Assessing the adsorption and photocatalytic activity of TiO2 nanoparticles for the gas phase acetaldehyde: A computational and experimental study

Herein, we report the photocatalytic activity of TiO2 NPs for the photodegradation of gas-phase acetaldehyde. TiO2 NPs with different morphologies were synthesized by using a hydrothermal method, which display distinctive dominant facets, including {001}, {101}, and {010}. The specific surface area values of TiO2 NPs showing different dominant facets, i.e., {001}, {101}, and {010} being measured as 92, 43.45, and 19 m(2)g(-1), respectively. A 100% photodegradation efficiency (PE) could be achieved with TiO2 {001} NPs for 500 ppm acetaldehyde with a flowing rate of 10 sccm, while those of TiO2 NPs with dominant {101} and {010} facets exhibited low PE such as 83% and 62%, respectively. The first principle calculation revealed that acetaldehyde molecule strongly adsorbs (E-ads = 0.606 eV) on TiO2 (001) surface while only weakly interacts with TiO2 (101) and (010) surfaces. We calculated the bandgap values of TiO2 NPs with different exposed facets, i.e., {001}, {101}, and {010} facets as 3.26, 3.23, and 3.21 eV, respectively. As an innovative exploration, this study isolates the photocatalytic activity of TiO2 NPs with unique morphologies and exposed facets, which can be exploited for the development of a potential photocatalyst for the photodegradation of other VOCs. (C) 2019 Elsevier B.V. All rights reserved.