Synthetic method for regulating and controlling morphology of zinc oxide by using silver as growth guiding agent

Abstract

The invention discloses a synthesis method for regulating and controlling the morphology of zinc oxide by using silver as a growth-directing agent, which comprises the following steps: (1) preparing a zinc nitrate solution, (2) preparing a zinc nitrate solution containing trace silver ions, (3) preparing a zinc nitrate solution containing trace silver ions, (4) performing a co-reduction process, and (5) washing and drying a material. Based on simple zinc nitrate and hydrazine hydrate oil bath thermal co-reduction, low-content silver ions are introduced, and the low-content silver ions are creatively put forward to serve as a crystal growth guiding agent to induce huge development of the morphology of zinc oxide. The raw materials are low in cost and environmentally friendly, the synthesis process is simple, convenient and easy to regulate and control, low-content silver ions are ingeniously introduced to serve as a crystal growth guiding agent, controllable development of the zinc oxide morphology is successfully achieved, and the diversity of the materials in the aspects of structural design and synthesis is expanded. The material has a wide application prospect in the field of preparation and development of new energy materials.

Description

Technical Field

[0001] This invention belongs to the field of new energy material synthesis and development, specifically, it relates to a synthesis method for controlling the morphology of zinc oxide using silver as a growth guide agent. Background Technology

[0002] Energy crisis and environmental pollution are two major challenges we face today, and the development and utilization of clean energy has become a core direction for global scientific research and industrial development. Therefore, innovation and breakthroughs in new energy materials are key to driving the future energy technology revolution. Among these, zinc oxide, as an important group II-VI wide-bandgap direct bandgap semiconductor material, exhibits enormous application potential in energy storage and conversion fields such as solar cells, photocatalysis, electrocatalysis, piezoelectricity, and sensors due to its excellent photoelectric properties, high chemical stability, and rich morphological diversity.

[0003] Generally, the performance of a material is highly dependent on its microstructure and structural characteristics. In the case of zinc oxide, different morphologies (such as nanorods, nanoflowers, and nanospheres) significantly affect key parameters such as specific surface area, active sites, electron transport paths, and photogenerated carrier separation efficiency, thus determining its final application performance. For example, one-dimensional zinc oxide structures provide directional electron transport paths, while three-dimensional hierarchical structures offer a large specific surface area and abundant active sites. Therefore, achieving precise design and controllable construction of the morphology and structure of zinc oxide crystals is a core prerequisite for maximizing its performance and driving its practical applications.

[0004] However, currently widely used methods for morphology-oriented synthesis of zinc oxide (such as hydrothermal, solvothermal, and vapor deposition methods) still have many limitations, making it difficult to achieve controllable evolution of multiple morphologies under the same method. Most methods heavily rely on specific template agents or stringent reaction conditions, resulting in complex processes, high costs, and poor reproducibility. Therefore, developing a novel zinc oxide crystal morphology regulation and construction technology that is simple to operate and highly controllable is of great significance for enhancing zinc oxide materials in diversified energy applications. Summary of the Invention

[0005] This invention provides a synthesis method for controlling the morphology of zinc oxide using silver as a growth guide agent. By introducing a low content of silver ions during the growth of zinc oxide crystals, silver ions can be used as crystal growth guide agents. Through specific adsorption, the chemical potential of the components can be adjusted, thereby affecting the crystal growth rate. This achieves successful control and preparation of zinc oxide morphology from pyramidal to flower-like and granular.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows: A method for synthesizing zinc oxide by using silver as a growth-directing agent to regulate its morphology, the method being as follows: (1) Preparation of zinc nitrate solution: Dissolve zinc nitrate in deionized water, then mix the homogeneous zinc nitrate solution with deionized water and stir thoroughly to obtain solution A; (2) Preparation of zinc nitrate solution containing trace silver ions: Dissolve zinc nitrate and trace silver nitrate separately in deionized water, then mix the homogeneous zinc nitrate solution and silver nitrate solution, and stir thoroughly to obtain solution B; (3) Preparation of zinc nitrate solution containing trace amounts of silver ions: Dissolve zinc nitrate and trace amounts of silver nitrate separately in deionized water, then mix the homogeneous zinc nitrate solution and silver nitrate solution, and stir thoroughly to obtain solution C; (4) Co-reduction process: Solutions A, B and C are transferred to three-necked flasks respectively, heated in an oil bath, and after reaching a certain temperature, hydrazine hydrate is added and the reaction is stirred; (5) Washing and drying of materials: After the precipitate forms following the reaction, it is cooled, centrifuged, washed, and dried to obtain zinc oxide materials with different morphologies, namely pyramidal zinc oxide, flower-like zinc oxide, and granular zinc oxide, denoted as Zn. 100 Zn 100 Ag 2.5 and Zn 100 Ag5.

[0007] The above technical solution can achieve the following beneficial effects: The technical method described in this invention overcomes the limitations of complex and demanding processes in zinc oxide morphology control. It creatively proposes a method to ingeniously control the morphology of zinc oxide from pyramidal to flower-like and granular forms by introducing a low content of silver ions as a growth guide agent. This enriches the diversity of zinc oxide materials in structural design and synthesis and broadens their application value.

