Preparation method of nickel-doped bionic wood flour structure cerium vanadate photocatalytic material

Abstract

The invention belongs to a manufacturing method of a photocatalytic material with a bionic wood structure, particularly relates to a preparation method of a nickel-doped cerium vanadate photocatalytic material with a bionic wood flour structure, designs and constructs a photocatalyst with high photocatalytic performance, and achieves the photocatalytic performance of the cerium vanadate photocatalytic material with the bionic wood flour structure by exerting the synergistic effect of a biological template method and metal doping. The target of efficiently degrading organic dye pollutants in wastewater is achieved. According to the invention, the wood flour is used as a biological template, the cerium vanadate is endowed with a higher specific surface area, the reaction active sites of the material are effectively increased, and meanwhile, the band gap of the cerium vanadate is reduced and the recombination of photon-generated carriers is inhibited through successful doping of nickel; under the synergistic effect of a biological template method and metal doping, the photocatalytic performance of the material is greatly improved. In addition, the photocatalytic material with high efficiency can be obtained through simple hydrothermal synthesis and high-temperature calcination methods, the cost is low, the process is simple, and meanwhile high-added-value utilization of natural wood is achieved.

Description

Technical Field

[0001] The invention belongs to the category of methods for manufacturing photocatalytic materials with bionic wood structures, and particularly relates to a method for preparing cerium vanadate photocatalytic materials with a nickel-doped bionic wood powder structure. Background Art

[0002] With the rapid development of industrialization and urbanization, serious environmental pollution and energy crisis have also arisen. Specifically, water pollution caused by pollutants such as natural organic matter, industrial dyes, microorganisms and heavy metals is a global challenge facing the world today. In recent years, semiconductor-based photocatalytic technology has received increasing attention in wastewater treatment due to its mild reaction conditions, relatively low energy consumption and environmental friendliness. At present, the development of photocatalytic materials that are efficient, stable, economical and rational in utilizing solar energy is of great practical significance.

[0003] Among many semiconductors, rare earth vanadates (MVO4, M = Ce, La, Pr, Nd) have been widely used to degrade pollutants in water due to their unique 4f-5d electronic layer structure and diverse electronic transition modes of rare earth elements. As a member of the rare earth vanadate family, tetragonal zircon cerium vanadate (CeVO4) has good light absorption properties in the UV-visible region and excellent redox properties. However, the low quantum efficiency of the original single CeVO4 and the rapid recombination of photogenerated carriers limit its wide application in the field of photocatalysis.

[0004] Recently, it has been reported that photocatalytic materials with high photocatalytic activity were prepared by controlling their morphology using the bio-template method. Natural wood as a template not only has the advantages of low cost and green environmental protection, but also can make the photocatalyst have a unique biological multi-scale hierarchical pore structure. Studies have shown that this unique biological microtubule structure gives the photocatalyst a larger specific surface area and more active sites, which is conducive to improving the photocatalytic activity.

[0005] Metal doping can change the band gap of semiconductors and improve the light absorption capacity of semiconductors. In addition, when metal ions are doped into the semiconductor lattice, oxygen vacancies are introduced to capture electrons, thereby achieving the purpose of suppressing the recombination of photogenerated carriers. Among various metal cations, dopants such as nickel (Ni) have attracted much attention due to their superior performance, low cost, easy availability, and non-toxicity.

[0006] Therefore, we can make full use of the natural multi-level structure of wood, use wood powder as a biological template, and introduce metal dopants on this basis to construct a composite material with higher photocatalytic performance, give play to the synergistic effect of biological template method and metal doping, and achieve the goal of efficiently degrading organic dye pollutants in wastewater. This has positive significance for the environmentally friendly treatment of water pollution, the effective alleviation of energy crisis, and the realization of high added value utilization of natural wood. Summary of the invention

[0007] The present invention aims at efficiently photocatalytically degrading organic dye pollutants in wastewater, and provides a method for preparing a nickel-doped bionic wood powder structure cerium vanadate photocatalytic material, which is characterized by: using wood powder as a biological template to give CeVO4 a unique microtubule structure, and introducing Ni as a metal dopant to construct a nickel-doped bionic wood powder structure cerium vanadate composite material with high photocatalytic performance, giving play to the synergistic effect of the biological template method and metal doping, and realizing efficient degradation of organic dye pollutants in wastewater.

[0008] A method for preparing a nickel-doped bionic wood powder structure cerium vanadate photocatalytic material comprises the following steps:

[0009] (1) Wood powder pretreatment: The spruce wood powder was soaked in 5% ammonia water for 24 hours, then rinsed with deionized water and anhydrous ethanol alternately for 3 times, and finally dried in a forced air drying oven at 80° C. for 24 hours to obtain pretreated wood powder.

