Decomposition of 3-chlorophenol on nitrogen modified TiO₂ photocatalysts

• Published in: Journal of hazardous materials 2012-02, Vol.203, p.128-136
• Main Authors: Mozia, Sylwia, Bubacz, Kamila, Janus, Magdalena, Morawski, Antoni W
• Format: Article
• Language: English
• Subjects: Calcination; carbon; Catalysis; chlorides; Chlorophenols - chemistry; Decomposition; Degradation; fluorescent lighting; incandescent lighting; Irradiation; mineralization; nitrogen; Nitrogen - chemistry; Photocatalysis; photocatalyst; Photocatalysts; Photochemistry; temperature; Titanium - chemistry; Titanium dioxide; ultraviolet radiation; Ultraviolet Rays
• ISSN: 0304-3894; 1873-3336
• DOI: 10.1016/j.jhazmat.2011.11.088

Photocatalytic activity of nitrogen modified TiO₂ calcined at temperatures of 100–350°C toward 3-chlorophenol (3-CP) degradation was studied. In the experiments the fluorescent UV lamp and the incandescent lamp emitting mainly Vis light were applied. The degradation efficiency was evaluated on a basis of changes of 3-CP, total organic carbon and Cl⁻ concentration. A significant improvement of the photoactivity of the N-modified photocatalysts compared to the reference sample was observed. The rate of 3-CP degradation increased with the calcination temperature, and the highest efficiency was achieved for TiO₂ annealed at 350°C. After 5h of UV irradiation in the presence of TiO₂/N-350 and reference TiO₂ the 3-CP concentration decreased for 77% and 36%, respectively. The 3-CP removal after 24h of Vis irradiation was 30% and 12% for the N-modified and reference samples, respectively. The 3-CP decomposition and mineralization were greatly influenced by pH of the solution, achieving the highest rate at pH 7 for the modified photocatalysts. An increase of the calcination temperature resulted in an increase of the rate of OH formation. The photocatalytic activity of the N-modified TiO₂ remained unchanged during repeated photocatalytic degradation cycles.