Preparation method of iron-doped bismuth oxychloride visible light catalytic material
Fe-BiOCl was prepared by Fe ion doping and hydrolysis, which solved the problem of poor response of BiOCl under visible light and achieved efficient photocatalytic degradation of pollutants. The material has good application prospects.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2023-05-31
- Publication Date
- 2026-03-31
AI Technical Summary
Existing BiOCl materials do not respond well under visible light, and traditional preparation methods use strong acids, which leads to environmental pollution and makes it difficult to achieve efficient photocatalytic degradation of pollutants.
FeCl3·6H2O was used as the Fe source for metal ion doping, and Fe-BiOCl was prepared by a simple hydrolysis method to form a three-dimensional flower-like structure with uniformly assembled nanosheets, avoiding the use of strong acids and improving photocatalytic activity.
The prepared Fe-BiOCl material exhibits high efficiency in dye degradation under visible light, improving photocatalytic reaction efficiency, increasing specific surface area and active sites, and achieving efficient degradation of RhB and MO.
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Figure CN116713012B_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of chemical material preparation, specifically relating to a method for preparing an iron-doped bismuth oxychloride visible light photocatalytic material. The material is prepared by a simple hydrolysis method and has a very important application in the photocatalytic degradation of pollutants. Background Technology
[0002] Photocatalysis is a novel green oxidation-reduction technology widely used for the removal of recalcitrant organic matter from water. Compared to other photocatalytic materials, nano-BiOCl has attracted widespread attention in environmental pollution control due to its unique layered structure and strong internal electrostatic field, resulting in high photocatalytic activity, low cost, good stability, and safety. However, it also suffers from a wide band gap and poor response under visible light. In the traditional process of preparing BiOCl by hydrolysis of BiCl3, strong acids such as concentrated hydrochloric acid are usually used to create an acidic environment, followed by hydrolysis in deionized water. This invention, based on the principles of simple, green, and pollution-free processes, uses FeCl3·6H2O as the Fe source for metal ion doping. Simultaneously, the acidic solvent environment after FeCl3 dissolves in water is beneficial for the Bi2O3 raw material to produce Bi ions. 3+ The process involves dissolving and further hydrolyzing BiOCl, simultaneously addressing the challenges of green synthesis and extended photoresponse. Metal ion doping promotes interfacial charge transfer, thereby achieving higher visible-light-driven catalytic activity. This invention utilizes Fe via a simple hydrolysis method. 3+ BiOCl was doped to construct a Fe-BiOCl material with a uniformly assembled three-dimensional flower-like structure and highly efficient visible-light photocatalytic activity. The results show that Fe-BiOCl possesses visible-light photocatalytic properties and can efficiently degrade dye pollutants. Summary of the Invention
[0003] This invention provides a method for preparing an iron-doped bismuth oxychloride visible light photocatalyst. The specific preparation steps are as follows:
[0004] (1) Prepare a certain amount of CaCl2 and FeCl3·6H2O mixed solution 50mL, add 1mmol Bi2O3, stir magnetically for 30min, dissolve evenly and let stand for 1h, and record it as solution A.
[0005] (2) Measure 50-100 mL of deionized water into a beaker and label it as solution B.
[0006] (3) Take the supernatant of solution A after standing and slowly drip it into solution B. After standing for 12 hours, a precipitate is obtained. The precipitate is washed with deionized water and anhydrous ethanol and centrifuged. The precipitate is dried in an oven at 60°C for 12 hours to obtain Fe-BiOCl.
[0007] (4) The preferred preparation process is Fe-BiOCl prepared by simple hydrolysis. The concentration of CaCl2 is 2.0 mol / L, the concentration of FeCl3·6H2O is 0.3 mol / L, and the amount of deionized water in solution B is 100 mL.
[0008] This process uses a simple hydrolysis method to prepare Fe-BiOCl, which requires neither hydrochloric acid nor high-temperature calcination, making it simple and safe. This method can convert Fe... 3+ Incorporating BiOCl transforms its sheet-like structure into a uniformly assembled three-dimensional flower-like structure of nanosheets, with a diameter of approximately 0.5-1 μm, a single sheet size of about 0.5 μm, a thickness of about 10 nm, and a specific surface area of up to 78.94 m². 2 g -1 Increasing the specific surface area of photocatalytic materials can increase the number of active sites for photocatalytic response and improve their photocatalytic reaction efficiency.
[0009] The main advantages of this invention are as follows:
[0010] (1) Using readily available and non-toxic raw materials such as CaCl2, Bi2O3 and FeCl3·6H2O, Fe-BiOCl photocatalytic materials with good application prospects in the field of environmental purification can be prepared through a simple process.
[0011] (2) The material has good dye adsorption performance and visible light catalytic response characteristics under visible light irradiation, and can efficiently degrade RhB and MO. Attached Figure Description
[0012] Figure 1 These are scanning electron microscope (SEM) images of the Fe-BiOCl photocatalytic materials in Examples 1-4.
