Effect of visible light catalyst Ag6Si2O7–TiO2 with core-shell nanostructure on performance of poly(vinylidene fluoride)-g-poly (ethylene glycol) methyl ether methacrylate/poly(vinylidene fluoride) high flux ultrafiltration membranes

Combining photocatalysts are frequently used to address the issue of poly(vinylidene fluoride) (PVDF) membranes being susceptible to contamination. The main constraints of existing photocatalyst-modified films are the narrow light utilization range and the generally limited enhancement of hydrophilicity and flux of the films modified by a single photocatalyst. Herein, a novel visible light photocatalyst Ag₆Si₂O₇–TiO₂ with a core–shell nanostructure and a large specific surface area was prepared by in situ deposition. The casting solution was supplemented with Ag₆Si₂O₇–TiO₂ and 1.35 g PVDF-g-poly (ethylene glycol) methyl ether methacrylate (PEGMA) prepared by ATRP and then a film through non-solvent-induced phase transformation was prepared. M1 with 0.25 g Ag₆Si₂O₇–TiO₂ has ideal overall performance in filtration of pure water and 20 mg/L SA solution. Its pure water flux, recovery flux, and rejection were found to be 1471 and 1091 L/(m² h), and 88.1%, respectively. Additionally, M1 has the best-increased flux by 20.3% greater under visible light (VIS) irradiation than under shading condition. To measure changes in flux and rejection under three conditions (shading, UV light, and VIS light), M1 was chosen as the representative membrane. There is no significant difference in filtering performance between UV and VIS, nevertheless, both are much better than no light. The photocatalytic degradation impact of M1 on ceftiofur sodium was next examined under UV and VIS circumstances, and the degradation effect of M1 under the two conditions was good and comparable, approximately 70% and 65%, respectively. It indicates that the modified membranes have excellent VIS responsiveness, flux, and anti-pollution performance.

Graphical Abstract