[0008] The zinc oxide morphologies regulated by silver as a growth guide agent in this invention are uniform pyramidal morphology, flower cluster morphology, and granular morphology.

[0009] The method described in this invention has the advantages of low raw material cost and environmental friendliness, simple synthesis process and easy control. By simply reducing zinc nitrate and hydrazine hydrate in an oil bath, and by controlling the introduction of low silver ion content, the morphology of zinc oxide can be regulated from pyramidal to flower cluster and granular by using low silver ion content as a growth guide agent.

[0010] The preparation method described in this invention can be used to synthesize materials in the fields of energy storage and conversion, such as batteries, catalysts, and sensors. It is a novel material synthesis method that meets the design requirements of new energy materials and diversified energy applications. Attached Figure Description

[0011] Figure 1 In Example 1, 'a' refers to Zn prepared by the method described in Example 1. 100Scanning electron microscope image of the material; b is the Zn prepared by the method in Example 2. 100 Ag 2.5 Scanning electron microscope image of the material; c is the Zn prepared by the method in Example 3. 100 Scanning electron microscope image of Ag5 material; Figure 2 Zn prepared by the methods of Examples 1, 2 and 3 100 Zn 100 Ag 2.5 and Zn 100 X-ray powder diffraction pattern of Ag5 material. Detailed Implementation

[0012] The following is in conjunction with the appendix Figure 1-2 The present invention will be further described as follows: By introducing low concentrations of silver ions during the growth of zinc oxide crystals, the chemical potential of different components can be affected through specific adsorption, thereby altering the original crystal growth rate. This allows for the regulation of the zinc oxide morphology from pyramidal to flower-like and granular forms, with the following expressions: Zn 100 Zn 100 Ag 2.5 and Zn 100 Ag5 belongs to the field of new energy nanomaterial synthesis technology. Based on the simple co-reduction of zinc nitrate and hydrazine hydrate in an oil bath, this invention creatively proposes that low-content silver ions can act as crystal growth guides to induce significant morphological changes in zinc oxide. The raw materials used in this invention are inexpensive and environmentally friendly, and the synthesis process is simple and easily controlled. By cleverly introducing low-content silver ions as crystal growth guides, controllable morphological changes in zinc oxide are successfully achieved, expanding the diversity of this type of material in structural design and synthesis. This material has broad application prospects in the preparation and development of new energy materials. Example

[0013] The method for preparing pyramidal zinc oxide without the introduction of silver ions is as follows: (1) Dissolve 10 mmol of zinc nitrate in 100 mL of deionized water, then mix the homogeneous zinc nitrate solution with 100 mL of deionized water and stir thoroughly to obtain solution A; (2) Transfer solution A to a three-necked flask, heat it in an oil bath until it reaches 80°C, add 100 mmol of hydrazine hydrate, and stir the reaction for 2 h. (3) After the reaction, a precipitate forms. The precipitate is then cooled, centrifuged, washed, and dried (vacuum drying at 60°C for 12 h) to obtain a zinc oxide material with a pyramidal morphology, denoted as Zn. 100 .

[0014] Figure 1 a is Zn prepared by the method in Example 1.100 The scanning electron microscope image of the material shows that Zn 100 The uniform pyramidal morphology confirmed the successful synthesis of the novel pyramidal zinc oxide.

[0015] Figure 2 Zn prepared by the method in Example 1 100 The X-ray powder diffraction pattern of the material allows observation of Zn. 100 The material exhibits a good zinc oxide (ZnO) crystal structure, confirming the successful synthesis of zinc oxide in this invention. Example

[0016] The preparation method of the flower-like zinc oxide morphology with trace amounts of silver ions is as follows: (1) Dissolve 10 mmol zinc nitrate and 0.25 mmol silver nitrate in 100 mL of deionized water, then mix the homogeneous zinc nitrate solution and silver nitrate solution and stir thoroughly to obtain solution B; (2) Transfer solution B to a three-necked flask, heat it in an oil bath until it reaches 80°C, add 100 mmol of hydrazine hydrate, and stir the reaction for 2 h. (3) After the reaction, a precipitate forms. The precipitate is then cooled, centrifuged, washed, and dried (vacuum drying at 60°C for 12 h) to obtain a zinc oxide material with a flower-like morphology, denoted as Zn. 100 Ag 2.5 .

[0017] Figure 1 b is the Zn prepared by the method in Example 2. 100 Ag 2.5 The scanning electron microscope (SEM) image of the material shows that after the introduction of trace silver ions during crystal growth, Zn... 100 Ag 2.5 The morphology exhibits a uniform flower-like cluster shape, confirming that the introduction of low-content silver ions can successfully act as a crystal growth guide to regulate the morphology of zinc oxide; among them, trace amounts of silver ions can achieve a huge transformation of zinc oxide morphology from pyramidal to flower-like cluster.

