BiOBr/Ag/AgBr heterojunctions decorated carbon fiber cloth with broad-spectral photoresponse as filter-membrane-shaped photocatalyst for the efficient purification of flowing wastewater.

The development of recyclable photocatalysts with broad-spectral photoresponse has drawn much attention for the practical application in flowing wastewater treatment. Herein, we have reported the construction of BiOBr/Ag/AgBr junctions on carbon fiber cloth (CFC) as broad-spectral-response filter-membrane-shaped photocatalyst that is efficient and easily recyclable. With CFC as the substrate, BiOBr nanosheets (diameter: 0.5-1 μm) were firstly synthesized by a hydrothermal method, and then Ag/AgBr nanoparticles (size: 100-300 nm) were prepared on the surface of CFC/BiOBr by using a chemical bath deposition route. CFC/BiOBr/Ag/AgBr presents superior flexibility and wide UV-Vis-NIR photoabsorption (from 200 to 1000 nm). Under visible light irradiation, CFC/BiOBr/Ag/AgBr (area: 4 × 4 cm2) can remove 99.8% rhodamine B (RhB), 99.0% acid orange 7 (AO7), and 93.0% tetracycline (TC) after 120 min, better than CFC/BiOBr (95.4% RhB, 55.0% AO7 and 91.2% TC). Interestingly, when CFC/BiOBr/Ag/AgBr is served as a filter-membrane in a photoreactor to purify the flowing sewage (RhB, rate: ~1.5 L h-1), the degradation rate of RhB goes up to 90.0% after ten filtering grades. Therefore, CFC/BiOBr/Ag/AgBr has great potential to purify the flowing wastewater as a novel filter-membrane-shaped photocatalyst.