CN112808272B - Nano composite substrate with SERS activity and degradation performance and preparation method thereof - Google Patents

Abstract

A method of preparing a nanocomposite substrate having SERS activity and degradation properties, comprising: reacting MgCl ₂ Dissolving ultrapure water to form a solution a; adding ammonia water and anhydrous ethanol into the solution a under stirring to form solution b, filtering, washing to separate Mg (OH) ₂ And (4) precipitating. The precipitate is calcined at high temperature for a period of time to obtain MgO. Subsequently dispersing it in H ₂ O ₂ To form a suspension c, and separating the solid from the suspension to obtain MgO as a product ₂ . Adding MgO ₂ Ultrasonically mixing with polyetherimide to obtain suspension d, centrifuging and washing for several times, adding gold nanoparticles into the resuspended d, ultrasonically treating, washing, and resuspending to form gold nanoparticles and MgO ₂ The complex of (a); soaking carbon nanotube sponge in the gold nanoparticles and MgO ₂ Forming a nanocomposite substrate. The method of the invention is carried out with MgCl ₂ Synthesis of MgO for precursors ₂ And then the nano composite substrate with SERS activity and degradation performance is respectively assembled with the gold nanoparticles and the carbon nanotube sponge.

Description

A nanocomposite substrate with SERS activity and degradation performance and its preparation method

technical field

The invention relates to degradation and SERS activity, in particular to a method for preparing a nanocomposite substrate with SERS activity and degradation performance.

Background technique

_In a typical Fenton reaction, _H2O2 is usually used as an oxidizing agent to degrade organic pollutants. However, liquid hydrogen peroxide is unstable and highly biotoxic at high concentrations. Therefore, high-purity magnesium peroxide (MgO ₂ ) nanoparticles were used and used instead of H ₂ O ₂ to degrade organic dyes. As a noble metal, gold nanoparticles are adsorbed on the surface of the noble metal. Under laser irradiation, a strong surface-enhanced Raman scattering (SERS) signal will be generated, but the prepared nanomaterials are difficult to recycle. In addition, dispersed catalysts and reinforcing materials are difficult to recycle, which will cause secondary pollution to the environment. The large specific surface area and pore structure of carbon-based materials enable them to adsorb organic pollutants in water bodies, and at the same time, carry out loading and recovery of materials for catalytic reactions.

Contents of the invention

The purpose of the present invention is to provide a preparation method of a nanocomposite material with SERS activity and degradation performance, improve the problem of single function of the material, and improve the non-recyclable problem of multifunctional nanomaterials by assembling with carbon nanotube sponge.

In order to realize the above-mentioned purpose of the invention, the technical scheme of the present invention is specifically as follows:

A method for preparing a nanocomposite substrate with SERS activity and degradation performance, comprising the following steps:

S1: Dissolve _MgCl2 in ultrapure water to form solution a; add ammonia water and absolute ethanol to solution a under constant stirring to form solution b, and filter and wash solution b to separate Mg(OH) ₂ as a precipitate;

S2: calcining the precipitate at high temperature for a period of time to obtain MgO;

S3: then disperse it in H ₂ O ₂ to form a suspension c, and separate the solid from the suspension to obtain the product MgO ₂ ;

S4: Ultrasonic mixing of _MgO2 and polyetherimide to obtain suspension d, centrifuged and washed several times;

S5: Add gold nanoparticles to d after resuspension, sonicate for a period of time, centrifuge and wash several times, and form a complex of gold nanoparticles and MgO ₂ after resuspension;

S6: Soak the carbon nanotube sponge in the composite of gold nanoparticles and MgO ₂ to form a nanocomposite substrate.

As a preferred technical solution, in the step S3, the concentration of H ₂ O ₂ is 30%.

As a preferred technical solution, the step S4 includes: ultrasonically mixing _MgO2 and polyetherimide to obtain a suspension d, centrifuging and washing several times; the concentration of polyetherimide is 0.01%, and ultrasonication at room temperature for 2 hours , centrifuged and washed with ultrapure water for 6 times.

As a preferred technical solution, the step S5 includes: adding gold nanoparticles to d after resuspension, sonicating at room temperature for ₂ hours, centrifuging and washing with ultrapure water for 4 times, and forming a complex of gold nanoparticles and MgO after resuspension.

As a preferred technical solution, the step S6 includes: acidifying the carbon nano-sponge, and then soaking the carbon nano-tube sponge in a composite of gold nanoparticles and MgO ₂ to form a nano-composite substrate.

The invention also provides the nanocomposite substrate with SERS activity and degradation performance prepared by the above method.

Compared with prior art, the beneficial effect of the present invention:

The method of the present invention is that MgO ₂ and gold nanoparticles are assembled by electrostatic self-assembly. Utilize the degradation performance of _MgO2 and the surface plasmon resonance effect of gold nanoparticles, combine the two to realize the multifunctional properties of the material;

The method of the invention utilizes the strong adsorption performance of the carbon material to adsorb and enrich the organic pollutants, and then load the composite material to improve the problem that the dispersed catalyst is difficult to recover.

