阅读说明：本技术 一种聚吡咯-二氧化铈-金复合纳米材料 (Polypyrrole-cerium dioxide-gold composite nano material ) 是由 祝琳 张彦 吕雪 梅雪娜 王志杰 张乐陶 郑可心 于 2020-08-05 设计创作，主要内容包括：本发明公开了一种聚吡咯-二氧化铈-金复合纳米材料。首先制备金纳米颗粒,将带负电的金胶体溶液与L-精氨酸和硝酸铈混合,L-精氨酸的胍基、羧基分别连接金及Ce<Sup>3+</Sup>,加热条件下获得二氧化铈-金复合纳米材料,二者互相掺杂后可提高二氧化铈的催化能力及金纳米颗粒的稳定性,利用原位聚合法在二氧化铈表面修饰聚吡咯,增加材料导电性、吸收可见光的范围。本发明所述的聚吡咯-二氧化铈-金复合纳米材料稳定性好,制备方法操作简单,对可见光的吸收范围较宽,具有优异的光催化性能,应用前景良好。(The invention discloses a polypyrrole-cerium dioxide-gold composite nano material. Firstly, preparing gold nanoparticles, mixing a gold colloid solution with negative electricity with L-arginine and cerium nitrate, wherein guanidino and carboxyl of the L-arginine are respectively connected with gold and Ce 3+ The cerium dioxide-gold composite nano material is obtained under the heating condition, the catalytic capability of the cerium dioxide and the stability of the gold nano particles can be improved after the cerium dioxide-gold composite nano material and the cerium dioxide are mutually doped, and polypyrrole is modified on the surface of the cerium dioxide by utilizing an in-situ polymerization method, so that the conductivity of the material is increased, and the range of absorbing visible light is widened. The polypyrrole-cerium dioxide-gold composite nanomaterial disclosed by the invention is good in stability, simple in preparation method operation, wide in visible light absorption range, excellent in photocatalytic performance and good in application prospect.)

1. A polypyrrole-cerium dioxide-gold composite nano material is characterized by comprising the following preparation steps:

(1) mixing the reducing agent solution with the chloroauric acid solution to obtain a gold colloid solution;

(2) adding 0.085 g of L-arginine into 10 mL of ultrapure water, and ultrasonically mixing uniformly to obtain an L-arginine solution;

(3) dissolving 0.0035 g of cerium nitrate in 20-40 mL of ethanol water solution with volume fraction of 50%, adding 1-5 mL of prepared gold colloid solution, and dropwise adding 10 mL of prepared L-arginine solution at room temperature; heating the mixed solution at 80 ℃ under the action of magnetic stirring for 2-4 hours for reaction, centrifuging for 15 minutes at the rotating speed of 12000 r/min, removing supernatant, and washing with acetone for several times to obtain cerium dioxide-gold composite nanoparticles;

(4) weighing 500 mg of prepared cerium dioxide-gold composite nano particles, dispersing the cerium dioxide-gold composite nano particles in 10 mL of ultrapure water, quickly adding 50 mu L of pyrrole, magnetically stirring for 30 minutes, dropwise adding 10 mL of 10 mg/mL ferric chloride solution into the mixed solution, continuously stirring for 12 hours, continuously standing at room temperature for 8 hours, centrifuging for 15 minutes at the rotation speed of 10000 r/min, removing supernatant, washing with ethanol and the ultrapure water for several times, and drying in an oven at 60 ℃ for 24 hours to obtain the polypyrrole-cerium dioxide-gold composite nano material.

2. The polypyrrole-ceria-gold composite nanomaterial according to claim 1, wherein the reducing agent used in the synthesis method of the gold colloid solution in the step (1) is sodium citrate, sodium borohydride or L-methionine.

Technical Field

The invention relates to a polypyrrole-cerium dioxide-gold composite nano material, belonging to the field of preparation of composite nano materials.

