Preparation method and application of calcium cuprate nanosheet with ultrafast relaxation time
阅读说明：本技术 一种具有超快弛豫时间的铜酸钙纳米片的制备方法和应用 (Preparation method and application of calcium cuprate nanosheet with ultrafast relaxation time ) 是由 郑晶莹 吴文圣 郝瑞娴 陈奇俤 詹红兵 于 2021-08-10 设计创作，主要内容包括：本发明公开了一种具有超快弛豫时间的Ca-2CuO-3纳米片的制备方法和应用,属于非线性光学材料制备领域。其是以Ca(NO-3)-2·4H-2O、Cu(NO-3)-2·3H-2O和C-6H-8O-7·H-2O为原料,加入二乙二醇单丁醚进行超声搅拌溶解后,先后经水浴搅拌、油浴搅拌后进行蒸干,再将所得物质研磨成细粉后进行烧结,以得到块体粉末Ca-2CuO-3,最后将所得块体粉末Ca-2CuO-3加入乙醇进行球磨,而得到含Ca-2CuO-3纳米片的悬浮液。本发明制备工艺简单,操作可控性强,所得产品厚度尺寸较小,且经测试,所得Ca-2CuO-3纳米片具有较大的三阶非线性系数和超快的载流子弛豫时间,对光子学和光电子学的发展具有重大意义。(The invention discloses Ca with ultra-fast relaxation time 2 CuO 3 A preparation method and application of a nano-sheet belong to the field of nonlinear optical material preparation. It is Ca (NO) 3 ) 2 ·4H 2 O、Cu(NO 3 ) 2 ·3H 2 O and C 6 H 8 O 7 ·H 2 Adding diethylene glycol monobutyl ether into O as a raw material, ultrasonically stirring and dissolving, then stirring in a water bath and an oil bath, evaporating to dryness, grinding the obtained substance into fine powder, and sintering to obtain block powder Ca 2 CuO 3 Finally, the obtained block powder Ca 2 CuO 3 Adding ethanol for ball milling to obtain Ca-containing powder 2 CuO 3 A suspension of nanoplatelets. The preparation process is simple and the operation is simpleThe controllability is strong, the thickness of the obtained product is small, and the obtained Ca is tested 2 CuO 3 The nano sheet has larger third-order nonlinear coefficient and ultrafast carrier relaxation time, and has great significance for the development of photonics and optoelectronics.)
1. Ca with ultrafast relaxation time2CuO3The preparation method of the nanosheet is characterized by comprising the following steps:
(1) respectively weighing a certain amount of Ca (NO)3)2·4H2O、Cu(NO3)2·3H2O、C6H8O7·H2Adding diethylene glycol monobutyl ether to carry out ultrasonic stirring and dissolving to obtain a stable blue solution;
(2) placing the obtained blue solution into a water bath kettle at the temperature of 60-100 ℃, stirring for 1-3 h at constant temperature, transferring into an oil bath kettle, stirring for 1-3 h at the constant temperature of 100-150 ℃, and obtaining a blue-white sticky block-shaped substance;
(3) transferring the obtained substance to an evaporating dish for evaporation to obtain brown powder, grinding the obtained brown powder into fine powder, placing the fine powder into a crucible, sintering the fine powder at the temperature of 600-1200 ℃ for 1-3 h, naturally cooling the fine powder, grinding the fine powder again to be uniform, and obtaining block powder Ca2CuO3；
(4) 0.5-1 g of block powder Ca is taken2CuO3Adding 10-30 mL of absolute ethyl alcohol into a ball milling tank, and ball milling for 40-80 h to obtain Ca2CuO3And (3) carrying out centrifugal separation on the ethanol suspension of the nanosheets, and taking the supernatant to obtain the nano-particles.
2. The Ca of claim 12CuO3Method for producing nanoplates, characterized in that Ca (NO) is used3)2·4H2O、Cu(NO3)2·3H2O and C6H8O7·H2The molar ratio of O is 2:1:4-2:1: 8.
