Ultrafine Titanium Oxide Sol via Liquid Phase Hydrolysis
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Solution Overview
Problem
Conventional methods fail to produce ultrafine particulate titanium oxide with high dispersivity and purity, which is critical for applications in photocatalysts, solar cells, and lithium ion batteries, due to issues like particle agglomeration, impurity presence, and limited specific surface area.
Innovation Solution
A liquid phase method involving the hydrolysis of titanium tetrachloride, where the temperature and mixing time are controlled within specific ranges, followed by cooling and dechlorination, to produce titanium oxide sol with an average primary particle diameter of 3 to 8 nm and high anatase content, resulting in ultrafine particulate titanium oxide with enhanced dispersivity and low impurity levels.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the gas phase method is used to produce titanium oxide, then high crystalinity and excellent dispersivity can be obtained, but particle growth and sintering occur during reaction at high temperature, reducing specific surface area
Solution Approach 1:
The invention uses liquid phase hydrolysis instead of gas phase reaction, transitioning from high-temperature gas phase process to controlled liquid phase process. This allows titanium oxide to form at lower temperatures, preventing particle growth and sintering while maintaining high crystalinity and dispersivity, thus preserving specific surface area
Solution Approach 2:
The invention changes the temperature parameter from high temperature (>500°C) in gas phase method to lower temperature (0-100°C) in liquid phase method. This parameter change prevents particle growth and sintering, maintaining both high dispersivity and high specific surface area simultaneously
2Temperature
If conventional liquid phase method is used, then lower temperature processing is achieved, but particle agglomeration occurs, reducing dispersivity
Solution Approach 1:
The invention adds a dechlorination step before drying to remove hydrochloric acid that causes agglomeration. By performing this preliminary action, the titanium oxide particles remain dispersed during subsequent drying and heating processes, preventing agglomeration and maintaining high dispersivity
Solution Approach 2:
The invention converts the harmful effect of hydrochloric acid (causing agglomeration) into a beneficial process by using dechlorination to remove it. The controlled removal of HCl prevents particle agglomeration, transforming a potential problem into a solution that maintains particle dispersivity
3Ease of manufacture
If titanium oxide with low dispersivity is used, then no additional treatment is needed, but excessive energy is required for crushing aggregates and deflocculation processes are needed
Solution Approach 1:
The invention performs preliminary dispersing during the sol formation process itself, creating well-dispersed titanium oxide particles before drying. This preliminary action eliminates the need for subsequent energy-intensive crushing and deflocculation processes, reducing overall energy consumption while maintaining processing simplicity
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The method achieves ultrafine particulate titanium oxide with higher specific surface area and excellent dispersivity, suitable for photocatalysts, solar cells, and lithium ion battery electrodes without the need for additional pulverizing treatments or dispersing agents, improving their performance and industrial value.
Implementation Method 1
a method for producing titanium oxide sol by the hydrolysis of titanium tetrachloride in the liquid phase method
Implementation Method 2
cooling it to less than 60°C within 15 minutes after the mixing is completed
Data Source
AI summary
The present invention relates to a method for producing titanium oxide sol, comprising mixing an aqueous titanium tetrachloride solution into water at a temperature of 80°C or higher within 60 seconds while maintaining the mixed solution at the temperature and cooling it to less than 60°C within 15 minutes after the mixing is completed in a method for producing titanium oxide sol by the hydrolysis of titanium tetrachloride in the liquid phase method; the highly-dispersive ultrafine particulate titanium oxide sol obtained by the method, wherein an average primal particle diameter (DBET) calculated from the BET specific surface area is 3 to 8 nm, the cumulative 50% volume particle diameter (D50DLS) measured by the dynamic light scattering method and DBET have the relationship represented by D50DLS = k x DBET (k in the formula is a value of 1 or more and less than 5) and the anatase content is 70% or more; the ultrafine particulate titanium oxide obtained by drying the titanium oxide sol; and the production method and use thereof. The ultrafine particulate titanium oxide according to the present invention is suitable for use in the photocatalyst, solar cell, dielectric material, material for the electrode of lithium ion batteries, and the like without requiring specific pulverizing treatment or dispersing agent and has a great value industrially.