Titanate@TiO2 core–shell nanobelts with an enhanced photocatalytic activity

Abstract

Composite titanate@TiO₂ nanobelts with a core–shell heterostructure were prepared and applied for the photocatalytic degradation of benzoic acid (BA) under UV light irradiation. The composite materials prepared using layered titanate with or without the presence of cetyl trimethylammonium bromide (CTAB) were characterized by X-ray diffraction, physical adsorption–desorption of nitrogen, and scanning/transmission electron microscope techniques. Results showed that pre-treatment of layered titanate with CTAB effectively promoted the disassembly of layered K₂Ti₄O₉ to exfoliate into platelets and the deposition of anatase nanoparticles on both sides of the platelets, leading to maximized interfacial contacts between the two components. In addition, the dense aggregation of TiO₂ nanoparticles in the shell, the interparticle interaction between K₂Ti₄O₉ and TiO₂ and the anisotropically shaped structure of K₂Ti₄O₉ cumulatively improved the spatial dissociation and migration of electron–hole pairs, resulting in a retarded electron–hole recombination and an enhanced photocatalytic performance. The composite photocatalysts were stable and could be repeatedly used for the removal of BA from water.