3. Ca prepared by the method of claim 12CuO3The nano sheet is applied to the aspect of manufacturing an ultrafast laser.
Technical Field
The invention belongs to the field of preparation of nonlinear optical materials, and particularly relates to Ca with ultrafast relaxation time2CuO3Preparation and application of the nano-sheet.
Background
Emerging technologies are emerging continuously, and people's life is gradually improved. Technologies in defense science and technology, industrial applications and living facilities have contributed to optoelectronic devices such as field effect transistors, saturable absorbers, photoelectric modulators, etc., and photoelectric materials are the main factors that dominate the performance of these devices. The use of optoelectronic materials has made possible a variety of photonic devices (e.g., pulsed lasers, optical switches, optical modulators, photodetectors, and optical waveguide devices) that are currently in widespread use. However, there are still certain requirements for the related properties of the optoelectronic materials, such as fast carrier mobility, large nonlinear effect, etc., so as to develop optical switching devices and optical limiter devices with better performance. Therefore, optoelectronic materials with good nonlinear effects and suitable carrier relaxation times are the object of common search by researchers at present. Ca2CuO3Is a strong electron-related material, and has attracted researchers' attention due to its special properties such as low dimensionality and spin-charge separation.
In addition, the reduced size of the material makes its presence in the liquid phase more stable and less prone to precipitation, while the presence of the entire system is more stable if the material particles are present homogeneously in the liquid phase. Therefore, it is also important to explore a simple way to reduce the size of materials. Related to Ca2CuO3In the preparation of (A), there are methods of using epitaxial laser ablation to grow a thin film of the material, or by epitaxyThe material is obtained by a warm solid phase sintering method. Or using sol-gel method to obtain Ca with smaller size and single particle2CuO3The material, however, still has a size of about 1 μm, and Ca is not incorporated2CuO3The size of the single crystal is reduced to the nanometer scale. And Ca2CuO3The stable preparation of the nano-sheet can provide certain conditions for the development of future photonics and optoelectronics.
Disclosure of Invention
The invention aims to provide Ca with ultra-fast relaxation time2CuO3Preparation method and application of nanosheet, and Ca obtained by preparation method2CuO3Nanomaterials have small dimensions and are characterized by large third-order non-linear coefficients and ultra-fast carrier relaxation times.
In order to achieve the purpose, the invention adopts the following technical scheme:
ca with ultrafast relaxation time2CuO3A method of making nanoplatelets comprising the steps of:
(1) respectively weighing a certain amount of Ca (NO)3)2·4H2O、Cu(NO3)2·3H2O and C6H8O7·H2Adding a proper amount of diethylene glycol monobutyl ether into the mixture to be ultrasonically stirred and dissolved to obtain a stable blue solution; wherein Ca (NO) is used3)2·4H2O、Cu(NO3)2·3H2O and C6H8O7·H2The molar ratio of O is 2:1:4-2:1: 8;
(2) placing the obtained blue solution into a water bath kettle at the temperature of 60-100 ℃, stirring for 1-3 h at constant temperature, transferring into an oil bath kettle, stirring for 1-3 h at the constant temperature of 100-150 ℃, and obtaining a blue-white sticky block-shaped substance;
(3) transferring the obtained substance into an evaporating dish, placing the evaporating dish on a universal electronic furnace for evaporation to dryness to obtain brown powder, grinding the obtained brown powder into fine powder, placing the fine powder into a crucible, sintering the fine powder for 1-3 hours at the temperature of 600-1200 ℃, naturally cooling the fine powder and grinding the fine powder uniformly again to obtain block powder Ca2CuO3；
(4) 0.5-1 g of block powder Ca is taken2CuO3Adding 10-30 mL of absolute ethyl alcohol into a ball milling tank, and ball milling for 40-80 h to obtain Ca2CuO3And (3) carrying out centrifugal separation on the ethanol suspension of the nanosheets under the action of 1000-9000 rpm, and taking supernatant fluid to obtain the nano-particles.
