阅读说明：本技术 球状的具有核壳结构的磷钼酸钾粉体的制备方法及其用途 (Preparation method and application of spherical potassium phosphomolybdate powder with core-shell structure ) 是由 李涛海 余双文 李星 于 2020-05-11 设计创作，主要内容包括：本发明公开了一种球状的具有核壳结构的磷钼酸钾粉体的制备方法与用途。在本发明中,将KCl溶液缓慢地滴入黄色的磷钼酸溶液中,滴入过程中不断地磁力搅拌,得到黄色的悬浮液后,继续搅拌一定时间,使其反应完全,静置,得到黄色的沉淀物。将沉淀物离心分离,洗涤,真空干燥,得到所述球状的具有核壳结构的磷钼酸钾粉体。本发明可以在无需添加表面活性剂的情况下制备出具有均一形貌的核壳球状分层的磷钼酸钾粉体材料,且制备工艺简单,周期短,生产过程安全,效率高,所制得的磷钼酸钾粉体材料在少量的30%双氧水辅助下可以在可见光下催化降解有机污染物。(The invention discloses a preparation method and application of spherical potassium phosphomolybdate powder with a core-shell structure. In the invention, a KCl solution is slowly dropped into a yellow phosphomolybdic acid solution, and is continuously magnetically stirred in the dropping process to obtain a yellow suspension, and then is continuously stirred for a certain time to completely react, and is kept stand to obtain a yellow precipitate. And centrifugally separating, washing and vacuum drying the precipitate to obtain the spherical potassium phosphomolybdate powder with the core-shell structure. The method can prepare the core-shell spherical layered potassium phosphomolybdate powder material with uniform morphology without adding a surfactant, has simple preparation process, short period, safe production process and high efficiency, and the prepared potassium phosphomolybdate powder material can catalyze and degrade organic pollutants under visible light with the assistance of a small amount of 30 percent hydrogen peroxide.)

1. A preparation method of spherical potassium phosphomolybdate powder material with a core-shell structure is characterized by comprising the following steps:

1) weighing a proper amount of phosphomolybdic acid, adding the phosphomolybdic acid into deionized water with a certain volume, and magnetically stirring to obtain a yellow phosphomolybdic acid solution A, wherein the concentration of the A is 0.05-0.2 g/mL;

2) weighing a proper amount of potassium chloride, adding the potassium chloride into deionized water with a certain volume, and magnetically stirring to obtain a clear and colorless potassium chloride solution B, wherein the concentration of the potassium chloride solution B is 0.05-0.1 g/mL;

3) slowly dripping the potassium chloride solution B into a yellow phosphomolybdic acid solution A at the speed of 0.5mL/min, continuously and slowly stirring at the temperature of 0-10 ℃ until the solution becomes turbid, stopping stirring, continuously dripping the residual potassium chloride solution, and finally, changing the solution into a yellow suspension C;

4) standing the suspension C for a period of time to obtain yellow precipitate, performing centrifugal separation on the precipitate, alternately washing the precipitate for 3 times by using deionized water and absolute ethyl alcohol to obtain a semi-finished product, and drying the obtained semi-finished product in a vacuum drying oven at the temperature of 80 ℃ for 12 hours under normal pressure to obtain yellow potassium phosphomolybdate powder, namely spherical potassium phosphomolybdate powder with a core-shell structure;

the chemical formula of the phosphomolybdic acid is H₃PMo₁₂O₄₀；

The chemical formula of the potassium phosphomolybdate powder material is K₃PMo₁₂O₄₀•4H₂O。

2. The method for preparing the spherical potassium phosphomolybdate powder material with the core-shell structure according to claim 1, wherein the diameter of the potassium phosphomolybdate powder sphere is 5 μm, and the thickness of the core shell is 50 nm.

3. The preparation method of the spherical potassium phosphomolybdate powder material with the core-shell structure as claimed in claim 1, wherein the potassium phosphomolybdate powder prepared by the method is used as a photocatalyst, and can effectively catalyze and degrade rhodamine B and quinoline blue under visible light with the assistance of a small amount of 30% hydrogen peroxide.

Technical Field

The invention relates to a preparation method and application of spherical potassium phosphomolybdate powder with a core-shell structure, belonging to the chemical field of inorganic nano materials.

Background

Polyoxometalates (POMs) are inorganic compounds with a certain structure composed of elements such as metals (generally transition metals), oxygen and the like. The catalyst not only has special properties of acidity, oxidation-reduction property and the like, but also has structural characteristics of a complex and a metal oxide, can be used as a catalyst, and is widely applied to the research in the field of catalysis and functional materials. The photochemistry and photocatalysis of polyoxometallates have attracted great attention over the past decades due to their diverse molecular structures and unique redox properties. Studies have shown that polyoxometallates have the same photochemical properties as semiconductor photocatalysts. Therefore, it can be used as photocatalyst to degrade organic dye.

