阅读说明：本技术 对硝基苯基重氮盐共价修饰二硫化锡薄膜非线性杂化材料及其制备方法 (Non-linear hybrid material of paranitrobenzene basic diazonium salt covalent modification stannic sulfide thin film and preparation method thereof ) 是由 张弛 魏志远 伏露露 于 2021-09-22 设计创作，主要内容包括：本发明涉及一种对硝基苯基重氮盐共价修饰二硫化锡薄膜非线性杂化材料及其制备方法,通过化学液相沉积法将二硫化锡薄膜沉积到导电玻璃上后使用碘化钾活化的对硝基苯基重氮盐对其进行共价修饰。与现有技术相比,本发明中,由于有效的电荷传输相互作用改变了二硫化锡的激发态行为,因此增强了其反饱和吸收性能,对后续开发近红外飞秒激光下的非线性光学材料具有重要借鉴意义。(The invention relates to a p-nitrophenyl diazonium salt covalent modification stannic disulfide film nonlinear hybrid material and a preparation method thereof. Compared with the prior art, the excited state behavior of the tin disulfide is changed due to effective charge transfer interaction, so that the reverse saturation absorption performance of the tin disulfide is enhanced, and the method has important reference significance for the subsequent development of the nonlinear optical material under the near-infrared femtosecond laser.)

1. The p-nitrophenyl diazonium salt covalently modified tin disulfide film nonlinear hybrid material is characterized by comprising SnS₂Thin film and covalent bonding to SnS₂Nitrobenzene on the film.

2. The p-nitrophenyl diazonium salt covalently modified tin disulfide thin film nonlinear hybrid material according to claim 1, wherein the hybrid material has rapidly decreasing absorption with increasing wavelength before 400nm and smoothly weak absorption in the 400nm-1000nm region.

3. The p-nitrophenyl diazonium salt covalently-modified tin disulfide thin film nonlinear hybrid material as claimed in claim 1, wherein the hybrid material has a reverse saturation absorption at 800nm that is higher than that of SnS₂And (5) lifting the film.

4. The p-nitrophenyl diazonium salt covalently-modified tin disulfide thin film nonlinear hybrid material as claimed in claim 1, wherein the hybrid material has irregular protrusions and defective pores.

5. The preparation method of the p-nitrophenyl diazonium salt covalently-modified tin disulfide thin film nonlinear hybrid material as claimed in claim 1, comprising the steps of:

deposition of SnS on a conductive glass FTO by chemical liquid deposition₂A film;

activating p-nitrophenyl diazonium salt to obtain activated p-nitrophenyl free radical solution;

dropwise adding the activated p-nitrophenyl radical solution to SnS₂On the film, obtaining the hybrid material SnS₂-NO₂Namely the p-nitrophenyl diazonium salt covalence modified tin disulfide film nonlinear hybrid material.

6. The preparation method of the p-nitrophenyl diazonium salt covalently-modified tin disulfide thin film nonlinear hybrid material according to claim 5, comprising the steps of:

s1: placing the conductive glass FTO in an ethanol solution of thioacetamide and stannous chloride dihydrate, heating in a water bath, standing, washing the conductive glass FTO, and drying to obtain SnS₂A film;

s2: mixing the solution of p-nitrophenyl diazonium salt with an equimolar amount of potassium iodide solution to obtain an activated p-nitrophenyl radical solution;

s3: dropwise adding the activated p-nitrophenyl radical solution to SnS in the shade₂On the film, after reaction, unreacted and adsorbed impurities are washed away to obtain the SnS hybrid material₂-NO₂Namely the p-nitrophenyl diazonium salt covalence modified tin disulfide film nonlinear hybrid material.

7. The method for preparing the p-nitrophenyl diazonium salt covalently modified tin disulfide thin film nonlinear hybrid material according to claim 5 or 6, wherein the p-nitrophenyl diazonium salt is p-nitrophenyl tetrafluoroborate diazonium salt.