Ca prepared by the above method2CuO3The nano sheet can be used for preparing an ultrafast laser. Further, Ca prepared by the present invention2CuO3The nano sheet has a larger third-order nonlinear absorption coefficient, the saturated absorption effect of the nano sheet is suitable for being used as a Q-switching or mode-locking module in ultrashort pulse laser, and the anti-saturated absorption effect of the nano sheet is suitable for manufacturing devices such as data optical storage, two-photon fluorescence imaging, optical amplitude limiting and the like; meanwhile, the ultra-fast carrier relaxation time is also suitable for manufacturing pulse lasers, photoelectric detectors, solar cells, light emitting diodes, phototransistors and the like.
The invention has the following remarkable advantages:
(1) the invention adopts a ball milling method to mix Ca2CuO in a block3The size of the calcium carbonate is reduced to nano level and is in a nano sheet shape, and the Ca-containing particles with uniform particle size distribution and better stability are obtained by centrifugal separation2CuO3A suspension sample of nanoplatelets.
(2) Ca prepared by the invention2CuO3The nano sheet has larger third-order nonlinear coefficient and ultrafast carrier relaxation time, and has great significance for the development of photonics and optoelectronics.
Drawings
FIG. 1 shows Ca obtained in example 12CuO3SEM image (a) of nanosheets, EDS distribution map (b) of Ca, EDS distribution map (c) of Cu and EDS energy spectrum (d). The obtained material is shown in a sheet shape by an electron micrograph, and Ca can be confirmed by EDS spectrogram content analysis2CuO3The presence of a material.
FIG. 2 shows Ca obtained in example 12CuO3XRD pattern and Raman spectrum of the nano-sheet. As can be seen from the XRD pattern, almost all the peaks are well matched, confirming Ca2CuO3Is stored inThe ball milling can not damage Ca2CuO3The object image of the material. Further confirmation of Ca was confirmed by Raman spectroscopy2CuO3Is present.
FIG. 3 shows Ca obtained in example 12CuO3The single-chip TEM spectrogram (a) of the nanosheets and an HRTEM image (b) of an enlarged area thereof, wherein the inset image is a corresponding electron diffraction pattern. It assisted in demonstrating that the phase composition of the resulting material is Ca2CuO3It is a polycrystalline structure.
FIG. 4 shows Ca obtained in example 12CuO3AFM images (a) of the nanoplatelets and their dashed lines indicate the profile of the change in height (b). As can be seen from the figure, the heights of the four selected different flaky materials are all about 40 nm, which proves that the obtained sample is in a nanometer scale in the dimension of height, and proves that the ball-milled sample is a nanosheet.
FIG. 5 shows Ca obtained in example 12CuO3Ultraviolet-visible absorption spectrogram of the nanosheet. As can be seen, the material has good absorption of light in the 400-800 nm region.
FIG. 6 shows Ca obtained in example 12CuO3Open-cell Z-scan analysis curves of the nanoplatelets at incident light of 500 nm (a) and 800 nm (b). The analysis can obtain the larger third-order nonlinear absorption coefficient.
FIG. 7 shows Ca obtained in example 12CuO3The nano-sheet respectively detects carrier kinetic curves of three wavelengths under the condition that the pump light is 400 nm. It has an ultra-fast carrier relaxation time by further analysis.
FIG. 8 shows Ca prepared in comparative example2CuO3Sample plot of agglomerated particles.
Detailed Description
In order to make the present invention more comprehensible, the technical solutions of the present invention are further described below with reference to specific embodiments, but the present invention is not limited thereto.
