Synthesis and application of mixed effect composite light-piezoelectric catalyst (MBA2-XDFCBAX) CuCl4

Abstract

The invention relates to a preparation method of a perovskite type ferroelectric material photo-piezoelectric catalyst (MBA2-XDFCBAX) CuCl4 nanocrystal, which comprises the following steps: (1) preparing an organic phase solution, and dissolving 0.4 (2-X) mmol of MBA-Cl powder and 0.4 X mmol of DFCBA-Cl powder in 1ml of DMF (Dimethyl Formamide); (2) preparing an inorganic phase solution, taking 1ml of DMF (Dimethyl Formamide), dissolving 0.4 mmol of CuCl2. 2H2O powder, and adding 250ml of oleic acid; (3) mixing and reacting the two-phase solution for 10 minutes, injecting into 40 milliliters of vigorously stirred ethyl acetate, centrifuging, washing for three times, and drying to obtain synthesized substance powder; and (4) carrying out photo-piezoelectric catalytic degradation on the organic dye Sudan red (III) by using the catalyst. The synthesis method can be operated at room temperature and is low in cost. The catalyst does not contain heavy metal elements harmful to the environment, and is an environment-friendly green catalyst.

Description

Technical Field

[0001] The present invention relates to the field of photocatalysis and photo-piezoelectric catalysis, and in particular to a photo-piezoelectric catalyst (MBA) of a perovskite-type ferroelectric material. 2-X DFCBA X )Preparation method of CuCl4 nanocrystals. Background Art

[0002] Human development is inseparable from energy, and the use of energy inevitably causes damage to the environment. Now, the intensification of environmental pollution and the insufficient supply of renewable energy have become dual challenges that hinder the sustainable development of society. Photocatalysis has been widely studied in recent years, and is mainly used in the fields of environmental remediation and energy conversion. When traditional semiconductor photocatalysts are excited by bandgap-matched photons, they produce strong redox active substances, which can mineralize organic matter in water bodies. Traditional semiconductors are expensive, have low solar energy utilization efficiency, and photogenerated carriers are easy to recombine, which hinders the practical large-scale application of photocatalytic technology. Researchers use perovskite ferroelectric materials as catalysts to introduce the piezoelectric effect into the photocatalytic reaction process. The polarization electric field generated can inhibit the recombination of photogenerated carriers and greatly improve the photocatalytic efficiency.

[0003] The mixing effect has a significant effect on the structure and dynamic properties of perovskites, especially in photovoltaics. + / MA + / FA + ) and B position (pb 2+ / Sn 2+ / Bi 3+ The selective substitution of ) ions allows for the precise design of composite perovskite systems with specialized functions. Component engineering can yield properties including optoelectronics, superconductivity, ferroelectricity, piezoelectric response, giant magnetoresistance, multiferroic coupling, and catalytic activity.

[0004] (4-Methoxybenzylamine)2CuCl4 (abbreviated as (MBA)2CuCl4) has a high dielectric response and undergoes a structural phase transition at 430.25K, which is mainly caused by the order-disorder transition of organic amine ions. The material has significant reversible thermochromic properties at 300K-390K, changing from yellow to dark brown, indicating the temperature of the object by color change, and can be used in related fields such as smart windows. (3,3-Difluorocyclobutylamine)2CuCl4 (abbreviated as (DFCBA)2CuCl4) is a multiaxial ferroelectric with four ferroelectric axes and eight polarization directions, and undergoes a ferroelectric transition at 380K. The band gap width of both perovskite materials is around 2.3eV, making them potentially excellent photocatalysts. Based on the crystal structure of (MBA)2CuCl4, we used the hybrid effect to transform DFCBA +Organic cations are inserted into the inorganic layer to introduce piezoelectric effect and test the composite material (MBA 2-X DFCBA X )CuCl4 efficiency under photo-piezoelectric catalysis. The purpose is to test the photo-, piezoelectric, and photo-piezoelectric catalytic efficiency under different X coefficients.

