Terephthalic acid modified bismuth oxychloride-based composite photocatalyst as well as preparation method and application thereof
Through the preparation of terephthalic acid-modified bismuth oxychloride-based composite photocatalyst, the problems of visible light absorption efficiency and photogenerated carrier recombination of traditional photocatalysts in dye wastewater treatment are solved, and efficient organic dye degradation is achieved, and the catalyst morphology changes improve catalytic activity and degradation rate.
Patent Information
- Application Number
- CN202510419024.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-04-03
- Publication Date
- 2025-07-04
AI Technical Summary
When treating dye wastewater, traditional semiconductor photocatalysts have problems such as insufficient visible light absorption efficiency, serious photogenerated carrier recombination and low catalyst recycling rate, which limits their industrial application.
By preparing a terephthalic acid-modified oxybis chlorine-based composite photocatalyst, a terephthalic acid is interposed into the layered structure of oxybis chlorine to form a three-dimensional cross-layer thin-layer sheet structure, increasing the specific surface area and effectively separating photogenerated electrons and holes.
The catalytic degradation efficiency of visible light of organic dyes is significantly improved, the catalytic activity and stability is improved, the degradation rate reaches 99.8%, and the method is simple and energy-saving.
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Figure CN120243121A_ABST
Abstract
Description
Technical Field
[0001] The present invention belongs to the technical field of inorganic synthesis, and specifically discloses a terephthalic acid modified bismuth oxychloride-based composite photocatalyst, a preparation method thereof, and an application thereof. Background Art
[0002] The accelerating advancement of the global industrialization and modernization processes has significantly exacerbated the problem of water environmental pollution. Among them, the printing and dyeing industrial wastewater has become one of the main pollution sources threatening the ecological system balance and human health due to its complex composition, high toxicity, high chromaticity, and difficult degradation characteristics. In this context, the research and development of efficient and low-cost advanced sewage purification technologies are of great strategic significance for achieving environmental sustainable development. As an emerging green catalytic system, semiconductor photocatalysis technology exhibits broad application prospects in the field of environmental governance by virtue of its strong redox ability, low secondary pollution, and solar energy-driven characteristics. This technology can not only achieve the mineralization and degradation of organic pollutants but also be synchronously applied to multiple functions such as photocatalytic hydrogen production from water splitting, air purification, and antibacterial treatment. At present, although the theoretical research on traditional semiconductor photocatalysis is relatively mature, there are still three major technical bottlenecks in the actual treatment of dye wastewater: (1) the low matching degree between the band gap of the intrinsic semiconductor material and the solar spectrum leads to insufficient visible light absorption efficiency; (2) the rapid recombination of photo-generated carriers (electron-hole pairs) seriously weakens the quantum yield; (3) the difficult solid-liquid separation of nano-scale catalysts results in low recovery and utilization rates. These technical defects severely restrict the industrialization promotion process of semiconductor photocatalysis technology. Summary of the Invention
[0003] The purpose of the present invention is to provide a terephthalic acid modified bismuth oxychloride-based composite photocatalyst, a preparation method thereof, and an application thereof, and by means of morphology regulation, to solve the problem of limited visible light response range caused by the wide band gap of traditional bismuth oxychloride, thereby significantly improving the photocatalytic efficiency of organic dye degradation.
[0004] In order to achieve the above purpose, the technical solution adopted by the present invention is: a terephthalic acid modified bismuth oxychloride-based composite photocatalyst, which is composed of a bismuth oxychloride suspension and a terephthalic acid solution with a solute molar ratio of 1:2 to 2:1.
[0005] The method for preparing a terephthalic acid modified bismuth oxychloride-based composite photocatalyst includes the following steps:
[0006] First step, magnetically stir the bismuth oxychloride suspension and the terephthalic acid solution with a molar ratio of 1:2 to 2:1 respectively.
[0007] Second step, add the magnetically stirred terephthalic acid solution to the magnetically stirred bismuth oxychloride suspension dropwise in 3 times at a dropping rate of 20 - 30 drops / min. After the dropping is completed, perform room temperature stirring to obtain a solid-phase product.
[0008] In the third step, the solid-phase product obtained in the second step is centrifuged and washed 3 to 4 times each with ultrapure water and absolute ethanol.
[0009] In the fourth step, the solid-phase product washed in the third step is vacuum-dried at a temperature of 50 to 80 °C for 6 to 10 h to obtain a terephthalic acid-modified bismuth oxychloride-based composite photocatalyst.
[0010] A further preferred scheme is that the preparation method of the bismuth oxychloride suspension is: weighing bismuth nitrate pentahydrate and potassium chloride with a molar ratio of 1:2 to 2:1, placing them in a transparent glass sample tube, adding an appropriate amount of ultrapure water thereto, sealing the tube, and ultrasonically treating for 10 to 20 min at a temperature of 20 to 30 °C to obtain the bismuth oxychloride suspension.