8. The method for preparing the p-nitrophenyl diazonium salt covalently-modified tin disulfide thin film nonlinear hybrid material according to claim 6, wherein in step S1, any one or more of the following conditions are included:

(i) before the conductive glass FTO is used, the conductive glass FTO is sequentially cleaned in acetone, water and isopropanol to remove pollutants and avoid the influence on the subsequent chemical liquid phase deposition;

(ii) the molar ratio of thioacetamide to stannous chloride dihydrate is 2-4: 1; preferably the molar ratio of thioacetamide to stannous chloride dihydrate is 3: 1;

(iii) the concentration of the stannous chloride dihydrate is 10-15 mMol/L; preferably, the concentration of the stannous chloride dihydrate is 12 mMol/L;

(iv) heating in a water bath to 45-50 ℃, keeping for 3-5 h, and then slowly cooling and standing for 9-15 h; preferably heating to 48 ℃ in a water bath, keeping for 4h, then slowly cooling and standing for 12 h;

(v) the drying temperature is 40-60 ℃; the drying temperature is preferably 50 ℃.

9. The method for preparing the p-nitrophenyl diazonium salt covalently-modified tin disulfide thin film nonlinear hybrid material as claimed in claim 6, wherein in step S2, the concentration of the solution of the p-nitrophenyl diazonium salt is 8-12 mMol/L; the concentration of the solution of the paranitrobenzyl diazonium salt is preferably 10 mMol/L.

10. The method for preparing the p-nitrophenyl diazonium salt covalently-modified tin disulfide thin film nonlinear hybrid material according to claim 6 or 9, wherein in the step S3, any one or more of the following conditions are included:

(i) after the activated p-nitrophenyl radical solution is obtained, dripping the solution immediately;

(ii) washing with solvent including water, ethanol and dichloromethane after reaction;

(iii) the dropwise adding amount of the activated p-nitrophenyl free radical solution is 0.5-2mL/4cm²SnS₂A film; preferably, the dropping amount is 1mL/4cm²SnS₂A film.

Technical Field

The invention belongs to the field of organic-inorganic functional composite materials and strong laser protection materials, and particularly relates to a p-nitrophenyl diazonium salt covalently modified tin disulfide film nonlinear hybrid material and a preparation method thereof.

Background

The optical material with good nonlinear response under strong laser has potential application in the fields of optical conversion, optical communication, optical amplitude limiting, data storage and the like, and is one of important branches of modern optical materials. Two-dimensional materials have excellent nonlinear optical properties due to strong quantum confinement effects and photo-material interactions. The organic-inorganic hybrid material formed by further modifying the organic molecular form with nonlinear optical activity in the two-dimensional material has more excellent nonlinear response than the original two-dimensional material due to effective charge interaction and synergistic effect, and thus becomes one of hot spots of the nonlinear optical material. Among them, the most widely studied is an organic-inorganic hybrid material based on a two-dimensional carbon material, such as a porphyrin-graphene oxide hybrid material system, on one hand, graphene oxide has many active sites and has various modification approaches such as esterification, acylation, radical addition, and the like. On the other hand, graphene oxide has a reverse saturation behavior under the action of nano laser due to nonlinear scattering and two-photon absorption, while porphyrin has a reverse saturation absorption behavior enhanced due to long triplet state service life, and the graphene oxide and porphyrin have stronger reverse saturation absorption under the action of nanosecond laser after being bonded. However, the effect of graphene oxide and porphyrin-graphene oxide hybrid materials in the field of femtosecond near-infrared laser is very weak.

Disclosure of Invention

Transition metal disulfides are layered materials with adjustable band gaps and various crystal forms, and in the layered structure, two sides of a transition metal layer are connected with a sulfur atom layer and then stacked through Van der Waals force. Because the transition metal is wrapped in the sulfur atom layer, and the sulfur atom is a saturated stable structure, the chemical activity of the transition metal is much lower than that of graphene oxide. The chemical nature of the transition metal disulfide may be altered by a number of drastic physicochemical methods to facilitate subsequent modification. The organic iodides and organic diazonium salts may be modified by butyl lithium stripped molybdenum disulfide. Molybdenum disulfide stripped by chlorosulfonic acid contains abundant sulfur defects and can therefore modify organothiols or organodithioheterocycles. The modification means usually relates to flammable and explosive chemical reagents, and the selection of disulfide with proper transition metal for mild and efficient modification is one of the difficulties in the current research.

