阅读说明：本技术 一种零维/二维结构氧化铜与电气石复合光催化材料的制备方法 (Preparation method of zero-dimensional/two-dimensional structure copper oxide and tourmaline composite photocatalytic material ) 是由 尹艳红 余昌强 吴子平 刘先斌 黎业生 于 2019-11-15 设计创作，主要内容包括：一种零维/二维结构氧化铜与电气石复合光催化材料的制备方法。本方法以天然电气石、碱以及金属铜盐为原料,采用沉淀-水热法制备氧化铜/电气石复合材料,过程如下：首先,超声制备电气石/水悬浮体系；其次,将铜盐溶解于上述悬浮体系,逐滴加入碱溶液并剧烈搅拌；最后,将所得混合体系装入反应釜中进行水热反应,所得产物经洗涤,干燥,研磨即可得到零维/二维结构氧化铜与电气石复合光催化材料。电气石的引入,不仅可以缓解二维氧化铜纳米片的团聚,而且还能够有效地提高氧化铜的光催化性能。本发明操作简单、条件温和、成本低廉、原料来源丰富,且合成的复合材料具有良好的光催化活性和耐久性。(A preparation method of a zero-dimensional/two-dimensional structure copper oxide and tourmaline composite photocatalytic material. The method takes natural tourmaline, alkali and metal copper salt as raw materials, adopts a precipitation-hydrothermal method to prepare the copper oxide/tourmaline composite material, and comprises the following steps: firstly, preparing a tourmaline/water suspension system by ultrasonic; secondly, dissolving copper salt in the suspension system, dropwise adding an alkali solution and violently stirring; and finally, putting the obtained mixed system into a reaction kettle for hydrothermal reaction, washing, drying and grinding the obtained product to obtain the zero-dimensional/two-dimensional structure copper oxide and tourmaline composite photocatalytic material. Due to the introduction of the tourmaline, the agglomeration of the two-dimensional copper oxide nanosheets can be relieved, and the photocatalytic performance of the copper oxide can be effectively improved. The method has the advantages of simple operation, mild conditions, low cost and rich raw material sources, and the synthesized composite material has good photocatalytic activity and durability.)

1. A preparation method of a zero-dimensional/two-dimensional structure copper oxide and tourmaline composite photocatalytic material is characterized by comprising the following steps of: the invention adopts natural polar mineral tourmaline and adopts a mild precipitation-hydrothermal method to induce the growth of zero-dimensional copper oxide nano particles on the surface of a two-dimensional copper oxide nano sheet.

2. The preparation method of the zero-dimensional/two-dimensional structure copper oxide and tourmaline composite photocatalytic material as claimed in claim 1, which is characterized by comprising the following steps in sequence:

(1) preparing tourmaline powder: removing impurities from tourmaline mineral particles, washing with ultrapure water, drying in an oven, ball-milling by using a planetary ball mill, and sieving to obtain tourmaline powder with the diameter of 200-800 nm;

(2) preparing a copper hydroxide/tourmaline suspension: adding a certain amount of tourmaline powder into deionized water, stirring, and performing ultrasonic dispersion to obtain a tourmaline suspension A; adding copper metal salt into the suspension, and stirring and dissolving to obtain suspension B; under the condition of stirring, dropwise adding the prepared alkali solution into the suspension B, and continuously stirring for 2 hours to obtain a suspension C;

(3) and (3) putting the suspension C obtained in the step (2) into a polytetrafluoroethylene reaction kettle, carrying out hydrothermal reaction at a certain temperature for a certain time, naturally cooling to room temperature, washing, drying and grinding to obtain the zero-dimensional/two-dimensional structure copper oxide and tourmaline composite photocatalytic material.

3. The preparation method of the zero-dimensional/two-dimensional structure copper oxide and tourmaline composite photocatalytic material as claimed in claim 2, wherein the preparation method comprises the following steps: the tourmaline in the step (1) is any one of lithium tourmaline, iron tourmaline, magnesium tourmaline and the like.

4. The preparation method of the zero-dimensional/two-dimensional structure copper oxide and tourmaline composite photocatalytic material as claimed in claim 2, wherein the preparation method comprises the following steps: the copper metal salt in the step (2) is any one of copper acetate, copper nitrate, copper chloride, copper sulfate and the like.

5. The preparation method of the zero-dimensional/two-dimensional structure copper oxide and tourmaline composite photocatalytic material as claimed in claim 2, wherein the preparation method comprises the following steps: the alkali solution in the step (2) is any one of a lithium hydroxide solution, a sodium hydroxide solution, a potassium hydroxide solution and the like.

6. The preparation method of the zero-dimensional/two-dimensional structure copper oxide and tourmaline composite photocatalytic material as claimed in claim 2, wherein the preparation method comprises the following steps: the molar ratio of the copper metal salt to the tourmaline in the step (2) is 13: 1-65: 1.