[0011] A further preferred scheme is that the preparation method of the terephthalic acid solution is: weighing terephthalic acid and 0.1 mol / L sodium hydroxide solution with a mass ratio of 0.05:1 to 0.1:1, adding the 0.1 mol / L sodium hydroxide solution to terephthalic acid according to the said ratio, sealing the tube, and ultrasonically treating for 10 to 20 min at a temperature of 20 to 30 °C to obtain the terephthalic acid solution.
[0012] The terephthalic acid-modified bismuth oxychloride-based composite photocatalyst of the present invention is applied to the visible-light catalytic degradation of organic dyes.
[0013] Applying the terephthalic acid-modified bismuth oxychloride-based composite photocatalyst prepared in this scheme to the degradation of organic dyes: measuring 50 mL of the prepared 20 mg / L rhodamine B solution into a quartz beaker, accurately weighing 20 mg of the catalyst with an electronic balance, adding it to the rhodamine B solution, and stirring in the dark for 30 min to achieve adsorption-desorption equilibrium; transferring the mixed solution to a 30 W household LED lamp for a photocatalytic degradation experiment, taking 4 mL of the rhodamine B solution every 10 min, and centrifuging to separate and taking the supernatant to measure ultraviolet light.
[0014] Compared with the prior art, the beneficial effects of the present invention are as follows:
[0015] (1) The present invention prepares a terephthalic acid-modified bismuth oxychloride-based composite photocatalyst by a simple room-temperature stirring method, and this method has various advantages such as simplicity, energy saving, and high efficiency;
[0016] (2) The present invention organically combines bismuth oxychloride and terephthalic acid, and terephthalic acid is intercalated into the layered structure of bismuth oxychloride, making the originally layered structure formed by the alternation of [Bi2O2] layers and double-halogen layers more hierarchical, having sufficient space to polarize the corresponding atoms and atomic orbitals, and effectively separating photogenerated electrons and holes; 2+ The layered structure formed by the alternation of layers and double-halogen layers has a richer hierarchy, has sufficient space to polarize the corresponding atoms and atomic orbitals, and effectively separates photogenerated electrons and holes;
[0017] (3) The microscopic morphology of the prepared terephthalic acid-modified bismuth oxychloride-based composite photocatalyst changes from the layered structure of bismuth oxychloride to a three-dimensional cross-linked thin flake shape, with an increased specific surface area and an increased contact area with pollutants during the degradation process, which is conducive to improving the catalytic activity. Description of the Drawings
[0018] Figure 1 are the XRD patterns of different photocatalysts;
[0019] Figure 2 is the scanning electron microscope image of the bismuth oxychloride photocatalyst;
[0020] Figure 3 is the scanning electron microscope image of the terephthalic acid-modified bismuth oxychloride-based composite photocatalyst obtained in this example;
[0021] Figure 4 is the degradation efficiency diagram of Rhodamine B in different photocatalytic systems;
[0022] Figure 5 is the cyclic stability diagram of the degradation of Rhodamine B by the terephthalic acid-modified bismuth oxychloride-based composite photocatalyst obtained in this example;
[0023] Figure 6 is the free radical capture experiment diagram of the degradation of Rhodamine B by the composite photocatalyst obtained in this example. Detailed Description of the Embodiments
[0024] The following is a further detailed description through specific embodiments:
[0025] Example 1
[0026] The terephthalic acid-modified bismuth oxychloride-based composite photocatalyst described in this example is composed of a bismuth oxychloride suspension and a terephthalic acid solution with a solute molar ratio of 1:1.
[0027] Among them, the preparation method of the bismuth oxychloride suspension is to weigh bismuth nitrate pentahydrate and potassium chloride with a mass ratio of 1:1, place them in a transparent glass sample tube, add an appropriate amount of ultrapure water, seal it, and ultrasonically treat it for 15 min at a temperature of 25 °C to obtain the bismuth oxychloride suspension.
[0028] The preparation method of the terephthalic acid solution is: weigh terephthalic acid and 0.1 mol / L sodium hydroxide solution with a mass ratio of 0.08:1, add 0.1 mol / L sodium hydroxide solution to terephthalic acid according to the above ratio, seal it, and ultrasonically treat it for 15 min at a temperature of 25 °C to obtain the terephthalic acid solution.
[0029] The method for preparing the terephthalic acid-modified bismuth oxychloride-based composite photocatalyst includes the following steps:
[0030] First step: Magnetically stir the bismuth oxychloride suspension and the terephthalic acid solution with a molar ratio of 1:1 respectively.
