阅读说明：本技术 基于飞秒激光的高催化活性金纳米棒的制备方法及其系统 (Preparation method and system of gold nanorod with high catalytic activity based on femtosecond laser ) 是由 闫剑锋 朱德志 赵玥 于 2019-09-18 设计创作，主要内容包括：本发明涉及一种基于飞秒激光的高催化活性金纳米棒的制备方法及其系统,属于飞秒激光应用技术领域。本方法首先通过种子液生长法合成金纳米棒溶液；然后将金纳米棒溶液离心,滴在硅基底上；然后将飞秒激光引入到硅基底,通过控制入射到硅基底的脉冲波长和辐照时间,从而实现金纳米棒的选择性烧蚀,制备出具有高指数晶面的金纳米棒,从而提高金纳米棒的催化活性。本发明方法,相比于已有的化学法等,利用飞秒激光脉冲辐照金纳米棒,合理设计激光偏振和波长,即可制备出高催化活性金纳米棒,制备过程相对简单。本发明的基于飞秒激光的高催化活性金纳米棒制备系统,可以任意调整飞秒激光偏振方向和波长,而且操作方便。(The invention relates to a preparation method and a system of a gold nanorod with high catalytic activity based on femtosecond laser, belonging to the technical field of femtosecond laser application. The method comprises the steps of firstly, synthesizing a gold nanorod solution by a seed solution growth method; then centrifuging the gold nanorod solution, and dripping the gold nanorod solution on a silicon substrate; then the femtosecond laser is introduced into the silicon substrate, and selective ablation of the gold nanorod is realized by controlling the pulse wavelength and the irradiation time of the laser incident to the silicon substrate, so that the gold nanorod with a high-index crystal face is prepared, and the catalytic activity of the gold nanorod is improved. Compared with the existing chemical method and the like, the method of the invention utilizes femtosecond laser pulses to irradiate the gold nanorods, reasonably designs laser polarization and wavelength, can prepare the gold nanorods with high catalytic activity, and has relatively simple preparation process. The gold nanorod preparation system with high catalytic activity based on the femtosecond laser can randomly adjust the polarization direction and wavelength of the femtosecond laser, and is convenient to operate.)

1. A preparation method of gold nanorods with high catalytic activity based on femtosecond laser is characterized in that: the method comprises the following steps:

(1) Synthesizing a gold seed solution:

Injecting a tetrachloroauric acid solution with the molar concentration of 0.01mol/L into a hexadecyl trimethyl ammonium bromide solution with the molar concentration of 0.1mol/L, then adding a sodium borohydride solution with the molar concentration of 0.01mol/L at one time, and rapidly stirring for 2-4 minutes to obtain a gold seed solution, wherein the molar concentrations of tetrachloroauric acid, hexadecyl trimethyl ammonium bromide and sodium borohydride in the gold seed solution are respectively (0.3-0.5) mmol/L, (0.07-0.09) mol/L and (0.7-0.9) mmol/L;

(2) synthesizing a gold nanorod solution by a seed solution growth method:

A cetyl trimethyl ammonium bromide solution with the molar concentration of 0.1mol/L and tetrachloroauric acid (HAucll) with the molar concentration of 0.01mol/L₄) Solution and silver nitrate (AgNO) with the molar concentration of 0.01mol/L₃) The solution was mixed and stirred, and ascorbic acid (C) was added thereto at a molar concentration of 0.1mol/L₆H₈O₆) Obtaining a mixed solution, wherein the molar concentrations of cetyl trimethyl ammonium bromide, tetrachloroauric acid, silver nitrate and ascorbic acid in the mixed solution are respectively 0.07-0.09 mol/L, 0.4-0.6 mmol/L, 0.06-0.07 mmol/L and 0.6-0.9 mmol/L, adding the gold seed solution obtained in the step (1) into the mixed solution, standing for 3 hours to obtain a gold nanorod solution, and the volume ratio of the gold seed solution in the gold nanorod solution to the mixed solution is 1 (143-250);