Aiming at the current situation that the response of the existing nano hybrid material is weaker in the field of femtosecond near infrared laser, the invention aims to provide the p-nitrophenyl diazonium salt covalently modified tin disulfide film nonlinear hybrid material and the preparation method thereof, and further enhance the nonlinear performance of tin disulfide in the field of femtosecond near infrared laser through covalent modification. The method has the advantages that the prepared nano hybrid material is simple and easy to prepare, low in price and short in time consumption, and has larger reverse saturable absorption in the femtosecond near infrared laser field.

The purpose of the invention can be realized by the following technical scheme:

the invention provides a p-nitrophenyl diazonium salt covalent modified tin disulfide film nonlinear hybrid material, which is prepared from SnS₂Thin film and covalent bonding to SnS₂Nitrobenzene on the film.

Preferably, the hybrid material has an absorption that decreases with increasing wavelength before 400nm and a smoothly weak absorption in the 400nm-1000nm region.

Preferably, the hybrid material has reverse saturation absorption at 800nm higher than that of SnS₂And (5) lifting the film. The nonlinear absorption coefficient beta of the crystal is SnS₂381cm GW of film^-1Lifting to 832cm GW^-1。

Preferably, the hybrid material has irregular protrusions and defective pores.

The second aspect of the invention provides a preparation method of the p-nitrophenyl diazonium salt covalently modified tin disulfide thin film nonlinear hybrid material, which comprises the following steps:

deposition of SnS on a conductive glass FTO by chemical liquid deposition₂A film;

activating p-nitrophenyl diazonium salt to obtain activated p-nitrophenyl free radical solution;

dropwise adding the activated p-nitrophenyl radical solution to SnS₂On the film, obtaining the hybrid material SnS₂-NO₂Namely the p-nitrophenyl diazonium salt covalence modified tin disulfide film nonlinear hybrid material.

Preferably, the preparation method comprises the following steps:

s1: placing the conductive glass FTO in an ethanol solution of thioacetamide and stannous chloride dihydrate, heating in a water bath, standing, washing the conductive glass FTO, and drying to obtain SnS₂A film;

s2: mixing the solution of p-nitrophenyl diazonium salt with an equimolar amount of potassium iodide solution to obtain an activated p-nitrophenyl radical solution;

S3：dropwise adding the activated p-nitrophenyl radical solution to SnS in the shade₂On the film, after reaction, unreacted and adsorbed impurities are washed away to obtain the SnS hybrid material₂-NO₂Namely the p-nitrophenyl diazonium salt covalence modified tin disulfide film nonlinear hybrid material.

Preferably, the p-nitrophenyl diazonium salt is p-nitrophenyl tetrafluoroborate diazonium salt.

Preferably, in step S1, before the conductive glass FTO is used, the conductive glass FTO is washed in acetone, water and isopropanol in sequence to remove contaminants and avoid affecting subsequent chemical liquid deposition. Preferably, the conductive glass FTO has a size of 20 × 20 × 2 mm.

Preferably, in the step S1, the molar ratio of thioacetamide to stannous chloride dihydrate is 2-4: 1; it is further preferred that the molar ratio of thioacetamide to stannous chloride dihydrate is 3: 1.

Preferably, in the step S1, the concentration of the stannous chloride dihydrate is 10-15 mMol/L; further preferably, the concentration of stannous chloride dihydrate is 12 mMol/L.

Preferably, in the step S1, heating in a water bath to 45-50 ℃, keeping for 3-5 h, and then slowly cooling and standing for 9-15 h; further preferably, the mixture is heated to 48 ℃ in a water bath for 4 hours, and then slowly cooled and kept stand for 12 hours.

Preferably, in the step S1, the drying temperature is 40-60 ℃; further preferably, the drying temperature is 50 ℃.

Preferably, in the step S2, the concentration of the solution of the p-nitrophenyl diazonium salt is 8-12 mMol/L; it is further preferred that the concentration of the solution of the paranitrobenzyl diazonium salt is 10 mMol/L.

