CN-122006754-A - Preparation method and application of Fe/Cu/BiOCl composite photocatalyst

Abstract

The invention discloses a preparation method and application of an Fe/Cu/BiOCl composite photocatalyst, which are based on a simple one-step hydrothermal method to synthesize the Fe 3+ 、Cu 2+ co-doped BiOCl composite photocatalyst, and the energy band structure of the BiOCl can be effectively regulated and controlled by regulating the doping proportion of Fe and Cu ions. Compared with undoped BiOCl and Fe/Cu single metal ion doped BiOCl, the Fe and Cu co-doped sample has stronger visible light absorption capability and lower electron-hole recombination efficiency. When the doping mole ratio of Fe 3+ to Cu 2+ is 9:1, the photocatalysis performance of the composite photocatalyst is optimal, and the removal rate of Cr (VI) after 120min of visible light irradiation reaches 91.3 percent, which is obviously higher than 64.4 percent of pure BiOCl. In addition, the composite photocatalyst also has good stability and recycling performance, and has potential application value in the field of water treatment.

Inventors

• ZHANG XIA
• HAN JIAXIN
• FAN JING
• ZHU GUIFEN
• LIU YONGLI
• TAN BING

Assignees

• 河南师范大学

Dates

Publication Date

20260512

Application Date

20251230

Claims (5)

1. 1. A preparation method of a Fe/Cu/BiOCl composite photocatalyst is characterized in that Bi (NO 3 ) 3 ·5H 2 O、Fe(NO 3 ) 3 ·9H 2 O and Cu (NO 3 ) 2 ·3H 2 O are used as raw materials to prepare the Fe/Cu/BiOCl composite photocatalyst at 150-170 ℃ based on a hydrothermal method), the energy band structure of the BiOCl can be effectively regulated and controlled by optimizing the doping ratio of Fe and Cu ions to be 9:1, the obviously enhanced visible light absorption performance and lower electron-hole composite efficiency are shown, the photocatalytic degradation of Cr (VI) can be realized, and the prepared Fe/Cu/BiOCl composite photocatalyst has a flower-shaped spherical morphology; the XPS spectrum of the Fe/Cu/BiOCl composite photocatalyst has binding energy at 159.4eV, 164.8eV, 530.6eV, 531.6eV, 198.2eV, 199.8eV, 710.5eV, 722.9eV and 940.9eV, 159.4eV and 164.8eV in Bi 4f spectrum correspond to Bi 4f 7 / 2 and Bi 4f 5 / 2 respectively, O1 s spectrum corresponds to lattice oxygen and surface adsorption oxygen at 530.6eV and 531.6eV respectively, 198.2eV and 199.8eV in Cl 2p spectrum belong to Cl 2p 3/ 2 and Cl 2p 1/ 2 respectively, 710.5eV and 722.9eV in Fe 2p spectrum correspond to Fe 2p 3/ 2 and Fe 2p 1/ 2 respectively, 940.9eV in Cu 2p spectrum corresponds to Cu 2p 3/ 2 respectively, and the specific surface area of the Fe/Cu/BiOCl composite photocatalyst is increased after Fe/Cu co-doping, which is favorable for providing more remarkable reactive sites.
2. 2. The preparation method of the Fe/Cu/BiOCl composite photocatalyst according to claim 1 is characterized by comprising the specific preparation steps of adding Bi (NO 3 ) 3 ·5H 2 O、Fe(NO 3 ) 3 ·9H 2 O and Cu (NO 3 ) 2 ·3H 2 O) into an ethylene glycol solution, stirring until a clear and transparent solution is formed, then adding NaCl, continuously stirring and uniformly mixing, transferring the mixed solution into a polytetrafluoroethylene lining reaction kettle, reacting at 150-170 ℃ for 2-4 h, cooling to room temperature after the reaction is finished, centrifugally separating and precipitating, washing with deionized water and ethanol alternately for a plurality of times, and drying to obtain the Fe/Cu/BiOCl composite photocatalyst.
3. 3. Use of the Fe/Cu/BiOCl composite photocatalyst prepared according to the method of claim 1 or 2 in a photocatalytic reduction reaction.
4. 4. Use of a Fe/Cu/BiOCl composite photocatalyst prepared according to the method of claim 1 or 2 in photocatalytic reduction of Cr (VI).
5. 5. Use of the Fe/Cu/BiOCl composite photocatalyst prepared according to the method of claim 1 or 2 in the photocatalytic removal of Cr (VI) in a Cr (VI) contaminated water body.

