阅读说明：本技术 一种铁基复合光催化剂及其制备方法 (Iron-based composite photocatalyst and preparation method thereof ) 是由 张世界 余志勤 刘雄 于 2019-08-09 设计创作，主要内容包括：本发明涉及光催化材料技术领域,为解决传统光催化剂可见光响应范围较窄、光利用率低的问题,提供了一种铁基复合光催化剂及其制备方法,包括以下步骤：(1)在含有Fe<Sup>3+</Sup>和Fe<Sup>2+</Sup>的铁盐水溶液中加入阴离子表面活性剂和甲苯并混合均匀,氮气保护下,加热搅拌条件下乳化,得到Fe<Sub>3</Sub>O<Sub>4</Sub>乳液；(2)在Fe<Sub>3</Sub>O<Sub>4</Sub>乳液中依次加入碱液,无水乙醇和g-C<Sub>3</Sub>N<Sub>4</Sub>/ZnO-Ce配体,氮气保护下搅拌反应,反应完成后除去溶剂,洗涤产物至滤液呈中性,真空干燥后得到铁基复合光催化剂。本发明以铁基氧化物为基质,通过与g-C<Sub>3</Sub>N<Sub>4</Sub>和Ce依靠分子间弱相互作用力进行负载,通过负载和配体,拓宽铁基催化剂的禁带宽度,扩大了其对可见光的光响应范围,使其能被可见光激发,实现高效的可见光响应。(The invention relates to the technical field of photocatalytic materials, and provides an iron-based composite photocatalyst and a preparation method thereof, aiming at solving the problems of narrow visible light response range and low light utilization rate of the traditional photocatalyst, wherein the preparation method comprises the following steps: (1) in the presence of Fe 3+ And Fe 2+ Adding an anionic surfactant and toluene into the ferric salt aqueous solution, uniformly mixing, and emulsifying under the condition of heating and stirring under the protection of nitrogen to obtain Fe 3 O 4 An emulsion; (2) in Fe 3 O 4 Adding alkali liquor, absolute ethyl alcohol and g-C into the emulsion in sequence 3 N 4 and/ZnO-Ce ligand is stirred and reacted under the protection of nitrogen, the solvent is removed after the reaction is finished, the product is washed until the filtrate is neutral, and the iron-based composite photocatalyst is obtained after vacuum drying. The invention takes iron-based oxide as a matrix, and the iron-based oxide is reacted with g-C 3 N 4 Ce is loaded by virtue of weak intermolecular interaction force, the forbidden bandwidth of the iron-based catalyst is widened by the load and the ligand, the photoresponse range of the iron-based catalyst to visible light is expanded, the iron-based catalyst can be excited by the visible light, and high efficiency is realizedEffective visible light response.)

1. The preparation method of the iron-based composite photocatalyst is characterized by comprising the following steps of:

(1) in the presence of Fe³⁺And Fe²⁺Adding an anionic surfactant and toluene into the ferric salt aqueous solution, uniformly mixing, and emulsifying under the condition of heating and stirring under the protection of nitrogen to obtain Fe₃O₄An emulsion;

(2) fe obtained in step (1)₃O₄Adding alkali liquor, absolute ethyl alcohol and g-C into the emulsion in sequence₃N₄and/ZnO-Ce ligand is stirred and reacted under the protection of nitrogen, the solvent is removed after the reaction is finished, the product is washed until the filtrate is neutral, and the iron-based composite photocatalyst is obtained after vacuum drying.

2. According to the rightThe method for preparing an iron-based composite photocatalyst as claimed in claim 1, wherein in the step (2), the g-C is₃N₄the/ZnO-Ce ligand is prepared by the following method: uniformly mixing urea, zinc salt and cerium salt, placing the mixture in a closed container, heating to 500-650 ℃ at a heating rate of 3-5 ℃/min, calcining for 3-6 h, and cooling to room temperature to obtain g-C₃N₄a/ZnO-Ce ligand.

3. The preparation method of the iron-based composite photocatalyst as claimed in claim 2, wherein the mass ratio of the urea to the zinc salt to the cerium salt is (1-2): (0.1-0.8): (0.02-0.1).

