A method for preparing multi-dimensional morphology transition metal nanomaterials in the same reaction system at room temperature

Abstract

The present invention discloses a method for preparing multi-dimensional morphology transition metal nanomaterials in the same reaction system at room temperature. First, polyether F127, thiourea, and Co(NO3)2·6H2O are dissolved in a mixed solution of deionized water and ethanol to obtain solution A. Then, formaldehyde, ethylenediamine, and dopamine are added to solution A in different orders under stirring at room temperature to obtain solution B, and the stirring reaction is continued until the end. The reaction product obtained is centrifuged and washed, and then dried and pulverized to obtain a brown end product. In the present invention, cobalt hexahydrate nitrate, thiourea, and dopamine are used as precursors, polyether F127 is used as a surfactant, and formaldehyde and ethylenediamine are used as cross-linking agents. By cleverly adjusting the precursors (feeding order) and reaction conditions, precise control and construction of the geometric morphology of N / S / Co co-doped nanomaterials are achieved, and cobalt-doped nanomaterials with uniform size and stable morphology, such as nanospheres, nanowires, nanosheets, and nanoflowers, are obtained.

Description

Technical Field

[0001] The present invention relates to the technical field of nanomaterial preparation, and more specifically to a method for preparing multi-dimensional transition metal nanomaterials in the same reaction system under room temperature conditions. Background Art

[0002] Due to their high active surfaces, unique electron transport orbits, and abundant surface vacancies, transition metal nanomaterials exhibit excellent catalytic activity, selectivity, and stability in many catalytic reaction systems, and have become one of the hot materials in the field of catalysis research. With the continuous expansion and in-depth research, higher requirements are also put forward for the diversification of the morphology of metal nanomaterials.

[0003] The performance of transition metal nanomaterials depends to a large extent on factors such as the composition, morphology, size, and structure of nanoparticles. Therefore, the controllable preparation of multi-dimensional morphologies of transition metal nanomaterials is one of the key research directions in current nanomaterial research. Generally, nanomaterials can be classified into zero-dimensional, one-dimensional, two-dimensional, and three-dimensional morphologies according to their morphological dimensions. Existing preparation methods for multi-dimensional transition metal nanomaterials usually require adding reducing agents, protecting agents, and etching agents in different reaction systems, resulting in a cumbersome and time-consuming preparation process. Moreover, the preparation process usually requires high-temperature and high-pressure experimental conditions, with extremely low controllability of the material morphology, and it is difficult to obtain target materials with uniform size and stable morphology. Currently, at the nanoscale, the precise design and controllable construction of the morphology of nanomaterials are still one of the difficult problems in the field of nanomaterial research. Therefore, exploring and developing a new method for precisely constructing metal nanomaterials with multi-dimensional geometric morphologies in the same reaction system under mild conditions can realize the creation of more new nanomaterials with both structural artistry and functional advancement, which is a major breakthrough in the field of nanotechnology research. Summary of the Invention

[0004] In view of this, the present invention provides a method for precisely constructing N / S / Co co-doped nanomaterials with multi-dimensional geometric morphologies in the same aqueous solvent reaction system under room temperature conditions. Based on the synthesis strategy of solution self-assembly, cobalt nitrate hexahydrate, thiourea, and dopamine are used as precursors, polyether F127 is used as a surfactant, and formaldehyde and ethylenediamine are used as cross-linking agents. By cleverly adjusting the precursors (feeding order) and reaction conditions, precise regulation and construction of the geometric morphology of N / S / Co co-doped nanomaterials are achieved, and cobalt-doped nanomaterials in the forms of nanospheres, nanowires, nanosheets, and nanoflowers with uniform size and stable morphology are obtained. The preparation method involved in the present invention can effectively overcome the deficiencies in the synthesis of existing transition metal nanomaterials with multi-dimensional geometric morphologies, and provides new ideas for the innovative research and development of transition metal nanomaterials with multi-dimensional geometric morphologies.

[0005] To achieve the above object, the present invention adopts the following technical solutions:

[0006] A method for preparing multi-dimensional morphology transition metal nanomaterials in the same reaction system at room temperature, comprising the following steps:

[0007] (1) Dissolve polyether F127, thiourea and Co(NO3)2·6H2O in a mixed solution of deionized water and ethanol to obtain solution A;

[0008] (2) Add formaldehyde, ethylenediamine and dopamine to solution A in different orders under stirring at room temperature to obtain solution B, and continuously stir the reaction until it ends;

[0009] (3) Centrifuge and wash the reaction product obtained in step (2), and then dry and crush it to obtain a brown final product.

