Synthesis and Characterization of N and Fe-Doped TiO 2 Nanoparticles for 2,4-Dimethylaniline Mineralization.

The present study aimed to evaluate the feasibility of developing low-cost N- and Fe-doped TiO 2 photocatalysts for investigating the mineralization of 2,4-dimethylaniline (2,4-DMA). With a single anatase phase, the photocatalysts showed high thermal stability with mass losses of less than 2%. The predominant oxidative state is Ti 4+ , but there is presence of Ti 3+ associated with oxygen vacancies. In materials with N, doping was interstitial in the NH 3 /NH 4+ form and for doping with Fe, there was a presence of Fe-Ti bonds (indicating substitutional occupations). With an improved band gap energy from 3.16 eV to 2.82 eV the photoactivity of the photocatalysts was validated with an 18 W UVA lamp (340-415 nm) with a flux of 8.23 × 10 -6 Einstein s -1 . With a size of only 14.45 nm and a surface area of 84.73 m 2 g -1 , the photocatalyst doped with 0.0125% Fe mineralized 92% of the 2,4-DMA in just 180 min. While the 3% N photocatalyst with 12.27 nm had similar performance at only 360 min. Factors such as high surface area, mesoporous structure and improved E bg , and absence of Fe peak in XPS analysis indicate that doping with 0.0125% Fe caused a modification in TiO 2 structure.