One-step direct synthesis of water-repellent materials and their use in wiper sensors

Abstract

This invention relates to the field of hydrovoltaic power generation and its applications, providing a one-step method for synthesizing amorphous carbon thin films using a plasma-enhanced chemical vapor deposition (PECVD) apparatus, and its application in a voltage-type wiper sensor. The invention uses acetylene, argon, and hydrogen as precursors, and synthesizes amorphous carbon thin films by adding baffles to the target substrate to mitigate plasma erosion. Compared to traditional hydrovoltaic materials, this invention improves upon the complex transfer process required for traditional graphene thin films and eliminates the need for doping with other metal catalysts. The one-step direct synthesis of amorphous carbon thin films significantly reduces process costs and environmental pollution. Furthermore, this invention provides a novel wiper-type raindrop sensor that automatically adjusts the rotation speed of a servo motor based on the voltage generated by falling raindrops.

Description

Technical Field

[0001] This invention relates to the field of water-based materials and their applications, and provides a method for synthesizing amorphous carbon thin films in one step using a plasma-enhanced chemical vapor deposition apparatus, as well as an application of a voltage-type windshield wiper sensor. Background Technology

[0002] With the increasing depletion of non-renewable energy sources, renewable new energy materials have become a research hotspot. Among them, hydro-voltaic power generation, a new way to convert water energy into electrical energy, has opened up a new field in the direction of new energy power generation (see Nat. Nanotechnol. 2018, 13, 1109-1119; Adv. Funct. Mater. 2019, 29, 1901069; ACS Materials Lett. 2021, 3, 193-209). Unlike previous hydropower technologies, which convert water energy into mechanical energy and then into electrical energy, hydro-voltaic power generation is a relatively mature technology, but it is extremely demanding in terms of environmental requirements, requires large scale, and is costly. In contrast, hydro-voltaic power generation, based on the electric double-layer pseudocapacitance (EDL) theory, can combine water energy with wind and solar energy for power generation, making it green, environmentally friendly, and lower in cost. Hydro-voltaic power generation has various power generation modes, such as drip potential, drag potential, evaporation potential, and wave potential. This invention mainly focuses on the research and application of drip potential.

[0003] Researchers have discovered that carbon materials possess excellent water-drop potential properties. From the initial carbon nanotubes to the current graphene, through in-depth exploration of the mechanism, it has been found that modifying the substrate and doping with nitrogen can effectively improve the water-drop potential of materials (see J. Am. Chem. Soc. 2018, 140, 13746-13752; J. Mater. Chem. A 2019, 7, 12038-12049). However, currently, the synthesis of graphene requires substrate transfer, a cumbersome and time-consuming process that hinders industrial-scale production. Secondly, research on drop potential is relatively simplistic, failing to consider the impact of different experimental conditions on the results. Most importantly, there are currently no practical applications of drop potential research. Summary of the Invention

[0004] This invention aims to solve at least one of the above-mentioned technical problems by providing a one-step method for synthesizing water-voltaic materials, i.e., amorphous carbon thin films, using a plasma-enhanced chemical vapor deposition (PECVD) apparatus. The effects of different experimental parameters on its water-voltaic performance are discussed, and finally, its application in a voltage-type raindrop sensor is demonstrated.

[0005] The first aspect of this invention provides a method for directly synthesizing amorphous carbon thin films in a one-step plasma-enhanced chemical vapor deposition process, comprising the following steps:

[0006] S1. The substrate is ultrasonically dispersed and cleaned, and then placed in an oven to dry.

[0007] S2. Place the cleaned substrate into the high-temperature zone of the plasma-enhanced chemical vapor deposition apparatus, and place a large baffle directly above it. Then turn on the vacuum pump and introduce a certain amount of protective gas.

[0008] S3. Continue to introduce protective gas and raise the temperature at a constant rate until the temperature reaches 800-900℃.

[0009] S4. When the temperature reaches 800-900℃, continue to introduce protective gas, turn on the plasma generator, and introduce a certain amount of acetylene.

[0010] S5. Continue step S4 and maintain a constant temperature for a period of time;

[0011] S6. After the reaction is complete, turn off the plasma generator and acetylene gas, and wait for the plasma-enhanced chemical vapor deposition device to cool down naturally, finally obtaining an amorphous carbon film.

