Photoresponse two-dimensional nanofluid film as well as preparation method and application thereof

Abstract

The invention relates to the technical field of nanofluid films, in particular to a photoresponse two-dimensional nanofluid film and a preparation method and application thereof. A preparation method of a photoresponse two-dimensional nanofluid film comprises the following steps that S1, a pure Ti sheet is placed in dilute nitric acid to be soaked, oxides and impurities on the Ti sheet are removed, and the Ti sheet is washed clean with ultrapure water; s2, the Ti sheet is placed on an anode, a three-layer two-dimensional nanofluid film TNAs is prepared through an anodic oxidation method, and electrolyte is prepared from ultrapure water, ethylene glycol and ammonium fluoride; s3, performing electrochemical deposition on the TNAs in the S3 by using a three-electrode system to prepare a fluid film TNAs / CdS; and the electrolyte is prepared from sodium thiosulfate pentahydrate, cadmium chloride and hydrochloric acid. According to the invention, the effect of photocatalytic degradation of organic matters is realized while concentration power generation of the photoresponse two-dimensional nanofluid film is carried out.

Description

Technical Field

[0001] The present invention relates to the technical field of nanofluid films, and in particular to a light-responsive two-dimensional nanofluid film and a preparation method and application thereof. Background Art

[0002] Titanium dioxide nanopore arrays have a uniform tubular structure. At the same time, anatase phase titanium dioxide has a wide bandgap, thus providing channels for ion transport and exhibiting good photoactivity, making it widely used in photoelectrochemical systems. In two-dimensional nanomaterial TNAs, under conditions of unilateral light irradiation, the photogenerated electrons and holes in the material separate, leaving positively charged holes on the illuminated side while electrons move toward the backlit side, making it negatively charged. As a result, the surface charge distribution of two-dimensional nanomaterial TNAs is asymmetric, and the separated carriers can drive charged ions to move through the electrolyte, thereby generating a transmembrane current caused by directional ion transport. However, the photoelectric conversion efficiency of pure titanium dioxide is low, electrons and holes are easily recombine, and the photocatalytic degradation ability is relatively low. Summary of the Invention

[0003] The purpose of the present invention is to address the above-mentioned deficiencies in the prior art and to provide a light-responsive two-dimensional nanofluid film and a preparation method and application thereof.

[0004] The first object of the present invention is to provide a method for preparing a light-responsive two-dimensional nanofluid film, comprising the following steps:

[0005] S1. Soak the pure Ti sheet in dilute nitric acid to remove oxides and impurities on the Ti sheet, and then rinse it with ultrapure water;

[0006] S2 and Ti sheets were placed at the anode, and three-layer two-dimensional nanofluid film TNAs were prepared by anodic oxidation. The electrolyte was composed of ultrapure water, ethylene glycol and ammonium fluoride.

[0007] S3. Electrochemically depositing the TNAs in S3 using a three-electrode system to prepare a nanofluid film TNAs / CdS; the electrolyte is prepared using sodium thiosulfate pentahydrate, cadmium chloride and hydrochloric acid.

[0008] Furthermore, in step S2, the volume-to-mass ratio of ultrapure water, ethylene glycol, and ammonium fluoride in the electrolyte is 20-70 ml: 400-500 ml: 2-3 g.

[0009] Furthermore, in step S2, anodization is performed at a voltage of 10-25 V for 0.5-1.5 h.

[0010] Furthermore, in step S3, the pH of the electrolyte is 2-4; and the molar ratio of sodium thiosulfate pentahydrate to cadmium chloride is 1-3:1.

[0011] Further, in step S3, the electrodeposition voltage is 3V, and the deposition time is 10-30 min.

[0012] A second object of the present application is to provide a photoresponsive two-dimensional nanofluidic membrane prepared by the above method.

[0013] A third object of the present application is to provide an application of the photoresponsive two-dimensional nanofluidic membrane as described above as a light-coupled salt differential cell diaphragm.

[0014] A fourth object of the present application is to provide an application of the photoresponsive two-dimensional nanofluidic membrane as described above as a photocatalyst for degrading organic matter.

