Thermoelectric and hygroelectric power generation materials based on metal-phase molybdenum disulfide double-layer conductive fabrics, preparation methods and applications

Abstract

The present invention relates to a thermoelectric and hygroelectric power generation material based on a metal-phase molybdenum disulfide double-layer conductive fabric, a preparation method and an application thereof. Using metal-phase molybdenum disulfide as the base material, an ammonium ion intercalation hydrothermal method is used to in-situ grow a vertical array of 1T-phase molybdenum disulfide nanosheets on the surface of carbonized silk fibers to construct a p-type semiconductor, which provides abundant nano-channels for the efficient moisture absorption and flow of water, generating a high current density output; using a cotton fabric as the substrate, an n-type semiconductor is constructed by forming a 1T-phase molybdenum disulfide / titanium carbide van der Waals heterostructure on the surface of cotton fibers. The large specific surface area of the 1T-phase molybdenum disulfide / titanium carbide van der Waals heterostructure enables rapid electron migration. The present invention constructs a textile-based thermoelectric and hygroelectric generator through the orderly encapsulation of p-type 1T-phase molybdenum disulfide / carbonized silk, n-type 1T-phase molybdenum disulfide / titanium carbide-cotton fabric and aluminum electrodes, realizing the efficient collection and conversion of low-grade thermal energy and moisture energy, and can be applied to intelligent wearables, flexible sensing and energy conversion.

Description

Technical Field

[0001] The present invention relates to a double-layer conductive fabric based on a vertical array of metal-phase molybdenum disulfide and a molybdenum disulfide / titanium carbide van der Waals heterojunction, a synthesis method thereof, and applications thereof in intelligent wearables, flexible sensing, and energy technologies, belonging to the technical field of material preparation and applications. Background Art

[0002] Advanced fabrics with optoelectronic and mechanical integration functions present attractive prospects in flexible sensing, energy harvesting, and storage to meet the growing characteristics of miniaturization and integration of nanotechnology in intelligent wearable devices (see the literature: Chem. Soc. Rev. 2021 , 50, 7009). Textile-based generators can effectively collect and convert low-grade energy from the environment or the human body and convert it into affordable and sustainable electricity, which has attracted extensive attention in the next generation of energy conversion technologies (see the literature: Nat. Nanotechnol. 2021 , 16, 811). However, these textile-based generators usually suffer from low output power density and poor environmental adaptability, resulting in huge challenges for their portable applications in complex and variable environments (see the literature: Nat. Mater. 2019 , 18, 608). It is worth noting that integrated generators with the ability to synergistically absorb various forms of energy in the environment, such as representative cases of light-coordinated "wet electric generators" and solar thermoelectric devices, provide a promising approach for record-high current density (see the literature: Nat. Energy 2016 , 1, 16138).

[0003] Molybdenum disulfide, as a typical representative of transition metal dichalcogenides (TMDS), has been widely used in energy conversion and storage such as electrochemical hydrogen absorption, electrodes, and supercapacitors due to its unique physical and chemical properties derived from its special layered structure. Molybdenum disulfide usually exists in a semiconductor phase (2H phase) and a metal phase (1T phase). The 2H phase is thermodynamically stable, but its large direct bandgap leads to poor inherent conductivity, while the conductivity of the 1T phase is several orders of magnitude higher than that of the 2H phase. However, the metastable nature of the 1T phase poses great challenges in its preparation and application.

[0004] Chinese invention patent CN114530287B discloses a method for in-situ synthesizing 2H-phase molybdenum disulfide on carbonized silk and exfoliating with n-butyllithium to prepare 1T-phase molybdenum disulfide. The prepared wet power generation material can achieve a voltage output of 0.8 V and a current output of 0.4 mA. However, due to the poor conductivity of the 2H phase and the dangerous preparation method of n-butyllithium being explosive in the presence of water, its industrialization and commercial application are greatly limited. Summary of the Invention

[0005] Aiming at the deficiencies existing in the existing preparation process of molybdenum disulfide wet power generation materials grown on carbonized silk, such as complex process and single performance, the present invention provides a thermo-hygroelectric power generation material, preparation method and application based on a bilayer conductive fabric of metal-phase molybdenum disulfide, which has better conductivity and hydrophilicity, higher current density and voltage output, and has a simple preparation process, low energy consumption, can simultaneously have the functions of thermoelectric power generation and hygroelectric power generation, and can efficiently convert thermal energy and hygroenergy.