7. The preparation method of the zero-dimensional/two-dimensional structure copper oxide and tourmaline composite photocatalytic material as claimed in claim 2, wherein the preparation method comprises the following steps: the concentration and the dosage of the alkali in the step (2) are respectively 1.25-6.25 mol/L and 20 mL.

8. The preparation method of the zero-dimensional/two-dimensional structure copper oxide and tourmaline composite photocatalytic material as claimed in claim 2, wherein the preparation method comprises the following steps: the reaction temperature in the step (3) is 140-200 ℃, and the reaction time is 4-12 h.

Technical Field

The invention relates to a preparation method of a zero-dimensional/two-dimensional structure copper oxide and tourmaline composite photocatalytic material, and particularly relates to the formation of the zero-dimensional/two-dimensional structure copper oxide induced by tourmaline minerals.

Background

The copper oxide is a p-type semiconductor with a narrow forbidden band width (1.2 eV), and has great application value in photocatalytic degradation of organic pollutants, photocatalytic carbon dioxide reduction and photocatalytic water decomposition. The factors that limit the photocatalytic performance of copper oxide mainly include (1) the rapid recombination of photo-generated electron/hole pairs; (2) the nano copper oxide has high surface energy, so that a large block structure is easily formed due to adhesion, and the exposure of active sites on the surface of the material is reduced. At present, the research on copper oxide modification mainly comprises the steps of constructing a copper oxide-based heterojunction (such as zero-dimensional copper oxide/two-dimensional titanium dioxide, zero-dimensional copper oxide/three-dimensional zinc oxide, two-dimensional copper oxide/two-dimensional ferric oxide, zero-dimensional copper oxide/two-dimensional carbon nitride, and two-dimensional copper oxide/zero-dimensional silver phosphate) and dispersing copper oxide on a material (such as a carbon nanotube and graphene) which has a large specific surface area and good electron transmission capability, so that more adsorption-light reaction sites can be exposed, and the separation of photo-generated electron/hole pairs can be promoted. However, these methods are either complicated in preparation process and difficult to obtain an ideal heterojunction; or the material preparation cost is high, which is not beneficial to practical application.

Tourmaline is a natural polar silicate mineral with permanent spontaneous polarization, and its polaritycAt both ends in the axial direction 10⁶~10⁷The strong electric field of V/m has the characteristics of pyroelectricity, piezoelectricity, far infrared emission and the like. Researches show that the electric field on the surface of the tourmaline can effectively promote the separation of photo-generated electron/hole pairs, thereby improving the photocatalytic efficiency. Meanwhile, far infrared rays emitted by the tourmaline can activate water molecules and reduce the size of water molecular beams, so that the oxygen content in a water phase is increased, and the photocatalytic oxidation reaction can be promoted to a certain extent. Xie et al (Enhanced catalytic ef fi catalysis of FeMnTiOxSCR catalysts through addition of catalytic nanoparticles during the degradation of the catalystone-step sol-gel process Materials Letters, 2018, 217: 60-63) shows that the tourmaline can also regulate the growth of nano Materials in a solid phase reaction.

The invention adopts tourmaline with rich source, low price and good chemical stability to adjust the growth of the nano copper oxide crystal, and the zero-dimensional/two-dimensional structure copper oxide and tourmaline composite photocatalytic material is obtained. The introduction of functional mineral material tourmaline can simplify the preparation process, reduce the preparation cost and improve the photocatalytic performance of the material. The invention provides a certain guiding significance for the preparation of the zero-dimensional/two-dimensional structure material and the tourmaline functional composite material.

Disclosure of Invention

Aiming at the characteristics of complex preparation process, high cost and the like in the existing copper oxide modification, the invention aims to induce and prepare the zero-dimensional/two-dimensional structure copper oxide and tourmaline composite photocatalytic material by introducing tourmaline. On one hand, the introduction of the tourmaline can block the migration of ions in a reaction system, thereby inhibiting the growth of copper oxide crystals; on the other hand, the tourmaline can provide nucleation-growth sites for copper oxide and promote the formation of a good contact interface between the copper oxide and the tourmaline.