[0015] A fifth object of the present application is to provide a light-coupled power generation device, which uses the photoresponsive two-dimensional nanofluidic membrane as described above as a diaphragm, and in the preparation process, the side of the diaphragm facing the other electrode is the front side, the electrolyte solutions with concentration difference are on both sides of the diaphragm, the electrolyte solution with low concentration is on the front side of the diaphragm, and the light-irradiated side is the front side.

[0016] Further, the high-concentration electrolyte solution contains a pollutant to be degraded.

[0017] Further, the pollutant to be degraded is methylene blue.

[0018] When the three-layer two-dimensional nanofluidic film TNAs prepared by the present application is obtained by controlling the type of electrolyte, the morphology under a microscope is three-layer distribution, and no heat treatment process is required. CdS is deposited on the surface of the TNAs by electrodeposition, CdS is a common photocatalytic degradation material, has strong light absorption and light degradation performance, and when CdS and titanium dioxide are in close contact, a z-type heterojunction is formed, forming an interlaced band gap structure. This heterojunction structure enables the spontaneous directional migration of carriers, inhibits the recombination of electrons and holes, and thus enhances the photoelectric conversion efficiency and the photocatalytic degradation ability of titanium dioxide. At the same time, the TNAs / CdS nanosheet after compounding has a three-layer distribution in morphology under a microscope, which further improves the contact area of TNAs / CdS with organic matter and the area irradiated by light, thereby achieving better photocatalytic degradation efficiency and concentration difference power generation effect.

[0019] The raw materials of the present application are simple and easy to obtain, low in price, mild in reaction conditions, simple and feasible in preparation process, high in repeatability, and can be produced on a large scale to realize industrialization.

[0020] The present application realizes the effect of photocatalytic degradation of organic matter while generating power by the photoresponsive two-dimensional nanofluidic membrane. BRIEF DESCRIPTION OF DRAWINGS

[0021] Figure 1is a scanning electron microscope image of the TNAs / CdS material prepared in Example 1 of the present invention;

[0022] Figure 2 is the XRD pattern of the TNAs / CdS material prepared in Example 1 of the present invention;

[0023] Figure 3 is a photocatalytic degradation diagram of the TNAs / CdS material prepared in Example 1 of the present invention;

[0024] Figure 4 1 is a graph of the open circuit potential and short circuit current of the TNAs / CdS material prepared in Example 1 of the present invention;

[0025] Figure 5 1 is a power density diagram of the TNAs / CdS material prepared in Example 1 of the present invention at different concentration gradients;

[0026] Figure 6 is the simulated wastewater power generation of the TNAs / CdS material prepared in Example 1 of the present invention;

[0027] Figure 7 is a scanning electron microscope image of a cross section of the TNAs / CdS material prepared in Example 1 of the present invention;

[0028] Figure 8 This is an EDS image of the TNAs / CdS material prepared in Example 1 of the present invention;

[0029] Figure 9-15 They correspond to the morphologies of TNAs at different voltages and oxidation times in Table 1 ;

[0030] Figure 16-18 The power density comparisons of TNAs and TNAs / CdS under 5-fold, 50-fold, and 500-fold concentration gradients are shown respectively;

[0031] Figure 19 It is the power generated by the concentration difference of TNAs / CdS under different light intensities and 500-fold concentration gradient;

[0032] Figure 20 Comparison of the degradation effect of methylene blue by TNAs / CdS at different S and Cd ratios;

[0033] Figure 21 This is a comparison of the degradation effects of methylene blue by the titanium sheet, TNAs, and TNAs / CdS in Example 1. DETAILED DESCRIPTION

[0034] The following are specific embodiments of the present invention and the accompanying drawings to further describe the technical solutions of the present invention, but the present invention is not limited to these embodiments.

[0035] Example 1

[0036] The steps for preparing the photoresponsive two-dimensional nanofluid film TNAs / CdS material are as follows:

[0037] S1. Weigh 50 ml of ultrapure water, 450 ml of ethylene glycol, and 2.75425 g of ammonium chloride, and mix them thoroughly to obtain an electrolyte for anodization.