4. The method for preparing the iron-based composite photocatalyst as claimed in claim 2, wherein the zinc salt is zinc acetate or zinc nitrate; the cerium salt is cerium nitrate or cerium acetate.

5. The method for preparing the iron-based composite photocatalyst as claimed in claim 1, wherein in the step (1), the heating temperature is 70-85 ℃; fe in the aqueous iron salt solution³⁺And Fe²⁺The mass ratio of the substances is (0.5-3): (0.5-2).

6. The method for preparing an iron-based composite photocatalyst according to claim 1, wherein in step (1), Fe is contained in the iron salt aqueous solution³⁺The concentration of (A) is 0.5-1.0 mg/L, Fe²⁺The concentration of (b) is 0.1-0.8 mg/L.

7. The preparation method of the iron-based composite photocatalyst according to claim 1, wherein in the step (1), the mass ratio of the ferric salt aqueous solution, the anionic surfactant and the toluene is (1-2): (0.1-0.8): (8-15); the anionic surfactant is selected from one of alkyl sulfate of C8-C14 and alkyl sulfonate of C8-C14.

8. According to the rightThe method for preparing an iron-based composite photocatalyst as claimed in claim 1, wherein in the step (2), the g-C is₃N₄Amount of substance of/ZnO-Ce ligand and Fe₃O₄Fe contained in the emulsion₃O₄The ratio of the amounts of substances (1): (2-10).

9. The method for preparing an iron-based composite photocatalyst as claimed in claim 1, wherein in the step (2), the solvent is removed by adsorbing the catalyst with a magnet.

10. An iron-based composite photocatalyst obtainable by the method of any one of claims 1 to 7.

Technical Field

The invention relates to the technical field of photocatalytic materials, in particular to an iron-based composite photocatalyst and a preparation method thereof.

Background

Photocatalytic technology began in the early seventies of the twentieth century. From stricter to stricterThe serious environmental problem and the energy exhaustion caused by the shortage of petroleum resources greatly improve the research enthusiasm of people for new energy. In 1972, Fujishima and Honda et al for the first time discovered that titanium dioxide crystals can split water into hydrogen and oxygen under light, and since then new photocatalytic technologies are becoming more and more popular. Thereafter, much about TiO₂Researches on hydrogen production by photocatalytic water splitting and polluted wastewater degradation and the like emerge. At present, photocatalysis has been used for photodegrading organic pollutants and carrying out photocatalytic reduction on CO₂The fields of photolysis hydrogen (oxygen) production, dye-sensitized solar cells, sterilization and the like have wide application prospects. Research shows that the photocatalytic technology is utilized to treat polluted wastewater and cracked water to produce hydrogen, and new clean energy is continuously provided for human beings.

However, the industrialization of the photocatalytic technology still has great challenges, and from the viewpoint of renewable energy and environmental protection, the conventional photocatalyst has low energy utilization efficiency in the visible region of sunlight. Such as TiO₂The forbidden band width is large, and the forbidden band can only absorb 5% of ultraviolet light in solar energy and does not respond to 43% of visible light in the solar energy. Therefore, it is the most important research direction in the current photocatalytic research field to obtain high-efficiency photocatalyst through the modification of the traditional photocatalyst and the search of a novel visible light photocatalyst.

Chinese patent literature discloses a graphite-phase carbon nitride nanosheet-based composite photocatalytic material and a preparation method and application thereof, and application publication No. CN 109107601A. However, the graphite-phase carbon nitride nanosheet-based composite photocatalytic material disclosed by the invention is narrow in visible light response range and low in light utilization rate.

Disclosure of Invention

The invention provides an iron-based composite photocatalyst with a wide visible light response range and a high light utilization rate, aiming at overcoming the problems of a narrow visible light response range and a low light utilization rate of a traditional photocatalyst.

The invention also provides a preparation method of the iron-based composite photocatalyst, which is simple to operate, has no special requirements on equipment and is easy to realize industrial production.

