Design of Multifunctional Titania-Based Photocatalysts by Controlled Redox Reactions
authors Lopes, D; Daniel-da-Silva, AL; Sarabando, AR; Arias-Serrano, BI; Rodriguez-Aguado, E; Rodriguez-Castellon, E; Trindade, T; Frade, JR; Kovalevsky, AV
nationality International
journal MATERIALS
author keywords photocatalysis; TiO2; anatase; silicon carbide; Taguchi plan; redox reaction
keywords METHYLENE-BLUE; SOL-GEL; TIO2 NANOPARTICLES; DEGRADATION; ANATASE; SILICA; RUTILE
abstract his work aims at the preparation of multifunctional titania-based photocatalysts with inherent capabilities for thermal co-activation and stabilisation of anatase polymorph, by designing the phase composition and microstructure of rutile-silicon carbide mixture. The processing involved a conventional solid state route, including partial pre-reduction of rutile by SiC in inert Ar atmosphere, followed by post-oxidation in air. The impacts of processing conditions on the phase composition and photocatalytic activity were evaluated using Taguchi planning. The XRD studies confirmed the presence of rutile/anatase mixtures in the post-oxidised samples. The results emphasise that pre-reduction and post-oxidation temperatures are critical in defining the phase composition, while post-oxidation time is relevant for the photocatalytic performance. Microstructural studies revealed the formation of core-shell particles, which can suppress the photocatalytic activity. The highest apparent reaction rate of the photodegradation of methylene blue was observed for the sample pre-reduced in Ar at 1300 degrees C for 5 h and then calcined in air at 400 degrees C for 25 h. Though its performance was 1.6-times lower than that for the same amount of nanostructured industrial P25 photocatalyst, it was achieved in the material possessing 2-3 times lower surface area and containing 50 mol% of SiO2 and SiC, thus demonstrating excellent prospects for further improvements.
publisher MDPI
year published 2020
volume 13
issue 3
digital object identifier (doi) 10.3390/ma13030758
web of science category Materials Science, Multidisciplinary
subject category Materials Science
unique article identifier WOS:000515503100265

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