[0013] Figure 2 These are X-ray diffraction patterns of the Fe-BiOCl photocatalytic materials in Examples 1-4.
[0014] Figure 3 These are the MO diagrams of the Fe-BiOCl photocatalytic materials in Examples 1-4 under visible light degradation.
[0015] Figure 4 The curves are N2 adsorption-desorption curves of the Fe-BiOCl photocatalytic material in Example 3.
[0016] Figure 5 This is the X-ray photoelectron spectrum of the Fe-BiOCl photocatalytic material in Example 3.
[0017] Figure 6 This is a graph showing the efficiency of the Fe-BiOCl photocatalyst material in Example 3 in completely degrading RhB and MO under visible light. Detailed Implementation
[0018] The present invention will be further described below with reference to specific embodiments and accompanying drawings. These embodiments are provided to enable those skilled in the art to better understand the invention and do not constitute any limitation on the invention.
[0019] Example 1
[0020] (1) Prepare 50 mL of a mixed solution of 2.0 mol / L CaCl2 and 0.1 mol / L FeCl3·6H2O, add 1 mmol Bi2O3, stir magnetically for 30 min, and let stand for 1 h after dissolving evenly. This solution is called solution A.
[0021] (2) Measure 100 mL of deionized water into a beaker and label it as solution B.
[0022] (3) Take the supernatant of solution A after standing and slowly drip it into solution B. After standing for 12 hours, a precipitate is obtained. The precipitate is washed with deionized water and anhydrous ethanol and centrifuged. The precipitate is dried in an oven at 60°C for 12 hours to obtain Fe-BiOCl, which is recorded as 0.1BiOCl.
[0023] (4) The photocatalytic performance of Fe-BiOCl was evaluated using a 300W xenon lamp visible light source and MO with a concentration of 10 mg / L. The degradation rate was calculated using the formula η = C / C0 × 100%, where C and C0 represent the concentration of MO at reaction time t min and 0 min, respectively.
[0024] Figure 1 a is a scanning electron microscope image of Fe-BiOCl in this embodiment. It can be seen that it has a well-uniformly assembled three-dimensional flower-like structure with a diameter of 0.5-1 μm, a single piece size of about 0.5 μm, and a thickness of about 10 nm.
[0025] Figure 2 The green line in this embodiment is the X-ray diffraction pattern of Fe-BiOCl. It can be seen that the diffraction peaks of Fe-BiOCl are consistent with the characteristic peaks of the standard card of BiOCl (JCPDS Card No. 85-086), and no other impurity peaks appear, indicating good crystallization.
[0026] Figure 3 The black line in the middle shows the degradation effect of Fe-BiOCl on MO under visible light in this embodiment. It can be seen that the Fe-BiOCl obtained in this embodiment has a good visible light response to MO. The adsorption rate is 36% after 60 min of dark reaction and the degradation rate of MO reaches 63% after 120 min of light irradiation.
[0027] Example 2
[0028] (1) Prepare 50 mL of a mixed solution of 2.0 mol / L CaCl2 and 0.2 mol / L FeCl3·6H2O, add 1 mmol Bi2O3, stir magnetically for 30 min, and let stand for 1 h after dissolving evenly. This solution is called solution A.
[0029] (2) Measure 100 mL of deionized water into a beaker and label it as solution B.
[0030] (3) Take the supernatant of solution A after standing and slowly drip it into solution B. After standing for 12 hours, a precipitate is obtained. The precipitate is washed by centrifugation with deionized water and anhydrous ethanol. The precipitate is dried in an oven at 60°C for 12 hours to obtain Fe-BiOCl, which is recorded as 0.2BiOCl.
[0031] Figure 3 The red line shows the degradation effect of Fe-BiOCl on MO under visible light. It can be seen that the Fe-BiOCl obtained in this embodiment has a good visible light response to MO. The adsorption rate is 38% after 60 min of dark reaction and the degradation rate of MO reaches 62% after 120 min of light irradiation.
[0032] Example 3
[0033] (1) Prepare 50 mL of a mixed solution of 2.0 mol / L CaCl2 and 0.3 mol / L FeCl3·6H2O, add 1 mmol Bi2O3, stir magnetically for 30 min, and let stand for 1 h after dissolving evenly. This solution is called solution A.
[0034] (2) Measure 100 mL of deionized water into a beaker and label it as solution B.
[0035] (3) Take the supernatant of solution A after standing and slowly drip it into solution B. After standing for 12 hours, a precipitate is obtained. The precipitate is washed by centrifugation with deionized water and anhydrous ethanol. The precipitate is dried in an oven at 60°C for 12 hours to obtain Fe-BiOCl, which is recorded as 0.3BiOCl.
[0036] Figure 3 The blue line shows the degradation effect of Fe-BiOCl on MO under visible light. It can be seen that the Fe-BiOCl obtained in this embodiment has a good visible light response. The adsorption rate is 46% after 60 min of dark reaction and the degradation rate of MO reaches 73% after 120 min of light irradiation, which is the best degradation effect.
