Preparation and Characterization of Various Interstitial N-Doped TiO2 Catalysts from Different Nitrogen Dopants for the Treatment of Polluted Water

Abstract

In this work N-doped TiO₂ nano particle photocatalysts were prepared through a sol-gel procedure using three different types of nitrogen dopants urea, diethanolamine (DEA) and triethylamine (TEN). Multiple techniques (XRD, TEM, SEM, EDX, BET, Raman and UV-Visible absorption) were commanded to characterize the crystal structure of N-doped TiO₂. The catalytic activity of the N-doped TiO₂ under ultraviolet (UV) and visible light irradiation is evidenced by the decomposition of 2-chlorophenol, showing that nitrogen atoms in the N-doped TiO₂ are responsible for the visible light catalytic activity. It is suggested that doped nitrogen here is located at the interstitial site of TiO₂ lattice. Amongst investigated nitrogen precursors diethanolamine provided the highest visible light absorption ability of interstitial N-doped TiO2 with the smallest energy band gap and the smallest anatase crystal size, resulting in the highest efficiency in 2-cholorophenol degradation. The photocatalytic activity and 2-CP mineralization ability of all N-doped TiO₂ can be arranged in the following order:  TiO₂/DEA > TiO₂/TEN > TiO₂/UREA > un-doped TiO₂.

Keywords: 2-chlorophenol, Photocatalytic degradation, N-doped TiO₂, Different Nitrogen Dopants, urea, diethanolamine (DEA), triethylamine (TEN) and Catalytic Activity.