[0031] Second step: Add the magnetically stirred terephthalic acid solution to the magnetically stirred bismuth oxychloride suspension drop by drop in 3 times at a dropping rate of 25 drops / min. After the addition is completed, perform stirring at room temperature to obtain a solid-phase product.
[0032] Third step: Centrifuge the solid-phase product obtained in the second step, and wash it 3 times each with ultrapure water and absolute ethanol.
[0033] Fourth step: Vacuum-dry the solid-phase product washed in the third step at 60 °C for 8 h to obtain the terephthalic acid-modified bismuth oxychloride-based composite photocatalyst.
[0034] Example 2
[0035] The terephthalic acid-modified bismuth oxychloride-based composite photocatalyst described in this example is composed of a bismuth oxychloride suspension and a terephthalic acid solution with a solute molar ratio of 1:1.
[0036] Among them, the preparation method of the bismuth oxychloride suspension: Weigh bismuth nitrate pentahydrate and potassium chloride with a mass ratio of 1:1, place them in a transparent glass sample tube, add an appropriate amount of ultrapure water to it, seal it, and ultrasonicate for 10 min at a temperature of 20 °C to obtain the bismuth oxychloride suspension.
[0037] The preparation method of the terephthalic acid solution is: Weigh terephthalic acid and 0.1 mol / L sodium hydroxide solution with a mass ratio of 0.08:1, add 0.1 mol / L sodium hydroxide solution to terephthalic acid according to the above ratio, seal it, and ultrasonicate for 10 min at a temperature of 20 °C to obtain the terephthalic acid solution.
[0038] The method for preparing the terephthalic acid-modified bismuth oxychloride-based composite photocatalyst includes the following steps:
[0039] First step: Magnetically stir the bismuth oxychloride suspension and the terephthalic acid solution with a molar ratio of 1:1 respectively.
[0040] Second step: Add the magnetically stirred terephthalic acid solution to the magnetically stirred bismuth oxychloride suspension drop by drop in 3 times at a dropping rate of 20 drops / min. After the addition is completed, perform stirring at room temperature to obtain a solid-phase product.
[0041] Third step: Centrifuge the solid-phase product obtained in the second step, and wash it 3 times each with ultrapure water and absolute ethanol.
[0042] Fourth step: Vacuum-dry the solid-phase product washed in the third step at 50 °C for 6 h to obtain the terephthalic acid-modified bismuth oxychloride-based composite photocatalyst.
[0043] Example 3
[0044] The terephthalic acid modified bismuth oxychloride-based composite photocatalyst described in this example is composed of a bismuth oxychloride suspension and a terephthalic acid solution with a solute molar ratio of 1:1.
[0045] Among them, for the preparation method of the bismuth oxychloride suspension, weigh bismuth nitrate pentahydrate and potassium chloride with a mass ratio of 1:1, place them in a transparent glass sample tube, add an appropriate amount of ultrapure water thereto, seal it, and ultrasonicate for 20 min at a temperature of 30 °C to obtain the bismuth oxychloride suspension.
[0046] The preparation method of the terephthalic acid solution is as follows: weigh terephthalic acid and 0.1 mol / L sodium hydroxide solution with a mass ratio of 0.08:1, add 0.1 mol / L sodium hydroxide solution to terephthalic acid according to the above ratio, seal it, and ultrasonicate for 20 min at a temperature of 30 °C to obtain the terephthalic acid solution.
[0047] The method for modifying the bismuth oxychloride-based composite photocatalyst with terephthalic acid includes the following steps:
[0048] First step, magnetically stir the bismuth oxychloride suspension and the terephthalic acid solution with a molar ratio of 1:1 respectively.
[0049] Second step, add the magnetically stirred terephthalic acid solution to the magnetically stirred bismuth oxychloride suspension dropwise in 3 portions at a dropping rate of 30 drops / min. After the dropping is completed, perform stirring at room temperature to obtain a solid-phase product.
[0050] Third step, centrifuge the solid-phase product obtained in the second step, and wash it 4 times each with ultrapure water and absolute ethanol.
[0051] Fourth step, vacuum-dry the solid-phase product washed in the third step at a temperature of 80 °C for 10 h to obtain the terephthalic acid modified bismuth oxychloride-based composite photocatalyst.
[0052] The terephthalic acid modified bismuth oxychloride-based composite photocatalyst obtained in this example is used as a photocatalyst for the degradation of Rhodamine B.
[0053] Apply the terephthalic acid modified bismuth oxychloride-based composite photocatalyst prepared in the present invention to the degradation of organic dyes: measure 50 mL of the prepared 20 mg / L Rhodamine B solution into a quartz beaker, accurately weigh 20 mg of the catalyst with an electronic balance, add it to the Rhodamine B solution, and stir in the dark for 30 min to achieve adsorption-desorption equilibrium; transfer the mixed solution to a 30 W household LED lamp for photocatalytic degradation experiment. Take 4 mL of the Rhodamine B solution every 10 min, and centrifuge to separate and take the supernatant to measure the ultraviolet light.
