Effect of nitrogen-doping temperature on the structure and photocatalytic activity of the B,N-doped TiO 2

Abstract

B,N-TiO 2 photocatalysts were synthesized by boron doping firstly and subsequently nitrogen doping in NH 3 at variable temperatures. The effects of the nitrogen doping temperature on the structure and photocatalytic activity of the B,N-codoped TiO 2 were investigated. The as-prepared samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), UV–vis diffuse reflectance spectrum (DRS), electron paramagnetic resonance (EPR) and X-ray photoelectron spectroscopy (XPS). The photocatalytic activity was evaluated with photocatalytic degradation of methyl orange dye (MO) under visible light and UV–visible light irradiation. The results suggested that the boron and nitrogen can be incorporated into the TiO 2 lattice either interstitially or substitutionally or both, while the Ti–O–B–N structure plays a vital role in photocatalytic activity in visible light region. The optimal nitrogen doping temperature is 550 °C. Higher temperature may form many oxygen vacancies and Ti 3+ species, resulting in the decrease of photocatalytic activity in visible light.