Does water in synthesized TiO2 have an effect on the photocatalytic activity? Towards a spectacular response

摘要

The influence of hydroxyl radicals on the photocatalytic performance of synthesized TiO2 resulting from the addition of water was studied. Two TiO2 samples were prepared using the sol-gel method followed by calcination at 600 degrees C. The aim of this work was to study the effect of water on the photocatalytic activity of a model compound formic acid (FA) by comparing between the titanium oxide synthesized with water (TiO2-600-w) and without water (TiO2-600). The TiO2-600-w, consisting of anatase and a little rutile, was the most active catalyst, whereas pure anatase (in case of TiO2-600), showed low photocatalytic efficiency. In this study, we confirmed that the filling of the TiO2 surface by hydroxyl radicals could produce better photocatalytic activity by reducing e(-)/h(+) recombination. It is notable, however, that with TiO2-600-w, the degradation rate (found under UV) was about 4-5 times greater than that obtained with TiO2-600. This result suggests that the presence of water was very important in the synthesis of TiO2 and brought a dramatic gain in the photocatalytic response as well. (C) 2017 Elsevier B.V. All rights reserved.