[0012] Hydrovoltaic power generation is a novel renewable energy source, in which carbon materials exhibit particularly excellent hydrovoltaic properties. However, traditional graphene fabrication processes are quite complex, and risks of contamination and breakage may arise during the transfer process. This invention primarily optimizes this complex process by placing a large baffle on the target substrate to effectively reduce plasma erosion and enables the direct one-step synthesis of amorphous carbon films.

[0013] Preferably, in step S1: the quartz plate is placed in ethanol or acetone and ultrasonically dispersed for 5-10 minutes, and the temperature of the oven is set to 60-80℃ for 2-5 minutes.

[0014] Preferably, in step S2: the vacuum degree of this step is 0.01-10 Pa, the gas is one or both of argon and hydrogen, and the gas flow rate is 1-20 sccm.

[0015] Preferably, in step S3: the heating rate is 5-25 min / ℃, and the temperature is heated to a specified temperature of 800-900℃.

[0016] Preferably, in step S4: during the isothermal process at 800-900℃, the power of the plasma generator is between 100-300W, and the flow rate of acetylene is 5-20 sccm.

[0017] Preferably, in step S5: the vacuum degree of this step is 20-50 Pa, the gas is argon, hydrogen, or acetylene, and the gas flow rate is 1-20 sccm.

[0018] Preferably, in step S6, argon and hydrogen are continuously introduced as protective gases.

[0019] Preferably, the substrate is a quartz plate.

[0020] A second aspect of the present invention provides the influence of different factors such as height, angle, and droplet size on the magnitude of the droplet potential voltage.

[0021] A third aspect of the present invention provides the application of the above-mentioned water-voltaic material in a voltage-type windshield wiper sensor, specifically providing a model of a voltage-type windshield wiper sensor.

[0022] The present invention can achieve at least one of the following beneficial effects:

[0023] 1) The method for preparing amorphous carbon thin films according to the present invention does not require the doping of metal elements or the addition of catalysts, is pollution-free, and can be reused;

[0024] 2) The preparation process of this invention is simple, can be produced directly in one step without disordered subsequent processing, and can be used for large-scale production;

[0025] 3) This invention discusses the influence of different parameters on the dripping potential, further refining the data for hydroelectric power generation;

[0026] 4) The application of the voltage-type raindrop sensor in this invention provides a new and practical approach to the potential of water droplets, enabling hydroelectric power generation to be truly applied in real life. Attached Figure Description

[0027] Figure 1 Schematic diagram of a plasma-enhanced chemical vapor deposition apparatus;

[0028] Figure 2 The image shows the Raman spectrum of the amorphous carbon thin film material obtained in Example 1.

[0029] Figure 3 This is a field emission scanning electron microscope image of the amorphous carbon thin film material obtained in Example 1;

[0030] Figure 4 This is a transmission electron microscope image of the amorphous carbon thin film material obtained in Example 1;

[0031] Figure 5 Selected area electron diffraction pattern of the amorphous carbon thin film material obtained in Example 1;

[0032] Figure 6 Contact angle test of the amorphous carbon thin film material obtained in Example 1;

[0033] Figure 7 The transmittance of the amorphous carbon thin film material obtained in Example 1 was tested.

[0034] Figure 8 This is a schematic diagram of the titration potential of the amorphous carbon thin film material obtained in Example 1;

[0035] Figure 9 This is a titration potential-voltage diagram of the amorphous carbon thin film material obtained in Example 1;

[0036] Figure 10 The graph shows the relationship between the droplet potential height and the angular voltage of the amorphous carbon film obtained in Example 1.

[0037] Figure 11 This is a graph showing the relationship between the droplet size and voltage of the amorphous carbon film obtained in Example 1.

[0038] Figure 12 This is a physical image of the voltage-type windshield wiper sensor device with the amorphous carbon thin film obtained in Example 1;

[0039] Figure 13 This is a connection diagram of the voltage-type wiper sensor device for the amorphous carbon thin film obtained in Example 1;

[0040] Explanation of reference numerals in the attached figures:

[0041] 1-Gas;

[0042] 2-Plasma generator;

[0043] 3-High temperature zone;

[0044] 4-Baffle;

[0045] 5-Substrate. Detailed Implementation

[0046] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0047] like Figure 1 As shown, a preferred embodiment of the present invention provides a plasma-enhanced chemical vapor deposition apparatus, including a plasma generator 2 and a chemical vapor deposition device, wherein the chemical vapor deposition device has a high-temperature zone 3.