Description of drawings

Figure 1(a) X-ray powder diffraction pattern (XRD) of MgO ₂ ; (b) X-ray powder diffraction pattern (XRD) of MgO ₂ @Au;

Figure 2(a) Scanning electron microscope (SEM) of MgO ₂ ; (b) Scanning electron microscope (SEM) of MgO ₂ @Au; (c) UV image of MgO ₂ @Au degradation of organic pollutants; (d) MgO ₂ SERS spectrum of 10 ^-4 M organic pollutants measured by @Au;

Fig. 3(a) Scanning electron microscope (SEM) image of sponge-loaded MgO ₂ @Au; (b) SERS spectra of sponge-loaded MgO ₂ @Au composite before and after degradation of organic pollutants.

Detailed ways:

The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only some of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without making creative efforts belong to the protection scope of the present invention.

Example

1. The synthesis method of MgO ₂ @Au:

Dissolve MgCl ₂ in ultrapure water to form solution a; add ammonia water and absolute ethanol to solution a under constant stirring to form solution b, and filter and wash solution b to separate Mg(OH) ₂ precipitate. This precipitate is calcined at high temperature for a period of time to obtain MgO. It is subsequently dispersed in _H2O2 to form a suspension c, from which the solid is separated to _give the product _MgO2 . Mix _MgO2 and polyetherimide ultrasonically to obtain a suspension d, centrifuge and wash several times, then add gold nanoparticles to the resuspended d, ultrasonicate for a period of time, centrifuge and wash several times, and form gold nanoparticles after resuspension Complexes with _MgO2 . Figure 1 shows the XRD of MgO ₂ and MgO ₂ @Au obtained under the above experimental conditions. The XRD pattern (1a) shows that the obtained product is MgO ₂ with good crystallinity, and the pattern (1b) shows that the complex of MgO ₂ and gold nanoparticles self-assembles successfully through electrostatic interaction. Figure 2(a) is the scanning electron microscope image (SEM) of MgO ₂ , (b) is the scanning electron microscope image (SEM) of MgO ₂ @Au, it can be seen from Figure 2(a) and 2(b) that magnesium peroxide It is a massive structure formed by the accumulation of nanoparticles with a particle size of about 70nm; the surface of gold nanoparticles with a particle size of about 70nm is attached with MgO ₂ with a small particle size. Figure 2(c) is the UV diagram of the degradation of organic pollutants by MgO ₂ @Au, and the results show that the composite can effectively degrade organic pollutants. Figure 2(d) is the SERS spectrum of 10 ^-4 M organic pollutants measured by MgO ₂ @Au. From the spectrum, it can be analyzed that the complex has SERS activity.

2. Carbon nanotube sponge loaded with MgO ₂ @Au:

The carbon nanotube sponge was soaked in the above-mentioned composite of gold nanoparticles and MgO ₂ to form a nanocomposite substrate. Fig. 3(a) Scanning electron microscope (SEM) image of sponge-loaded MgO ₂ @Au; (b) SERS spectra of sponge-loaded MgO ₂ @Au composite before and after degradation of organic pollutants. The SEM images indicated that the MgO ₂ @Au nanocomposites were successfully attached to the sponge. Figure 3(b) shows that the material loaded on the sponge does not affect the performance of the material, and the sponge can play a good role in collecting the dispersed catalyst.

Claims (6)

1. A preparation method of a nanocomposite substrate with SERS activity and degradation performance, characterized in that, comprising the following steps: S1: Dissolve _MgCl2 in ultrapure water to form solution a; add ammonia water and absolute ethanol to solution a under constant stirring to form solution b, and filter and wash solution b to separate Mg(OH) ₂ as a precipitate; S2: calcining the precipitate at high temperature for a period of time to obtain MgO; S3: then disperse it in H ₂ O ₂ to form a suspension c, and separate the solid from the suspension to obtain the product MgO ₂ ; S4: Ultrasonic mixing of _MgO2 and polyetherimide to obtain suspension d, centrifuged and washed several times; S5: Add gold nanoparticles to d after resuspension, sonicate for a period of time, centrifuge and wash several times, and form a complex of gold nanoparticles and MgO ₂ after resuspension; S6: Soak the carbon nanotube sponge in the composite of gold nanoparticles and MgO ₂ to form a nanocomposite substrate. _2. The preparation method according to claim ₁ , characterized in that, in the step S3, the concentration of H2O2 is 30%. 3. The preparation method according to claim ₁ , characterized in that, said step S4 comprises: mixing MgO with polyetherimide ultrasonically to obtain a suspension d, and centrifugally washing several times; the concentration of polyetherimide 0.01%, sonicated at room temperature for 2 hours, and centrifuged and washed with ultrapure water for 6 times. 4. The preparation method according to claim 1, characterized in that the step S5 comprises: adding gold nanoparticles into the resuspended d, ultrasonication at room temperature for 2 hours, centrifugal washing with ultrapure water for 4 times, and forming after resuspension Composite of gold nanoparticles and _MgO2 . 5. preparation method according to claim 1, is characterized in that, described step S6 comprises: carbon nano-sponge is carried out acidification treatment, then carbon nano-tube sponge is soaked in gold nanoparticle and MgO in the _compound , forms Nanocomposite substrates. 6. A nanocomposite substrate with SERS activity and degradation properties prepared by the method according to any one of the preceding claims.

Images