The invention prepares the zero-dimensional/two-dimensional structure copper oxide and tourmaline composite photocatalytic material by the following process steps:

(1) preparing tourmaline powder: the tourmaline mineral particles are subjected to impurity removal and ultra-pure water washing. Drying in an oven, ball-milling by using a planetary ball mill, and sieving to obtain tourmaline powder with the diameter of 200-800 nm;

(2) preparing a copper hydroxide/tourmaline suspension: adding a certain amount of tourmaline powder into deionized water, and performing ultrasonic dispersion to obtain a tourmaline suspension A; adding copper metal salt into the suspension A, and stirring and dissolving to obtain a suspension B; under the condition of stirring, dropwise adding the prepared alkali solution into the suspension B, and continuously stirring for 2 hours to obtain a suspension C;

(3) and (3) putting the suspension C obtained in the step (2) into a polytetrafluoroethylene reaction kettle, carrying out hydrothermal reaction at a certain temperature for a period of time, and naturally cooling to room temperature. And washing, drying and grinding to obtain the zero-dimensional/two-dimensional structure copper oxide and tourmaline composite photocatalytic material.

The copper metal salt in the step (2) is one of copper acetate, copper nitrate, copper chloride, copper sulfate and the like; the alkali solution is one of lithium hydroxide solution, sodium hydroxide solution, potassium hydroxide solution and the like; the molar ratio of the copper metal salt to the tourmaline is 13: 1-65: 1, and the alkali concentration and the dosage are 1.25-6.25 mol/L and 20mL respectively.

The reaction temperature in the step (3) is 140-200 ℃, and the reaction time is 4-12 h.

The invention utilizes the tourmaline with permanent spontaneous polarization, not only regulates the growth of copper oxide crystals in liquid phase reaction and induces the formation of copper oxide nano particles so as to increase the reactive active sites on the surface of the copper oxide, but also can effectively promote the separation and utilization of photo-generated electron/hole pairs. Firstly, copper ions are adsorbed to the surface of tourmaline particles through coulomb attraction; secondly, when the alkaline solution is added, copper ions form copper hydroxide on the surface of the tourmaline in situ; and finally, dehydrating the copper hydroxide in the hydrothermal reaction to generate copper oxide in situ. The tourmaline effectively inhibits the growth of copper oxide nano-sheet crystal grains and promotes the growth of zero-dimensional copper oxide nano-particles on the surface of the two-dimensional copper oxide nano-sheet. Due to the zero-dimensional nano particles, the original two-dimensional nano sheet with a smooth surface becomes rough, so that the agglomeration of the nano sheet is relieved, and the exposure of active sites is promoted. Copper oxide grows in situ on the surface of the tourmaline, so that a good contact interface is established between the tourmaline and the tourmaline, and a channel is provided for the rapid separation of photo-generated electron/hole pairs. The raw materials used in the invention have rich sources and low price, and are green and environment-friendly; the preparation process is simple and the practicability is strong; the obtained copper oxide has a zero-dimensional/two-dimensional structure and has wide application prospect.

The invention has the following beneficial effects: the invention adopts a precipitation-hydrothermal method with mild conditions, and induces the growth of zero-dimensional copper oxide nano particles on the surface of a two-dimensional copper oxide nano sheet by adding tourmaline into a liquid phase system for the growth of copper oxide crystals. The addition of the tourmaline can promote the exposure of active sites on the copper oxide and the separation of photo-generated electron/hole pairs, thereby improving the photocatalytic performance of the copper oxide. Firstly, adding an alkali solution into the surface of tourmaline through electrostatic adsorption to obtain copper hydroxide deposited in situ; secondly, through hydrothermal reaction, zero-dimensional/two-dimensional structure copper oxide is formed at the same time, and the zero-dimensional copper oxide nanoparticles grow on the surface of the two-dimensional copper oxide nanosheets, so that the agglomeration of the two-dimensional nanosheets is relieved, and the exposure of active sites is effectively promoted. Compared with the traditional copper oxide modification research, the method adopts the tourmaline which is cheap and rich in source, and effectively promotes the exposure of the active sites on the surface of the copper oxide and improves the utilization efficiency of photo-generated electron/hole pairs by a simple precipitation-hydrothermal method. The invention has certain guiding significance for simplifying the modification process of the copper oxide, improving the practical application value of the copper oxide and modifying other materials.

Drawings

FIG. 1 is a scanning electron microscope photograph of (a) copper oxide and (b) copper oxide/tourmaline composite photocatalytic material according to the present invention.

FIG. 2 shows a nitrogen adsorption-desorption curve diagram (a) and a corresponding Barrett-Joyner-Halenda pore size distribution curve diagram (b) of copper oxide, tourmaline and a copper oxide/tourmaline composite photocatalytic material according to the present invention.

FIG. 3 shows the methylene blue degradation curve of the copper oxide/tourmaline composite photocatalytic material with different copper oxide and tourmaline ratios under the irradiation of visible light.

Detailed Description

The following are specific embodiments of the present invention. It should be noted that the description of the embodiments is provided to help understanding of the present invention, but the scope of the present invention is not limited to the following examples. In addition, the technical features involved in the respective embodiments of the present invention described below may be combined with each other as long as they do not conflict with each other.