[0018] Figure 2 Zn prepared by the method in Example 2 100 Ag 2.5 The X-ray powder diffraction pattern of the material allows observation of Zn. 100 Ag 2.5 In addition to exhibiting a good zinc oxide (ZnO) crystal structure, the material also showed a weak silver (Ag) crystal phase, confirming the successful synthesis of zinc oxide crystals and the participation of trace silver. Example

[0019] The preparation method of particulate zinc oxide with trace amounts of silver ions is as follows: (1) Dissolve 10 mmol zinc nitrate and 0.5 mmol silver nitrate in 100 mL of deionized water, then mix the homogeneous zinc nitrate solution and silver nitrate solution and stir thoroughly to obtain solution C; (2) Transfer solution C to a three-necked flask, heat it in an oil bath until it reaches 80°C, add 100 mmol of hydrazine hydrate, and stir the reaction for 2 h. (3) After the reaction, a precipitate forms. The precipitate is then cooled, centrifuged, washed, and dried (vacuum drying at 60°C for 12 h) to obtain a zinc oxide material with a granular morphology, denoted as Zn. 100 Ag5.

[0020] Figure 1 c is the Zn prepared by the method in Example 3. 100 The scanning electron microscope (SEM) image of Ag5 material shows that after the introduction of trace amounts of silver ions during crystal growth, Zn... 100 The Ag5 material exhibits a uniform granular morphology, further confirming that the introduction of low-content silver ions can successfully act as a crystal growth guide to regulate the morphology of zinc oxide; among them, trace amounts of silver ions can achieve a significant transformation of the zinc oxide morphology from pyramidal to granular.

[0021] Figure 2 Zn prepared by the method in Example 3 100 The X-ray powder diffraction pattern of Ag5 material shows that Zn can be observed. 100 In addition to exhibiting a good zinc oxide (ZnO) crystal structure, the Ag5 material also showed a slightly enhanced silver (Ag) crystal phase, confirming the successful synthesis of zinc oxide crystals and the participation of trace amounts of silver.

[0022] In summary, it can be seen that by controlling the introduction of low amounts of silver ions, silver can be successfully used as a growth guide to regulate the morphology of zinc oxide. In particular, the introduction of trace amounts of silver ions has successfully achieved a significant transformation of the morphology of zinc oxide from pyramidal to flower-like and granular.

[0023] The above descriptions are all preferred embodiments of the present invention. For those skilled in the art, any modifications to the present invention in various equivalent forms without departing from the principle of the present invention shall fall within the protection scope of the appended claims.

Claims

1. A method for synthesizing zinc oxide using silver as a growth-directing agent to regulate its morphology, characterized in that: The method is as follows: (1) Preparation of zinc nitrate solution: Dissolve zinc nitrate in deionized water, then mix the homogeneous zinc nitrate solution with deionized water and stir thoroughly to obtain solution A; (2) Preparation of zinc nitrate solution containing trace silver ions: Dissolve zinc nitrate and trace silver nitrate separately in deionized water, then mix the homogeneous zinc nitrate solution and silver nitrate solution, and stir thoroughly to obtain solution B; (3) Preparation of zinc nitrate solution containing trace amounts of silver ions: Dissolve zinc nitrate and trace amounts of silver nitrate separately in deionized water, then mix the homogeneous zinc nitrate solution and silver nitrate solution, and stir thoroughly to obtain solution C; (4) Co-reduction process: Solutions A, B and C are transferred to three-necked flasks respectively, heated in an oil bath, and after reaching a certain temperature, hydrazine hydrate is added and the reaction is stirred; (5) Washing and drying of materials: After the precipitate forms following the reaction, it is cooled, centrifuged, washed, and dried to obtain zinc oxide materials with different morphologies, namely pyramidal zinc oxide, flower-like zinc oxide, and granular zinc oxide, denoted as Zn. 100 Zn 100 Ag 2.5 and Zn 100 Ag5.

2. The method for synthesizing zinc oxide using silver as a growth-directing agent to regulate its morphology according to claim 1, characterized in that: In step (1), the amount of zinc nitrate is 5-15 mmol and the amount of deionized water is 50-150 mL.

3. The method for synthesizing zinc oxide using silver as a growth-directing agent to regulate its morphology according to claim 1, characterized in that: In step (2), the amount of zinc nitrate is 5~15 mmol, the amount of silver nitrate is 0.1~0.75 mmol, and the amount of deionized water is 50~150 mL.

4. The method for synthesizing zinc oxide using silver as a growth-directing agent to regulate its morphology according to claim 1, characterized in that: In step (3), the amount of zinc nitrate is 5~15 mmol, the amount of silver nitrate is 0.1~0.75 mmol, and the amount of deionized water is 50~150 mL.

5. The method for synthesizing zinc oxide using silver as a growth-directing agent to regulate its morphology according to claim 1, characterized in that: In step (4), the temperature is 50~100℃, the amount of hydrazine hydrate is 50~150 mmol, and the reaction time is 1~3 h.

6. The method for synthesizing zinc oxide using silver as a growth-directing agent to regulate its morphology according to claim 1, characterized in that: In step (5), the drying conditions are 50~70℃ and 10~15 h of vacuum drying.

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