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

A lepidocrocite-type tianate, K0.81Ti1.73Li0.27O4, was coupled with TiO2−xNy by a hydrothermal method in order to give the visible-light responsiveness. After treating K0.81Ti1.73Li0.27O4 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 K0.81Ti1.73Li0.27O4/TiO2−xNy sandwich-like composite showed excellent photocatalytic activity for the decomposition of NOx gas under both visible-light and UV light irradiation (λ > 510, 400, 290 nm), being superior to that of TiO2−xNy or commercial TiO2 (AEROXIDE® TiO2 P 25) powders.

A sandwich-like composite was obtained by incorporating TiO2−xNy nanoparticles into the cracks of K0.81Ti1.73Li0.27O4 plate-like particles. The specific surface area together with the porosity were increased, and the photocatalytic activity in deNOx reaction was significantly enhanced especially under irradiation of visible-light with the wavelength λ > 510 nm.Figure optionsDownload as PowerPoint slide