[0038] S2. Polish the Ti sheet and use it as the anode. Use the platinum electrode as the cathode. Use the electrolyte in S1 and anodic oxidation at a voltage of 20 V for 1 h. Then rinse thoroughly with ultrapure water and dry at room temperature for 24 h to obtain TNAs.

[0039] S3. Weigh 0.248 g of Na2S2O3·5H2O and 0.228 g of CdCl2·2.5H2O, fully dissolve them in 100 ml of ultrapure water, and then adjust the pH to 3.0 with HCl to prepare an electrolyte for electrochemical deposition;

[0040] The TNAs in S2 were used as the cathode, Ag / AgCl as the reference electrode, and the platinum electrode as the anode. The electrolyte in S3 was used and electrochemical deposition was performed at a voltage of 3 V for 20 minutes. The TNAs / CdS was then washed with ultrapure water and dried at room temperature for 24 hours. The side facing the platinum electrode was the front side.

[0041] A mixed solution of 4ml of 500mmol / L KCl, 1ml of 5mg / L MB, and 5ml of 1mmol / L KCl were injected into the front and back sides of the prepared TNAs / CdS, respectively. Ag / AgCl electrodes were connected to an external load through wires to perform concentration-difference power generation. At the same time, light with a wavelength of 365nm and an intensity of 100% was applied to the low-concentration side. Current was output to test its output power density, and the high-concentration methylene blue content was measured every 10 minutes.

[0042] Example 2

[0043] The steps for preparing the photoresponsive two-dimensional nanofluid film TNAs / CdS material are as follows:

[0044] According to the data in Table 1, the voltage and oxidation time of step S2 in Example 1 were modified to obtain different TNAs, and the rest were the same as in Example 1.

[0045] Table 1

[0046] Figure 9 Figure 10 Figure 11 Figure 12 Figure 13 Figure 14 Figure 15 t(min) 60 60 30 45 75 90 60 V(V) 10 15 20 20 20 20 25

[0047] Example 3

[0048] The steps for preparing the photoresponsive two-dimensional nanofluid film TNAs / CdS material are as follows:

[0049] S1. Weigh 50 ml of ultrapure water, 450 ml of ethylene glycol, and 2.75425 g of ammonium chloride, and mix them thoroughly to obtain an electrolyte for anodization.

[0050] S2. Polish the Ti sheet and use it as the anode. Use the platinum electrode as the cathode. Use the electrolyte in S1 and anodic oxidation at a voltage of 20 V for 1 h. Then rinse thoroughly with ultrapure water and dry at room temperature for 24 h to obtain TNAs.

[0051] S3. Weigh 0.124 g of Na2S2O3·5H2O and 0.228 g of CdCl2·2.5H2O, fully dissolve them in 100 ml of ultrapure water, and then adjust the pH to 3.0 with HCl to prepare an electrolyte for electrochemical deposition;

[0052] TNAs in S2 was used as the cathode, Ag / AgCl as the reference electrode, and a platinum electrode as the anode. Electrochemical deposition was performed for 20 min at a voltage of 3 V using the electrolyte in S3. The product was then washed with ultrapure water and dried at room temperature for 24 h to obtain TNAs / CdS.

[0053] 4ml of a mixed solution of 500mmol / L KCl and 1ml of 5mg / LMB and 5ml of 1mmol / L KCl were injected into the left and right sides of the prepared TNAs / CdS, respectively. Ag / AgCl electrodes were used and connected to a load via wires to perform concentration-differential power generation. At the same time, light with a wavelength of 365nm and an intensity of 100% was applied to the low-concentration side. Current was output to test its output power density, and the high-concentration methylene blue content was measured every 10 minutes.

[0054] Example 4

[0055] The steps for preparing the photoresponsive two-dimensional nanofluid film TNAs / CdS material are as follows:

[0056] S1. Weigh 50 ml of ultrapure water, 450 ml of ethylene glycol, and 2.75425 g of ammonium chloride, and mix them thoroughly to obtain an electrolyte for anodization.

[0057] S2. Polish the Ti sheet and use it as the anode. Use the platinum electrode as the cathode. Use the electrolyte in S1 and anodic oxidation at a voltage of 20 V for 1 h. Then rinse thoroughly with ultrapure water and dry at room temperature for 24 h to obtain TNAs.