[0005] According to the applicant's understanding, the composite material (MBA) that introduces piezoelectricity through hybrid effect 2-X DFCBA X )The application of CuCl4 in photo-piezoelectric catalysis has not been reported. Summary of the Invention

[0006] The purpose of the present invention is to synthesize composite materials (MBA 2-X DFCBA X The CuCl4 photo-piezoelectric catalyst catalyzes the degradation of organic dyes through the material's intrinsic light excitation and piezoelectric effect. Varying the X coefficient yields varying catalytic efficiencies, demonstrating the success of our hybrid approach and the anticipated photo-piezoelectric catalytic effect. The composite material is simple to synthesize, and as a copper-based material, it does not introduce toxic metal elements, making it an environmentally friendly green catalyst.

[0007] The specific technical solutions of the present invention are as follows:

[0008] (1) Synthesis of 4-methoxybenzylamine hydrochloride (MBA-Cl): Mix 5 mL of 4-methoxybenzylamine (MBA) with 15 mL of ethanol in an ice-water bath, add 10 mL of hydrochloric acid (37%), and stir for 2 h. Remove the solvent by rotary evaporation at 60°C, wash with anhydrous ether several times, and dry in an oven at 40°C for 12 h to obtain MBA-Cl powder.

[0009] (2) Synthesis by ligand-assisted reprecipitation (MBA) 1.5 DFCBA 0.5 )CuCl4 composite material: First, prepare the organic phase solution, take 1mL NN dimethylformamide (DMF) to dissolve 0.6mmol (103.5mg) MBA-Cl and 0.2mmol (28.7mg) 3,3-difluorocyclobutylamine hydrochloride (DFCBA-Cl) mixed powder. Then prepare the inorganic phase solution, take 1mL DMF to dissolve 0.4mmol (0.0684g) CuCl2·2H2O powder, and add 250μL oleic acid organic ligand to the system. The two-phase solution was mixed and reacted for 10min, and injected into 40mL of vigorously stirred ethyl acetate, and a change from colorless to yellow emulsion was observed. The mixed solution was centrifuged at 10000rpm for 3min to separate the yellow precipitate and the slightly yellow transparent supernatant. The precipitate was purified by washing with ethyl acetate three times, and finally dried in vacuum at 40℃ for 12h, and (MBA was successfully synthesized.1.5 DFCBA 0.5 )CuCl4 powder;

[0010] (3) Synthesis of (MBA-DFCBA)CuCl4 composite material by ligand-assisted reprecipitation method: First, prepare the organic phase solution, take 1mL NN dimethylformamide (DMF) to dissolve 0.4mmol (68.4mg) MBA-Cl and 0.4mmol (57.4mg) DFCBA-Cl mixed powder. Then prepare the inorganic phase solution, take 1mL DMF to dissolve 0.4mmol (68.4mg) CuCl2·2H2O powder, and add 250μL oleic acid organic ligand to the system. The two phase solutions are mixed and reacted for 10min, and injected into 40mL ethyl acetate with vigorous stirring. A change from colorless to yellow emulsion is observed. The mixed solution is centrifuged at 10000rpm for 3min to separate the yellow precipitate and the slightly yellow transparent supernatant. The precipitate is purified by washing with ethyl acetate three times, and finally vacuum dried at 40℃ for 12h to successfully synthesize (MBA-DFCBA)CuCl4 powder;

[0011] (4) Photo-piezoelectric catalytic degradation of organic dyes by two composite materials: (MBA 1.5 DFCBA 0.5 )CuCl4 (28.9 mg) and (MBA-DFCBA)CuCl4 (28 mg) catalyst samples were uniformly dispersed in a 5 mg / L Sudan Red (III) ethyl acetate solution and magnetically stirred for 30 minutes in the dark to allow the dye molecules to reach a dynamic adsorption-desorption equilibrium at the catalyst active sites. UV light was used for illumination and ultrasonic cleaning were performed. 3 mL of the reaction solution was removed every 15 minutes and centrifuged at 12,000 rpm. UV-visible light was used to measure the intensity of the characteristic absorption peak of the supernatant at 502 nm. The intensity of the characteristic absorption peak was used to quantitatively evaluate the photocatalytic degradation efficiency of the catalyst.