[0048] A preferred embodiment of the present invention provides a method for synthesizing amorphous carbon thin films in one step using a plasma-enhanced chemical vapor deposition apparatus, comprising the following steps:

[0049] S1. Ultrasonically disperse and clean the substrate 5, then place it in an oven to dry;

[0050] S2. Place the cleaned substrate 5 into the high-temperature zone 3 of plasma-enhanced chemical vapor deposition, and place a large baffle 4 directly above it. Then turn on the vacuum pump to evacuate the vacuum and introduce a certain amount of protective gas.

[0051] S3. Continue to introduce protective gas and raise the temperature at a constant rate until the temperature reaches 800-900℃.

[0052] S4. When the temperature reaches 800-900℃, continue to introduce protective gas, turn on the plasma device, and introduce a certain amount of acetylene.

[0053] S5. Continue step S4 and maintain a constant temperature for a period of time;

[0054] S6. After the reaction is complete, turn off the plasma device and acetylene gas, and wait for the plasma-enhanced chemical vapor deposition device to cool down naturally, finally obtaining the amorphous carbon film of water-based material.

[0055] In step S1: Place the quartz plate in ethanol or acetone and ultrasonically disperse for 5-10 minutes, then set the oven temperature to 60-80℃ for 2-5 minutes.

[0056] In step S2: the vacuum degree of this step is 0.01-10 Pa, the gas is one or both of argon and hydrogen, and the gas flow rate is 1-20 sccm.

[0057] In step S3: the heating rate is 5-25 min / ℃, and the temperature is heated to the specified temperature of 800-900℃.

[0058] In step S4: During the isothermal process at 800-900℃, the power of the plasma generator is between 100-300W, and the flow rate of acetylene is 5-20sccm.

[0059] In step S5: the vacuum degree of this step is 20-50 Pa, the gas is argon, hydrogen, or acetylene, and the gas flow rate is 1-20 sccm.

[0060] The following are specific examples, using hydrogen, argon, and acetylene as examples.

[0061] Example 1

[0062] 1) Wash the quartz plate with ethanol three times, then put it in an oven to dry at 60℃ for 5 minutes.

[0063] 2) Take out the dried quartz plate and place it in the first half of the high-temperature zone of the plasma-enhanced chemical vapor deposition apparatus. Then, continuously purge the air inside with argon gas for 10 minutes at a flow rate of 20 sccm.

[0064] 3) After step 2) is completed, change the argon gas flow rate to 10 sccm and introduce 1 sccm of hydrogen gas for 5 minutes.

[0065] 4) After step 3) is completed, the heating zone of the plasma-enhanced chemical vapor deposition apparatus is heated to 900°C at a heating rate of 20 min / °C.

[0066] 5) When the temperature reaches 900℃, 5 sccm of acetylene is introduced, and the plasma device is turned on to 100W. The temperature is maintained at this level for 30 minutes. The heating is then turned off, and the furnace is cooled down to room temperature. During this process, 10 sccm of argon and 1 sccm of hydrogen are introduced. An amorphous carbon film is obtained on the substrate in the high-temperature zone.

[0067] Field emission electron microscope images of the amorphous carbon film are attached. Figure 3 As shown, uniform particles can be observed adhering to the surface; a transmission microscope image of the amorphous carbon film is attached. Figure 4 As shown, a thin carbon film can be observed.

[0068] Example 2

[0069] The preparation method is basically the same as in Example 1, except that the plasma power in step 5) is 200W.

[0070] Example 3

[0071] The preparation method is basically the same as in Example 1, except that the plasma power in step 5) is 300W.

[0072] Example 4

[0073] The preparation method is basically the same as in Example 1, except that in step 3), the flow rate of argon is 20 sccm and the flow rate of hydrogen is 1 sccm.

[0074] Example 5

[0075] The preparation method is basically the same as in Example 1, except that the flow rate of argon gas in step 3) is 1 sccm and the flow rate of hydrogen gas is 10 sccm.

[0076] Example 6

[0077] The preparation method is basically the same as in Example 1, except that the flow rate of argon gas in step 3) is 5 sccm and the flow rate of hydrogen gas is 5 sccm.

[0078] Example 7

[0079] The preparation method is basically the same as in Example 1, except that the constant temperature in step 4) is 800℃.

