Preparation method of perylene-based composite material and application of perylene-based composite material in photohydrolysis hydrogen production

Abstract

The application relates to a preparation method of a perylene-based composite material and application of the perylene-based composite material in photohydrolysis hydrogen production. Perylene-3,4,9,10-tetracarboxylic dianhydride is mixed with imidazole in DMF, then 2,4,6-tris(4-aminophenyl)-1,3,5-triazine dissolved in DMF and carbon nitride are added drop by drop into the above solution under the condition of stirring at 180 DEG C. After heating reaction, the mixture is cooled to room temperature and methanol is added. The precipitate is collected by filtration, and is washed with DMF and methanol. The dried powder is refluxed with methanol to remove residual imidazole, and a dark red powder is obtained. The application obtains a perylene-based composite material with stable structure and good performance, the material has ideal characteristics such as a narrow band gap and a negative conduction band potential, is beneficial to visible light driven hydrogen production, is an ideal photocatalyst, and has a wide application prospect in the field of photohydrolysis hydrogen production.

Description

Technical Field

[0001] This invention belongs to the field of organic non-metallic materials technology, specifically relating to a method for preparing a perylene-based composite material and its application in photohydrolysis hydrogen production. Background Technology

[0002] Over the past half-century, with the growth of the world's population and the rapid development of industrialization, the widespread use of traditional fossil fuels has not only caused many environmental problems but has also triggered an energy crisis to some extent. Therefore, there is an urgent need to find a green and clean new energy source. Inspired by chlorophyll photosynthesis in plants, scientists have designed a carrier material for artificial photosynthesis to efficiently convert solar energy into chemical energy. This efficient solar thermal and photoelectric conversion is considered one of the most important strategies for solving the future energy crisis. Among different photocatalytic processes, photocatalytic water splitting is the most studied reaction, and the hydrogen produced is an ideal fuel. However, currently reported photocatalysts still suffer from serious defects such as photogenerated electron-hole recombination, insufficient reaction sites, and low efficiency, posing a significant challenge to further practical applications. Therefore, developing suitable and stable photocatalysts to achieve efficient water splitting for hydrogen production is of great significance for resource conservation and environmental protection. Composite materials possess ideal properties, such as narrow band gaps and negative conduction band potentials, which are beneficial for visible light-driven hydrogen production, making them ideal photocatalysts. Summary of the Invention

[0003] The purpose of this invention is to provide a method for preparing a composite material with simple and readily available raw materials, a simple preparation method, and good catalytic performance, and its application in photocatalytic water splitting for hydrogen production.

[0004] To achieve the above objectives, the technical solution of the present invention is as follows: A method for preparing a perylene-based composite material, comprising the following steps: mixing perylene-3,4,9,10-tetracarboxylic dianhydride and imidazole in N,N-dimethylformamide; then adding 2,4,6-tris(4-aminophenyl)-1,3,5-triazine and g-C3N4 dissolved in N,N-dimethylformamide dropwise to the above solution under high temperature stirring conditions and reacting; after heating the reaction, cooling the mixture to room temperature and adding methanol, collecting the precipitate, washing, drying, and removing residual imidazole to obtain the perylene-based composite material.

[0005] The above-mentioned method for preparing a composite material uses a molar ratio of perylene-3,4,9,10-tetracarboxylic dianhydride to 2,4,6-tris(4-aminophenyl)-1,3,5-triazine = 2:3.

[0006] In the above-mentioned method for preparing a composite material, the N,N-dimethylformamide solution of 2,4,6-tris(4-aminophenyl)-1,3,5-triazine is slowly added to the perylene-3,4,9,10-tetracarboxylic acid dianhydride solution at a rate of 5-8 drops per minute.

[0007] The above-mentioned method for preparing a composite material involves reacting at 180°C for 48 hours.

[0008] In the above-mentioned method for preparing a composite material, the residual imidazole is removed by refluxing methanol.

[0009] In the above-mentioned method for preparing a composite material, the reflow is performed at 80°C for 24 hours.

[0010] Application of perylene-based composite materials prepared by any of the above preparation methods in photohydrolysis hydrogen production.