[0012] In step (1), the volume ratio of MBA to anhydrous ethanol is 1:3.

[0013] In step (2), the X factor is shown to be 0.5.

[0014] In step (3), the X coefficient is shown to be 1.

[0015] In step (4), in the photo-piezoelectric catalytic degradation of organic dyes experiment, in order to ensure the consistency of experimental conditions, the two composite materials need to be set to equimolar mass, so the two composite catalyst samples are 28.9 mg and 28 mg respectively.

[0016] This patent synthesizes two composite materials (MBA) by combining the mixing effect with the ligand-assisted reprecipitation method.1.5 DFCBA 0.5 )CuCl4, (MBA-DFCBA)CuCl4. The synthesis method of the two composite materials is simple and can be operated at room temperature. By changing the X coefficient value, the two composite materials have different photo-piezoelectric efficiencies, which is different from DFCBA + The piezoelectric effect can improve the separation efficiency of photogenerated carriers and realize a new way to improve the photocatalytic efficiency by mechanical means. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 For two composite materials (MBA 1.5 DFCBA 0.5 )CuCl4, (MBA-DFCBA)CuCl4 catalyst X-ray diffraction (XRD) pattern comparison;

[0018] Figure 2 Composite Materials (MBA 2-X DFCBA X ) Schematic diagram of the CuCl4 crystal structure;

[0019] Figure 3 For two composite materials (MBA 1.5 DFCBA 0.5 )CuCl4, (MBA-DFCBA)CuCl4 catalyst scanning electron microscopy (SEM) comparison images;

[0020] Figure 4 For the composite material (MBA in Example 4 1.5 DFCBA 0.5 ) Comparison of the UV absorption spectra of CuCl4 for the degradation of Sudan (III) under the conditions of no catalyst, photocatalysis, piezoelectric catalysis, and photo-piezoelectric catalysis;

[0021] Figure 5 This is a comparison chart of the ultraviolet absorption spectrum catalytic efficiency of the composite material (MBA-DFCBA) CuCl4 in Example 5 for degradation of the organic dye Sudan Red (III) under the conditions of no catalyst, photocatalysis, piezoelectric catalysis, and photo-piezoelectric catalysis; DETAILED DESCRIPTION

[0022] Example 1

[0023] Composite Materials (MBA 1.5 DFCBA 0.5)CuCl4 and (MBA-DFCBA)CuCl4 catalyst synthesis: First, prepare the organic phase solution, take 1mL DMF to dissolve 0.4(2-X)mmol of MBA-Cl powder and 0.4Xmmol of DFCBA-Cl powder (X=0.5, 1); then prepare the inorganic phase solution, take 1mL DMF to dissolve 0.4mmol (0.0684g) of CuCl2·2H2O powder, and add 250μL of oleic acid organic ligand to the system. The two-phase solution was mixed and reacted for 10min, and injected into 40mL of vigorously stirred ethyl acetate, and a change from colorless to yellow emulsion was observed. The mixed solution was centrifuged at 10000rpm for 3min to separate a yellow precipitate and a slightly yellow transparent supernatant. The precipitate was purified by washing with ethyl acetate three times, and finally dried in vacuum at 40℃ for 12h, and (MBA) was successfully synthesized. 1.5 DFCBA 0.5 )CuCl4 and (MBA-DFCBA)CuCl4 powders.

[0024] Example 2

[0025] We are 2-X DFCBA X )CuCl4 crystal structure was analyzed. Figure 1 The XRD results show that we have successfully prepared (MBA 2-X DFCBA X )CuCl4. Figure 2 As shown in the crystal structure diagram, there is an inorganic layer of CuCl6 octahedron and an organic cation MBA + and DFCBA + Embedded in the middle of the inorganic layer, it is a two-dimensional structure. The change of the X coefficient is directly related to the MBA between the organic layers. + and DFCBA + The ratio of organic cations is large, and the crystallinity is poor during the crystallization process because of the large difference in the relative radius between the two, and a relatively regular crystal morphology is not formed.

