TiO2/BiOI p-n junction-decorated carbon fibers as weavable photocatalyst with UV-vis photoresponsive for efficiently degrading various pollutants

Abstract Fabricating p-n junctions is an effective strategy to broaden the photoabsorption range and promote electron-hole separation of semiconductor photocatalysts. However, most of the p-n junctions are powder-shaped. Herein, TiO2/BiOI as the model of the p-n junction was applied to be fixed on carbon fiber (CF) to fabricate weavable CF/TiO2/BiOI bundles, which shows strong and broad-spectrum photoabsorption in 200-800 nm. Besides, these bundles were further weaved into cloth (0.1 g, 4×4 cm2), which exhibits superior adsorption and photodegradation efficiency for various pollutants with visible (Vis) or UV-Vis light irradiation. The obtained CF/TiO2/BiOI cloth can efficiently remove 99.2% methylene blue (MB), 100% rhodamine B (RhB), 100% tetracycline (TC), 97.1% ciprofloxacin (CIP) and 98.9% levofloxacin (LVFX) in 80 min under UV-vis light irradiation, which is higher than that under Vis (91.3% MB, 95.7% RhB, 90.3% TC, 92.7% CIP and 93.8% LVFX) light irradiation. After five cycles, CF/TiO2/BiOI cloth still retains an excellent photocatalytic activity for LVFX degradation (92.1%) under UV-vis irradiation with an easy reusing process. This study provides some insights into the fabrication of reusable macroscopical photocatalysts with high efficiency for environmental purification.