Friction nanogenerator based on spherical origami structure and its application in removal of methylene blue from dye wastewater

Abstract

The application discloses a kind of spherical paper folding structure's friction nanogenerator (Q-TENG), collection water wave energy constructs self-powered catalytic degradation system, for the removal of dye wastewater methylene blue (MB).Each paper folding structure unit in Q-TENG is based on the working mechanism of contact separation mode, Z-TENG array can be extruded into electrical energy by the movement of solid elastic ball, i.e. the water wave energy collected is converted into electrical energy.This paper folding structure unit is composed of multiple pairs of CM3 composite film as positive material, FEP film as negative material frictional electricity pair.Constructed by rectifier bridge after multiple structure units are connected in parallel, for driving the catalytic degradation of MB.This work improves the efficiency of self-driven electrochemical system to degrade MB, and provides a new development direction for the treatment of MB dye wastewater.

Description

Technical Field

[0001] This invention relates to the field of triboelectric nanogenerators, and in particular to a triboelectric nanogenerator with a spherical origami structure. Background Technology

[0002] The pollution caused by methylene blue (MB) dye wastewater is increasing, making its effective treatment a pressing issue. Electrocatalytic degradation is a potentially advanced wastewater treatment technology because it generates hydroxyl radicals, breaking down dye molecules into smaller inorganic molecules. In the traditional Fenton process, hydrogen peroxide (H₂O₂) is easily decomposed, requiring continuous H₂O₂ replenishment. Electrocatalytic technology overcomes this drawback to some extent by utilizing electrochemical reactions; however, it still suffers from high energy consumption in MB wastewater treatment. Summary of the Invention

[0003] To address the high energy consumption issue in the electrocatalytic technology for treating methylene blue (MB) wastewater, this invention provides a spherical origami-structured triboelectric nanogenerator (Q-TENG) for the removal of methylene blue (MB) from dye wastewater, thereby improving the efficiency of the self-driven electrochemical system in degrading MB.

[0004] The above-mentioned objectives of the present invention are achieved through the following technical solutions:

[0005] A triboelectric nanogenerator with a spherical origami structure mainly consists of a spherical shell, a solid elastic ball, an origami structure unit, and a double helical spring. The spherical shell is composed of two hemispheres, and the solid elastic ball, the origami structure unit, and the double helical spring are arranged inside the spherical shell. The solid elastic ball is located at the center of the spherical shell. One end of the double helical spring is fixed to the outer wall of the solid elastic ball, and the other end of the double helical spring is fixed to the inner wall of the spherical shell. The origami structure unit includes a negative electrode material strip made of fluorinated ethylene propylene film and a positive electrode material strip made of CM3 composite film. The negative electrode material strip and the positive electrode material strip are cross-folded to form the origami structure unit. The spring body is cross-inserted and fixed in the V-shaped angle of the origami structure unit.

[0006] Preferably, there is one solid elastic ball and five origami structure units, which are located directly below, in front of, behind, to the left and to the right of the solid elastic ball, respectively.

[0007] Preferably, the spherical shell is provided with a slot assembly, which includes a slot block disposed on the upper hemisphere and a corresponding slot disposed on the lower hemisphere.

[0008] Preferably, the spherical outer shell has a circular hole for the wire to pass through.

[0009] Preferably, the negative electrode material strip is made by bonding two identical fluorinated ethylene propylene films to the front and back of the same conductive adhesive.

[0010] Preferably, the positive electrode material strip is made by attaching eight identical CM3 composite films to the front and back sides of the conductive adhesive.

[0011] The present invention discloses a spherical origami-structured triboelectric nanogenerator (Q-TENG) that collects water wave energy to construct a self-powered catalytic degradation system for the removal of methylene blue (MB) from dye wastewater.