[0006] The technical solution to achieve the object of the present invention is to provide a preparation method of a thermo-hygroelectric power generation material based on a bilayer conductive fabric of metal-phase molybdenum disulfide, including the following steps:

[0007] (1) Ultrasonically wash and dry the silk knitted fabric with absolute ethanol and deionized water, and perform carbonization treatment for 60 - 90 min under the protection of an inert gas atmosphere at a temperature of 700 - 950 °C to obtain a carbonized silk knitted fabric; dissolve ammonium molybdate tetrahydrate and thiourea in deionized water according to a mass ratio of 1:1.5 - 1:3.0 to obtain a 1T-phase molybdenum disulfide seed solution with a mass concentration of 5 - 15 g / L, add the carbonized silk knitted fabric after carbonization treatment for impregnation treatment for 30 - 90 min, and the mass ratio of the carbonized silk knitted fabric to the mass of the seed solution is 1:100 - 1:300, and then perform hydrothermal reaction at a temperature of 180 - 220 °C for 15 - 20 h; after cooling, take out the fabric, perform ultrasonic cleaning and drying to obtain a p-type 1T-phase molybdenum disulfide conductive carbonized silk knitted fabric;

[0008] (2) Add titanium carbide aluminide with a mass ratio of 1:15 - 1:30 to a mixed solution of lithium fluoride and hydrochloric acid with a volume concentration of 5 - 15 %, react at a temperature of 35 - 55 °C for 12 - 36 h, ultrasonically treat the obtained product with ethanol and water for 30 - 90 min respectively, and then perform centrifugation treatment at 3000 - 4000 revolutions per minute to obtain a dispersion of few-layer titanium carbide nanosheets; mix 1T-phase molybdenum disulfide and titanium carbide nanosheets according to a molar ratio of 1:1.0 - 1:2.5, ultrasonically treat for 1.5 - 3.5 h to obtain a molybdenum disulfide / titanium carbide dispersion; spray the molybdenum disulfide / titanium carbide dispersion on one side of a cotton knitted fabric after being cleaned with ethanol and deionized water, and then perform baking treatment at a temperature of 50 - 80 °C for 10 - 15 min; repeat the spraying and baking operations 5 - 10 times to obtain an n-type 1T-phase molybdenum disulfide / titanium carbide conductive cotton knitted fabric;

[0009] (3) Stack and encapsulate the p-type 1T-phase molybdenum disulfide conductive carbonized silk knitted fabric obtained in step (1), the n-type 1T-phase molybdenum disulfide / titanium carbide conductive cotton knitted fabric obtained in step (2), and the aluminum metal electrode in an orderly manner to obtain a thermo-hygroelectric power generation material based on a bilayer conductive fabric of metal-phase molybdenum disulfide.

[0010] The technical solution of the present invention includes a thermo-hygroelectric power generation material based on a bilayer conductive fabric of metal-phase molybdenum disulfide, which is obtained by using a 1T-phase molybdenum disulfide / carbonized silk knitted fabric as a p-type semiconductor, a 1T-phase molybdenum disulfide / titanium carbide cotton knitted fabric as an n-type semiconductor and a water storage layer, and an aluminum metal electrode as a negative electrode, and then encapsulating; the size is 3×1 cm 2 of the 1T-phase molybdenum disulfide / carbonized silk knitted fabric, with a resistance of 0.39 - 1.54 kΩ, a complete wetting time of deionized water of 1 s, and a water contact angle of 15° - 30°; the size is 2×1 cm 2 of the 1T-phase molybdenum disulfide / titanium carbide cotton knitted fabric, with a resistance of 0.31 - 0.87 kΩ, and a water contact angle of 10° - 25° after being wetted with deionized water for 10 s.

[0011] The application of the thermo-hygroelectric power generation material based on a bilayer conductive fabric of metal-phase molybdenum disulfide described in the present invention is to use it to prepare a power generation device with both thermal energy and humidity energy.