[0058] S3. Weigh 0.372 g of Na2S2O3·5H2O and 0.228 g of CdCl2·2.5H2O, fully dissolve them in 100 ml of ultrapure water, and then adjust the pH to 3.0 with HCl to prepare an electrolyte for electrochemical deposition;

[0059] TNAs in S2 was used as the cathode, Ag / AgCl as the reference electrode, and a platinum electrode as the anode. Electrochemical deposition was performed for 20 min at a voltage of 3 V using the electrolyte in S3. The product was then washed with ultrapure water and dried at room temperature for 24 h to obtain TNAs / CdS.

[0060] 4ml of a mixed solution of 500mmol / L KCl and 1ml of 5mg / LMB and 5ml of 1mmol / L KCl were injected into the left and right sides of the prepared TNAs / CdS, respectively. Ag / AgCl electrodes were used and connected to a load via wires to perform concentration-differential power generation. At the same time, light with a wavelength of 365nm and an intensity of 100% was applied to the low-concentration side. Current was output to test its output power density, and the high-concentration methylene blue content was measured every 10 minutes.

[0061] In summary, the TNAs / CdS concentration difference power generation device of the present invention is capable of degrading pollutants while performing concentration difference power generation, providing a new type of power generation device while improving the power density of power generation.

[0062] Figure 1 This is a scanning electron microscope image of the front and back of the TNAs / CdS material prepared in Example 1 of the present invention. It can be seen that a layer of CdS particles is formed on both the front and back of the TNAs.

[0063] Figure 2 This is the XRD pattern of the TNAs / CdS material prepared in Example 1 of the present invention. The results show that TNAs is mainly composed of anatase phase titanium dioxide, and the TNAs / CdS composite material not only retains the anatase phase of TNAs, but also has the characteristic diffraction peak of CdS.

[0064] Figure 3 This is a photocatalytic degradation diagram of the TNAs / CdS material prepared in Example 1 of the present invention. After 120 minutes of degradation, the methylene blue is significantly reduced.

[0065] Figure 4 Figure 2 is a graph of the open circuit potential and short circuit current of the TNAs / CdS material prepared in Example 1 of the present invention. The results show that with the increase of the concentration gradient, the open circuit potential and short circuit current of TNAs / CdS are improved. At the same time, the open circuit potential and short circuit current of TNAs / CdS are also improved based on the comparison of whether light is added or not.

[0066] Figure 5 1 is a power density diagram of the TNAs / CdS material prepared in Example 1 of the present invention at different concentration gradients. As the concentration gradient increases, the maximum power density is also improved.

[0067] Figure 6 The simulated wastewater power generation power of the TNAs / CdS material prepared in Example 1 of the present invention is 1W / m2 under a concentration gradient of 500 times. 2 , which fully demonstrates that the material can also generate electricity during the degradation process.

[0068] Figure 7 This is a cross-sectional scanning electron microscope image of the TNAs / CdS material prepared in Example 1 of the present invention. The composited TNAs / CdS nanosheets have a three-layer morphology under the microscopic view. It can be seen from the image that CdS is only composited on the upper and lower surfaces of the TNAs, and there are almost no CdS particles in the TNAs tube.

[0069] Figure 8 This is an EDS image of the TNAs / CdS material prepared in Example 1 of the present invention. Cd and S elements are evenly distributed on the surface of TNAs, proving the uniform deposition of CdS.

[0070] Figure 9-15 The images of the TNAs at different voltages and oxidation times in Table 1 correspond to the morphologies. A comparison of the images shows that when the voltage is too low, the TNAs fail to form well-defined nanopores, while when the voltage is too high, the TNAs deform. A voltage of 20V produces the best nanoarray. Furthermore, when the oxidation time is too short, dense nanopores cannot form, while when the time is too long, the arrangement of the nanopores becomes chaotic. The best nanopore formation occurs when the oxidation time is 1 hour. In summary, a voltage of 20V and an oxidation time of 1 hour produce the best nanopore formation.

[0071] Figure 16-18 The power density comparisons of TNAs and TNAs / CdS under 5-fold, 50-fold and 500-fold concentration gradients are shown. It can be seen that the power generation efficiency of the composite TNAs / CdS is significantly improved, and under the same conditions, the power generation power of TNAs / CdS is significantly better than that of TNAs.