[0011] The above application is carried out as follows: Perylene-based composite material is added to deionized water, then ascorbic acid is added as a sacrificial reagent, Pt is added as a co-catalyst, the entire system is vacuum treated to keep the reaction system at a low temperature, a xenon lamp is used as a visible light source, and then photocatalytic hydrogen production is carried out under magnetic stirring.

[0012] In the above applications, the concentration of perylene-based composite materials in water is 0.11-0.2 mg / ml.

[0013] In the above application, the low-temperature state is achieved by using cooling water at a temperature of 5°C to keep the reaction system at a low temperature.

[0014] The beneficial effects of this invention are as follows:

[0015] 1. The material prepared in this invention involves reacting perylene-3,4,9,10-tetracarboxylic dianhydride and 2,4,6-tris(4-aminophenyl)-1,3,5-triazine and then loading them onto g-C3N4 for application in photocatalytic water splitting for hydrogen production. g-C3N4 is a metal-free semiconductor material with a band gap of 2.7 eV. Due to its large light absorption, it accounts for the largest electron transfer in the CB region. The most important aspect of the g-C3N4 structure is the single nitrogen electron pair, which provides a pair of electrons connected by a π bond, which is beneficial for visible light-driven hydrogen production. Therefore, it exhibits good catalytic hydrogen production performance.

[0016] 2. This invention provides a method for one-step synthesis of composite materials using readily available raw materials. The material prepared by this invention is applied to photohydrolysis for hydrogen production, exhibiting high hydrogen yield with a hydrogen production rate of 800 μmol·g⁻¹. -1 ·h -1 about.

[0017] 3. The method of this invention uses readily available and simple raw materials, and the operation steps are straightforward. The material exhibits good photocatalytic hydrogen production performance. The composite material prepared by the method of this invention shows promising potential in photocatalytic water splitting for hydrogen production. Attached Figure Description

[0018] Figure 1 This is the FT-IR image of the composite material prepared in Example 1.

[0019] Figure 2 This is the XRD pattern of the composite material prepared in Example 1.

[0020] Figure 3 This is the UV-vis image of the composite material prepared in Example 1.

[0021] Figure 4 This is the Mott-Shokey diagram of the composite material prepared in Example 1.

[0022] Figure 5 This is a graph showing the hydrogen production of the composite material prepared in Example 1.

[0023] Figure 6 This is a graph showing the hydrogen production rate of the composite material prepared in Example 1. Detailed Implementation

[0024] Example 1 Composite Material

[0025] (I) The preparation method is as follows:

[0026] 0.157 g of perylene-3,4,9,10-tetracarboxylic dianhydride (PTCDA) and 20 g of imidazole were mixed in 17 mL of DMF and stirred at 180 °C. 0.6 mmol of 2,4,6-tris(4-aminophenyl)-1,3,5-triazine (TAPT) and 1 mmol of g-C3N4 dissolved in 3 mL of DMF were added dropwise over approximately 20 minutes. The solution was reacted at 180 °C for 48 hours. The mixture was then cooled to room temperature and methanol was added. The precipitate was collected by filtration and washed with DMF and methanol. The dried powder was refluxed with methanol at 80 °C to remove residual imidazole, yielding a deep red powder.

[0027] (II) Test Results

[0028] Figure 1 This is the FT-IR image of the composite material prepared in Example 1. (From...) Figure 1 As can be seen in the infrared absorption curve of the composite material, a value of 1698 cm⁻¹ can be observed. -1 1654cm -1 The asymmetric stretching vibration peak of the carbonyl group in the imide, and 1350 cm⁻¹ -1 The CNC stretching vibration peak at 3338 cm⁻¹.-1 The stretching vibration peak of -NH2 at the site disappeared. This proves that the PTCDA and TAPT reactions proceeded as designed.

[0029] Figure 2 This is the XRD pattern of the composite material prepared in Example 1. From... Figure 2 As can be seen from the results, the material prepared in Example 1 did not have the characteristic peaks of the raw materials, proving that the reaction of PTCDA and TAPT proceeded as designed in the experiment.

