Size and shape effect on the photocatalytic efficiency of TiO2 brookite

Stéphanie Pigeot-Remy (1) , Damia Gregori (2) , Roumayssaa Hazime (2) , Alexandre Hérissan (3) , Chantal Guillard (4) , Corinne Ferronato (5) , Sophie Cassaignon (1) , Christophe Colbeau-Justin (3) , Olivier Durupthy (1)

1 LCMCP - Laboratoire de Chimie de la Matière Condensée de Paris
2 IRCELYON - Institut de recherches sur la catalyse et l'environnement de Lyon
3 LCPO - Laboratoire de Chimie Physique D'Orsay
4 CARE - IRCELYON-Catalytic and Atmospheric Reactivity for the Environment
5 ATARI - IRCELYON-Approches thermodynamiques, analytiques et réactionnelles intégrées

Thanks to aqueous sol-gel chemistry, it is now possible to prepare several phase pure TiO 2 brookite colloidal systems that significantly differ on nanoparticles size and shape. This TiO 2 polymorph is more difficult to be obtained as phase pure material than anatase or rutile. Here we have prepared a set of four different sol–gel brookite syntheses with particles size ranging from 10 to 500 nm and significantly different morphologies as demonstrated by X-ray diffraction, Raman spectroscopy, and transmission electron microscopy. We have studied their photocatalytic activities in aqueous solution on phenol and formic acid. The brookite sample with higher specific surface displays better activity for both pollutants abatement than anatase and rutile reference samples and very close to the TiO 2 P25 commercial reference. Additional experimental characterization of photogenerated charge carriers and their lifetime is performed using time-resolved microwave conductivity. We could then explain why another efficient brookite material is able to compensate a significantly lower specific surface with a higher photon conversion rate. This study involving a broad set of pure phase brookite samples brings back that phase into the TiO 2 polymorphs racefor light-enhanced applications. It confirms that size/shape–activity correlationalready observed for the anatase polymorph is also valid for the brookite phase.

Domains: Catalysis; Environment and Society

Stéphanie Pigeot-Remy, Damia Gregori, Roumayssaa Hazime, Alexandre Hérissan, Chantal Guillard, et al.. Size and shape effect on the photocatalytic efficiency of TiO2 brookite. Journal of Materials Science, 2019, 54 (2), pp.1213-1225. ⟨10.1007/s10853-018-2924-x⟩. ⟨hal-01968937⟩