[0054] Figure 1 XRD patterns of different photocatalysts. The terephthalic acid modified bismuth oxychloride based composite photocatalyst obtained in the present invention has a good crystal form. By comparing with pure bismuth oxychloride and terephthalic acid, it can be seen that the two are successfully compounded, indicating that bismuth oxychloride and terephthalic acid have good compatibility;
[0055] Figure 2 Scanning electron microscope image of the bismuth oxychloride photocatalyst obtained in step (1) of the example. It can be seen that the morphology of bismuth oxychloride is a flaky structure with a relatively flat surface;
[0056] Figure 3 Scanning electron microscope image of the terephthalic acid modified bismuth oxychloride based composite photocatalyst obtained in this example. Compared with bismuth oxychloride, its morphology becomes a three-dimensional cross-linked thin flaky shape. Such a structure increases its specific surface area and can absorb more active substances during the degradation process, which is beneficial to the degradation of catalytic pollutants;
[0057] Figure 4 Degradation effect diagrams of Rhodamine B in different photocatalyst systems. Without adding any catalyst and adding terephthalic acid, the dark adsorption and photocatalytic degradation performance of Rhodamine B are both poor. The terephthalic acid modified bismuth oxychloride based composite photocatalyst obtained in the present invention has an adsorption of Rhodamine B similar to that of pure bismuth oxychloride. However, under visible light, the degradation rate of this composite photocatalyst for Rhodamine B is as high as 99.8% within 20 min, and the degradation rate and efficiency are both higher than those of pure bismuth oxychloride;
[0058] Figure 5 Cyclic stability diagram of the terephthalic acid modified bismuth oxychloride based composite photocatalyst for the degradation of Rhodamine B obtained in this example. After 4 cycles of catalysis, the degradation rate is about 81% after 60 minutes of illumination;
[0059] Figure 6 Free radical capture experiment diagram of the terephthalic acid modified bismuth oxychloride based composite photocatalyst for the degradation of Rhodamine B obtained in this example. Adding isopropyl alcohol for capture has little effect on the reaction, indicating that ·OH is not the active species in this degradation reaction; however, adding p-benzoquinone, EDTA, and AgNO3 significantly reduces the degradation effect. Therefore, the main active species in the photocatalytic degradation in the present invention are ·O2 - 、h + and e - .
Claims
1. A terephthalic acid modified bismuth oxychloride-based composite photocatalyst, characterized in that: It is composed of a bismuth oxychloride suspension and a terephthalic acid solution with a solute molar ratio of 1:2 to 2:
1.
2. Method for preparing terephthalic acid modified bismuth oxychloride based composite photocatalyst, characterized in that: It includes the following steps: First step, magnetically stir the bismuth oxychloride suspension and the terephthalic acid solution with a molar ratio of 1:2 to 2:1 respectively. Second step, add the magnetically stirred terephthalic acid solution in 3 portions dropwise to the magnetically stirred bismuth oxychloride suspension at a dropping rate of 20 - 30 drops / min. After the addition is complete, perform stirring at room temperature to obtain a solid-phase product. Third step, centrifuge the solid-phase product obtained in the second step, and wash it 3 - 4 times each with ultrapure water and absolute ethanol respectively. Fourth step, vacuum-dry the solid-phase product washed in the third step at a temperature of 50 - 80 °C for 6 - 10 h to obtain a terephthalic acid-modified bismuth oxychloride-based composite photocatalyst.
3. The modified bismuth oxychloride-based composite photocatalyst according to claim 1, characterized in that: The preparation method of the bismuth oxychloride suspension is as follows: Weigh bismuth nitrate pentahydrate and potassium chloride with a molar ratio of 1:2 to 2:1, place them in a transparent glass sample tube, add an appropriate amount of ultrapure water thereto, seal it, and ultrasonicate for 10 - 20 min at a temperature of 20 - 30 °C to obtain the bismuth oxychloride suspension.
4. The terephthalic acid-modified bismuth oxychloride-based composite photocatalyst according to claim 1, characterized in that: The preparation method of the terephthalic acid solution is as follows: Weigh terephthalic acid and 0.1 mol / L sodium hydroxide solution with a mass ratio of 0.05 - 0.
1. Add the 0.1 mol / L sodium hydroxide solution to terephthalic acid according to the said ratio, seal it, and ultrasonicate for 10 - 20 min at a temperature of 20 - 30 °C to obtain the terephthalic acid solution.
5. The modified bismuth oxychloride-based composite photocatalyst according to claim 1, wherein: It is applied to the visible-light catalytic degradation of organic dyes.