Preparation method for preparing photocatalyst by using biological material

Abstract

The invention relates to the technical field of preparation of photocatalysts from biological materials, and particularly discloses a method for preparing a photocatalyst from a biological material, which comprises the following steps: step 1, selecting biomass rich in carbon, and performing pretreatment in manners of drying, crushing, cleaning, hydrolyzing and the like; 2, carbonizing the pretreated biomass; 3, preparing a photocatalyst precursor; step 4, mixing the biomass charcoal powder with the photocatalyst precursor solution, and doping the carbon element into the photocatalyst; 5, performing high-temperature calcination on the mixture; and step 6, cooling, cleaning and drying the calcined sample to obtain the carbon-doped photocatalyst, wherein the biomass raw material is placed in a drying oven at 60-80 DEG C to be dried for 2-3 hours during drying in the step 1. According to the preparation method for preparing the photocatalyst by using the biological material, the COD (Chemical Oxygen Demand) of high-concentration organic wastewater can be reduced from 1000 mg / L to 200 mg / L or below under ultraviolet light.

Description

Technical Field

[0001] This invention relates to the field of photocatalyst preparation technology using biomaterials, specifically a method for preparing photocatalysts using biomaterials. Background Technology

[0002] Biomaterials refer to materials that interact with biological systems, primarily used in the medical field and less frequently applied in the environmental domain. Biochar, on the other hand, is a carbon material produced from organic materials through a pyrolysis process. Examples include rice husks, corn stalks, wheat straw, sawdust, branches, and fallen leaves. Even food processing waste and livestock manure can be sources of biochar. The production process typically involves heating raw materials in an oxygen-deficient environment, causing them to decompose at high temperatures. This process converts the organic matter in the raw materials into char, gaseous, and liquid byproducts. Different pyrolysis temperatures and times affect the properties of the final biochar. Applications of biochar include soil improvement, reducing greenhouse gas emissions, wastewater treatment, and soil pollution remediation. Through these applications, biochar helps improve soil fertility, increase water retention capacity, reduce fertilizer requirements in agriculture, and plays a role in environmental protection.

[0003] Photocatalysts are materials that promote chemical reactions under light irradiation. They utilize the energy of light to excite electrons and holes within the material, thereby driving the chemical reaction. Common photocatalysts include titanium dioxide (TiO2), zinc dioxide (ZnO), and graphene. They are widely used in environmental purification (water treatment, air purification), solar energy conversion (photocatalytic water splitting for hydrogen production), and organic synthesis. Optimizing the performance of photocatalysts typically involves adjusting their band gap, enhancing light absorption, and improving the electron-hole pair separation efficiency. Carbon doping refers to improving the performance of semiconductor materials by introducing carbon elements. This process is commonly used to improve the photoelectric properties, catalytic activity, or conductivity of materials. By introducing carbon atoms, the band gap of semiconductors is reduced, enabling them to absorb a wider spectral range, especially visible light. Carbon doping can enhance the light absorption capacity and electron-hole pair separation efficiency of photocatalysts. In some semiconductor materials, carbon doping can improve their conductivity or alter the migration characteristics of charge carriers. Carbon doping is an effective material modification technique that can significantly improve the performance of semiconductor materials and expand their potential in various applications. Therefore, carbon doping can effectively improve the performance of photocatalysis.

[0004] Currently, many photocatalysts (such as titanium dioxide) have wide band gaps, which means they can only absorb ultraviolet light, and ultraviolet light accounts for a small proportion of sunlight. This limits their application in visible light. Furthermore, under prolonged light exposure and chemical reaction conditions, some photocatalysts may degrade or fail, affecting their long-term reliability. Therefore, there is an urgent need to actively research and develop new photocatalyst materials to promote the application of photocatalysis technology in environmental remediation and energy conversion. Summary of the Invention

[0005] To achieve the above objectives, the present invention provides a method for preparing photocatalysts using biomaterials, comprising the following steps: The first step is to select biomass rich in carbon and pre-treat it through drying, crushing, washing and hydrolysis. The second step is to carbonize the pretreated biomass; Step 3: Preparation of photocatalyst precursor; Step 4: Mix the biomass char powder with the photocatalyst precursor solution to incorporate carbon elements into the photocatalyst; Step 5: Calcine the mixture at high temperature; Step 6: Cool the calcined sample, clean it, and dry it to obtain the carbon-doped photocatalyst.

[0006] Preferably, in the first step, the biomass raw material is placed in an oven at 60-80℃ and dried for 2-3 hours.

[0007] Preferably, the precursor in the third step is prepared by mixing tetrabutyl titanate and water in a mass ratio of 1:2.