Description

Preparation method and application of Fe/Cu/BiOCl composite photocatalyst Technical Field The invention belongs to the technical field of inorganic environment-friendly composite photocatalytic materials, and particularly relates to a preparation method and application of an Fe/Cu/BiOCl composite photocatalyst. Background With the rapid development of industries such as decorative chrome plating, corrosion-resistant chrome plating, papermaking and the like, the industrial consumption of chrome is continuously increased, so that a large amount of wastewater containing hexavalent chrome (Cr (VI)) is discharged into a water body, and potential threat is formed to human health. Cr (VI) has toxicity which is hundreds times that of trivalent chromium (Cr (III)), has extremely strong water solubility and carcinogenicity, and can cause serious damage to the enzyme system of human bodies through various exposure ways. In order to cope with environmental and health risks brought by Cr (VI), researchers have developed various treatment technologies such as bioremediation, chemical reduction, reverse osmosis and the like, but the methods often have the problems of high operation cost, insufficient environmental friendliness and the like, and limit the large-scale application of the methods. Photocatalytic technology has been attracting attention in terms of Cr (VI) removal and reduction due to its efficient, green, sustainable properties. The technology can directly convert high-toxicity Cr (VI) into low-toxicity Cr (III) by utilizing light energy, and is a water treatment method with good application prospect. BiOCl is a typical layered ternary oxide semiconductor material, having a PbFCl-like layered structure, the crystal of which is composed of alternating [ Bi 2O2]2+ layers and double Cl - layers, the intra-and inter-layer atoms being tightly bound. This unique layered configuration enables the formation of a built-in electric field within it, helping to suppress the recombination of photogenerated carriers. In addition, the BiOCl has the characteristics of rich raw material sources, simple preparation process, environmental friendliness and the like, and is an important photocatalytic material. However, the wider band gap (3.0-3.6 eV) makes it mainly absorb ultraviolet light, and the utilization efficiency of visible light is limited. The problem of rapid recombination of photogenerated carriers still restricts the improvement of the photocatalytic performance despite the presence of a built-in electric field. For this reason, various modification strategies have been proposed by researchers. For example, the specific surface area can be increased by regulating the morphology of the material (such as preparing nano rods, nano sheets and the like), the light absorption efficiency can be improved, or a heterojunction can be constructed to promote the separation of photon-generated carriers, or the energy band structure can be regulated by element doping, so that the spectral response range can be expanded. The doping of specific metal or nonmetal elements can effectively regulate the band gap of the material, and introduce a local electric field or a defect state into the crystal, which is helpful for separating photo-generated electrons and holes, thereby reducing the recombination rate. Ion co-doping is used as a high-efficiency material modification strategy, and by introducing two or more different ions at the same time, the method has obvious advantages in the field of photocatalytic materials. The method can produce synergistic effect to make different ions complement each other in performance, thereby improving the overall performance of the photocatalytic material. Meanwhile, the ion co-doping can effectively optimize the electronic structure of the photocatalytic material, improve the conductivity and promote the migration of carriers. In recent years, transition metal ion doping has received a great deal of attention in the preparation of BiOCl-based photocatalysts. The introduction of Fe 3+ and Cu 2+ can form a new energy level in the forbidden band of the material, so that the band gap width is effectively reduced, and the excitation and migration of photo-generated electrons are promoted. In addition, the ionic radii of Fe 3+ and Cu 2+ (respectivelyAnd) Are all smaller than Bi 3 +So that the dopant can easily enter into the BiOCl lattice, and effective doping is realized. The patent document of CN201610834591.1 discloses a preparation method of a composite photocatalyst Fe-BiOCl, which comprises the specific synthesis steps of dissolving bismuth nitrate in ethylene glycol to prepare solution 1, dissolving ferric chloride in ethylene glycol to prepare solution 2, dissolving cetyltrimethylammonium chloride in ethylene glycol to prepare solution 3, slowly dripping the solution 2 into the solution 1, continuously stirring, dripping the solution 3 into the solution 1, continuously stirring, putting into a m