In order to achieve the purpose, the invention adopts the following technical scheme:

a preparation method of an iron-based composite photocatalyst comprises the following steps:

(1) in the presence of Fe³⁺And Fe²⁺Adding an anionic surfactant and toluene into the ferric salt aqueous solution, uniformly mixing, and emulsifying under the condition of heating and stirring under the protection of nitrogen to obtain Fe₃O₄An emulsion;

(2) fe obtained in step (1)₃O₄Sequentially adding alkaline solution (such as NaOH), anhydrous ethanol and g-C into the emulsion₃N₄and/ZnO-Ce ligand is stirred and reacted under the protection of nitrogen, the solvent is removed after the reaction is finished, the product is washed until the filtrate is neutral, and the iron-based composite photocatalyst is obtained after vacuum drying.

Preferably, in step (2), the g-C₃N₄the/ZnO-Ce ligand is prepared by the following method: uniformly mixing urea, zinc salt and cerium salt, placing the mixture in a closed container (such as a crucible with a cover), heating to 500-650 ℃ at a heating rate of 3-5 ℃/min, calcining for 3-6 h, and cooling to room temperature to obtain g-C₃N₄a/ZnO-Ce ligand.

More preferably, the heating rate is 5 ℃/min; the calcination temperature is 550 ℃; the calcination time was 4 h.

The reaction principle of this step is that atoms are rearranged and doped with each other at high temperature, g-C₃N₄And Ce is loaded by virtue of weak intermolecular interaction force to form stable g-C₃N₄a/ZnO-Ce ligand structure.

Preferably, the mass ratio of the urea to the zinc salt to the cerium salt is (1-2): (0.1-0.8): (0.02-0.1).

Preferably, the zinc salt is zinc acetate or zinc nitrate; the cerium salt is cerium nitrate or cerium acetate.

Preferably, in the step (1), the heating temperature is 70-85 ℃; fe in the aqueous iron salt solution³⁺And Fe²⁺The mass ratio of the substances is (0.5-3): (0.5-2).

Preferably, in step (1), Fe is contained in the iron salt aqueous solution³⁺The concentration of (A) is 0.5-1.0 mg/L, Fe²⁺The concentration of (b) is 0.1-0.8 mg/L.

Preferably, in the step (1), the mass ratio of the ferric salt aqueous solution, the anionic surfactant and the toluene is (1-2): (0.1-0.8): (8-15).

Preferably, in the step (1), the anionic surfactant is one selected from alkyl sulfates of C8-C14 and alkyl sulfonates of C8-C14. The C8-C14 alkyl sulfate salt includes sodium lauryl sulfate; the C8-C14 alkyl sulfonate comprises sodium dodecyl benzene sulfonate and the like.

Preferably, in step (2), the g-C₃N₄Amount of substance of/ZnO-Ce ligand and Fe₃O₄Fe contained in the emulsion₃O₄The ratio of the amounts of substances (1): (2-10).

Preferably, in the step (2), the solvent is removed by adsorbing the catalyst with a magnet. The catalyst is adsorbed by the magnet, so that the operation is simple and convenient, and the separation efficiency is high.

An iron-based composite photocatalyst prepared by any one of the methods.

Therefore, the invention has the following beneficial effects:

(1) taking iron-based oxide as a matrix, and reacting with g-C₃N₄Ce is loaded by virtue of weak intermolecular interaction force, the forbidden bandwidth of the iron-based catalyst is widened by the load and the ligand, the photoresponse range of the iron-based catalyst to visible light is expanded, the iron-based catalyst can be excited by the visible light, and efficient visible light response is realized;

(2) the preparation method is simple to operate, has no special requirements on equipment, and is easy to realize industrial production.

Drawings

FIG. 1 is g-C obtained in example 1₃N₄SEM image of/ZnO-Ce ligand.

FIG. 2 is an SEM photograph of the iron-based composite photocatalyst prepared in example 1.

FIG. 3 is a FT-IR chart of the iron-based composite photocatalyst obtained in example 1.

FIG. 4 shows a UV-vis spectrum of the iron-based composite photocatalyst prepared in example 1.

Detailed Description

The technical solution of the present invention is further specifically described below by using specific embodiments and with reference to the accompanying drawings.

In the present invention, all the equipment and materials are commercially available or commonly used in the art, and the methods in the following examples are conventional in the art unless otherwise specified.