[0012] The present invention has the following beneficial effects:

[0013] The present invention discloses a spherical origami-structured triboelectric nanogenerator (Q-TENG). Each origami structural unit (Z-TENG) operates based on a contact separation mode mechanism. The Z-TENG array converts the motion compression of a solid elastic sphere into electrical energy, that is, it converts the collected water wave energy into electrical energy. The Z-TENG consists of multiple pairs of triboelectric couples using CM3 composite membranes as the positive electrode material and fluorinated ethylene propylene membranes (FEP membranes) as the negative electrode material. Multiple Z-TENGs are connected in parallel and rectified by a rectifier bridge to drive the catalytic degradation of bromine (MB). This work improves the efficiency of self-driven electrochemical systems in degrading MB, providing a new direction for the treatment of MB dye wastewater. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of the spherical shell structure of the triboelectric nanogenerator with the spherical origami structure of the present invention.

[0015] Figure 2 This is a schematic diagram of the triboelectric nanogenerator of the spherical origami structure of the present invention after removing the upper hemisphere of the spherical shell.

[0016] Figure 3 This is a schematic diagram of the triboelectric nanogenerator with a spherical origami structure according to the present invention.

[0017] Figure 4 This is a schematic diagram of the folding operation steps for a paper origami structural unit.

[0018] Explanation of reference numerals in the attached diagram: 1-Spherical shell, 2-Solid elastic ball, 3-Origami structure unit, 4-Double helical spring, 5-Negative electrode material strip, 6-Positive electrode material strip, 7-Slot block, 8-Slot, 9-Round hole. Detailed Implementation

[0019] As attached Figure 1 , Figure 2 , Figure 3As shown, the present invention discloses a triboelectric nanogenerator with a spherical origami structure, mainly composed of a spherical shell 1, a solid elastic ball 2, an origami structure unit 3, and a double helical spring 4. The spherical shell 1 is composed of two hemispheres, and the solid elastic ball 2, the origami structure unit 3, and the double helical spring 4 are arranged inside the spherical shell 1. The solid elastic ball 2 is located at the center of the spherical shell 1. One end of the double helical spring 4 is fixed to the outer wall of the solid elastic ball 2, and the other end of the double helical spring 4 is fixed to the inner wall of the spherical shell 1. The origami structure unit 3 includes a negative electrode material strip 5 made of fluorinated ethylene propylene film and a positive electrode material strip 6 made of CM3 composite film. The negative electrode material strip 5 and the positive electrode material strip 6 are folded together to form the origami structure unit. The main body of the double helical spring is inserted and fixed in the V-shaped angle of the origami structure unit. The positive electrode material strip 5 and the negative electrode material strip 6 are respectively connected to positive and negative electrode wires. The positive and negative electrode wires pass through the circular holes 9 opened on the spherical shell and are connected to the external circuit. It should be noted that the connection between the solid elastic ball, double helical spring, origami structure unit and spherical shell does not involve internal electrical conductivity. Therefore, the fixing connection between them is made by common double-sided tape or similar ordinary connection to ensure their fixation.

[0020] Preferably, the spherical shell is provided with a slot assembly, which includes a slot block 7 disposed on the upper hemisphere and a corresponding slot 8 disposed on the lower hemisphere.

[0021] Preferably, there is one solid elastic ball and five origami structure units, which are located directly below, in front of, behind, to the left and to the right of the solid elastic ball, respectively.

[0022] Preferably, the negative electrode material strip is made by bonding two identical fluorinated ethylene propylene films to the front and back of the same conductive adhesive.

[0023] Preferably, the positive electrode material strip is made by attaching eight identical CM3 composite films to the front and back sides of the conductive adhesive.

