A facile preparation of TiO2/ACF with C-Ti bond and abundant hydroxyls and its enhanced photocatalytic activity for formaldehyde removal

The quantum yields and efficiency(ACF) was prepared via a modified deposition-precipitation method to facilitate its photon absorption and of photogenerated charge carriers have been the major issues for photocatalysis on titania catalyst. The TiO2/ACF catalyst with anatase TiO2 uniformly dispersed on activated carbon fibers electron transfer, thus improve the quantum yields and efficiency of the photogenerated electrons and holes. XPS analysis on the catalyst demonstrates the existence of Ti3+ and Ti2+ species, C-Ti bond and abundant hydroxyls, which are also proved by UV-vis DRS and TG-DSC analysis. It is believed that the acid environment in preparation plays an essential role in the formation of C-Ti bond and surface hydroxyls, which can be tuned by changing hydrothermal synthesis time. The C-Ti bond can improve the electron transfer in the catalyst and the substantial surface hydroxyls lead to high absorption for UV lines and enhanced adsorption of water and formaldehyde, resulting in more active OH free radicals and the outstanding photocatalytic activity of TiO2/ACF, which is much higher than the titania powder for photocatalytic removal of low concentration formaldehyde. The essential role of surface hydroxyls for photocatalytic activity was confirmed surpassing that of chemical bond between carbon and titanium in TiO2-carbon composite for the first time. (C) 2017 Elsevier B.V. All rights reserved.