One-step synthesis of N-doped porous wall TiO2 nanotube arrays for efficient removal of dibutyl phthalate under visible light

Abstract

The N-doped porous wall TiO2 nanotube arrays (N@p-TNTAs) was synthesized by one-step anodization method for the first time. The excellent adsorption performance and visible light response of N@p-TNTAs result in significantly superior photocatalytic activity, due to the porous wall nanotube array structure and the successful doping of N element. The photocatalytic activity of catalyst was evaluated by using the refractory organic pollutants dibutyl phthalate (DBP) as target pollutant. >97 % of DBP was degraded after 3 h of irradiation with visible light, and the degradation kinetic constant was nearly 88 and 9 times higher than that of TiO2 nanotube arrays (TNTAs) and TiN, respectively. During the calcination process, due to the N doping, the orbital of N 2p and O 2p were mixed to produce new valence bands, which effectively shortened the bandgap width of N@p-TNTAs to have visible light response. Meanwhile, a part of N escaped in the form of gas, forming the structure of porous wall. In addition, N@p-TNTAs still showed outstanding photocatalytic activity after 6 cycles, which indicated that the structure of material was stable and can be widely used in environmental photocatalysis.