CN-117680168-B - Lignin carbon-based bismuth oxyhalide Z-type heterojunction composite material with regular flower-like morphology, and preparation method and application thereof

Abstract

The invention discloses a lignin carbon-based bismuth oxyhalide Z-type heterojunction composite material with regular flower-shaped morphology, a preparation method and application thereof, which utilizes lignin carbon induction and pH regulation with rich oxygen functional groups to synthesize the lignin carbon-based bismuth oxyhalide Z-type heterojunction composite material BiOX/C with the regular flower-shaped morphology, and the material has the advantages of wide spectral response range, high efficiency, strong stability, and the like, and the separation of photo-generated carriers and cavities is effectively promoted based on the flower-shaped morphology structure and the Z-type heterojunction of the material, so that the material has higher photo-reaction efficiency, and the defects of low quantum efficiency, slow degradation rate, poor stability, easy deactivation and the like of the traditional photocatalytic degradation organic pollutant material are effectively solved. The lignin carbon substrate material takes lignocellulose in agricultural wastes as a carbon source, is environment-friendly, low in production cost, simple and feasible in synthesis method, considerable in yield, mild in reaction condition in the photocatalytic degradation process of organic pollutants, simple and feasible in operation, and wide in application prospect.

Inventors

• SUN WANPENG
• ZHANG BINPENG
• LIU YUAN
• SUN CHUNFANG
• WANG MINGRUI
• MENG XIAOJUN
• Fan Pinbo

Assignees

• 河南工业大学

Dates

Publication Date

20260508

Application Date

20231122

Claims (7)

1. 1. The preparation method of the lignin carbon-based bismuth oxyhalide Z-type heterojunction composite material with the regular flower-shaped morphology is characterized by comprising the following steps of: s1, dissolving a template agent and lignin in ethylene glycol together, carrying out ultrasonic dispersion and mixing, and then heating and evaporating to dryness to obtain a raw material A; S2, heating the raw material A to 500-1000 ℃ at a heating rate of 1-5 ℃ per min under the protection of nitrogen flow, and roasting for 6-12 hours to obtain a precursor B; S3, adding the precursor B into a strong alkaline solution for heating reaction, and washing and drying after the reaction is finished to obtain lignin carbon; S4, dropwise adding an aqueous solution of halogen salt into an aqueous solution of bismuth salt and lignin carbon at a speed of 1-10 drops/second, uniformly mixing, adjusting the pH to 3-7, heating to 150-200 ℃ for reaction, and centrifuging, washing, drying and grinding after the reaction is finished to obtain the lignin carbon-based bismuth oxyhalide composite material with regular flower-shaped morphology; The halogen salt in the step S4 is a mixture of any two of potassium chloride, potassium bromide and potassium iodide; In the step S4, ammonia water is used for adjusting the pH value of the solution.
2. 2. The method for preparing the lignin carbon-based bismuth oxyhalide Z-type heterojunction composite material with the regular flower-shaped morphology as claimed in claim 1, wherein the template agent in the step S1 is silica microspheres, and the lignin is alkali lignin.
3. 3. The method for preparing the lignin carbon-based bismuth oxyhalide Z-type heterojunction composite material with the regular flower-shaped morphology as claimed in claim 2, wherein the mass ratio of the silica microspheres to the alkali lignin is 1:1-1:10.
4. 4. The method for preparing the lignin carbon-based bismuth oxyhalide Z-type heterojunction composite material with regular flower-shaped morphology as claimed in claim 1 is characterized in that the dosage molar ratio of the two halogen salts is 1:1-10:1.
5. 5. The method for preparing the lignin carbon-based bismuth oxyhalide Z-type heterojunction composite material with the regular flower-shaped morphology as claimed in claim 1, wherein the strong alkaline solution in the step S3 is sodium hydroxide solution, and the heating reaction temperature is 80 ℃.
6. 6. A lignin carbon-based bismuth oxyhalide Z-type heterojunction composite material with a regular flower-like morphology, prepared by the method of any one of claims 1-5.
7. 7. The use of the lignin carbon-based bismuth oxyhalide Z-type heterojunction composite material with regular flower-like morphology as claimed in claim 6 in a system for photocatalytic degradation of organic pollutants.

