Low-temperature hydrothermal synthesis of N-doped TiO2 from small-molecule amine systems and their photocatalytic activity.

Nitrogen-doped TiO2 nanopowders have been successfully synthesized by a one-step hydrothennal route under soft-chemistry conditions (150 degrees, 8 h) without high-temperature calcination using seven different types of nitrogen dopants: methylamine, ethylamine, diethylamine, ethylenediamine, triethylamine, triethanolamine and ammonia. X-ray diffraction, transmission electron microscopy, ultraviolet-visible spectroscopy, X-ray photoelectron spectroscopy, N2 adsorption-desorption isothenns and Fourier transform infrared spectroscopy were used to analyse the as-synthesized TiO2 powders. The results indicated that nitrogen was doped effectively and the structure and morphology of the titania samples were strongly influenced by the nitrogen sources.

Removal of anionic azo dye from aqueous solution via an adsorption-photosensitized regeneration process on a TiO2 surface.

Textile dye effluents are typically characterized by strong color and recalcitrance, even at very low concentration. The process of enrichment of anionic azo dye on the surface of TiO(2) fibers followed by photosensitization degradation under ambient air conditions was extensively investigated. Adsorption isotherms and zeta potentials were used to describe the "dye/TiO(2) surface" interface, taking into account the effects of pH on the nature and population of the surface groups on the TiO(2) fibers.