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