Preferably, in step S3, the activated p-nitrophenyl radical solution is obtained and then added dropwise.

Preferably, in step S3, the reaction is followed by washing with a solvent including water, ethanol, and dichloromethane.

Preferably, in step S3, the dropwise adding amount of the activated p-nitrophenyl radical solution is 0.5-2mL/4cm²SnS₂A film; preferably, the dropping amount is 1mL/4cm²SnS₂A film.

The invention discloses a paranitrobenzyl diazonium salt covalently modified tin disulfide thin film nonlinear hybrid material, which has weak absorption extending from 400nm to a near infrared region. Under the irradiation of 800nm near infrared laser, due to charge transfer, the electric charge comes from SnS₂The excited state absorption of the film is enhanced, thus preparing the SnS hybrid material₂-NO₂Relative to SnS₂The film has stronger reverse saturable absorption.

Compared with the prior art, the invention has the following beneficial effects:

first, SnS₂The synthesis of the film does not involve complicated experimental operation, and compared with the chemical vapor deposition method, the method has low cost and convenient working procedure.

Secondly, the activated diazonium salt modification reaction activity is higher, and the reaction time is shorter.

Third, the hybrid material SnS₂-NO₂Under the irradiation of 800nm femtosecond laser, the film has a higher SnS ratio than the parent material₂The film enhanced nonlinear absorption, while nitrobenzene itself had no nonlinear response.

Drawings

FIG. 1 shows SnS prepared according to the present invention₂-NO₂Schematic preparation route of hybrid material;

FIG. 2 shows SnS prepared according to example 1 of the present invention₂-NO₂Raman spectra of the hybrid materials and raw materials;

FIG. 3 shows SnS prepared in example 1 of the present invention₂The powder XRD spectrum of (1);

FIG. 4 shows SnS prepared in example 1 of the present invention₂-NO₂SEM image and elemental distribution map of (a);

FIG. 5 shows SnS prepared according to example 1 of the present invention₂-NO₂And fine spectra of sulfur and tin elements of XPS of the raw material;

FIG. 6 shows SnS prepared in example 1 of the present invention₂-NO₂And a nonlinear absorption spectrum of the raw material;

FIG. 7 shows a hybrid material SnS₂-NO₂And raw material SnS₂Perforated Z-scan junction for thin filmAnd (5) fruit pictures.

Detailed Description

The present invention will be described or further illustrated below with reference to specific examples, which are intended to provide a better understanding of the technical spirit of the present invention and are not intended to limit the scope of the present invention.

In the following examples, the diazo p-nitrophenyl tetrafluoroborate, thioacetamide and stannous chloride dihydrate used in the present invention are all commercial products of Annaggi chemical company.

Example 1:

preparation of p-nitrophenyl diazonium salt covalently modified tin disulfide thin film nonlinear hybrid material (see fig. 1):

first is SnS₂And (3) preparing the film, namely placing the prepared conductive glass FTO sheet with the size of 20 multiplied by 2mm in acetone, deionized water and isopropanol respectively, ultrasonically cleaning for 15min, and drying. Adding 200mL of ethanol, 2.8g of stannous chloride dihydrate and 2.7g of thioacetamide into a 250mL beaker, horizontally placing a dried FTO sheet at the bottom of the beaker, heating in a water bath for 4h after 48 ℃, then slowly cooling to room temperature, standing for 12h, and after a large amount of golden tin disulfide precipitates appear in the beaker, depositing SnS₂And taking out the FTO sheet of the film, washing the FTO sheet by using ethanol and deionized water until no obvious particles exist on the surface of the FTO, and drying the FTO sheet in a 50 ℃ oven.

Then to SnS₂Modifying the film, preparing 10mMol/L p-nitrophenyl diazonium tetrafluoroborate and potassium iodide deionized water solution, respectively taking 500 mu L, uniformly mixing, finding that the solution quickly turns yellow, and immediately dropwise adding 1mL of mixed solution into SnS₂Placing on film in shade for 10min to observe SnS₂A large number of bubbles are generated on the film, and then the modified SnS is added₂-NO₂Washing with ethanol, deionized water and dichloromethane, and drying to obtain SnS as target material₂-NO₂A film material.