[0012] The thermo-hygroelectric power generation device described in the present invention can be used in smart wearables and flexible sensing.

[0013] The present invention provides a better conductivity and hydrophilicity by in-situ growing a vertical array of 1T-phase molybdenum disulfide nanosheets on the surface of carbonized silk fibers through a simple method of ammonium ion intercalation hydrothermal treatment, providing rich nanochannels for the efficient moisture absorption and flow of water, thereby generating a higher current density output; at the same time, introducing a titanium carbide material with a large specific surface area to form a two-dimensional sheet-like van der Waals heterojunction with 1T-phase molybdenum disulfide nanosheets. At the same time, the rich oxygen-containing functional groups (-OH, =O) of the 1T-phase molybdenum disulfide / titanium carbide van der Waals heterojunction ensure more proton migration when the moisture-induced dissociation of oxygen-containing functional groups occurs, thereby generating a high voltage output. All in all, the orderly combination of the prepared 1T-phase molybdenum disulfide with carbonized silk and titanium carbide constructs a textile-based thermo-hygroelectric generator, which simultaneously realizes the efficient conversion of thermal energy and humidity energy and can be applied in directions such as energy conversion and flexible sensing.

[0014] The principle of the present invention is as follows: Conductive carbonized silk fabric with in-situ growth of p-type 1T-phase molybdenum sulfide prepared by ammonium ion intercalation hydrothermal method and conductive cotton knitted fabric loaded with n-type molybdenum sulfide / titanium carbide van der Waals heterojunction are orderly stacked and encapsulated to construct a p-n type thermo-hygroelectric power generation material. When the fabric is under dry conditions, driven by the temperature difference, an electric potential difference is generated by the directional movement of electrons due to the temperature difference at both ends of the p-n junction, enabling self-power generation. At the same time, the 1T-phase molybdenum sulfide / titanium carbide van der Waals heterojunction contains abundant oxygen-containing functional groups (-OH, =O). Under the induction of moisture, protons are dissociated from the oxygen-containing functional groups. The asymmetric distribution of the oxygen-containing functional groups in the two conductive fabrics and the formation of the double electric layer construct a proton concentration difference, enabling the directional migration of protons, thereby generating a high voltage and current output. The conversion of multiple energy forms in a single device is realized.

[0015] Compared with modern technologies, the beneficial effects of the present invention are as follows: The present invention prepares a conductive carbonized silk fabric with in-situ growth of 1T-phase molybdenum sulfide nanosheets and a conductive cotton knitted fabric with 1T molybdenum sulfide / titanium carbide van der Waals heterojunction by a simple ammonium ion intercalation hydrothermal method. The vertical array of nanosheets is orderly stacked to construct a three-dimensional nanostructured fluid channel, which promotes the rapid moisture absorption and flow and the migration of electrons. At the same time, the large specific surface area of the van der Waals heterojunction enables the rapid movement and collection of electrons, thereby realizing the collection and conversion of multiple energy forms (thermal energy, hygroscopic energy) in a single device of a multifunctional material, further improving the power generation performance. When integrated with masks, clothing, etc., it can realize the real-time monitoring of physiological states such as human breathing and movement. Moreover, the preparation process is simple and efficient, which is more suitable for commercial applications under the dual-carbon policy. Description of the Drawings

[0016] Figure 1 Scanning electron microscope (SEM) images of the conductive carbonized silk fabric with in-situ growth of 1T-phase molybdenum sulfide nanosheets and the conductive cotton fabric with 1T-phase molybdenum sulfide / titanium carbide before and after preparation in Example 1 of the present invention;

[0017] Figure 2 Cross-sectional scanning electron microscope (SEM) images of the thermo-hygroelectric power generation device made of the conductive carbonized silk fabric with in-situ growth of 1T-phase molybdenum sulfide nanosheets and the conductive cotton fabric with 1T-phase molybdenum sulfide / titanium carbide prepared in Example 1 of the present invention;

[0018] Figure 3 X-ray diffraction (XRD) patterns of the conductive carbonized silk fabric with in-situ growth of 1T-phase molybdenum sulfide nanosheets and the conductive cotton fabric with 1T-phase molybdenum sulfide / titanium carbide before and after preparation in Example 1 of the present invention;

