Synthesis and photocatalytic activity of N-doped Bi x Ti 1-x O 2 photocatalysts under energy saving lamp illumination

Abstract

This study presents a synthesis of N-doped Bi_xTi_1-xO₂ photocatalysts using a sol-gel method. To obtain the optimum doping of N and Bi and operational conditions for photocatalytic oxidation of formaldehyde, several key elements, including nitrogen and bismuth doping, initial concentration of formaldehyde, amount of photocatalysts among others were investigated under energy saving lamp illumination. The properties of the N-doped Bi_xTi_1-xO₂ photocatalysts were characterized by X-ray diffraction (XRD), Brunauer–Emmett–Teller (BET), scanning electron microscope (SEM), transmission electron microscope (TEM) and UV–visible reflectance diffuse spectroscopy. Experimental results show that an appropriate amount of N and Bi doping incorporated into the TiO₂ had produced an increase in photocatalytic activities. The Bi_xTi_1-xO₂–N(Y) photocatalysts with Bi/(Bi + Ti) and N/Ti molar ratio of 0.15 and 0.2, respectively, showed the highest photocatalytic activity. The highest activity was shown at 92% efficiencies for energy with 24-h continuous lighting of energy saving lamp illumination.