[0072] Figure 19 This is the concentration difference power generation power of TNAs / CdS under different light intensities and a 500-fold concentration gradient. It can be seen that with the increase of light intensity, the power density steadily increases, indicating that the higher the light intensity, the better the power generation effect.

[0073] Figure 20The comparison of the degradation effects of methylene blue by TNAs / CdS at different S and Cd ratios shows that when the S and Cd ratio is 2:1 (Example 1), the degradation effect of methylene blue is the best, which is better than the cases with a ratio of 1:1 (Example 3) and 3:1 (Example 4).

[0074] Figure 21 This is a comparison chart of the degradation effects of methylene blue by the titanium sheet, TNAs and TNAs / CdS in Example 1. It can be seen that the pure titanium sheet has almost no degradation efficiency on methylene blue and only has a very small adsorption effect, while the degradation effect of TNAs on methylene blue is slightly improved, but the degradation effect is still very poor. The degradation effect of TNAs / CdS is greatly improved compared with the other two materials, indicating that the photocatalytic performance of the composite material is greatly improved.

[0075] Any matters not mentioned above shall be subject to the existing technology.

[0076] Although some specific embodiments of the present invention have been described in detail through examples, those skilled in the art should understand that the above examples are for illustration only and are not intended to limit the scope of the present invention. Those skilled in the art of the present invention may make various modifications or additions to the described specific embodiments or replace them in similar ways, but they will not deviate from the direction of the present invention or exceed the scope defined by the appended claims. Those skilled in the art should understand that any modifications, equivalent replacements, improvements, etc. made to the above embodiments based on the technical essence of the present invention should be included in the scope of protection of the present invention.

Claims

1. A method for preparing a light-responsive two-dimensional nanofluid film, characterized in that: The following steps are involved: S1. Soak the pure Ti sheet in dilute nitric acid to remove oxides and impurities on the Ti sheet, and then rinse it with ultrapure water; S2 and Ti sheets were placed at the anode, and three-layer two-dimensional nanofluid film TNAs were prepared by anodic oxidation. The electrolyte was composed of ultrapure water, ethylene glycol and ammonium fluoride. S3. Electrochemically depositing the TNAs in S3 using a three-electrode system to prepare a nanofluid film TNAs / CdS; the electrolyte is prepared using sodium thiosulfate pentahydrate, cadmium chloride and hydrochloric acid.

2. The preparation method according to claim 1, wherein In step S2, the volume-to-mass ratio of ultrapure water, ethylene glycol, and ammonium fluoride in the electrolyte is 20-70 ml: 400-500 ml: 2-3 g.

3. The preparation method according to claim 1, wherein In step S2, anodization is performed at a voltage of 10-25 V for 0.5-1.5 h.

4. The preparation method according to claim 1, wherein In step S3, the pH of the electrolyte is 2-4; the molar ratio of sodium thiosulfate pentahydrate to cadmium chloride is 1-3:

1.

5. The preparation method according to claim 1, wherein In step S3, the electrodeposition voltage is 3 V and the deposition time is 10-30 min.

6. A light-responsive two-dimensional nanofluid film prepared by the preparation method according to any one of claims 1 to 5.

7. Use of the light-responsive two-dimensional nanofluid film as claimed in claim 6 as a separator for a light-coupled salt difference battery.

8. Use of the light-responsive two-dimensional nanofluid film as claimed in claim 6 as a photocatalyst for degrading organic matter.

9. An optically coupled power generation device, characterized in that: The light-responsive two-dimensional nanofluid membrane according to claim 6 is used as a diaphragm. During the preparation process, the side of the light-responsive two-dimensional nanofluid membrane that always faces the other electrode is the front side, and the two sides of the diaphragm are electrolyte solutions with concentration differences. The front side of the diaphragm has a low-concentration electrolyte solution, and the light-irradiated side is the front side.

10. The optically coupled power generation device according to claim 9, wherein: The high-concentration electrolyte solution contains a pollutant to be degraded; the pollutant to be degraded is methylene blue.

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