(3) carrying out centrifugal separation on the gold nanorod solution obtained in the step (2), wherein the centrifugal separation rotating speed is 5000-8000 rpm/min, the centrifugal separation time is 10-15 min, and dropping the gold nanorods obtained through centrifugal separation on a silicon substrate;

(4) enabling femtosecond laser pulses to be incident on the silicon substrate in the step (3), wherein the femtosecond laser flux is 0.2-2.1 mJ/cm²and the femtosecond laser irradiation time is 5-15 min, and the femtosecond laser wavelength is adjusted to change the surface electric field distribution of the gold nanorods on the silicon substrate, so that the partial stripping of the surface atoms of the gold nanorods is realized, and the gold nanorods with high catalytic activity are obtained.

2. The method for preparing gold nanorods with high catalytic activity according to claim 1, wherein in the step (4), the laser wavelength is 400-800 nm.

3. A femtosecond laser-based gold nanorod preparation system with high catalytic activity is characterized by comprising a femtosecond laser, an attenuator, a half-wave plate, a first reflector, a second reflector, an electric control shutter, a dichroic mirror, a frequency doubling crystal, an objective table, a beam splitter, a lighting lamp and a camera; wherein the content of the first and second substances,

The device comprises a femtosecond laser, an attenuator, a half-wave plate and a first reflector, wherein a coplanar shaft is formed by the femtosecond laser pulse generated by the femtosecond laser, the energy of the femtosecond laser pulse is adjusted by the attenuator, the polarization direction of the femtosecond laser pulse is adjusted by the half-wave plate, the propagation direction of the femtosecond laser pulse is changed by the first reflector and a second reflector, and the propagation direction of the femtosecond laser pulse is changed by an electronic control shutter.

Technical Field

The invention relates to a preparation method and a system of a gold nanorod with high catalytic activity based on femtosecond laser, belonging to the technical field of femtosecond laser application.

background

compared with spherical gold nanoparticles, the gold nanorods have adjustable plasmon characteristics, and have gained wide attention in numerous anisotropic gold nanoparticles. At present, the gold nanorods have good application prospects in the research fields of nanoelectronics, optics, biomedicine, catalysis and the like. In the catalytic application, the crystal face structure of the gold nanorod directly determines the catalytic performance, and how to efficiently regulate and control the crystal face structure of the gold nanorod is a difficult problem to be solved. At present, the surface of the gold nanorod is modified mainly by a chemical etching method so as to obtain a plurality of high-index crystal faces, but the morphology of the gold nanorod is influenced by various physical and chemical factors, the preparation condition is complex, and the controllability of the etching process is poor.

The laser can be effectively used for reshaping the gold nanoparticles, and the femtosecond laser has the characteristics of extremely short pulse width and extremely high intensity, so that more and more attention is paid in recent years. The femtosecond laser shaping of gold nanoparticles is usually carried out in a solution system, however, due to the influence of brownian motion of water molecules, the position of the nanoparticles relative to a light field is uncertain, so that selective ablation cannot be realized, more is the deformation of the whole particles, and a high-index crystal face cannot be obtained. Therefore, a method for preparing gold nanorods with high catalytic activity efficiently and simply is needed.

Disclosure of Invention

the invention aims to provide a preparation method and a system of a gold nanorod with high catalytic activity based on femtosecond laser.

The invention provides a preparation method of a gold nanorod with high catalytic activity based on femtosecond laser, which comprises the following steps:

(1) synthesizing a gold seed solution:

injecting a tetrachloroauric acid solution with the molar concentration of 0.01mol/L into a hexadecyl trimethyl ammonium bromide solution with the molar concentration of 0.1mol/L, then adding a sodium borohydride solution with the molar concentration of 0.01mol/L at one time, and rapidly stirring for 2-4 minutes to obtain a gold seed solution, wherein the molar concentrations of tetrachloroauric acid, hexadecyl trimethyl ammonium bromide and sodium borohydride in the gold seed solution are respectively (0.3-0.5) mmol/L, (0.07-0.09) mol/L and (0.7-0.9) mmol/L;

