Growth of sulfur-doped bismuth oxybromide nanosheets on carbon fiber cloth for photocatalytically purifying antibiotic wastewater.

Bismuth oxybromide (BiOBr) nanomaterials are well-known efficient powder-shaped photocatalyst for degrading antibiotic wastewater, but their practical applications have been limited by unsatisfactory photo-absorption, weak photocatalytic activity and poor recyclability. To address these issues, we demonstrate that the growing of S-doped BiOBr nanosheets on carbon fiber cloth (CFC) can lead to efficient photocatalysis with recyclable features. With carbon fiber cloth as the substrate, S-doped BiOBr (BiOBr-S) nanosheets (diameter: ∼500 nm, thicknesses: ∼5-90 nm) was prepared by solvothermal method with thiourea as dopant. With the increase of thiourea (0-0.2 g) in the precursor solution, BiOBr-S nanosheets exhibit a significant shift in the photo-absorption edge from 420 to 461 nm and decreased thicknesses from 90 to 5 nm, accompanying by the increased proportion of (010) exposed surface. Amony them, CFC/BiOBr-S can degrade various contaminants (such as 98.7 % levofloxacin (LVFX), 95.6 % ciprofloxacin (CIP) and 95.9 % tetracycline (TC)) with most degradation efficiency within 120 min of visible light irradiation, which are 1.6, 1.9 and 1.4 times than that of CFC/BiOBr (61.4 % LVFX, 49.5 % CIP and 67.1 % TC), respectively. Significantly, when CFC/BiOBr-S photocatalytic fabric is combined with a multi-stage flow device to treat the flowing wastewater (10 mg/L LVFX, rate: 1 L/h), 91.0 % LVFX can be degraded after tenth grade. Therefore, this study not only demonstrates the controllable preparation of S-doped BiOBr nanosheets with different thickness on CFC but also highlights the practical applications of fabric-based photocatalysts for purifying the flowing sewage efficiently.