[0024] The specific folding operation method of Z-TENG is as follows: Figure 4 As shown, the prepared positive and negative electrode material strips are first folded from a 2D sheet along predetermined creases to create a complex, flexible, and variable 3D structure. Each time, the bottom material strip is folded laterally onto the top material strip until the end, forming a structural unit. The spherical origami-structured triboelectric nanogenerator is assembled from five structural units. This origami-structure unit design is very simple and suitable for large-scale production. At the same time, the unique multi-layered origami structure effectively increases the contact area, significantly amplifying the triboelectric charge effect and electrostatic coupling effect, further improving the electrical output performance. The complex 3D-TENG can effectively improve the water wave energy collection efficiency.

[0025] Figure 4 A 3D schematic of the Z-TENG with a double-helix multilayer structure is shown, which can be easily constructed using origami designs (e.g., using a folded structure built from two electrode strips). One side of the two conductive tapes is a fluorinated ethylene propylene (FEP) film with a thickness of approximately 50 μm, which acts as the negative electrode of the Z-TENG, and the other side is a CM3 composite film, which acts as the positive electrode. The double-helix design gives the Z-TENG excellent elasticity and flexibility, making it lightweight and extremely sensitive to vibration. The entire Z-TENG structural unit can rebound from a compressed or stretched state to its initial state without any auxiliary elastic support. Based on these advantages, this structure has wide applications in various scenarios such as biomechanics, wearables, ocean energy, and water wave energy harvesting.

[0026] The preparation method of CM3 composite membrane is as follows:

[0027] 1.08 g of FeCl3·6H2O, 0.19 g of Cu(NO3)2·3H2O, and 0.72 g of 2-aminoterephthalic acid (NH2-TPA) were dissolved in 80 mL of dimethylformamide (DMF) and magnetically stirred for 3 hours. The homogeneous solution was then transferred to a 100 mL autoclave lined with polytetrafluoroethylene (PTFE) and heated continuously at 110 °C for 20 hours, followed by natural cooling to room temperature. The resulting suspension was washed three times alternately with DMF, anhydrous ethanol, and deionized water. After centrifugation, the resulting solid was dried in a vacuum oven at 60 °C for 6 hours to obtain M3, which consists of nanoparticles.

[0028] 1.99 g of M3 nanoparticles were dispersed in anhydrous ethanol and ultrasonically stirred for 1 h. Then, 0.5 g (octane-dry weight) of cellulose nanofibers (CNF) were added, and deionized water was added to dilute the mass concentration of the M3 nanoparticles from 1 wt% to 0.2 wt%. Next, the mixture was stirred at 25 °C for 2 h. Subsequently, the uniformly dispersed suspension was poured into a G5 sintered glass funnel for filtration along with PTFE, and dried at 60 °C for 20 min in an automated molding dryer (ESTANITHAAGE BBS-2, Germany). Finally, the dried film was cured in an oven at 120 °C to obtain the CM3 composite membrane.

[0029] The specific material dimensions used in this embodiment are as follows:

[0030] The spherical shell is composed of two acrylic hemispheres with a radius of 10cm. The length of the double helical spring is 3cm (the distance between the highest and lowest points in the extended state), and the radius of the solid elastic ball is 1cm.

[0031] Negative electrode material strip: Two identical fluorinated ethylene propylene films (width: 4cm, length: 16cm, thickness: 50μm) are respectively pasted on the front and back sides of the same conductive adhesive to form a negative electrode material strip; Positive electrode material strip: Eight CM3 films (width: 4cm, length: 4cm, thickness: 50μm) are respectively pasted on the front and back sides of another conductive adhesive to form a positive electrode material strip.