(2) Synthesizing a gold nanorod solution by a seed solution growth method:

A cetyl trimethyl ammonium bromide solution with the molar concentration of 0.1mol/L and tetrachloroauric acid (HAucll) with the molar concentration of 0.01mol/L₄) Solution and silver nitrate (AgNO) with the molar concentration of 0.01mol/L₃) The solution was mixed and stirred, and ascorbic acid (C) was added thereto at a molar concentration of 0.1mol/L₆H₈O₆) Obtaining a mixed solution, wherein the molar concentrations of cetyl trimethyl ammonium bromide, tetrachloroauric acid, silver nitrate and ascorbic acid in the mixed solution are respectively 0.07-0.09 mol/L, 0.4-0.6 mmol/L, 0.06-0.07 mmol/L and 0.6-0.9 mmol/L, adding the gold seed solution obtained in the step (1) into the mixed solution, standing for 3 hours to obtain a gold nanorod solution, and the volume ratio of the gold seed solution in the gold nanorod solution to the mixed solution is 1 (143-250);

(3) Carrying out centrifugal separation on the gold nanorod solution obtained in the step (2), wherein the centrifugal separation rotating speed is 5000-8000 rpm/min, the centrifugal separation time is 10-15 min, and dropping the gold nanorods obtained through centrifugal separation on a silicon substrate;

(4) enabling femtosecond laser pulses to be incident on the silicon substrate in the step (3), wherein the femtosecond laser flux is 0.2-2.1 mJ/cm²And the femtosecond laser irradiation time is 5-15 min, and the femtosecond laser wavelength is adjusted to change the surface electric field distribution of the gold nanorods on the silicon substrate, so that the partial stripping of the surface atoms of the gold nanorods is realized, and the gold nanorods with high catalytic activity are obtained.

In the step (4) of the preparation method of the gold nanorods with high catalytic activity, the laser wavelength can be 400-800 nm.

the invention provides a femtosecond laser-based gold nanorod preparation system with high catalytic activity, which comprises a femtosecond laser, an attenuator, a half-wave plate, a first reflector, a second reflector, an electric control shutter, a dichroic mirror, a frequency doubling crystal, an objective table, a beam splitter, a lighting lamp and a camera; the device comprises a femtosecond laser, an attenuator, a half-wave plate and a first reflector, wherein a common optical axis is formed by the femtosecond laser, femtosecond laser pulses generated by the femtosecond laser are subjected to energy adjustment through the attenuator, the polarization direction is adjusted through the half-wave plate, the propagation direction is changed through the first reflector and a second reflector, the propagation direction is changed through an electronic control shutter by a dichroic mirror, a frequency doubling crystal and an objective table are arranged on one side of the dichroic mirror, the wavelength is changed through the frequency doubling crystal, and finally the wavelength is irradiated onto the objective table.

The invention provides a preparation method and a system of gold nanorods with high catalytic activity based on femtosecond laser, which has the advantages that:

1. Compared with the existing chemical method and the like, the existing chemical etching method has complex reaction conditions and poor controllability of the reaction process, the femtosecond laser pulse is used for irradiating the gold nanorods, the laser polarization and the wavelength are reasonably designed, the gold nanorods with high catalytic activity can be prepared, and the preparation process is relatively simple.

2. the gold nanorod preparation system with high catalytic activity based on the femtosecond laser can randomly adjust the polarization direction and wavelength of the femtosecond laser, and is convenient to operate.

Drawings

FIG. 1 is a schematic structural diagram of a femtosecond laser-based gold nanorod preparation system with high catalytic activity.

FIG. 2 is a transmission electron microscope image of gold nanorods irradiated with laser light with a wavelength of 800nm in example 1 of the present invention.

