Photoelectrocatalytic degradation of atrazine by boron-fluorine co-doped TiO 2 nanotube arrays

Abstract

Atrazine, one of the most widespread herbicides in the world, is considered as an environmental estrogen and has potential carcinogenicity. In this study, atrazine was degraded on boron-fluorine co-doped TiO₂ nanotube arrays (B, F-TiO₂ NTAs), which had similar morphology with the pristine TiO₂ NTAs. The structure and morphology of TiO₂ nanotube samples were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), and UV-visible diffuse reflectance spectroscopy (DRS). It showed that the decoration of fluorine and boron made both the absorption in the visible region enhanced and the band edge absorption shifted. The efficiency of atrazine degradation by B, F-TiO₂ NTAs through photoelectrocatalysis was investigated by current, solution pH, and electrolyte concentration, respectively. The atrazine removal rate reached 76% through photoelectrocatalytic reaction by B, F-TiO₂ NTAs, which was 46% higher than that under the photocatalysis process. Moreover, the maximum degradation rate was achieved at pH of 6 in 0.01 M of Na₂SO₄ electrolyte solution under a current of 0.02 A and visible light for 2 h in the presence of B, F-TiO₂ NTAs. These results showed that B, F-TiO₂ NTAs exhibit remarkable photoelectrocatalytic activity in degradation of atrazine.