[0032] A spherical Q-TENG device with an origami-assisted multi-layered structure was designed by paralleling the structural units of the Z-TENG. After being sealed and waterproofed, the device was placed in a transparent PP water tank with adjustable vibration frequency. The tank is driven by a linear motor to move one side, generating water waves. The frequency and amplitude of the water waves are controlled by the acceleration of the linear motor. When the Q-TENG is triggered by the water waves, both the spherical shell and the solid elastic ball undulate with the water waves. Due to the presence of double helical springs, a phase difference exists between the two, causing relative motion of the solid elastic ball and contact separation motion of each Z-TENG structural unit, thereby generating periodic AC output voltage and current. This design has several advantages: First, the origami structure units are evenly distributed in every direction of the spherical Q-TENG. When the centrally movable solid elastic sphere oscillates within the sphere due to water wave vibration, at least two origami units (Z-TENGs) can generate energy through contact and separation, with one Z-TENG in a compressed state and the other in a stretched state. Second, the spherical Q-TENG can be excited to move in any direction, and the entire triboelectric structure is sealed within the sphere, avoiding the influence of external conditions such as air and moisture on its electrification performance. Finally, the presence of the double-helix spring structure makes the compression or stretching effect of the origami structure units more pronounced, further expanding the electrical output performance.

[0033] 1. Study the power generation performance of Q-TENG

[0034] The effects of different electrode pairs, Z-TENG numbers, and different triggering angles on its electrical performance were investigated.

[0035] For Z-TENG structural units with different numbers of electrode pairs (N = 2, 4, 6, 8) under the condition of linear motor acceleration a = 2 m / s², when N = 2, the open-circuit voltage is 104 V and the short-circuit current is 2.5 μA; when N = 4, the open-circuit voltage increases from 104 V to 128 V, an increase of 23%, and the short-circuit current increases from 2.5 μA to 5.3 μA, an increase of approximately 112%; when N = 6, the open-circuit voltage increases from 128 V to 146 V, an increase of 14%, and the short-circuit current increases from 5.3 μA to 14.9 μA, an increase of approximately 181%; when N = 8, the open-circuit voltage increases from 146 V to 195 V, an increase of approximately 34%, and the short-circuit current increases from 14.9 μA to 19.1 μA, an increase of approximately 28%.

[0036] The electrical performance of Q-TENGs with different numbers of Z-TENGs (M = 1, 2, 3, 4, 5, 6) was tested. When the number of Z-TENGs increased from 1 to 5, the open-circuit voltage increased from 41V to 179V, an increase of about 337%; the short-circuit current increased from 1.6μA to 9.4μA, an increase of about 488%.

[0037] Under the conditions of acceleration a = 3 m / s² and vibration distance of 8 mm, the electrical performance of the spherical Q-TENG was tested at different trigger angles α = 0°, 30°, 45°, 60°, and 90°. When α = 0° and 90°, the open-circuit voltage was 179V and 180V, and the short-circuit current was 8.1μA and 8.0μA, respectively; when α = 30° and 60°, the open-circuit voltage was 151V and 150V, and the short-circuit current was 6.6μA and 6.7μA, respectively; when α = 45°, the open-circuit voltage was 131V and the short-circuit current was 4.7μA. When the trigger angle increased from 0° to 45°, the electrical performance showed a trend of first decreasing and then increasing. The triggering states were the same when α = 0° and 90° and when α = 30° and 60°, therefore the electrical output performance was similar.

[0038] 2. Q-TENG self-driven catalytic degradation of MB dye wastewater

[0039] A 100 mg / L MB solution was prepared, and the pH was adjusted to the desired value using 0.1 mol / L H₂SO₄ and 0.1 mol / L NaOH solutions. The magnetic stirring speed was set to 300 rpm at room temperature. The experimental conditions were optimized to maximize the catalytic efficiency of the sample. Sampling times were set at 3 min, 5 min, 10 min, 20 min, 30 min, 40 min, 50 min, and 60 min. After sampling, 150 μL of methanol was added to the centrifuge tube using a 1 mL syringe to quench the ·OH groups in the sample solution and terminate the reaction. The solution was then filtered through a 0.22 μm pinhole filter. The absorbance of the dye supernatant solution was measured using a UV-Vis spectrophotometer, and the corresponding MB concentration was calculated.