Example 1
Ca2CuO3Preparation step of nanosheetThe method comprises the following steps:
(1) 6.28 mmol Ca (NO) were weighed separately3)2·4H2O、3.14 mmol Cu(NO3)2·3H2O and 12.56 mmol C6H8O7·H2Adding 16 mL of diethylene glycol monobutyl ether into a beaker, and ultrasonically stirring and dissolving to obtain a stable blue solution;
(2) placing the obtained blue solution into a water bath kettle at the temperature of 80 ℃, stirring for 2 hours at constant temperature, transferring into the oil bath kettle, stirring for 2 hours at the constant temperature of 130 ℃, and obtaining a blue-white sticky block-shaped substance;
(3) transferring the obtained substance to an evaporating dish, and placing the evaporating dish on a universal electronic furnace for evaporation to dryness to obtain brown powder. Grinding the obtained brown powder into fine powder, placing in a crucible, sintering at 900 deg.C for 1 h, naturally cooling, and grinding again to obtain block powder Ca2CuO3；
(4) 0.75 g of block powder Ca is taken2CuO3Putting the mixture into a ball milling tank, adding 20 mL of absolute ethyl alcohol, and ball milling for 60 hours to obtain Ca-containing solution2CuO3Transferring the suspension into a 50 mL centrifuge tube by using a disposable dropper, performing centrifugal separation under the action of 3000 rpm to obtain a precipitate and a supernatant, wherein the supernatant contains Ca2CuO3Nanosheets.
Ca obtained in example 12CuO3The lateral dimension of the nano-sheet is 100-500 nm, and the thickness of the nano-sheet is not higher than 40 nm.
Example 2
Ca2CuO3The preparation steps of the nano sheet are as follows:
(1) 6.28 mmol Ca (NO) were weighed separately3)2·4H2O、3.14 mmol Cu(NO3)2·3H2O and 18.84 mmol C6H8O7·H2Adding 10 mL of diethylene glycol monobutyl ether into a beaker, and ultrasonically stirring and dissolving to obtain a stable blue solution;
(2) placing the obtained blue solution into a water bath kettle at 60 ℃ and stirring at constant temperature for 1 h, and then transferring the blue solution into the oil bath kettle and stirring at constant temperature of 100 ℃ for 1 h to obtain a blue-white sticky block-shaped substance;
(3) transferring the obtained substance to an evaporating dish, and placing the evaporating dish on a universal electronic furnace for evaporation to dryness to obtain brown powder. Grinding the obtained brown powder into fine powder, placing in a crucible, sintering at 600 deg.C for 1 h, naturally cooling, and grinding again to obtain block powder Ca2CuO3；
(4) 0.5 g of bulk powder Ca is taken2CuO3Putting the mixture into a ball milling tank, adding 10 mL of absolute ethyl alcohol, and ball milling for 40 h to obtain Ca-containing solution2CuO3Ethanol suspension of nanoplatelets. Transferring the obtained suspension into a 50 mL centrifuge tube by using a disposable dropper, performing centrifugal separation under the action of 1000 rpm, and then obtaining a precipitate and a supernatant, wherein the obtained supernatant contains Ca2CuO3Nanosheets.
Ca obtained in example 22CuO3The lateral dimension of the nano-sheet is 100-800 nm, and the thickness of the nano-sheet is not higher than 80 nm.
Example 3
Ca2CuO3The preparation steps of the nano sheet are as follows:
(1) 6.28 mmol Ca (NO) were weighed separately3)2·4H2O、3.14 mmol Cu(NO3)2·3H2O and 25.12 mmol C6H8O7·H2Adding 20 mL of diethylene glycol monobutyl ether into a beaker, and ultrasonically stirring for dissolving to obtain a stable blue solution;
(2) placing the obtained blue solution into a water bath kettle at 100 ℃ and stirring for 3 h at constant temperature, and then transferring the blue solution into the oil bath kettle and stirring for 3 h at constant temperature of 150 ℃ to obtain a blue-white sticky block-shaped substance;
(3) transferring the obtained substance to an evaporating dish, and placing the evaporating dish on a universal electronic furnace for evaporation to dryness to obtain brown powder. Grinding the obtained brown powder into fine powder, placing in a crucible, sintering at 1200 deg.C for 3 h, naturally cooling, and grinding again to obtain block powder Ca2CuO3；
(4) Taking 1 g of blockPowder Ca2CuO3Putting the mixture into a ball milling tank, adding 30 mL of absolute ethyl alcohol, and ball milling for 80 hours to obtain Ca-containing solution2CuO3Ethanol suspension of nanoplatelets. Transferring the obtained suspension into a 50 mL centrifuge tube by using a disposable dropper, performing centrifugal separation under the action of 2000 rpm, and then obtaining a precipitate and a supernatant, wherein the obtained supernatant contains Ca2CuO3Nanosheets.