[0019] Figure 4 Raman spectra (Roman) of the conductive carbonized silk fabric with in-situ growth of 1T-phase molybdenum sulfide nanosheets and the conductive cotton fabric with 1T-phase molybdenum sulfide / titanium carbide before and after preparation in Example 1 of the present invention;

[0020] Figure 5 For Example 1 of the present invention, the two-line method resistance test chart and water contact angle chart before and after the preparation of the 1T-phase molybdenum disulfide nanosheet in-situ grown carbonized silk fabric and the 1T-phase molybdenum disulfide / titanium carbide conductive cotton fabric are shown;

[0021] Figure 6 For Example 1 of the present invention, the thermoelectric performance test of the 1T-phase molybdenum disulfide nanosheet in-situ grown carbonized silk fabric and the 1T-phase molybdenum disulfide / titanium carbide conductive cotton fabric is shown;

[0022] Figure 7 For Example 1 of the present invention, the wet electricity generation performance test of the 1T-phase molybdenum disulfide nanosheet in-situ grown carbonized silk fabric and the 1T-phase molybdenum disulfide / titanium carbide conductive cotton fabric is shown;

[0023] Figure 8 For Example 1 of the present invention, the flexible sensing test of the 1T-phase molybdenum disulfide nanosheet in-situ grown carbonized silk fabric and the 1T-phase molybdenum disulfide / titanium carbide conductive cotton fabric is shown.

[0024] Figure 2 Among them, 1. Non-woven fabric; 2. 1T-phase molybdenum disulfide nanosheet in-situ grown carbonized silk fabric; 3. 1T-phase molybdenum disulfide / titanium carbide conductive cotton fabric; 4. Aluminum electrode. Embodiment

[0025] The technical solution of the present invention will be further elaborated through the following drawings and examples. Example 1

[0026] Take a silk knitted fabric with dimensions of 6×40 cm 2 Ultrasonically wash and dry it with ethanol and deionized water, lay it flat in a tube furnace and introduce argon for 1.5 h, and perform carbonization treatment at 800 °C for 60 min. After cooling to room temperature, obtain a carbonized silk fabric.

[0027] Accurately weigh 0.36 g of ammonium molybdate tetrahydrate and 0.72 g of thiourea, add them to 60 mL of deionized water, prepare a growth solution, vigorously stir for 30 min, then add a carbonized silk fabric with dimensions of 3×3 cm 2 and continuously stir for 15 min. Transfer it to a 100 mL polytetrafluoroethylene reaction kettle, perform hydrothermal reaction at 200 °C for 18 h. After cooling to room temperature, take out the fabric, ultrasonically clean it 3 times with ethanol and deionized water respectively, and then place it in a 60 °C vacuum drying oven for drying for 12 h to obtain a conductive carbonized silk fabric with 1T-phase molybdenum disulfide nanosheets in-situ grown.

[0028] Accurately weigh 2.5 g of aluminum carbonitride and add it to a mixed solution of 50 mL of lithium fluoride and hydrochloric acid. Stir at a temperature of 45 °C for 24 h. Wash the product with deionized water until the pH > 6, then ultrasonically treat it with 150 mL of ethanol and deionized water for 1 h respectively, and centrifuge at 3500 revolutions per minute for 20 min to obtain a dispersion of few-layer titanium carbide nanosheets; accurately weigh 0.2 g of 1T-phase molybdenum disulfide and add it to 10 mL of the titanium carbide nanosheet dispersion. After stirring for 30 min, ultrasonically treat it for 2 h under the condition of a power of 1200 watts to obtain a molybdenum disulfide / titanium carbide nanosheet dispersion; accurately measure 1 mL of the molybdenum disulfide / titanium carbide dispersion with a pipette and spray it onto one side of a washed and dried cotton knitted fabric, and bake it in an oven at 60 °C for 10 min. Repeat the above operation 7 times, and then dry it in a vacuum drying oven at 60 °C for 12 h to obtain a 1T-phase molybdenum disulfide / titanium carbide conductive cotton knitted fabric.