Description

Lignin carbon-based bismuth oxyhalide Z-type heterojunction composite material with regular flower-like morphology, and preparation method and application thereof Technical Field The invention relates to the technical field of functional materials, in particular to a lignin carbon-based bismuth oxyhalide Z-type heterojunction composite material with regular flower-shaped morphology, and a preparation method and application thereof. Background In recent years, resource shortage and environmental pollution become more and more critical problems threatening future survival and development of human beings, and new phenomena, new theories and new technologies capable of degrading various pollutants safely, rapidly, with low energy consumption and high efficiency are developed and utilized to become hot spots continuously explored by vast scientific researchers. Due to the advantages of green, mild, energy saving and the like, in recent years, solar energy is used as the only energy source to drive the removal of pollutants in water, and the method gradually becomes one of the strategies for relieving the shortage of energy and protecting the water environment. The development of high-efficiency, environment-friendly, high-stability and low-cost light response materials, which are key steps for realizing high-efficiency water purification, also become the focus of attention of current and future scientists. The mechanism of the photocatalytic degradation treatment of organic pollution of a semiconductor is to utilize the strong oxidizing property of holes or some active species generated by electrons and holes in water, such as hydroxyl free radicals (OH) and superoxide free radicals (O 2-) and secondary free radicals thereof, wherein the free radicals can be subjected to a series of reactions of addition, substitution, electron transfer and the like with organic pollutants in a system, and the degradation of the organic pollutants is realized by breaking chemical bonds such as C-C bonds, C-H bonds and the like existing in the organic matters and finally converting the chemical bonds into CO 2 and H 2 O. Although the conventional semiconductor photocatalyst represented by TiO 2 has a series of advantages of high stability, no toxicity, low cost and the like, the band gaps of the conventional semiconductor photocatalyst are wider (for example, anatase TiO 2 and rutile phase TiO 2 are 3.2eV and 3.0eV respectively), and ultraviolet light with smaller occupied area can be only utilized, so that the practical application of the conventional semiconductor photocatalyst is limited. In addition, the photo-generated electrons and holes of the nano titanium dioxide are easy to be combined, nano particles are easy to be agglomerated, and the like, so that the photo-catalytic activity of the TiO 2 is greatly reduced. Therefore, the development of the photocatalytic material with wide spectral response and high catalytic activity is very practical. In recent years, a series of novel semiconductor photocatalytic materials have been developed to address these problems, including metal oxide (Ag 2O、ZnO、SnO2、ZrO2), vanadate (BiAlVO 7、BiVO4), tungsten molybdate (Bi 2MoO6、Bi2WO6), bismuth oxyhalide (BiOCl, biOBr, biOI), and the like. Wherein bismuth oxyhalide BiOX (X=Cl, br and I) composed of multiple components of main groups V-VI-VII has a layered structure in which [ Bi 2O2]2+ bonds are cross-bonded with halogens, so that an internal electric field perpendicular to [ Bi 2O2]2+ and halogen is formed inside the BiOX crystal, separation of photo-generated electrons and holes can be promoted, and the BiOX semiconductor has excellent photocatalytic activity. In addition, the band gap of the BiOX semiconductor is reduced from 4.18eV (BiOF) to 1.7eV (BiOI) along with the increase of the atomic number, so that the photocatalytic activity range of the material is greatly expanded, and the material has wide application prospect in the field of degrading organic pollutants. However, the BiOX material has a few problems, biOCl has no visible light response basically, so that the utilization of sunlight is limited, the energy band width of BiOBr is proper, the absorption range of visible light is narrow, the energy band structure needs to be further regulated, the forbidden band width of BiOI is narrow, the photo-generated carriers and holes are easy to recombine, and the photo-catalytic efficiency is low. Disclosure of Invention The invention aims to solve the technical problem of low photocatalytic efficiency of BiOX materials in the prior art, and provides a lignin carbon-based bismuth oxyhalide Z-type heterojunction composite material with a regular flower-shaped morphology, and a preparation method and application thereof. The invention aims to solve the technical problems, and adopts the technical scheme that the preparation method of the lignin carbon-based bismuth oxyhalide Z-type heterojunction composite material with the regular fl