[0010] (2) Preparation of precursor solution: Add a certain amount of Ni(NO3)2·6H2O and Ce(NO3)3·6H2O to deionized water, stir until completely dissolved, then add the pretreated wood powder in step (1), stir until uniformly mixed (referred to as suspension A). Dissolve NH4VO3 in deionized water, heat to 60°C, and stir until completely dissolved (referred to as suspension B).

[0011] (3) Preparation of nickel-doped bionic wood powder structure cerium vanadate: In a water bath, add suspension B in step (2) dropwise to suspension A. After stirring evenly, transfer the mixed solution to a Teflon-lined steel autoclave and keep it at 180°C for 24 hours. Rinse the precipitate obtained by centrifugation with deionized water and anhydrous ethanol alternately for 3 times, and then place it in a forced air drying oven and dry it at 80°C overnight. Finally, grind the dried precipitate into powder, place it in a tube furnace, heat it to 550°C at a heating rate of 5°C / min, and calcine it in an air atmosphere for 4 hours to obtain a nickel-doped bionic wood powder structure cerium vanadate photocatalytic material.

[0012] The spruce wood powder in the step (1) is sieved, and the sieve mesh number is 100 meshes.

[0013] In the step (2), the amounts of Ce(NO3)3·6H2O and NH4VO3 are both 2.5 mmol.

[0014] The water bath temperature in step (3) is 80°C.

[0015] During the dropwise addition in step (3), 5% ammonia water is used to adjust the pH value of the mixed solution to between 8 and 8.5.

[0016] The advantages of the nickel-doped bionic wood powder structure cerium vanadate photocatalytic material manufactured by the manufacturing method of the present invention are: on the one hand, wood powder, as a biological template, gives CeVO4 a higher specific surface area, effectively increases the reaction active sites of the material, and at the same time, the successful doping of Ni narrows the band gap of CeVO4 and inhibits the recombination of photogenerated carriers. The photocatalytic performance is greatly improved under the synergistic effect of the biological template method and metal doping; on the other hand, a photocatalytic material with high photocatalytic efficiency can be obtained through a simple hydrothermal synthesis and high-temperature calcination method, which achieves high added value utilization of natural wood while being low in cost and simple in process. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 This is the SEM image of the nickel-doped bionic wood powder structure cerium vanadate photocatalytic material prepared in Example 1.

[0018] Figure 2 This is the degradation curve of methylene blue of the nickel-doped bionic wood powder structure cerium vanadate photocatalytic material prepared in Example 1. DETAILED DESCRIPTION

[0019] The present invention is further described in detail below in conjunction with specific embodiments. The following content is only an example and explanation of the concept of the present invention. The technical personnel in the relevant technical field can make various modifications or repairs to the specific embodiments described, as long as they do not deviate from the concept of the present invention or exceed the scope defined by the claims, they all belong to the protection scope of the present invention.

[0020] Example 1

[0021] (1) Wood powder pretreatment: Spruce wood powder after passing through a 100-mesh sieve was soaked in 5% ammonia water for 24 hours, then rinsed with deionized water and anhydrous ethanol alternately for 3 times, and finally dried in a forced air drying oven at 80° C. for 24 hours to obtain pretreated wood powder.

[0022] (2) Preparation of precursor solution: Add 0.006 g of Ni(NO3)2·6H2O and 2.5 mmol of Ce(NO3)3·6H2O to deionized water, stir until completely dissolved, then add the pretreated wood powder in step (1) and stir until uniformly mixed (referred to as suspension A). Dissolve 2.5 mmol of NH4VO3 in deionized water, heat to 60°C, and stir until completely dissolved (referred to as suspension B).

[0023] (3) Preparation of nickel-doped bionic wood powder structure cerium vanadate: Under 80°C water bath conditions, the suspension B in step (2) was added dropwise to the suspension A. During this operation, the pH value of the mixed solution was adjusted to between 8 and 8.5 using 5% ammonia water. After stirring evenly, the mixed solution was transferred to a Teflon-lined steel autoclave and kept at 180°C for 24 hours. The precipitate obtained by centrifugation was rinsed alternately with deionized water and anhydrous ethanol for 3 times, and then placed in a forced air drying oven and dried overnight at 80°C. Finally, the dried precipitate was ground into powder, placed in a tubular furnace, heated to 550°C at a heating rate of 5°C / min, and calcined in an air atmosphere for 4 hours to obtain a nickel-doped bionic wood powder structure cerium vanadate photocatalytic material (Ni / T-CeVO4-1wt).