[0029] Take a 1T-phase molybdenum disulfide conductive carbonized silk fabric with a size of 2.5×1 cm 2 and a 1T-phase molybdenum disulfide / titanium carbide conductive cotton knitted fabric with a size of 2×1 cm 2 and stack them orderly to obtain a thermoelectric and hygroelectric power generation material based on 1T-phase molybdenum disulfide; together with an aluminum electrode with a size of 2.5×1 cm 2 After being orderly encapsulated with non-woven fabric, a flexible thermoelectric and hygroelectric power generation device is obtained.

[0030] After testing, the prepared flexible thermoelectric and hygroelectric power generation device exhibits accurate temperature recognition and monitoring capabilities, has a Seebeck coefficient of 23.5 μV / K, and the thermoelectric and hygroelectric power generation device can be integrated with a mask to monitor the human breathing frequency for the purpose of health monitoring.

[0031] Wetting the device with 0.5 mL of deionized water exhibits amazing hygroelectric power generation performance, which can generate a high voltage of 1.16 V, a current of 0.68 mA, and a power output of 32.26 μW / cm 2 and the duration can reach 25000 s.

[0032] Connect 5 to 9 thermoelectric and hygroelectric power generation devices prepared by the scheme of this embodiment in series. In the dry state, the mutual conversion between fingertip thermal signals / language can be realized; in the wet state, a voltage of 4.8 V can be generated, which can successfully drive wearable electronic devices such as LEDs, thermohygrometers, and electronic watches.

[0033] See attached Figure 1, are the scanning electron microscope (SEM) images before and after the preparation of 1T-phase molybdenum disulfide nanosheet in-situ grown on carbonized silk fabric and 1T-phase molybdenum disulfide / titanium carbide conductive cotton fabric in this example; Figures (a)-(c) are SEM images at different magnifications before and after the growth of 1T-phase molybdenum disulfide nanosheet in-situ grown on carbonized silk fabric; Figures (d)-(f) are SEM images at different magnifications before and after the preparation of 1T-phase molybdenum disulfide / titanium carbide conductive cotton fabric; It can be seen that the vertically arrayed molybdenum disulfide nanosheets grown in-situ on the smooth carbonized silk surface are uniform in thickness; The molybdenum disulfide / titanium carbide van der Waals heterojunction was successfully loaded on the cotton knitted surface by the method of unilateral spraying-baking.

[0034] See Appendix Figure 2 , are the interface scanning electron microscope (SEM) images of the thermoelectric and hygroelectric device prepared in this example; The 1T-phase molybdenum disulfide nanosheet in-situ grown on carbonized silk fabric 2 and the 1T-phase molybdenum disulfide / titanium carbide conductive cotton fabric 3 are stacked, an aluminum electrode 4 is set, and after being encapsulated by non-woven fabric 1, a thermoelectric and hygroelectric device with a size of 2.5×1 cm 2 , and a thickness of 1.07 mm is prepared.

[0035] See Appendix Figure 3 , are the X-ray diffraction (XRD) images before and after the preparation of 1T-phase molybdenum disulfide nanosheet in-situ grown on carbonized silk fabric and 1T-phase molybdenum disulfide / titanium carbide conductive cotton fabric in this example; Figure (a) is the X-ray diffraction image of 1T-phase molybdenum disulfide nanosheet in-situ grown on carbonized silk fabric and 1T-phase molybdenum disulfide / titanium carbide conductive cotton fabric; Figure (b) is the X-ray diffraction image of 1T-phase molybdenum disulfide / titanium carbide conductive cotton fabric and 1T-phase molybdenum disulfide / titanium carbide conductive cotton fabric; The results confirm the successful preparation and growth of 1T-phase molybdenum disulfide, and the successful loading of the molybdenum disulfide / titanium carbide van der Waals heterojunction on the cotton fabric.

[0036] See Appendix Figure 4 , are the Raman spectroscopy (Roman) images before and after the preparation of 1T-phase molybdenum disulfide nanosheet in-situ grown on carbonized silk fabric and 1T-phase molybdenum disulfide / titanium carbide conductive cotton fabric in this example; Figure (a) is the Raman spectroscopy image of 1T-phase molybdenum disulfide nanosheet in-situ grown on carbonized silk fabric and 1T-phase molybdenum disulfide / titanium carbide conductive cotton fabric; Figure (b) is the Raman spectroscopy image of 1T-phase molybdenum disulfide / titanium carbide conductive cotton fabric and 1T-phase molybdenum disulfide / titanium carbide conductive cotton fabric; The results further confirm the successful preparation and growth of 1T-phase molybdenum disulfide, and the successful loading of the molybdenum disulfide / titanium carbide van der Waals heterojunction on the cotton fabric.