[0008] It has the following beneficial effects: This method for preparing photocatalysts using biomaterials requires that carbon and other elements form bonds in the material to successfully prepare the photocatalyst. The prepared material can reduce the COD of high-concentration organic wastewater from 1000 mg / L to below 200 mg / L under ultraviolet light. Detailed Implementation

[0009] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0010] In the first embodiment, the present invention provides a technical solution: a method for preparing photocatalysts using biomaterials, comprising the following steps: Step 1: Select rice husk biomass rich in carbon and dry it in a 60℃ oven for 2 hours; The second step is to crush the dried rice husk biomass and wash it with ethanol several times. The third step is to place the cleaned rice husk biomass material in a 2% (v / v) dilute sulfuric acid solution for 12 hours to hydrolyze it. Step 4: Carbonize the hydrolyzed rice husk biomass under a nitrogen protective atmosphere for 2 hours to obtain carbon powder; Step 5: Tetrabutyl titanate and water are mixed and hydrolyzed at a mass ratio of 1:2 to prepare a photocatalyst precursor; Step 6: Mix the biochar powder with the photocatalyst precursor solution to obtain a mixture; Step 7: Place the mixture in a muffle furnace and treat it at 500°C for 2 hours. Step 8: Cool the calcined sample to room temperature; Step 9: Wash the cooled material five times with deionized water and dry it at room temperature to obtain the carbon-doped photocatalyst.

[0011] In a second embodiment, the present invention provides a technical solution: a method for preparing photocatalysts using biomaterials, comprising the following steps: The first step is to select rice husk biomass rich in carbon and dry it in a 70℃ oven for 2.5 hours; The second step is to crush the dried rice husk biomass and wash it with ethanol several times. The third step is to place the cleaned rice husk biomass material in a 3.5% (v / v) dilute sulfuric acid solution for 18 hours to hydrolyze it. Step 4: Carbonize the hydrolyzed rice husk biomass under a nitrogen protective atmosphere for 2.5 hours to obtain carbon powder; Step 5: Tetrabutyl titanate and water are mixed and hydrolyzed at a mass ratio of 1:2 to prepare a photocatalyst precursor; Step 6: Mix the biochar powder with the photocatalyst precursor solution to obtain a mixture; Step 7: Place the mixture in a muffle furnace and treat it at 650°C for 3 hours. Step 8: Cool the calcined sample to room temperature; Step 9: Wash the cooled material six times with deionized water and dry it at room temperature to obtain the carbon-doped photocatalyst.

[0012] In the third embodiment, the present invention provides a technical solution: a method for preparing photocatalysts using biomaterials, comprising the following steps: Step 1: Select rice husk biomass rich in carbon and dry it in an 80℃ oven for 3 hours; The second step is to crush the dried rice husk biomass and wash it with ethanol several times. The third step is to place the cleaned rice husk biomass material in a 5% (v / v) dilute sulfuric acid solution for 24 hours to hydrolyze it. Step 4: Place the hydrolyzed rice husk biomass under a nitrogen protective atmosphere for 3 hours to carbonize it and obtain carbon powder. Step 5: Tetrabutyl titanate and water are mixed and hydrolyzed at a mass ratio of 1:2 to prepare a photocatalyst precursor; Step 6: Mix the biochar powder with the photocatalyst precursor solution to obtain a mixture; Step 7: Place the mixture in a muffle furnace and treat it at 800°C for 4 hours. Step 8: Cool the calcined sample to room temperature; Step 9: Wash the cooled material eight times with deionized water and dry it at room temperature to obtain the carbon-doped photocatalyst.

[0013] Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. All other embodiments obtained by those skilled in the art and related fields based on the embodiments of the present invention without inventive effort should fall within the scope of protection of the present invention. Structures, devices, and operating methods not specifically described and explained in the present invention, unless otherwise specified or limited, shall be implemented according to conventional means in the art.

Claims

1. A production method for producing a photocatalyst using a biological material, characterized by comprising the steps of: The method comprises the following steps: ​ First, select biomass containing rich carbon, and pretreat the biomass by drying, crushing, washing and hydrolysis; Second, carbonize the pretreated biomass; Third, prepare a photocatalyst precursor; Fourth, mix the biomass carbon powder with the photocatalyst precursor solution, so that the carbon element is doped into the photocatalyst; Fifth, calcine the mixture at high temperature; Sixth, cool, wash and dry the calcined sample to obtain the carbon-doped photocatalyst. 2.The method for preparing a photocatalyst using a biomaterial according to claim 1, characterized in that: In the first step, the biomass raw material is dried in an oven at 60-80°C for 2-3 hours. 3.The method for preparing a photocatalyst using a biomaterial according to claim 1, characterized in that: In the third step, the precursor is prepared by mixing tetrabutyl titanate and water at a mass ratio of 1:2.