[0040] The experiment of Q-TENG self-driven catalytic degradation of MB was conducted in an electrolysis device. The MB solution was transferred to the electrolysis device, and the Q-TENG was connected to convert the collected water wave energy into electrical energy to power the device. Under a rectified current of 10 μA, a Pt sheet (10 × 10 mm) was used as the anode, and a carbon sheet (10 × 10 mm) was used as the cathode for electrocatalytic degradation of MB. Other operating procedures were the same as in the catalytic degradation experiment. The degradation effect of MB was calculated according to equation (3-1), and the removal rate of MB was calculated according to equation (3-2).

[0041]

[0042]

[0043] In the formula:

[0044] D: The degradation effect of MB;

[0045] C: Concentration of MB at different reaction times;

[0046] C0: Initial concentration of MB;

[0047] Q: MB removal rate.

[0048] This embodiment explores the effects of different Fe... 2+ The effect of Q-TENG self-powered operation on MB catalytic degradation efficiency was investigated under different addition amounts, H2O2 addition amounts, and pH values. First, the Q-TENG was rectified, and the rectified Q-TENG was connected to the electrolytic cell via a wire. Catalytic degradation experiments were conducted under the following conditions: rectified current of 11 μA, initial MB concentration of 100 mg / L, volume of 50 mL, and water wave acceleration a = 5 m / s².

[0049] In an MB solution with a H2O2 concentration of 19.50 mmol / L and a pH of 3.0, the effects of adding different amounts of Fe were investigated, with and without Q-TENG-driven power supply. 2+ The catalytic degradation efficiency of MB after 60 min. Fe 2+ With the same amount of Fe added, compared to the control group without Q-TENG power supply, the addition of different amounts of Fe under the drive of Q-TENG resulted in different performance. 2+ The experimental group, when Fe 2+ When the addition amount was 0.1 mL, the degradation efficiency of MB increased from 26.6% to 34.8%, an increase of 30.8%; when Fe 2+ When the addition amount was 0.2 mL, the degradation efficiency of MB increased from 38.3% to 45.1%, an increase of 17.8%; when Fe 2+ When the addition amounts were 1.0 mL and 2.0 mL, the removal rates of MB increased by 7.1% and 4.0%, respectively. This indicates that under Q-TENG-driven conditions, compared to the control group without Q-TENG power supply, the degradation rate of MB was significantly increased, with the increase rate remaining between 4.0% and 38.3%. 2+ The increase was greatest when the amount added was 0.2 mL.

[0050] This study investigated the effects of varying H2O2 concentrations on the degradation efficiency of myxobacteria (MB), compared to the control group without Q-TENG power supply. At an H2O2 concentration of 0.20 mmol / L, the MB degradation efficiency increased from 25.3% to 30.7%, a 21.3% increase; at 0.39 mmol / L, it increased from 74.3% to 78.4%, a 5.5% increase; and at H2O2 concentrations of 3.90 mmol / L and 19.50 mmol / L, the MB removal rates increased by 7.3% and 4.0%, respectively. These results indicate that under Q-TENG-driven conditions, the MB degradation rate was significantly increased compared to the control group without Q-TENG power supply, with increases ranging from 4.0% to 21.3%, and the largest increase was observed at an H2O2 concentration of 0.20 mmol / L.

[0051] The catalytic degradation efficiency of MB was investigated after 60 min by changing the pH value of the solution with and without Q-TENG-driven power supply. Under the self-driven power supply of Q-TENG, compared with the control group without Q-TENG-driven power supply, the degradation efficiency of MB increased from 29.5% to 35.7% at a solution pH of 7.0, an increase of 21.1%; at a solution pH of 6.6, the degradation efficiency increased from 40.5% to 50.2%, an increase of 23.9%; and at solution pH values ​​of 5.0, 4.0, and 3.0, the MB removal rates increased by 8.7%, 6.1%, and 4.0%, respectively. These experimental results show that under Q-TENG-driven power supply, the degradation rate of MB is significantly increased compared with the control group without Q-TENG-driven power supply, with increases ranging from 4.0% to 23.9%, and the largest increase is observed at a solution pH of 6.6.

