NANOCOMPOSITES BASED ON TIO2-SNO2: INFLUENCE OF ACID-BASED AND STRUCTURAL-ADSORPTION PROPERTIES ON THE PHOTOCATALYTIC ACTIVITY

• Main Authors: Anastasiya S. Kutuzova, Tetiana A. Dontsova, Olga V. Linyucheva
• Format: Article
• Language: English
• Published: Igor Sikorsky Kyiv Polytechnic Institute 2020-03-01
• Series: KPI Science News
• Subjects: nanocomposites tio2-sno2; hydrolytic method; hydrothermal method; acidic-basic sites; photocatalysis
• Online Access: http://scinews.kpi.ua/article/view/198020

Background. TiO2-SnO2 nanocomposites receive a lot of attention due to their efficient application in heterogeneous photocatalysis. Coupling TiO2 with SnO2 contributes to the suppression of charge carriers’ recombination and enhances photocatalytic performance of the material. Although considerable research on TiO2-SnO2 system has been conducted, there is still a great uncertainty about the most efficient ways of its synthesis, effective synthesis conditions and the most appropriate reagents. Objective. The purpose of the paper is comparison of two synthesis methods (hydrolytic and hydrothermal) and different precursors to obtain TiO2-SnO2 composites; assessment of the influence of different factors on the final properties of photocatalysts. Methods. Synthesis of TiO2-SnO2 nanocomposites allowed studying the effect of SnO2 content on acid-base and structural-adsorption properties that eventually determine photocatalytic performance. Photocatalytic decomposition of organic dyes of various types (methylene blue and Congo red) was used to evaluate photoactivity of materials. Results. Both synthesis methods allowed obtaining of TiO2 and TiO2-SnO2 nanocomposites with crystallite size of 3–24 nm. Hydrolytic synthesis using TiCl4 resulted in pure rutile TiO2, while hydrothermal synthesis using TTIP resulted in pure anatase TiO2. Addition of SnO2 enhanced photocatalytic activity of the samples obtained by hydrothermal method – a sample with 1% SnO2 exhibited photocatalytic activity 30% higher than pure TiO2 sample. Conclusions. Samples obtained by hydrothermal method have both acidic and basic Brønsted sites and are universal sorbents and photocatalysts that remove cationic and anionic dyes. Composites obtained by hydrolytic method contain only basic Brønsted sites and are therefore active for cationic dyes. Surface properties of materials play a crucial role that ultimately determines photocatalytic activity of the materials.