[0010] Furthermore, for the preparation of zero-dimensional nanospheres:

[0011] In step (1), the weight ratio of polyether F127:thiourea:Co(NO3)2·6H2O = 3:3.75:1.5, and the amount of polyether F127 in the mixed solution of deionized water and ethanol is 0.005 g / mL;

[0012] The volume ratio of deionized water:ethanol = 1:0, formaldehyde:ethylenediamine:dopamine = 0.7 mL:0.3 mL:0.3 g, and the weight ratio of dopamine:polyether F127 = 1:1; Add dopamine, ethylenediamine, and formaldehyde in sequence, with a stirring speed of 1250 rpm and a stirring time of 24 h.

[0013] Furthermore, for the preparation of one-dimensional nanowires:

[0014] In step (1), the weight ratio of polyether F127:thiourea:Co(NO3)2·6H2O = 3:3.75:1.5, and the amount of polyether F127 in the mixed solution of deionized water and ethanol is 0.005 g / mL;

[0015] The volume ratio of deionized water:ethanol = 1:1, formaldehyde:ethylenediamine:dopamine = 0.7 mL:0 mL:0.3 g, and the weight ratio of dopamine:polyether F127 = 1:1; Add dopamine and formaldehyde in sequence, with a stirring speed of 1250 rpm and a stirring time of 24 h.

[0016] Furthermore, for the preparation of two-dimensional nanosheets:

[0017] In step (1), the weight ratio of polyether F127:thiourea:Co(NO3)2·6H2O = 0:3.75:1.5, and the amount of Co(NO3)2·6H2O in the mixed solution of deionized water and ethanol is 0.0025 g / mL;

[0018] Volume ratio of deionized water: ethanol = 1:0, formaldehyde: ethylenediamine: dopamine = 0.7 mL: 0.3 mL: 0.3 g, weight ratio of dopamine: Co(NO3)2·6H2O = 2:1; ethylenediamine, formaldehyde, and dopamine were added sequentially, the stirring speed was 180 rpm, and the stirring time was 24 h.

[0019] Further, preparation of three-dimensional nanoflowers:

[0020] In step (1), the weight ratio of polyether F127: thiourea: Co(NO3)2·6H2O = 3: 3.75: 1.5, and the amount of the polyether F127 in the mixed solution of deionized water and ethanol was 0.005 g / mL;

[0021] Volume ratio of deionized water: ethanol = 1:0, formaldehyde: ethylenediamine: dopamine = 0.7 mL: 0.3 mL: 0.3 g, weight ratio of dopamine: polyether F127 = 1:1; ethylenediamine, formaldehyde, and dopamine were added sequentially, the stirring speed was 180 rpm, and the stirring time was 24 h.

[0022] Preferably, in step (3), the centrifugation speed was 10,000 rpm and the time was 5 min; deionized water, ethanol, and deionized water were added sequentially for washing.

[0023] Preferably, in step (3), the drying temperature was 80 °C and the time was 24 h.

[0024] Through the above technical solutions, compared with the prior art, the present invention discloses a method for preparing multi-dimensional morphology transition metal nanomaterials in the same reaction system under room temperature conditions, having the following beneficial effects:

[0025] The present invention realizes the preparation of cobalt metal nanomaterials with multi-dimensional morphology in the same reaction system by using the solution self-assembly method under room temperature conditions, including zero-dimensional nanospheres, one-dimensional nanowires, two-dimensional nanosheets, and three-dimensional nanoflowers. The synthesis method is simple and controllable, and has the potential for large-scale industrial production. Moreover, the morphology and size of the multi-dimensional cobalt metal nanomaterials prepared by the present invention have good uniformity and stability. Description of the Drawings

[0026] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are only the embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained according to the provided drawings without creative efforts.

