Enhanced visible-light photocatalytic activity in K0.81Ti1.73Li0.27O4/TiO2-xNy sandwich-like composite

A lepidocrocite-type tianate, K0.8Ti1.73Li0.27O4, was coupled with TiO2-xNy by a hydrothermal method in order to give the visible-light responsiveness. After treating K0.8Ti1.73Li0.27O4 in a HCl aqueous solution to peel off and/or split the titanate plates, nano-sized nitrogen doped titania particles were added to form a sandwich-like bridging structure possessing high specific surface area and porosity. The prepared K0.8Ti1.73Li0.27O4/TiO2-xNy sandwich-like composite showed excellent photocatalytic activity for the decomposition of NOx gas under both visible-light and UV light irradiation (lambda > 510, 400, 290 nm), being superior to that of TiO2-xNy or commercial TiO2 (AEROXIDE (R) TiO2 P 25) powders. (C) 2009 Elsevier B.V. All rights reserved.