Phosphomolybdic acid is a polyacid of Keggin structure, which is capable of reacting with a counter cation (K)⁺、NH₃ ⁺Etc.) combine to form phosphomolybdates. The potassium phosphomolybdate is synthesized by reacting a certain amount of phosphomolybdic acid with a certain amount of potassium chloride, and the preparation method and conditions are different, and the shape and the size of the potassium phosphomolybdate are different. According to literature reports, potassium phosphomolybdate with different shapes and sizes has been synthesized, such as by using a solid phase method and forming K₃PMo₁₂O₄₀•8H₂O-nano-ions (Chinese Journal of Spectroscopy laboratory, 2002, 19, 86-88); synthesis of star-like nanostructured K by liquid phase method₃PMo₁₂O₄₀•nH₂K for O (chem. Commun., 2002, 2032-₃PMo₁₂O₄₀•nH₂O (Dalton trans, 2013, 42, 15637-. A series of characterization and performance studies are carried out on the potassium phosphomolybdate with different morphologies. But has not found its application in photocatalytic research.

K prepared by the invention₃PMo₁₂O₄₀•4H₂O is a micron sphere with a multilayer shell coated core-shell structure and uniform appearance. It is prepared at normal temperature and pressure without adding any additiveA surfactant. The compound is used as a photocatalyst and is applied to degradation of organic dyes (rhodamine B and quinoline blue). The results show that 30% H is present in very small amounts₂O₂And (3) the organic dyes (rhodamine B and quinoline blue) are efficiently degraded under the assistance of visible light.

Disclosure of Invention

The invention aims to solve the technical problem of providing a preparation method and application of spherical potassium phosphomolybdate powder with a core-shell structure in the prior art.

The technical scheme adopted by the invention for solving the technical problems is as follows: a preparation method of spherical potassium phosphomolybdate powder with a core-shell structure is characterized in that a phosphomolybdate solution and a potassium chloride solution are stirred at room temperature to react to form yellow suspension, and the yellow suspension is centrifugally separated, washed and dried to obtain the spherical potassium phosphomolybdate powder with the core-shell structure, and specifically comprises the following steps:

1) weighing a proper amount of phosphomolybdic acid, adding the phosphomolybdic acid into deionized water with a certain volume, and magnetically stirring to obtain a yellow phosphomolybdic acid solution A, wherein the concentration of the A is 0.05-0.2 g/mL;

2) weighing a proper amount of potassium chloride, adding the potassium chloride into deionized water with a certain volume, and magnetically stirring to obtain a clear and colorless potassium chloride solution B, wherein the concentration of the potassium chloride solution B is 0.05-0.1 g/mL;

3) slowly dripping the potassium chloride solution B into a yellow phosphomolybdic acid solution A at the speed of 0.5mL/min, continuously and slowly stirring at the temperature of 0-10 ℃ until the solution becomes turbid, stopping stirring, continuously dripping the residual potassium chloride solution, and finally, changing the solution into a yellow suspension C;

4) standing the suspension C for a period of time to obtain yellow precipitate, performing centrifugal separation on the precipitate, alternately washing the precipitate for 3 times by using deionized water and absolute ethyl alcohol to obtain a semi-finished product, and drying the obtained semi-finished product in a vacuum drying oven at the temperature of 80 ℃ for 12 hours under normal pressure to obtain yellow potassium phosphomolybdate powder, namely spherical potassium phosphomolybdate powder with a core-shell structure;

the chemical formula of the phosphomolybdic acid is H₃PMo₁₂O₄₀；

The chemical formula of the potassium phosphomolybdate powder material is K₃PMo₁₂O₄₀•4H₂O；

Preferably, the diameter of the potassium phosphomolybdate powder ball is 5 μm, and the thickness of the core shell is 50 nm.

Furthermore, the invention also provides application of the spherical potassium phosphomolybdate powder with the core-shell structure, and the potassium phosphomolybdate powder can be used as a photocatalyst and can effectively catalyze and degrade rhodamine B and quinoline blue under visible light with the assistance of a small amount of 30% hydrogen peroxide.

Compared with the prior art, the invention has the characteristics that:

(1) the method is simple and convenient, easy to operate and mild in reaction condition;

(2) the preparation period is short, and a semi-finished product can be prepared within one day;

(3) spherical potassium phosphomolybdate with a uniform morphology and a core-shell structure is prepared without adding any surfactant.

(4) The prepared potassium phosphomolybdate powder has a small amount of 30% H₂O₂Under the assistance of the method, rhodamine B and quinoline blue can be efficiently degraded under visible light.

Drawings

FIG. 1 is an XRD pattern of potassium phosphomolybdate prepared in example 1 of the present invention.

FIG. 2 is an SEM photograph of potassium phosphomolybdate prepared in example 1 of the present invention, at a magnification of 3000.

FIG. 3 is an SEM photograph of potassium phosphomolybdate prepared in example 1 of the present invention, at 8000X magnification.

FIG. 4 is an ultraviolet-visible absorption spectrum of rhodamine B catalytically degraded by potassium phosphomolybdate prepared in example 1 under the assistance of a small amount of hydrogen peroxide under visible light.

Fig. 5 is an ultraviolet-visible absorption spectrum diagram of quinoline blue catalytically degraded by potassium phosphomolybdate prepared in example 1 under the assistance of a small amount of hydrogen peroxide under visible light.

Detailed Description

The present invention is further illustrated by the following specific examples.