[0037] See Appendix Figure 5, which are the two-wire method resistance test diagrams and water contact angle diagrams before and after the preparation of 1T-phase molybdenum disulfide nanosheet in-situ grown carbonized silk fabric and 1T-phase molybdenum disulfide / titanium carbide conductive cotton fabric in this embodiment; the size is 2.5×1 cm 2 The resistance of the 1T-phase molybdenum disulfide conductive carbonized silk fabric with a size of 2 is 1.37 kΩ. The growth of the vertical array of molybdenum disulfide nanosheets endows the carbonized silk with excellent hydrophilicity, and the water contact angle is 25°; the size is 2×1 cm 2 The resistance of the 1T-phase molybdenum disulfide / titanium carbide conductive cotton fabric is 0.58 kΩ.

[0038] See Appendix Figure 6 , which are the thermoelectric performance tests of the 1T-phase molybdenum disulfide nanosheet in-situ grown carbonized silk fabric and 1T-phase molybdenum disulfide / titanium carbide conductive cotton fabric prepared in this embodiment; the prepared thermo-hygroelectric device has a Seebeck coefficient of 23.5 μV / K, and the thermoelectric voltage has a good thermal response to temperature.

[0039] See Appendix Figure 7 , which are the hydroelectric performance tests of the 1T-phase molybdenum disulfide nanosheet in-situ grown carbonized silk fabric and 1T-phase molybdenum disulfide / titanium carbide conductive cotton fabric prepared in this embodiment; the size is 2×1 cm 2 For the thermo-hygroelectric device with a size of 2 , after being wetted with 0.5 mL of deionized water, it has an output voltage of 1.16 V and an output current of 0.687 mA, showing broad application prospects in energy technologies such as wearable flexible micro-power sources.

[0040] See Appendix Figure 8 , which are the flexible sensing tests of the 1T-phase molybdenum disulfide nanosheet in-situ grown carbonized silk fabric and 1T-phase molybdenum disulfide / titanium carbide conductive cotton fabric prepared in this embodiment: (a) The figure shows the thermal voltage signal diagram of the thermo-hygroelectric device integrated with a mask for monitoring the breathing frequency of the human body in different states; it is confirmed that the thermo-hygroelectric device has good responsiveness to heat sources, and the integration with the mask can be used to monitor the health status of the human body; (b) The figure shows the voltage and current change diagram of the thermo-hygroelectric device when pressed by a finger in the wetted state; it is confirmed that the wetted thermo-hygroelectric device has good responsiveness to pressure changes, and the integration of the near device with various joints of clothing can realize the real-time monitoring of human movement; the thermo-hygroelectric device also shows broad application prospects in flexible sensing. Example 2

[0041] Take a silk knitted fabric with a size of 5×40 cm 2 , ultrasonically wash it with ethanol and deionized water and dry it, lay it flat in a tube furnace and introduce argon for 1.5 h, perform carbonization treatment at 900 °C for 30 min, and after cooling to room temperature, obtain the carbonized silk fabric.

[0042] Accurately weigh 0.18 g of ammonium molybdate tetrahydrate and 0.36 g of thiourea, add them to 60 mL of deionized water to prepare a growth solution. After vigorously stirring for 30 min, add carbonized silk fabric with a size of 3×1 cm 2 and continue stirring for 15 min. Transfer it to a 100 mL polytetrafluoroethylene reaction kettle, carry out hydrothermal reaction at 180 °C for 24 h. After cooling to room temperature, take out the fabric, and ultrasonically clean it 3 times with ethanol and deionized water respectively, then place it in a vacuum drying oven at 60 °C and dry it for 12 h to obtain a conductive carbonized silk fabric with 1T-phase molybdenum sulfide nanosheets grown in-situ.

