Construction of TiO₂/Ag₃PO₄ nanojunctions on carbon fiber cloth for photocatalytically removing various organic pollutants in static or flowing wastewater

Plenty of power-shaped semiconductor nanomaterials have been used to photocatalytically degrade various pollutant wastewater in beakers, but they are difficult to be applied in the practical wastewater that is flowing in river or pipeline. Thus, the key to photocatalytically degrading the flowing wastewater is to develop flexible large-scale filter-membrane with high photocatalytic activity. To address the issue, with carbon fiber cloth (CFC) as the porous substrate and TiO₂/Ag₃PO₄ as ultraviolet/visible (UV/Vis) responsed components, we reported the in-situ growth of TiO₂/Ag₃PO₄ nanojunctions on CFC as filter-membrane-shaped photocatalyst. The resulting CFC/TiO₂/Ag₃PO₄ is composed of CFC whose surface is decorated with TiO₂ nanorods (length: 1 ± 0.5 μm, diameter: 150 ± 50 nm) and Ag₃PO₄ nanoparticles (diameter: 20-100 nm). CFC/TiO₂/Ag₃PO₄ displays a broad absorption region with two edges (~410 and ~510 nm), owing to the bandgaps of TiO₂ and Ag₃PO₄. Under Vis or UV-Vis light illumination, CFC/TiO₂/Ag₃PO₄ (4 × 4 cm²) can efficiently degrade more phenol (80.6%/89.4%), tetracycline (TC, 91.7%/94.2%), rhodamine B (RhB, 98.4%/99.5%) and acid orange 7 (AO7, 97.6%/98.3%) in the beaker than CFC/TiO₂ or CFC/Ag₃PO₄. Especially, CFC/TiO₂/Ag₃PO₄ (diameter: ~10 cm) as the filter-membrane was used to construct multiple device for degrading the flowing RhB wastewater. The removal efficiency of RhB increases from 19.6% at the 1st pool to 96.8% at the 8th pool. Therefore, this study brings some insights for purifying organic pollutants in static or flowing wastewater by using filter-membrane-shaped photocatalysts.