) Centrifuge the product obtained in step (4), wash it with anhydrous ethanol and deionized water respectively, and then dry and grind the centrifuged product to obtain the target product, high conductivity multifunctional composite material.

4. The method for preparing the highly conductive multifunctional composite material according to claim 3, characterized in that, In step (1), the molar ratio of cobalt chloride hexahydrate to ammonium molybdate is 1:1, and the ratio of the total molar amount of the two to the molar amount of tetrabutyl titanate is 5:

95.

5. The method for preparing the highly conductive multifunctional composite material according to claim 3, characterized in that, The specific steps (1) include: placing 0.3g of cobalt chloride hexahydrate and 0.22g of ammonium molybdate in 40mL of hydrochloric acid solution with a concentration of 2mol / L, stirring for 40min, then adding 17mL of tetrabutyl titanate dropwise, and continuing to stir for 1h.

6. The method for preparing the highly conductive multifunctional composite material according to claim 4 or 5, characterized in that, In step (2), the conditions for the gradient heating method are: first heat to 120℃ and hold for 1 hour, then heat to 180℃ and react for 24 hours; the calcination temperature is 450℃ and the time is 2 hours; the washing is done by washing twice with ethanol and deionized water respectively, the drying temperature is 80℃ and the drying time is 12 hours.

7. The method for preparing the highly conductive multifunctional composite material according to claim 6, characterized in that, In step (3), 0.2g of cetyltrimethylammonium bromide is dissolved in 50mL of water at 40℃ and stirred for 10min. Then, 1g of titanium dioxide powder obtained in step (2) is added and stirring is continued for 1h.

8. The method for preparing the highly conductive multifunctional composite material according to claim 7, characterized in that, In step (4), graphene is dispersed in 30 mL of water, and the mass ratio of graphene to titanium dioxide powder with a stable three-phase heterostructure obtained in step (2) is 7:

100. The mixture is ultrasonically treated for 60 minutes. Then, the obtained graphene dispersion is added to the product obtained in step (3), and the mixture is continuously stirred and compounded for 2 hours.

9. The method for preparing the highly conductive multifunctional composite material according to claim 8, characterized in that, In step (5), the product obtained in step (4) is centrifuged, washed twice with anhydrous ethanol and deionized water, dried at 80°C for 12 hours, and ground to obtain the target product, a high-conductivity multifunctional composite material.

10. The application of the high conductivity multifunctional composite material according to claim 1 in the preparation of automotive primer, wherein the composite material is mixed with polyvinylidene fluoride and N-methylpyrrolidone to form a slurry, which is then coated onto an automotive substrate or metal surface by spraying.

Images