Journal of Hazardous Materials, Vol.225, 21-27, 2012
Tantalum (oxy)nitrides nanotube arrays for the degradation of atrazine in vis-Fenton-like process
In order to overcome the limitation of the application of nanoparticles, tantalum (oxy)nitrides nanotube arrays on a Ta foil were synthesized and introduced in vis (visible light)-Fenton-like system to enhance the degradation of atrazine. At first, the anodization of tantalum foil in a mild electrolyte solution containing ethylene glycol and water (v:v = 2:1) plus 0.5 wt.% NH4F produced tantala nanotubes with an average diameter of 30 nm and a length of approximately 1 mu m. Then the nitridation of tantala nanotube arrays resulted in the replacement of N atoms to O atoms to form tantalum (oxy)nitrides (TaON and Ta3N5), as testified by XRD and XPS analyses. The synthesized tantalum (oxy)nitrides nanotubes absorb well in the visible region up to 600 nm. Under visible light, tantalum (oxy)nitrides nanotube arrays were catalytically active for Fe3+ reduction. With tantalum (oxy)nitrides nanotube arrays, the degradation of atrazine and the formation of the intermediates in vis/Fe3+/H2O2 system were significantly accelerated. This was explained by the higher concentration of Fe2+ and thus the faster decomposition of H2O2 with tantalum (oxy)nitrides nanotubes. In addition, tantalum (oxy)nitrides nanotubes exhibited stable performance during atrazine degradation for three runs. The good performance and stability of the tantalum (oxy)nitrides nanotubes film with the convenient separation, suggest that this film is a promising catalyst for vis-Fenton-like degradation. (C) 2012 Elsevier B.V. All rights reserved.
Keywords:Tantalum (oxy)nitrides nanotubes;Fenton-like;Fe3+ reduction;Visible light;Atrazine degradation