Effect of physical chemistry parameters in photocatalytic properties of TiO2 nanocrystals

We used a new synthesis of TiO2 anatase 6 nm nanocrystals prepared at room temperature (Hegazy and Prouzet, 2012 [10]) to explore the influence of different physical-chemical parameters on photocatalysis, and bench-tested the material against two commercial powders made of either pure anatase (Sigma (TM)), or composite anatase-rutile particles (P25 Degussa (TM)). The initial as-synthesised material demonstrates a low photocatalytic activity, which is greatly improved after thermal activation as a result of improved crystallinity without any drastic change in crystal size. The influence of several other parameters was studied, the resulting tests being compared with commercial products. The cumulative improvement provided by these different parameters led finally to a material that exhibits a higher photocatalysis compared to commercial anatase, and similar to the commercial material usually used for reference (P25). This study, which can apply to other titania materials, illustrates how the post-treatment and process adaptation can help to optimise an initial material. (C) 2013 Academie des sciences. Published by Elsevier Masson SAS. All rights reserved.