[0043] Accurately weigh 2.0 g of aluminum carbonitride and add it to a mixed solution of 40 mL of lithium fluoride and hydrochloric acid. Stir at a temperature of 45 °C for 18 h. Wash the product with deionized water until pH>6, then ultrasonically treat it with 100 mL of ethanol and deionized water for 1 h respectively, and centrifuge it at 3500 revolutions per minute for 20 min to obtain a dispersion of few-layer titanium carbide nanosheets; accurately weigh 0.15 g of 1T-phase molybdenum sulfide and add it to 10 mL of the titanium carbide nanosheet dispersion. After stirring for 45 min, ultrasonically treat it for 2.5 h under the condition of a power of 1200 watts to obtain a molybdenum sulfide / titanium carbide nanosheet dispersion; accurately measure 1 mL of the molybdenum sulfide / titanium carbide dispersion with a pipette and spray it on one side of the washed and dried cotton knitted fabric, then bake it in an oven at 60 °C for 10 min. Repeat the above operation 9 times, and then place it in a vacuum drying oven at 60 °C and dry it for 12 h to obtain a 1T-phase molybdenum sulfide / titanium carbide conductive cotton knitted fabric.

[0044] Take a 1T-phase molybdenum sulfide conductive carbonized silk fabric with a size of 1.5×1 cm 2 and a 1T-phase molybdenum sulfide / titanium carbide conductive cotton knitted fabric with a size of 1×1 cm 2 and stack them orderly to obtain a thermo-hygroelectric power generation material based on 1T-phase molybdenum sulfide; together with an aluminum electrode with a size of 1.5×1 cm 2 After orderly encapsulation with non-woven fabric, a flexible thermo-hygroelectric power generation device is obtained. Example 3

[0045] Take a silk knitted fabric with a size of 5×50 cm 2 Ultrasonically wash it with ethanol and deionized water and dry it. Lay it flat in a tube furnace and pass argon for 1.5 h. Carry out carbonization treatment at 850 °C for 90 min. After cooling to room temperature, obtain carbonized silk fabric.

[0046] Accurately weigh 0.72 g of ammonium molybdate tetrahydrate and 1.44 g of thiourea, add them to 60 mL of deionized water to prepare a growth solution. After vigorously stirring for 30 min, add carbonized silk fabric with a size of 3×6 cm 2The carbonized silk fabric was continuously stirred for 15 min, transferred to a 100 mL polytetrafluoroethylene reaction kettle, and hydrothermally reacted at 220 °C for 20 h. After cooling to room temperature, the fabric was taken out, ultrasonically cleaned 3 times with ethanol and deionized water respectively, and then dried in a vacuum drying oven at 60 °C for 12 h to obtain a conductive carbonized silk fabric with 1T-phase molybdenum sulfide nanosheets grown in-situ.

[0047] Accurately weigh 1.5 g of aluminum carbonitride and add it to a mixed solution of 30 mL of lithium fluoride and hydrochloric acid. Stir at a temperature of 45 °C for 36 h. Wash the product with deionized water until the pH > 6, then ultrasonically treat it with 100 mL of ethanol and deionized water for 1 h respectively, and centrifuge at 3500 revolutions per minute for 20 min to obtain a dispersion of few-layer titanium carbide nanosheets; accurately weigh 0.25 g of 1T-phase molybdenum sulfide and add it to 10 mL of the titanium carbide nanosheet dispersion. After stirring for 50 min, ultrasonically treat it for 1.5 h under the condition of a power of 1200 watts to obtain a molybdenum sulfide / titanium carbide nanosheet dispersion; accurately measure 1 mL of the molybdenum sulfide / titanium carbide dispersion with a pipette and spray it on one side of the washed and dried cotton knitted fabric, and bake it in an oven at 60 °C for 10 min. Repeat the above operation 5 times, and then dry it in a vacuum drying oven at 60 °C for 12 h to obtain a 1T-phase molybdenum sulfide / titanium carbide conductive cotton knitted fabric.

[0048] Take a 1T-phase molybdenum sulfide conductive carbonized silk fabric with a size of 5×2 cm 2 and a 1T-phase molybdenum sulfide / titanium carbide conductive cotton knitted fabric with a size of 4×2 cm 2 Stack them orderly to obtain a thermo-hygroelectric power generation material based on 1T-phase molybdenum sulfide; together with an aluminum electrode with a size of 5×2 cm 2 After being orderly encapsulated with non-woven fabric, a flexible thermo-hygroelectric power generation device is obtained.