[0030] Figure 3 This is the UV-Vis diffuse reflectance spectrum of the composite material prepared in Example 1. From... Figure 3 As can be seen, the material has a visible light response and exhibits strong visible light absorption performance in the 400-800nm ​​range.

[0031] Figure 4 This is the Mott-Shokey plot of the composite material prepared in Example 1. From... Figure 4 As can be seen from the data, the slope of the material in the Mott-Schottky diagram is positive, which confirms that it is an n-type semiconductor, and its flat band potential is -0.53V.

[0032] Example 2: Application of composite materials in photocatalytic water splitting for hydrogen production

[0033] Methods: 10 mg of photocatalyst was added to 90 mL of deionized water, followed by 10 mL of ascorbic acid as a sacrificial reagent. 3 wt% Pt was added as a co-catalyst using photodeposition. The entire system was vacuum-treated, and the reaction system was kept at a low temperature using cooling water at 5 °C. A xenon lamp equipped with an ultraviolet cutoff filter (λ≥420 nm) was used as the visible light source, and the photocatalytic experiment was conducted under magnetic stirring. The generated hydrogen gas was quantitatively detected at fixed time intervals using a GC7900 gas chromatograph. Results are as follows: Figure 5 and Figure 6 .

[0034] The experiment was conducted under xenon lamp irradiation equipped with an ultraviolet cutoff filter (λ≥420nm), and the reaction temperature was controlled by condensate. The photocatalytic water splitting hydrogen production performance of the composite material under visible light irradiation was investigated, such as... Figure 5 As shown, the hydrogen production of the material increases with time, and the hydrogen production is relatively high.

[0035] like Figure 6 As shown, the material exhibits good photocatalytic hydrogen production performance (800 μmol·g⁻¹). -1 ·h -1 )

[0036] It is evident that, regardless of the choice of catalyst or its hydrogen production performance, the composite material prepared in this patent exhibits absolute advantages in photocatalytic water splitting for hydrogen production. Therefore, this composite material has promising application prospects in the field of photocatalytic water splitting for hydrogen production.

Claims

1. A method for preparing a perylene-based composite material, characterized in that, The process includes the following steps: perylene-3,4,9,10-tetracarboxylic dianhydride and imidazole are mixed in N,N-dimethylformamide; then 2,4,6-tris(4-aminophenyl)-1,3,5-triazine and g-C3N4 dissolved in N,N-dimethylformamide are added dropwise to the above solution under high temperature stirring and the reaction is carried out; after heating the reaction, the mixture is cooled to room temperature and methanol is added, the precipitate is collected, washed, dried and the residual imidazole is removed to obtain the perylene-based composite material; The molar ratio of perylene-3,4,9,10-tetracarboxylic acid dianhydride to 2,4,6-tris(4-aminophenyl)-1,3,5-triazine is 2:

3. The N,N-dimethylformamide solution of 2,4,6-tris(4-aminophenyl)-1,3,5-triazine should be slowly added to the perylene-3,4,9,10-tetracarboxylic acid dianhydride solution at a rate of 5-8 drops per minute. The reaction conditions were: reacting at 180℃ for 48 h; The removal of residual imidazole is achieved by reflux of methanol. The reflux was performed at 80°C for 24 hours.

2. The application of the perylene-based composite material prepared by the preparation method of claim 1 in photohydrolysis hydrogen production.

3. The application according to claim 2, characterized in that, The method is as follows: Perylene-based composite material is added to deionized water, then ascorbic acid is added as a sacrificial reagent, Pt is added as a cocatalyst, the entire system is vacuum treated to keep the reaction system at a low temperature, a xenon lamp is used as a visible light source, and then photocatalytic hydrogen production is carried out under magnetic stirring.

4. The application according to claim 3, characterized in that, The concentration of perylene-based composite materials in water is 0.11-0.2 mg / ml.

5. The application according to claim 3, characterized in that, The low-temperature state is achieved by using cooling water at a temperature of 5 °C to keep the reaction system at a low temperature.

Images