[0080] Example 8

[0081] The preparation method is basically the same as in Example 1, except that the temperature holding time in step 5) is 15 min.

[0082] Example 9

[0083] The preparation method is basically the same as in Example 1, except that the temperature holding time in step 7) is 60 min.

[0084] The Raman spectra of amorphous carbon thin films synthesized directly in one step using plasma-enhanced chemical vapor deposition are shown in the attached figure. Figure 2 As shown, it can be seen that it is amorphous carbon; the scanning electron microscope image of the amorphous carbon thin film is attached. Figure 3 As shown, its surface morphology can be seen. Figure 6 The contact angle test of ultrapure water on the amorphous carbon membrane shows that the amorphous carbon membrane is hydrophilic. Figure 7 The light transmittance test shows that the light transmittance of the amorphous carbon film is over 80%, indicating good light transmittance.

[0085] Figure 8 This is a schematic diagram of titration potential. Figure 9 This demonstrates the excellent water-voltaic properties of the amorphous carbon film. Dropping 0.12 ml of 0.6 M NaCl continuously from a height of 15 cm onto the amorphous carbon film at a 70° angle to the ground generates a voltage of 120-160 mV. Figure 10 As shown, 0.05 ml of 0.6 M NaCl was used to test from a height of 15 cm to explore the relationship between height and angle. Figure 11 As shown, 0.6M NaCl was dropped from a height of 15cm onto an amorphous carbon film at a 70° angle to the ground to investigate the relationship between droplet size and the generated voltage. It can be seen that discussing the influence of different parameters on the droplet potential can further improve the data on hydroelectric power generation.

[0086] Figure 12 This is a picture of a voltage-type raindrop sensor, which mainly consists of a microcontroller, a servo motor, indicator lights, and an amorphous carbon film. Figure 13 This is the wiring diagram for a voltage-type raindrop sensor. At the input terminal (A0), a 10K resistor is connected in parallel with the amorphous carbon film. At the output terminal, the three pins of the servo motor are connected to port 5V and port 11 respectively, with the other pin grounded. An indicator light is connected to port 11. A voltmeter is connected to the positive and negative terminals of the amorphous carbon film to monitor the generated voltage in real time. A computer is connected between the microcontroller and the voltmeter to import the program into the microcontroller. Applying the amorphous carbon film to a voltage-type raindrop sensor provides a new and practical approach to raindrop potential, enabling hydroelectric power generation to be truly applied in daily life.

[0087] Finally, it should be noted that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A one-step method for directly synthesizing water-based photovoltaic materials, characterized in that, Includes the following steps: S1. Clean the substrate and dry it after cleaning; S2. Place the dried substrate into the high-temperature zone (3) of the plasma-enhanced chemical vapor deposition apparatus, and set a baffle (4) directly above the substrate in the high-temperature zone (3), evacuate the vacuum and then introduce a certain amount of protective gas. S3. Continue to introduce protective gas, and the high temperature zone (3) will heat up at a constant rate until the temperature reaches 800-900℃. S4. When the temperature in the high-temperature zone reaches 800-900℃, continue to introduce protective gas, start the plasma generator and introduce a certain amount of acetylene. S5, continue step S4, keep the temperature constant for 15-60 minutes; S6. After the reaction is complete, stop the plasma generator and stop the acetylene gas supply. Wait for the plasma-enhanced chemical vapor deposition device to cool down naturally. Finally, an amorphous carbon film is obtained, which is the water-based material. In step S3: the heating rate is 10-20℃ / min; In steps S2 to S4: the protective gas is one or both of argon and hydrogen, and the flow rate is 1-20 sccm; In step S4: the vacuum level is 10-20 Pa, the power of the plasma generator is 100-300 W, and the acetylene flow rate is 5 sccm.

2. The method for direct one-step synthesis of water-based materials according to claim 1, characterized in that, In step S1: the cleaning solvent is at least one of ultrapure water, ethanol, and acetone.

3. The method for direct one-step synthesis of water-based materials according to claim 1, characterized in that, In step S2: the substrate is a quartz plate.

4. The method for direct one-step synthesis of water-based materials according to claim 1, characterized in that, In step S6: Argon and hydrogen are continuously introduced as protective gases.

5. A water-based material, characterized in that, Prepared by the method according to any one of claims 1-4.

6. An application of the water-volt material as described in claim 5 in a voltage-type windshield wiper sensor.

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