Application of Glass Fiber-Based N-Doped Titania under Visible-Light Exposure for Photocatalytic Degradation of Aromatic Pollutants

Abstract

Flexible glass fiber-supported nitrogen-doped titanium dioxide (GF-N-TiO2) photocatalysts with different N/Ti ratio were prepared using a dip-coating method followed by a low-temperature heat-treatment process. In addition, their photocatalytic activities were evaluated for the degradation of aromatic volatile organic compounds (VOCs) under visible-light irradiation. The prepared GF-N-TiO2 photocatalysts were characterized using scanning electron microscopy, energy-dispersive X-ray spectroscopy, X-ray diffraction spectroscopy, and UV-visible spectroscopy. A control photolysis test performed using an uncoated GF displayed no detectable degradation of the target compounds under visible-light irradiation. The outlet-to-inlet concentration ratios of the target pollutants obtained using the GF-N-TiO2 photocatalysts were lower than that obtained using the GF-TiO2 photocatalyst. The photocatalytic activity of GF-N-TiO2 photocatalyst increased as the N-to-Ti ratio increased from 0.06 to 0.08 but decreased gradually as the N-to-Ti ratio increased further to 0.12, suggesting the existence of optimal N/Ti ratios. The outlet-to-inlet concentration ratio of all the target compounds displayed an increasing trend as both air flow rate and inlet concentration increased. Overall, the GF-N-TiO2 photocatalysts could be applied effectively for the degradation of aromatic VOCs under visible-light irradiation when operation conditions are optimized.