[0027] Figure 1 SEM image of the zero-dimensional nanospheres prepared in Example 1;

[0028] Figure 2 SEM image of the one-dimensional nanowires prepared in Example 2;

[0029] Figure 3 SEM image of the two-dimensional nanosheets prepared in Example 3;

[0030] Figure 4 SEM image of the three-dimensional nanoflowers prepared in Example 4;

[0031] Figure 5 XRD pattern of the prepared multi-dimensional morphology target material. Detailed implementation manners

[0032] The technical solutions of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0033] Example 1

[0034] Preparation method of zero-dimensional nanospheres, comprising the following steps:

[0035] Add 60 mL of deionized water to a reaction vessel, then sequentially weigh and add 0.3 g of polyether F127, 0.375 g of thiourea, and 0.15 g of cobalt nitrate hexahydrate. Subsequently, add a magnetic stirrer and stir for 15 min to fully dissolve the raw materials. Adjust the rotation speed to 1250 r / min and maintain it until the reaction ends; pour in 0.3 g of hydrochloric acid dopamine powder and wait for 5 min; then uniformly add 0.3 mL of ethylenediamine within 5 min. After the addition is completed, wait for another 5 min; finally, uniformly add 0.7 mL of formaldehyde to the solution within 5 min, cover the reaction vessel, and react for 24 h; after the reaction ends, centrifuge and wash to obtain the product. The centrifugation and washing rate is 10000 rpm for 5 min, and wash with deionized water, ethanol, and deionized water in sequence; after centrifugation, place the product in an 80 °C oven and dry for 24 h, and pulverize to obtain a brown powder.

[0036] Figure 1 SEM image of the product. The product is uniform zero-dimensional nanospheres with a sphere diameter of about 200 - 300 nm

[0037] Example 2

[0038] Preparation method of one-dimensional nanowires, comprising the following steps:

[0039] Add 30 mL of deionized water and 30 mL of absolute ethanol to the reaction vessel. Then, weigh and add 0.3 g of polyether F127, 0.375 g of thiourea, and 0.15 g of cobalt nitrate hexahydrate in sequence. Subsequently, add a magnetic stirrer and stir for 15 min to fully dissolve the raw materials. Adjust the rotation speed to 1250 r / min and maintain it until the reaction ends. Pour in 0.3 g of dopamine hydrochloride powder and wait for 5 min. Then, uniformly add 0.7 mL of formaldehyde to the solution within 5 min, cover the lid, and react for 24 h. After the reaction ends, centrifuge and wash to obtain the product. The centrifugation and washing rate is 10,000 rpm, and the time is 5 min. Wash with deionized water, ethanol, and deionized water in sequence. After centrifugation, place the product in an 80 °C oven and dry for 24 h. After pulverization, a brown powder is obtained.

[0040] Figure 2 It is the SEM image of the product. The product is uniform one-dimensional nanowires, and the diameter of the nanowires is about 200 nm.

[0041] Example 3

[0042] A preparation method of two-dimensional nanosheets, comprising the following steps:

[0043] Add 60 mL of deionized water to the reaction vessel. Then, weigh and add 0.375 g of thiourea and 0.15 g of cobalt nitrate hexahydrate in sequence. Subsequently, add a magnetic stirrer and stir for 15 min to fully dissolve the raw materials. Adjust the rotation speed to 170 - 180 r / min and maintain it until the reaction ends. Uniformly add 0.3 mL of ethylenediamine within 5 min. After adding, wait for 5 min. Uniformly add 0.7 mL of formaldehyde to the solution within 5 min, and immediately pour in 0.3 g of dopamine hydrochloride powder. Cover the lid and react for 24 h. After the reaction ends, centrifuge and wash to obtain the product. The centrifugation and washing rate is 10,000 rpm, and the time is 5 min. Wash with deionized water, ethanol, and deionized water in sequence. After centrifugation, place the product in an 80 °C oven and dry for 24 h. After pulverization, a brown powder is obtained.

[0044] Figure 3 It is the SEM image of the product. The product is uniform two-dimensional nanosheets, and the diameter of the nanosheets is about 400 nm.

[0045] Example 4

[0046] A preparation method of three-dimensional nanoflowers, comprising the following steps:

[0047] Add 60 mL of deionized water into the reaction vessel, then weigh and add 0.3 g of polyether F127, 0.375 g of thiourea, and 0.15 g of cobalt nitrate hexahydrate in sequence. Subsequently, add a magnetic stir bar and stir for 15 min to fully dissolve the raw materials. Adjust the rotation speed to 170 - 180 r / min and maintain it until the reaction ends; add 0.3 mL of ethylenediamine uniformly within 5 min, and wait for 5 min after the addition is completed; then add 0.7 mL of formaldehyde uniformly into the solution within 5 min, and immediately pour in 0.3 g of dopamine hydrochloride powder. Cover and react for 24 h; after the reaction ends, centrifuge and wash to obtain the product. The centrifugation and washing rate is 10,000 rpm for 5 min, and wash with deionized water, ethanol, and deionized water in sequence; after centrifugation, place the product in an oven at 80 °C and dry for 24 h, and crush to obtain a brown powder.