Claims

1. A preparation method of a thermoelectric and hygroelectric power generation material based on a double-layer conductive fabric of metallic phase molybdenum disulfide, characterized in that It includes the following steps: (1) Ultrasonically wash and dry the silk knitted fabric with absolute ethanol and deionized water, and carbonize it for 60 - 90 min under the protection of an inert gas atmosphere at a temperature of 700 - 950 °C to obtain a carbonized silk knitted fabric; dissolve ammonium molybdate tetrahydrate and thiourea in deionized water according to a mass ratio of 1:1.5 - 1:3.0 to obtain a 1T-phase molybdenum sulfide seed solution with a mass concentration of 5 - 15 g / L, add the carbonized silk knitted fabric after carbonization treatment and impregnate it for 30 - 90 min. The mass ratio of the carbonized silk knitted fabric to the seed solution is 1:100 - 1:300, and then carry out hydrothermal reaction at a temperature of 180 - 220 °C for 15 - 20 h; After cooling, take out the fabric, ultrasonically clean and dry it to obtain a p-type 1T-phase molybdenum sulfide conductive carbonized silk knitted fabric; (2) Add titanium carbide aluminide with a mass ratio of 1:15 - 1:30 to a mixed solution of lithium fluoride and hydrochloric acid with a volume concentration of 5 - 15 %, react at a temperature of 35 - 55 °C for 12 - 36 h, ultrasonically treat the obtained product with ethanol and water for 30 - 90 min respectively, and then centrifuge it at 3000 - 4000 revolutions per minute to obtain a dispersion of few-layer titanium carbide nanosheets; mix 1T-phase molybdenum sulfide and titanium carbide nanosheets according to a molar ratio of 1:1.0 - 1:2.5, ultrasonically treat for 1.5 - 3.5 h to obtain a molybdenum sulfide / titanium carbide dispersion; spray the molybdenum sulfide / titanium carbide dispersion on one side of the cotton knitted fabric after being cleaned with ethanol and deionized water, and then bake it at a temperature of 50 - 80 °C for 10 - 15 min; repeat the spraying and baking operations 5 - 10 times to obtain an n-type 1T-phase molybdenum sulfide / titanium carbide conductive cotton knitted fabric; (3) Stack and encapsulate the p-type 1T-phase molybdenum sulfide conductive carbonized silk knitted fabric obtained in step (1), the n-type 1T-phase molybdenum sulfide / titanium carbide conductive cotton knitted fabric obtained in step (2), and the aluminum metal electrode in an orderly manner to obtain a thermo-hygroelectric power generation material based on a bilayer conductive fabric of metal-phase molybdenum disulfide.

2. A thermoelectric and hygroelectric power generation material based on a metal-phase molybdenum disulfide bilayer conductive fabric, characterized in that: It is obtained by using 1T-phase molybdenum sulfide / carbonized silk knitted fabric as the p-type semiconductor, 1T-phase molybdenum sulfide / titanium carbide cotton knitted fabric as the n-type semiconductor and water storage layer, and aluminum metal electrode as the negative electrode layer, and then encapsulating. Size: 3×1 cm 2 The 1T-phase molybdenum sulfide / carbonized silk knitted fabric with a size of 3×1 cm has a resistance of 0.39 - 1.54 kΩ, a complete wetting time of 1 s with deionized water, and a water contact angle of 15° - 30°; the size is 2×1 cm 2 The 1T-phase molybdenum sulfide / carbonized titanium cotton knitted fabric with a size of 2×1 cm has a resistance of 0.31 - 0.87 kΩ, and a water contact angle of 10° - 25° when wetted with deionized water for 10 s.

3. The application of a heat and moisture generating material based on a metal-phase molybdenum disulfide bilayer conductive fabric as described in claim 2, characterized in that: It is used for preparing a power generation device with both thermal energy and moisture energy.

4. The application of a heat and moisture generating material based on a metal-phase molybdenum disulfide double-layer conductive fabric according to claim 3, characterized in that: The thermo-hygroelectric power generation device is used in smart wearable and flexible sensing.

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