Background

The photocatalytic oxidation-reduction reaction is used as a green and sustainable catalysis technology, has great potential in the aspects of solving environmental pollution and energy crisis, and the efficiency and stability of the photocatalyst are key factors influencing the photocatalytic performance. Cerium dioxide is an important n-type wide band gap semiconductor, and has been widely studied in the aspects of photocatalytic degradation of pollutants, decomposition of water to produce hydrogen, organic synthesis and the like due to the fact that cerium dioxide is used as a photocatalyst because of the advantages of abundant oxygen vacancies, high oxygen storage capacity, good chemical/photochemical stability and the like. However, the band gap energy of ceria is wide, and only the energy of ultraviolet light region can be utilized, which limits the development of ceria catalyst. At present, gold nanoparticles with plasma characteristics are compounded with wide-band-gap semiconductor cerium dioxide, so that charge transfer between crystal faces of core-shell nano crystals is facilitated, and the absorption of the visible light by the cerium dioxide is realized.

In addition, the gold nanoparticles are widely used as catalysts, easy agglomeration and inactivation are one of important factors restricting the development of the gold nanoparticles, and cerium dioxide can be used as a carrier of the gold nanoparticles to realize an ultra-small gold heterostructure on a semiconductor material. The cerium dioxide-gold composite nano structure can improve the stability and the dispersity of the gold nano material, is beneficial to the separation of electron-hole pairs, and has synergistic effect between the two to improve the catalytic performance.

At present, polypyrrole has attracted wide attention in the field of photocatalysis, has the advantages of small band gap, good chemical stability, good conductivity, low price, environmental friendliness and the like, is beneficial to charge transfer and electron-hole pair separation, and has visible light photocatalytic activity based on an n-electron conjugated system. Therefore, the polypyrrole-cerium dioxide-gold composite nanomaterial is prepared by combining the comprehensive advantages of cerium dioxide, gold nanoparticles and polypyrrole, the photocatalytic efficiency of the composite material can be greatly improved, and the technical requirements of green and efficient production can be better met.

Disclosure of Invention

Aiming at the existing problems, the invention provides a polypyrrole-cerium dioxide-gold composite nano material, which specifically comprises the following steps:

(1) mixing the reducing agent solution with the chloroauric acid solution to obtain a gold colloid solution;

(2) adding 0.085 g of L-arginine into 10 mL of ultrapure water, and ultrasonically mixing uniformly to obtain an L-arginine solution;

(3) dissolving 0.0035 g of cerium nitrate in 20-40 mL of ethanol water solution with volume fraction of 50%, adding 1-5 mL of prepared gold colloid solution, and dropwise adding 10 mL of prepared L-arginine solution at room temperature; heating the mixed solution at 80 ℃ under the action of magnetic stirring for 2-4 hours for reaction, centrifuging for 15 minutes at the rotating speed of 12000 r/min, removing supernatant, and washing with acetone for several times to obtain cerium dioxide-gold composite nanoparticles;

(4) weighing 500 mg of prepared cerium dioxide-gold composite nano particles, dispersing the cerium dioxide-gold composite nano particles in 10 mL of ultrapure water, quickly adding 50 mu L of pyrrole, magnetically stirring for 30 minutes, dropwise adding 10 mL of 10 mg/mL ferric chloride solution into the mixed solution, continuously stirring for 12 hours, continuously standing at room temperature for 8 hours, centrifuging for 15 minutes at the rotation speed of 10000 r/min, removing supernatant, washing with ethanol and the ultrapure water for several times, and drying in an oven at 60 ℃ for 24 hours to obtain the polypyrrole-cerium dioxide-gold composite nano material.

The reducing agent used for preparing the gold colloid solution is sodium citrate, sodium borohydride or L-methionine.

The invention has the beneficial effects that:

1. the particle size of the polypyrrole-cerium dioxide-gold composite nano material is about 50 nm, the specific surface area is large, more catalytic active sites can be exposed, and the photocatalytic activity is improved.

2. The polypyrrole-cerium dioxide-gold composite nanomaterial combines the excellent catalytic performance of three materials, has large specific surface area, good conductivity and wide visible light absorption range, effectively enhances the photocatalytic performance of the polypyrrole-cerium dioxide-gold composite nanomaterial, and greatly improves the stability of gold nanoparticles and cerium dioxide.

3. The polypyrrole-cerium dioxide-gold composite nanomaterial disclosed by the invention has the advantages of simple synthesis method, environmental friendliness, good repeatability, good stability, high catalytic efficiency, large-scale production value and excellent application potential in the field of photocatalysis.

Drawings

FIG. 1 is a scanning electron microscope image of the prepared polypyrrole-ceria-gold composite nanomaterial.

Detailed Description

In order to better understand the present invention, the following examples are further provided to illustrate the present invention, but the present invention is not limited to the following examples.