[0024] Example 2

[0025] (1) Wood powder pretreatment: Spruce wood powder after passing through a 100-mesh sieve was soaked in 5% ammonia water for 24 hours, then rinsed with deionized water and anhydrous ethanol alternately for 3 times, and finally dried in a forced air drying oven at 80° C. for 24 hours to obtain pretreated wood powder.

[0026] (2) Preparation of precursor solution: Add 0.019 g of Ni(NO3)2·6H2O and 2.5 mmol of Ce(NO3)3·6H2O to deionized water, stir until completely dissolved, then add the pretreated wood powder in step (1) and stir until uniformly mixed (referred to as suspension A). Dissolve 2.5 mmol of NH4VO3 in deionized water, heat to 60°C, and stir until completely dissolved (referred to as suspension B).

[0027] (3) Preparation of nickel-doped bionic wood powder structure cerium vanadate: Under 80°C water bath conditions, the suspension B in step (2) was added dropwise to the suspension A. During this operation, the pH value of the mixed solution was adjusted to between 8 and 8.5 using 5% ammonia water. After stirring evenly, the mixed solution was transferred to a Teflon-lined steel autoclave and kept at 180°C for 24 hours. The precipitate obtained by centrifugation was rinsed alternately with deionized water and anhydrous ethanol for 3 times, and then placed in a forced air drying oven and dried overnight at 80°C. Finally, the dried precipitate was ground into powder, placed in a tubular furnace, heated to 550°C at a heating rate of 5°C / min, and calcined in an air atmosphere for 4 hours to obtain a nickel-doped bionic wood powder structure cerium vanadate photocatalytic material (Ni / T-CeVO4-3wt).

[0028] Example 3

[0029] (1) Wood powder pretreatment: Spruce wood powder after passing through a 100-mesh sieve was soaked in 5% ammonia water for 24 hours, then rinsed with deionized water and anhydrous ethanol alternately for 3 times, and finally dried in a forced air drying oven at 80° C. for 24 hours to obtain pretreated wood powder.

[0030] (2) Preparation of precursor solution: Add 0.032 g of Ni(NO3)2·6H2O and 2.5 mmol of Ce(NO3)3·6H2O to deionized water, stir until completely dissolved, then add the pretreated wood powder in step (1) and stir until uniformly mixed (referred to as suspension A). Dissolve 2.5 mmol of NH4VO3 in deionized water, heat to 60°C, and stir until completely dissolved (referred to as suspension B).

[0031] (3) Preparation of nickel-doped bionic wood powder structure cerium vanadate: Under 80°C water bath conditions, the suspension B in step (2) was added dropwise to the suspension A. During this operation, the pH value of the mixed solution was adjusted to between 8 and 8.5 using 5% ammonia water. After stirring evenly, the mixed solution was transferred to a Teflon-lined steel autoclave and kept at 180°C for 24 hours. The precipitate obtained by centrifugation was rinsed alternately with deionized water and anhydrous ethanol for 3 times, and then placed in a forced air drying oven and dried overnight at 80°C. Finally, the dried precipitate was ground into powder, placed in a tubular furnace, heated to 550°C at a heating rate of 5°C / min, and calcined in an air atmosphere for 4 hours to obtain a nickel-doped bionic wood powder structure cerium vanadate photocatalytic material (Ni / T-CeVO4-5wt).

[0032] Example 4

[0033] (1) Wood powder pretreatment: Spruce wood powder after passing through a 100-mesh sieve was soaked in 5% ammonia water for 24 hours, then rinsed with deionized water and anhydrous ethanol alternately for 3 times, and finally dried in a forced air drying oven at 80° C. for 24 hours to obtain pretreated wood powder.

[0034] (2) Preparation of precursor solution: Add 0.045 g of Ni(NO3)2·6H2O and 2.5 mmol of Ce(NO3)3·6H2O to deionized water, stir until completely dissolved, then add the pretreated wood powder in step (1) and stir until uniformly mixed (referred to as suspension A). Dissolve 2.5 mmol of NH4VO3 in deionized water, heat to 60°C, and stir until completely dissolved (referred to as suspension B).

[0035] (3) Preparation of nickel-doped bionic wood powder structure cerium vanadate: Under 80°C water bath conditions, the suspension B in step (2) was added dropwise to the suspension A. During this operation, the pH value of the mixed solution was adjusted to between 8 and 8.5 using 5% ammonia water. After stirring evenly, the mixed solution was transferred to a Teflon-lined steel autoclave and kept at 180°C for 24 hours. The precipitate obtained by centrifugation was rinsed alternately with deionized water and anhydrous ethanol for 3 times, and then placed in a blast drying oven and dried overnight at 80°C. Finally, the dried precipitate was ground into powder, placed in a tube furnace, heated to 550°C at a heating rate of 5°C / min, and calcined in an air atmosphere for 4 hours to obtain a nickel-doped bionic wood powder structure cerium vanadate photocatalytic material (Ni / T-CeVO4-7wt).