[0037] Figure 4 The N2 adsorption-desorption curves of 0.3BiOCl are shown. According to IUPAC classification, the hysteresis loop of this sample belongs to type H3. Type H3 hysteresis loops are commonly found in layered aggregates, which is consistent with the morphology of the SEM. Figure 1c) The SEM image shows that the material is a three-dimensional flower-like structure with uniformly assembled nanosheets. Furthermore, pore size analysis reveals that the specific surface area of 0.3BiOCl is 78.94 m². 2 g -1 .
[0038] Figure 5 The valence states of elements and Fe doping in 0.3BiOCl are shown in the full scan spectrum as follows: Figure 5 As shown in (a), the presence of four elements, Bi, O, Cl and Fe, in the prepared composite material was confirmed. Figure 5 (b) The strong peaks in the Bi region at 159.4 eV and 164.7 eV belong to Bi 4f, respectively. 7 / 2 and Bi 4f 5 / 2 This is Bi 3+ Characteristic peaks; Figure 5 (c) In the O 1s region, the binding energy splits multiple times, which is related to the Bi-O bond and the hydroxyl groups on the material surface; Figure 5 The observed peak of 198.0 eV in (d) belongs to Cl 2p 3 / 2 The observed peak of 199.5 eV belongs to C12p. 1 / 2 ; Figure 5 In (e), the two peaks at 716.8 eV and 729.9 eV are Fe 2p 3 / 2 and Fe 2p 1 / 2 The two main peaks, with a spacing of 13.1 eV between them, prove the presence of Fe in 0.3BiOCl. 3+ The peak at 712.0 eV is Fe. 3+ The satellite peak.
[0039] Figure 6 The efficiency of 0.3 BiOCl in degrading RhB and MO under visible light is shown in the graph. It can be seen that the Fe-BiOCl obtained in this example has a good visible light response. The adsorption rate of RhB after 60 min of dark reaction is 30%, and RhB is completely degraded within 40 min of light irradiation. The adsorption rate of MO after 60 min of dark reaction is 46%, and MO is completely degraded within 240 min of light irradiation.
[0040] Example 4
[0041] (1) Prepare 50 mL of a mixed solution of 2.0 mol / L CaCl2 and 0.4 mol / L FeCl3·6H2O, add 1 mmol Bi2O3, stir magnetically for 30 min, and let stand for 1 h after dissolving evenly. This solution is called solution A.
[0042] (2) Measure 100 mL of deionized water into a beaker and label it as solution B.
[0043] (3) Take the supernatant of solution A after standing and slowly drip it into solution B. After standing for 12 hours, a precipitate is obtained. The precipitate is washed by centrifugation with deionized water and anhydrous ethanol. The precipitate is dried in an oven at 60°C for 12 hours to obtain Fe-BiOCl, which is recorded as 0.4BiOCl.
[0044] Figure 3 The green line shows the degradation effect of 0.4BiOCl on MO under visible light. It can be seen that the Fe-BiOCl obtained in this example has a good visible light response to MO. The adsorption rate is 39% after 60 min of dark reaction and 64% after 120 min of light irradiation.
[0045] Although the preferred embodiments of the present invention have been described above, the present invention is not limited to the specific embodiments described above. The specific embodiments described above are merely illustrative and not restrictive. Those skilled in the art can make many specific modifications under the guidance of the present invention without departing from the spirit and scope of the claims, and these modifications are all within the scope of protection of the present invention.
Claims
1. A method for preparing an iron-doped bismuth oxychloride visible light catalytic material, characterized in that, The method comprises the following steps: Step one: a certain amount of mixed solution of CaCl2 and FeCl3·6H2O is configured, then Bi2O3 powder is added, magnetic stirring is carried out for 30 min, after uniform dissolution, standing for 1 h, and the solution is recorded as solution A; Wherein, the concentration of CaCl2 is 1.0-2.5 mol / L, the concentration of FeCl3·6H2O is 0.1-0.6 mol / L, the volume of the mixed solution is 50 mL, and 1 mmol of Bi2O3 powder is added; Step two: 50-100 mL of deionized water is measured and placed in a beaker, and recorded as solution B; Step three: the supernatant of solution A after standing is slowly dropped into solution B, and the precipitate is obtained after standing for 12 h, the precipitate obtained by centrifugation is washed with deionized water and anhydrous ethanol, and dried in a 60℃ oven for 12 h to obtain Fe-BiOCl.
2. The method for preparing the iron-doped bismuth oxychloride visible light catalytic material according to claim 1, characterized in that, Fe-BiOCl is a three-dimensional flower-like structure uniformly assembled by nanosheets, with a diameter of 0.5-1 μm, a single sheet size of 0.5 μm, a thickness of 10 nm, and a specific surface area of 50-80 m 2 g -1 .