FIG. 2 shows deposited SnS₂The powder XRD spectrum of the film can be found outSnS theory of hexagonal lattice₂Coincidences, confirmed SnS₂And (3) efficient synthesis of the film.

FIG. 3 shows SnS₂Thin films and hybrid materials SnS₂-NO₂Raman spectrum of (S), SnS₂Only 311.9 cm on the film^-1Has a scattering peak corresponding to the in-plane vibration of S-Sn-S, namely A_1gA vibration mode. And the hybrid material SnS₂-NO₂Except for SnS₂A of film_1gThe vibrational mode also showed a vibrational mode such as C ═ C on p-nitrophenyl, confirming efficient covalent modification.

Concerning the hybrid material SnS₂-NO₂The surface topography of (a) is shown in fig. 4 as a uniformly distributed curled sheet with a thickness test of 250 nm. The element distribution map can find that the N elements are uniformly distributed except the Sn and S elements, which shows that the nitrobenzene is uniformly modified and SnS₂The surface of the film.

In order to further test the hybrid material SnS₂-NO₂The chemical structure of (A) is that the hybrid material SnS is carried out₂-NO₂And SnS₂XPS testing of films. SnS can be found in FIG. 5(b)₂Thin films and hybrid materials SnS₂-NO₂Sn 3d of the fine spectrum of Sn element is not changed, while the hybrid material SnS is shown in FIG. 5(a)₂-NO₂S2 p versus SnS of the fine spectrum of the S element of (a)₂The film has a new element bonding state, namely a signal peak of a C-S bond outside Sn-S, and strongly proves that the p-nitrobenzene and the SnS₂Covalent bonding between the films.

Hybrid material SnS₂-NO₂And raw material SnS₂Linear absorption of the thin film and the substrate conductive glass FTO is shown in FIG. 6, and the substrate FTO has strong absorption before 300nm, so that the substrate FTO has strong absorption to SnS₂Film and SnS₂-NO₂There is a large interference of the absorption signal before 300 nm. SnS after 300nm₂Film and SnS₂-NO₂The two spectra are similar, and have rapid and weak absorption with increasing wavelength before 400nm, and have stable and weak absorption edge extending to near infrared region after 400 nm. With the difference that the hybrid material SnS₂-NO₂Absorption in the visible and near infrared regions is higher than that of SnS₂The film increases, which may be caused by scattering of incident light after modification of the organic molecules.

FIG. 7 shows hybrid material SnS₂-NO₂And raw material SnS₂As a result of Z-scan of the opening of the film, both curves exhibited a valley shape depressed downward, i.e., reverse saturable absorption, under irradiation with a laser beam having a pulse width of 34fs and a pulse energy of 16nJ at a wavelength of 800 nm. SnS₂The normalized transmittance of the film at the focus is 80%, while the SnS hybrid material₂-NO₂Transmittance at focus is 67%, compare SnS₂The film is significantly increased. SnS discovery from curve fitting₂-NO₂Has a non-linear absorption coefficient beta of SnS₂381cm GW of film^-1Lifting to 832cm GW^-1. This can be attributed to p-nitrobenzene and SnS₂From SnS due to efficient charge transfer between films₂Excited state absorption of the thin film. From the above results, it was confirmed that the diazonium salt activated by potassium iodide not only can be conveniently and rapidly converted to SnS₂The film is subjected to covalent modification, and meanwhile, the nonlinear optical property of the film can be effectively regulated and controlled, so that reference is provided for designing a nonlinear optical material based on a two-dimensional material in the future.

The embodiments described above are intended to facilitate the understanding and use of the invention by those skilled in the art. It will be readily apparent to those skilled in the art that various modifications to these embodiments may be made, and the generic principles described herein may be applied to other embodiments without the use of the inventive faculty. Therefore, the present invention is not limited to the above embodiments, and those skilled in the art should make improvements and modifications within the scope of the present invention based on the disclosure of the present invention.