[0036] Example 5

[0037] (1) Wood powder pretreatment: Spruce wood powder after passing through a 100-mesh sieve was soaked in 5% ammonia water for 24 hours, then rinsed with deionized water and anhydrous ethanol alternately for 3 times, and finally dried in a forced air drying oven at 80° C. for 24 hours to obtain pretreated wood powder.

[0038] (2) Preparation of precursor solution: Add 0.064 g of Ni(NO3)2·6H2O and 2.5 mmol of Ce(NO3)3·6H2O to deionized water, stir until completely dissolved, then add the pretreated wood powder in step (1) and stir until uniformly mixed (referred to as suspension A). Dissolve 2.5 mmol of NH4VO3 in deionized water, heat to 60°C, and stir until completely dissolved (referred to as suspension B).

[0039] (3) Preparation of nickel-doped bionic wood powder structure cerium vanadate: Under 80°C water bath conditions, the suspension B in step (2) was added dropwise to the suspension A. During this operation, the pH value of the mixed solution was adjusted to between 8 and 8.5 using 5% ammonia water. After stirring evenly, the mixed solution was transferred to a Teflon-lined steel autoclave and kept at 180°C for 24 hours. The precipitate obtained by centrifugation was rinsed alternately with deionized water and anhydrous ethanol for 3 times, and then placed in a blast drying oven and dried overnight at 80°C. Finally, the dried precipitate was ground into powder, placed in a tubular furnace, heated to 550°C at a heating rate of 5°C / min, and calcined in an air atmosphere for 4 hours to obtain a nickel-doped bionic wood powder structure cerium vanadate photocatalytic material (Ni / T-CeVO4-10wt).

[0040] The above-mentioned specific embodiments are only exemplary embodiments of the present invention. The patent protection scope of the present invention includes but is not limited to the above-mentioned specific embodiments. Any method for manufacturing nickel-doped bionic wood powder structure cerium vanadate photocatalytic material that complies with the claims of the present invention should be included in the patent protection scope of the present invention.

Claims

1. A method for preparing a nickel-doped bionic wood powder structure cerium vanadate photocatalytic material, comprising the following steps: (1) Wood powder pretreatment: The spruce wood powder was soaked in 5% ammonia water for 24 hours, then rinsed with deionized water and anhydrous ethanol alternately for 3 times, and finally dried in a forced air drying oven at 80° C. for 24 hours to obtain pretreated wood powder. (2) Preparation of precursor solution: Add a certain amount of Ni(NO3)2·6H2O and Ce(NO3)3·6H2O to deionized water, stir until completely dissolved, then add the pretreated wood powder in step (1), stir until uniformly mixed (referred to as suspension A). Dissolve NH4VO3 in deionized water, heat to 60°C, and stir until completely dissolved (referred to as suspension B). (3) Preparation of nickel-doped bionic wood powder structure cerium vanadate: In a water bath, add suspension B in step (2) dropwise to suspension A. After stirring evenly, transfer the mixed solution to a Teflon-lined steel autoclave and keep it at 180°C for 24 hours. Rinse the precipitate obtained by centrifugation with deionized water and anhydrous ethanol alternately for 3 times, and then place it in a forced air drying oven and dry it at 80°C overnight. Finally, grind the dried precipitate into powder, place it in a tube furnace, heat it to 550°C at a heating rate of 5°C / min, and calcine it in an air atmosphere for 4 hours to obtain a nickel-doped bionic wood powder structure cerium vanadate photocatalytic material.

2. The method for preparing a nickel-doped bionic wood powder structure cerium vanadate photocatalytic material according to claim 1, characterized in that: The spruce wood powder in step (1) is sieved to a size of 100 meshes.

3. The method for preparing a nickel-doped bionic wood powder structure cerium vanadate photocatalytic material according to claim 1, characterized in that: In step (2), the amounts of Ce(NO3)3·6H2O and NH4VO3 are both 2.5 mmol.

4. The method for preparing a nickel-doped bionic wood powder structure cerium vanadate photocatalytic material according to claim 1, characterized in that: In step (3), the water bath temperature is 80°C.

5. The method for preparing a nickel-doped biomimetic wood powder structure cerium vanadate photocatalytic material according to claim 1, characterized in that: During the dropwise addition in step (3), 5% ammonia water is used to adjust the pH value of the mixed solution to between 8 and 8.5.

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