Study on the Reaction Mechanism of Water Release Process in the Synthesis of TiO_2 Materials

Lan You ； Wei Zou ； Yi Luo

《International Core Journal of Engineering》 9卷5期 (2023/05) Pp. 148-159

https://doi.org/10.6919/ICJE.202305_9(5).0018

摘要

The structure of titanium dioxide (TiO2) is closely related to its properties. The synthesis of TiO2 materials with regular morphology and structure has been the focus of attention in the fields of catalysis, materials and solar energy utilization. However, in the preparation process, because the titanium source is very easy to hydrolyze, the nucleation and generation processes are carried out simultaneously, and it is difficult to obtain TiO2 with regular morphology. In order to obtain TiO2 materials with regular morphology, it is usually necessary to control the content of water in the system or add complexing agents to the system to form stable complexes with titanium. In this paper, a chain reaction is designed to control the hydrolysis rate of titanium source, that is, a reaction with controllable water release rate is introduced to supply water for the hydrolysis of titanium source. TiO2 microspheres with regular morphology and good dispersion were prepared by sol‐gel method, using tetra‐n‐butyl titanate (TBOT) as titanium source, ethylene glycol as complex, acetone and ethylene glycol as ketal reaction under the catalysis of concentrated H2SO4 (98 %) to release water for hydrolysis of tetra‐n‐butyl titanate. Raman, FT‐IR, XPS and MALDI‐TOF‐MS were used to characterize the phase structure of the reaction system of TBOT and ethylene glycol, and GC and GC‐MS were used to characterize the phase structure and water release kinetics of the reaction process of acetone and ethylene glycol ketal; The surface morphology, thermal stability, specific surface area, pore size and photocatalytic performance of the prepared TiO2 microspheres were characterized by SEM, TEM, EDS, TG, UV‐Vis DRS, specific surface area and pore size analysis, and photocatalytic performance characterization. The results showed that the complex was Ti (OCH2CH2O)2, and the reaction of acetone and ethylene glycol ketal produced 2,2‐dimethyl‐1,3‐dioxolane and water, which provided "water source" for the reaction system, and the water release process followed the first‐order kinetic model; The prepared TiO2 microspheres have regular morphology, good dispersibility and thermal stability, large specific surface area, and excellent degradation effect on rhodamine B (RhB).

關鍵字

TiO2 ； Water Release Control ； Reaction Mechanism

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