[0052] The above experimental results show that Q-TENG self-powered degradation of MB can significantly improve the removal efficiency of MB. That is, it achieves the same degradation efficiency as MB degradation without Q-TENG self-powered degradation. Furthermore, Q-TENG self-powered degradation of MB can reduce the amounts of H2O2 and Fe. 2+ The amount used reduces the cost of MB degradation and improves recycling efficiency.

Claims

1. A triboelectric nanogenerator with a spherical origami structure, characterized in that: It mainly consists of a spherical shell, a solid elastic ball, an origami structure unit, and a double helical spring. The spherical shell is composed of two hemispheres, and the solid elastic ball, the origami structure unit, and the double helical spring are arranged inside the spherical shell. The solid elastic ball is located at the center of the spherical shell. One end of the double helical spring is fixed to the outer wall of the solid elastic ball, and the other end of the double helical spring is fixed to the inner wall of the spherical shell. The origami structure unit includes a negative electrode material strip made of fluorinated ethylene propylene film and a positive electrode material strip made of CM3 composite film. The negative electrode material strip and the positive electrode material strip are folded crosswise to form the origami structure unit. The spring body is inserted crosswise and fixed in the V-shaped angle of the origami structure unit. The preparation method of the CM3 composite membrane is as follows: 1.08 g of FeCl3·6H2O, 0.19 g of Cu(NO3)2·3H2O, and 0.72 g of 2-aminoterephthalic acid (NH2-TPA) were dissolved in 80 mL of dimethylformamide (DMF) and magnetically stirred for 3 hours. The homogeneous solution was then transferred to a 100 mL autoclave lined with polytetrafluoroethylene (PTFE) and heated continuously at 110 °C for 20 hours, followed by natural cooling to room temperature. The resulting suspension was washed three times alternately with DMF, anhydrous ethanol, and deionized water. After centrifugation, the resulting solid was dried in a vacuum oven at 60 °C for 6 hours to obtain M3, which consists of nanoparticles. 1.99 g of M3 nanoparticles were dispersed in anhydrous ethanol and ultrasonically stirred for 1 h. Then, 0.5 g of oven-dry cellulose nanofibers (CNF) were added, and deionized water was added to dilute the mass concentration of M3 nanoparticles from 1 wt% to 0.2 wt%. Next, the mixture was stirred at 25 °C for 2 h. Subsequently, the uniformly dispersed suspension was poured into a G5 sand core funnel for filtration along with PTFE, and dried at 60 °C for 20 min in an automatic molding dryer. Finally, the dried film was cured in an oven at 120 °C to obtain the CM3 composite membrane.

2. The triboelectric nanogenerator with a spherical origami structure according to claim 1, characterized in that: There is one solid elastic ball and five origami structure units, which are located directly below, in front of, behind, to the left and to the right of the solid elastic ball, respectively.

3. The triboelectric nanogenerator with a spherical origami structure according to claim 1, characterized in that: The spherical shell is provided with a slot assembly, which includes a slot block disposed on the upper hemisphere and a corresponding slot disposed on the lower hemisphere.

4. The triboelectric nanogenerator with a spherical origami structure according to claim 1, characterized in that: The spherical outer shell has a circular hole for the wire to pass through.

5. The triboelectric nanogenerator with a spherical origami structure according to claim 1, characterized in that: The negative electrode material strip is made by attaching two identical fluorinated ethylene propylene films to the front and back of the same conductive adhesive.

6. The triboelectric nanogenerator with a spherical origami structure according to claim 1, characterized in that: The positive electrode material strip is made by attaching eight identical CM3 composite films to the front and back sides of the conductive adhesive.

7. The application of a triboelectric nanogenerator with a spherical origami structure as described in any one of claims 1 to 6 in the removal of methylene blue from dye wastewater.

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