FIG. 3 is a transmission electron microscope image of gold nanorods irradiated with laser light with a wavelength of 400nm in example 2 of the present invention.

in fig. 1, 1 is a femtosecond laser, 2 is an attenuation plate, 3 is a half-wave plate, 4 is a first mirror, 5 is a second mirror, 6 is an electrically controlled shutter, 7 is a dichroic mirror, 8 is a BBO crystal, 9 is a silicon substrate, 10 is a stage, 11 is a beam splitter, 12 is an illumination lamp, and 13 is a camera.

Detailed Description

The invention provides a preparation method of a gold nanorod with high catalytic activity based on femtosecond laser, which comprises the following steps:

(1) Synthesizing a gold seed solution:

Tetrachloroauric acid (HAucll) with a molar concentration of 0.01mol/L₄) The solution was poured into a cetyltrimethylammonium bromide (CTAB) solution with a molar concentration of 0.1mol/L, and sodium borohydrate (NaBH) with a molar concentration of 0.01mol/L₄) Adding the solution at one time, and rapidly stirring for 2-4 minutes to obtain a gold seed solution, wherein the molar concentrations of tetrachloroauric acid, hexadecyltrimethylammonium bromide and sodium borohydride in the gold seed solution are (0.3-0.5) mmol/L, (0.07-0.09) mol/L and (0.7-0.9) mmol/L respectively;

(2) Synthesizing a gold nanorod solution by a seed solution growth method:

cetyl Trimethyl Ammonium Bromide (CTAB) solution with the molar concentration of 0.1mol/L and tetrachloroauric acid (HAucl) with the molar concentration of 0.01mol/L₄) Solution and silver nitrate (AgNO) with the molar concentration of 0.01mol/L₃) The solution was mixed and stirred, and ascorbic acid (C) was added thereto at a molar concentration of 0.1mol/L₆H₈O₆) Obtaining a mixed solution, wherein the molar concentrations of cetyl trimethyl ammonium bromide, tetrachloroauric acid, silver nitrate and ascorbic acid in the mixed solution are respectively 0.07-0.09 mol/L, 0.4-0.6 mmol/L, 0.06-0.07 mmol/L and 0.6-0.9 mmol/L, adding the gold seed solution obtained in the step (1) into the mixed solution, standing for 3 hours to obtain a gold nanorod solution, and the volume ratio of the gold seed solution in the gold nanorod solution to the mixed solution is 1 (143-250);

(3) carrying out centrifugal separation on the gold nanorod solution obtained in the step (2), wherein the centrifugal separation rotating speed is 5000-8000 rpm/min, the centrifugal separation time is 10-15 min, and dropping the gold nanorods obtained through centrifugal separation on a silicon substrate;

(4) Making femtosecond laser pulse incident on the silicon substrate in the step (3), and femtosecond laserThe luminous flux is 0.2-2.1 mJ/cm²and the femtosecond laser irradiation time is 5-15 min, and the femtosecond laser wavelength is adjusted to change the surface electric field distribution of the gold nanorods on the silicon substrate, so that the partial stripping of the surface atoms of the gold nanorods is realized, and the gold nanorods with high catalytic activity are obtained.

In the step (4) of the preparation method of the gold nanorods with high catalytic activity, the laser wavelength can be 400-800 nm.

3. a femtosecond laser-based gold nanorod preparation system with high catalytic activity is characterized by comprising a femtosecond laser, an attenuator, a half-wave plate, a first reflector, a second reflector, an electric control shutter, a dichroic mirror, a frequency doubling crystal, an objective table, a beam splitter, a lighting lamp and a camera; wherein the content of the first and second substances,

The device comprises a femtosecond laser, an attenuator, a half-wave plate and a first reflector, wherein a coplanar shaft is formed by the femtosecond laser pulse generated by the femtosecond laser, the energy of the femtosecond laser pulse is adjusted by the attenuator, the polarization direction of the femtosecond laser pulse is adjusted by the half-wave plate, the propagation direction of the femtosecond laser pulse is changed by the first reflector and a second reflector, and the propagation direction of the femtosecond laser pulse is changed by an electronic control shutter.

the following describes embodiments of the method of the invention: