CN-122010071-A - Hydrothermal synthesis method for regulating shape of titanium phosphate without template agent

Abstract

The invention discloses a hydrothermal synthesis method for regulating and controlling the morphology of titanium phosphate without a template agent and an obtained product, and belongs to the technical field of preparation of inorganic functional materials. The method does not use any organic surfactant or hard template agent, and comprises the steps of dissolving a titanium source in concentrated sulfuric acid-containing water, heating and refluxing to obtain a precursor solution, optionally adding at least one of sulfuric acid, citric acid or acetic acid as a second acid, adding a phosphoric acid solution, and performing hydrothermal reaction to obtain titanium phosphate powder. By regulating and controlling the adding amount of the phosphoric acid and whether the second acid is added, controllable preparation of the titanium phosphate microcosmic appearance can be realized under the template-free condition. The obtained titanium phosphate is a pure phase, and the morphology of the titanium phosphate comprises nano-sheets, nano-particles, flower-shaped microspheres assembled by the nano-sheets and the like. The method has simple process, low cost, and good application prospect, and avoids generation of impurity phases caused by high-temperature calcination.

Inventors

• ZHOU YU
• ZHANG ZHIFENG
• ZHOU HAIDONG
• MA ZEWEI
• CHEN WANGWU

Assignees

• 浙江爱科新材料有限公司

Dates

Publication Date

20260512

Application Date

20260206

Claims (10)

1. 1. The hydrothermal synthesis method for regulating and controlling the morphology of titanium phosphate without a template agent is characterized by comprising the following steps of: S1, dispersing a titanium source in water, adding a first acid solution to inhibit hydrolysis, and carrying out dissolution reaction under a heating condition to obtain a titanium source precursor solution, wherein the titanium source is at least one of titanium chloride, titanium sulfate, titanyl sulfate, titanium citrate and tetrabutyl titanate; s2, dropwise adding a phosphoric acid solution with the concentration of 1-14.6 mol/L into the titanium source precursor solution, and stirring for reaction to obtain a reaction precursor solution; s3, placing the reaction front liquid in a closed container, and carrying out hydrothermal reaction at 150-180 ℃; And S4, after the reaction is finished, carrying out solid-liquid separation, washing and drying on the product to obtain the titanium phosphate powder.
2. 2. The hydrothermal synthesis method for adjusting and controlling the morphology of titanium phosphate without a template agent according to claim 1, wherein in the step S1, the first acid solution is concentrated sulfuric acid, the temperature of the heating condition is 50-80 ℃, and the reaction time is at least 30 min.
3. 3. The hydrothermal synthesis method for adjusting and controlling the morphology of titanium phosphate without template according to claim 1, wherein after the step S1 is finished and before the step S2 is started, further comprising: and S1.5, adding at least one second acid solution selected from sulfuric acid, citric acid or acetic acid into the titanium source precursor solution, and uniformly mixing.
4. 4. The hydrothermal synthesis method for adjusting and controlling the morphology of titanium phosphate without a template agent according to claim 3, wherein in the step S1.5, the second acid solution is added into the titanium source precursor solution drop by drop, and the stirring time for uniformly mixing after the addition is more than 30 min.
5. 5. The method for hydrothermal synthesis of titanium phosphate morphology without template according to claim 4, wherein in step S1.5, the titanium source precursor solution is transferred to a room temperature environment before the second acid solution is added.
6. 6. The hydrothermal synthesis method for adjusting and controlling the morphology of titanium phosphate without a template according to claim 1, wherein in the step S2, the stirring reaction time is at least 30min.
7. 7. The method according to claim 1, wherein in the step S3, the hydrothermal reaction time is 3-24 h, and the filling volume of the pre-reaction liquid in the closed container is not more than 70%.
8. 8. The method according to claim 1, wherein in the step S4, the washing is performed with water until the pH of the washing solution is >5, the drying temperature is 120-150 ℃, and the drying time is 6-12 h.
9. 9. Titanium phosphate, characterized in that it is obtained by the template-free hydrothermal synthesis method according to any one of claims 1 to 8.
10. 10. The titanium phosphate according to claim 9, wherein the morphology of the titanium phosphate is any one of a sheet-like structure, a granular structure, or a three-dimensional microstructure formed by assembly of sheet-like structures.

Description

Hydrothermal synthesis method for regulating shape of titanium phosphate without template agent Technical Field The invention relates to the technical field of titanium phosphate preparation, in particular to a hydrothermal synthesis method for regulating and controlling the morphology of titanium phosphate without a template agent. Background Titanium phosphate is an important inorganic functional material with a layered structure or an open framework structure, and has been widely focused in recent years because of showing good application potential in the fields of ion storage, proton conduction, heterogeneous catalysis, selective adsorption and the like. Related researches show that the electrochemical performance, mass transfer performance, interfacial reactivity and other macroscopic properties of the titanium phosphate material are greatly dependent on the microstructure characteristics and morphology states of the titanium phosphate material. Therefore, the controllable preparation of the microcosmic appearance of the titanium phosphate material is realized, and is an important precondition for improving the comprehensive performance and expanding the application field. In the prior art, the synthesis method of titanium phosphate mainly comprises a traditional reflux method, a hydrothermal method, a solvothermal method and the like. The traditional reflux method has relatively simple process conditions, but generally has longer reaction period, and the obtained product has lower crystallinity and insufficient phase purity, so that the requirement of high-performance application on a material structure is difficult to meet. In contrast, the hydrothermal method can provide higher temperature and pressure environment in a closed system, is favorable for the full growth and rearrangement of crystals, has obvious advantages in the aspects of shortening the reaction time and improving the crystallinity and the phase purity, and becomes one of important technical routes for preparing the titanium phosphate. In terms of morphology regulation of titanium phosphate, current research has focused on introducing templating agents to guide the directional growth of crystals. Specifically, the template-oriented method generally utilizes the spatial confinement effect or interfacial interaction of a soft template (including a surfactant, a polymer, etc.) or a hard template (porous inorganic material) to induce the growth of titanium phosphate in a specific direction, thereby obtaining specific morphologies such as nano-sheets, nano-rods, microspheres, etc. The method can realize a certain degree of morphology design on the laboratory scale, and is widely adopted in related researches. However, the morphology regulation strategy depending on the template agent still has a plurality of defects in practical application, namely, the hard template method generally involves a plurality of steps such as preparation and removal of the template, the process flow is complex, high-efficiency and low-cost large-scale production is difficult to realize, the organic template agent used in the soft template method is often removed by means of high-temperature calcination and the like after the reaction is finished, and the titanium phosphate material is easy to undergo phase change under the high-temperature condition and is converted into heterogeneous phases such as titanium pyrophosphate (TiP 2O7) which is more stable in thermodynamics, so that the purity of the product phase is reduced, and even the original functional characteristics are lost. In addition, the introduction of the template agent can possibly bring problems of impurity residue, increased environmental burden and the like, so that the industrial application prospect is further limited, although the hydrothermal method has advantages in improving the crystallization quality of the titanium phosphate, the existing research focuses on the influence of hydrothermal conditions on the crystal form or the crystallinity, and the deep research and mature technical scheme still lacks for fully excavating the regulation potential of a hydrothermal system and realizing systematic and controllable synthesis of the morphology of the titanium phosphate under the condition of not depending on the template agent. The prior art does not form a titanium phosphate preparation method which has simple process, definite control variable and can give consideration to shape controllability and scale feasibility. Therefore, developing a technical method which is based on a hydrothermal system, does not need to introduce external template agents and can realize controllable synthesis of the morphology of the titanium phosphate is still a technical problem to be solved in the field. Disclosure of Invention The invention aims to solve the technical problems of complex process, high cost, difficult post-treatment and easiness in introducing a titanium pyrophosphate heterogeneous phase, poor