Three types of TiO‐compound‐based nanobelts (Na2Ti3O7, H2Ti3O7, TiO2) are prepared from commercial TiO2 powders via an alkaline hydrothermal process. Nanostructured sheets based on the as‐synthesized nanobelts are prepared using a paper‐making process. The nanobelts are connected with hydrogen bonds or/and bridge oxygen atoms and packed together, forming a paperlike porous network structure, with an average pore size of ∼500 nm. The electrical properties and gas sensing of the nanostructured sheets are demonstrated to display sensitivity down to sub‐ppb levels. H2Ti3O7 nanobelts decorated with Ag nanoparticles have also been applied as an antibacterial agent.

Defect-induced ferromagnetism in nanoparticles has recently attracted extensive attention. We report here that (111) twinned BaTiO3 crystallites synthesized through a modified hydrothermal method can exhibit ferromagnetic properties. The unexpected ferromagnetism is verified to originate from the point defects. We also find that UV irradiation can significantly enhance the ferromagnetism through creating more lattice defects. The photochromic effect is also observed and discussed.

No abstract

We report here the selective formation of nanosized cavities on barium titanate (BaTiO 3 ) nanocubes through a simple acid etching route in hydrothermal environment. Microstructural analysis reveals that the etching process is size dependent with small cavity preferentially formed on the nanocubes greater than a characteristic length of ∼60 nm. A dislocation assisted etching mechanism is proposed to account for the experimental observations and discussed on the basis of the classical dislocation theory. This simple method could be extended to other perovskites for fabricating novel and complex ferroelectric nanostructures.

TiO2 nanobelts, with typical widths of 50 to 200 nm, thicknesses of 20-50 nm, supported noble metals (Ag, Au) are prepared by the photocatalytic reduction method. The as-made samples were characterized by Transmission electron microscopy (TEM), Field-emission scanning electron microscopy (SEM), X-ray diffraction (XRD), X-ray Photoelectron Spectroscopy (XPS) and energy-dispersive X-ray spectroscopy (EDS). The results show that silver particles, with the grain size of about 10 nm, deposited on the surface of nanobelts are uniform. And the grain size of Au on the surface of nanobelts is about 30 nm. In this method, the as-made TiO2 nanobelt is not only used as support, but also as photocatalyst to reduce the noble metal ions.