[0048] Figure 4 Figure 4 is the SEM image of the product. The product is uniform three-dimensional nanoflowers, and the diameter of the nanoflowers is about 400 - 500 nm.

[0049] Figure 5 Figure 5 is the XRD pattern of the prepared multi-dimensional morphology target material. It can be seen from Figure 5 the figure that the diffraction peaks of the target material basically coincide with the diffraction peaks of the calibration cards Co (JCPDS card no. 15 - 0806) and Co9S8 (JCPDS card no. 75 - 2023). The diffraction peaks at diffraction angles 2θ = 44.3°, 51.4°, and 75.8° correspond to the (111), (200), and (220) crystal planes of Co respectively; the diffraction peaks at diffraction angles 2θ = 15.8°, 30.29°, 31.6°, 39.99°, 47.96°, and 52.47° correspond to the (111), (311), (222), (331), (511), and (440) crystal planes of Co9S8 respectively. The above results preliminarily prove that both Co and Co9S8 crystal phases coexist in the prepared target material.

[0050] The various embodiments in this specification are described in a progressive manner. Each embodiment focuses on the differences from other embodiments. For the same or similar parts among the various embodiments, reference can be made to each other. The above description of the disclosed embodiments enables those skilled in the art to implement or use the present invention. Various modifications to these embodiments will be obvious to those skilled in the art. The general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to these embodiments shown herein, but will conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for preparing multi-dimensional morphology transition metal nanomaterials in the same reaction system at room temperature, characterized in that, It includes the following steps: (1) Dissolve polyether F127, thiourea, and Co(NO3)2·6H2O in a mixed solution of deionized water and ethanol to obtain solution A; (2) Add formaldehyde, ethylenediamine, and dopamine to solution A in different orders under stirring at room temperature to obtain solution B, and continue stirring until the reaction ends; (3) Centrifuge and wash the reaction product obtained in step (2), and then dry and crush it to obtain a brown end product; Among them, in the preparation of one-dimensional nanowires: In step (1), the weight ratio of polyether F127:thiourea:Co(NO3)2·6H2O = 3: 3.75:1.5, the amount of polyether F127 in the mixed solution of deionized water and ethanol is 0.005 g / mL, and the volume ratio of deionized water:ethanol = 1:1; In step (2), formaldehyde:ethylenediamine:dopamine = 0.7 mL:0 mL:0.3 g; by weight, dopamine in step (2):polyether F127 in step (1) = 1:1; add dopamine and formaldehyde in sequence, the stirring speed is 1250 rpm, and the stirring time is 24 h; In the preparation of two-dimensional nanosheets: In step (1), the weight ratio of polyether F127:thiourea:Co(NO3)2·6H2O = 0:3.75:1.5, the amount of Co(NO3)2·6H2O in the mixed solution of deionized water and ethanol is 0.0025 g / mL, and the volume ratio of deionized water:ethanol = 1:0; In step (2), formaldehyde:ethylenediamine:dopamine = 0.7 mL:0.3 mL:0.3 g, by weight, dopamine in step (2):Co(NO3)2·6H2O in step (1) = 2:1; add ethylenediamine, formaldehyde, and dopamine in sequence, the stirring speed is 180 rpm, and the stirring time is 24 h; In the preparation of three-dimensional nanoflowers: In step (1), the weight ratio of polyether F127:thiourea:Co(NO3)2·6H2O = 3: 3.75:1.5, the amount of polyether F127 in the mixed solution of deionized water and ethanol is 0.005 g / mL, and the volume ratio of deionized water:ethanol = 1:0; In step (2), formaldehyde:ethylenediamine:dopamine = 0.7 mL:0.3 mL:0.3 g, by weight, dopamine in step (2):polyether F127 in step (1) = 1:1; add ethylenediamine, formaldehyde, and dopamine in sequence, the stirring speed is 180 rpm, and the stirring time is 24 h.

2. The method for preparing a multi-dimensional morphology transition metal nanomaterial in the same reaction system under room temperature conditions according to claim 1, wherein In step (3), the centrifugation speed is 10,000 rpm and the time is 5 min; add deionized water, ethanol, and deionized water for washing in sequence.

3. A method for preparing multi-dimensional morphology transition metal nanomaterials in the same reaction system under room temperature conditions according to claim 1, characterized in that, In step (3), the drying temperature is 80 °C and the time is 24 h.

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