Abstract: N-doped nano-TiO₂ loaded on activated carbon fiber (N-TiO₂/ACF) photocatalysts were fabricated by sol-gel-adsorption method. The structure and morphology of the photocatalysts were characterized by XRD, SEM, and UV-Vis diffuse reflectance spectra. The photocatalytic activities of the photocatalysts were evaluated by measuring the degradation of pure silk dyeing wastewater. The results showed that N-doped nano-TiO₂ particles of N-TiO₂/ACF were anatase phase, and the crystallite size of N-doped nano-TiO₂ was about 15.3 nm. The absorption band edge of N-doped nano-TiO₂ exhibited an evident red-shift to 603 nm.

Under metal halide lamp irradiation for 180 min, the degradation rate was 97.2%, when the dosing quantity of N-TiO₂/ACF is 0.77 g/200 mL, and the removal rate of COD was 80.6%, when the dosing quantity was 2.31g/200 mL. N-TiO₂/ACF exhibited high durability for practical applications.

Key words: sol-gel method; N-TiO₂/ACF; visible light photocatalysis; silk dyeing wastewater