[0026] Example 3

[0027] Scanning electron microscopy (SEM) was used to examine the (MBA 1.5 DFCBA 0.5 )CuCl4 and (MBA-DFCBA)CuCl4 composites were subjected to micromorphological analysis to show the characteristics of their micromorphology in terms of grain size. Figure 3 (a) and (b) show the composite material (MBA 1.5 DFCBA 0.5 )CuCl4 morphology features a flake structure with a size of less than 10 μm and a thickness of 100 nm. Figure 3 (c) and (d) show the morphology of the composite material (MBA-DFCBA) CuCl4, which is a flake structure with a size of less than 1μm. The difference between the two materials is due to the different X coefficients. + and DFCBA + This is caused by different proportions of organic cations and differences in crystallinity.

[0028] Example 4

[0029] 28.9mg (MBA 1.5 DFCBA 0.5 )CuCl4 catalyst was evenly dispersed in 90mL of 5mg / L Sudan Red (III) solution and adsorbed for 30min under light-proof conditions. Four groups of experiments were carried out: blank control, light irradiation only, ultrasound only, and light irradiation + ultrasound. 3mL of the reaction solution was taken out at intervals of 15min and centrifuged at 12000rpm / min. The change in the characteristic absorption peak intensity of the supernatant at 502nm was measured by UV-vis. The photocatalytic degradation efficiency of the catalyst was quantitatively evaluated by the numerical value of the characteristic absorption peak intensity. In the absence of a catalyst, Sudan Red (III) did not degrade. (MBA 1.5 DFCBA 0.5 )The photocatalytic, piezoelectric catalytic and photo-piezoelectric catalytic efficiencies of CuCl4 are 12.2%, 8.4% and 86.7% respectively.

[0030] Example 5

[0031] 28 mg (MBA-DFCBA) CuCl4 catalyst was evenly dispersed in 90 mL of 5 mg / L Sudan Red (III) solution and adsorbed for 30 minutes in the dark. Four groups of experiments were conducted: blank control, light irradiation only, ultrasound alone, and light irradiation + ultrasound. 3 mL of the reaction solution was taken out every 15 minutes and centrifuged at 12,000 rpm / min. The characteristic absorption peak intensity of the supernatant at 502 nm was measured by UV-vis. The photocatalytic degradation efficiency of the catalyst was quantitatively evaluated by the numerical value of the characteristic absorption peak intensity, such as Figure 4 、 Figure 5 In the absence of a catalyst, Sudan Red (III) did not degrade, and the photocatalytic, piezocatalytic, and photo-piezocatalytic efficiencies of (MBA-DFCBA)CuCl4 were 8.9%, 11.1%, and 39.4%, respectively.

Claims

1. Hybrid effect composite photo-piezoelectric catalyst (MBA 2-X DFCBA X ) Synthesis and application of CuCl4, characterized in that The steps include: (1) 4-methoxybenzylamine (MBA) was mixed with ethanol in an ice-water bath, reacted in hydrochloric acid (37%), and then rotary evaporated to dryness, washed with anhydrous ether, and dried to obtain MBA-Cl powder; (2) Prepare an organic phase solution by dissolving 0.4(2-X) mmol of MBA-Cl powder and 0.4X mmol of DFCBA-Cl powder (X = 0.5, 1) in DMF; (3) Prepare the inorganic phase solution by dissolving 0.4 mmol of CuCl2·2H2O powder in DMF and adding oleic acid organic ligand to the system; (4) After the two-phase solution is mixed and reacted, the precipitate and the supernatant are separated by centrifuge, the precipitate is washed and purified, and dried to obtain (MBA 2-X DFCBA X )CuCl4 powder.

2. The method according to claim 1, characterized in that In step (1), the volume ratio of MBA to ethanol is 1:

3.

3. The method according to claim 1, characterized in that In step (2), the values ​​of the X coefficient are 0.5 and 1. The photo-piezoelectric catalytic efficiency of these two composite catalysts is greatly improved compared with photocatalysis.

4. The method according to claim 1, characterized in that In steps (2) and (3), the molar ratio of the organic phase to the inorganic phase is 2:1.

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