Ca obtained in example 32CuO3The lateral dimension of the nano-sheet is 100-600 nm, and the thickness of the nano-sheet is not higher than 60 nm.
Nonlinear optical performance testing
For Ca obtained in example 12CuO3The nanosheet is subjected to Z scanning and pumping detection characterization.
In the Z-scan test, 500 nm and 800 nm incident light was used, and the effect of the substrate was excluded by testing a blank ethanol solution. The nonlinear absorption coefficients under four different incident energies under two incident wavelengths are respectively calculated, the nonlinear absorption under the same wavelength is subjected to average calculation to a certain degree, the nonlinear absorption coefficients under 500 nm incident light and 800 nm incident light are respectively 0.084 cm/GW and 0.00019cm/GW, and the fact that the nonlinear absorption coefficients have larger third-order nonlinear absorption coefficients is proved.
In the pumping detection test, a femtosecond laser with the wavelength of 400 nm is used as a pumping beam, and the detection light is super-continuous white light. Kinetic curves of the probe light at 543.2 nm, 562.9 nm and 582.6 nm are analyzed, carrier kinetic curves at 562.9 nm are fitted, and two time constant values tau are obtained1= 0.41 ps and τ2= 2.10 ps, which reflects a very fast recovery process. By reaction with other substances (e.g. WS)2、MoS2CNTs, graphene, etc.), Ca2CuO3The relaxation time of the nano-sheet is ultra-fast, which shows that the nano-sheet is expected to be used for constructing a high-performance optical modulation device (such as an ultra-fast laser) with ultra-fast response.
Comparative example
(1) 3.14 mmol of Cu (NO)3)2·3H2O and 6.28 mmol Ca (NO)3)2·H2O was dissolved in 8 mL of DGME, and the mixture was stirred to homogeneity. Then, 0.66 g of anhydrous citric acid was added to the solution. The resulting light blue solution was heated at 80 ℃ to remove excess water and then further heated at 130 ℃ for 1 h to make it more viscous and finally to form a xerogel. The xerogel is then placed at 250 ℃ for 1 h and the resulting powder is heated at 800 ℃ for 1 h and cooled to room temperature.
(2) And carrying out hydrothermal treatment on the prepared gel powder, transferring the gel powder into a stainless steel autoclave lined with polytetrafluoroethylene, heating the gel powder for 20 hours at 180 ℃, carrying out centrifugal separation, and washing for multiple times. Finally, carrying out post heat treatment on the powder, and calcining the powder in air at 900 ℃ for 1 h to obtain Ca2CuO3Agglomerating the particles. It was detected to have no large third-order nonlinear absorption coefficient and no ultrafast relaxation time.
Ca compared to comparative example2CuO3Agglomerated particles, the invention uses a ball milling method to agglomerate Ca2CuO3The size of the calcium carbonate is reduced to nano level and then the calcium carbonate is in a nano sheet shape, and the Ca-containing calcium carbonate with uniform particle size distribution and better stability can be obtained through centrifugal separation2CuO3A suspension sample of the nanosheets, and having a large third-order nonlinear coefficient and an ultrafast carrier relaxation time.
The above description is only a preferred embodiment of the present invention, and all equivalent changes and modifications made in accordance with the claims of the present invention should be covered by the present invention.