Incorporating Mesoporous Anatase TiO2 Spheres to Conductive Carbon Black Filled PVDF Membrane for Self-Cleaning Photo(electro)catalytic Filtration

Polyvinylidene fluoride (PVDF) membranes have been widely used for micro/ultrafiltration. However, their hydrophobicity leads to serious membrane fouling over time during the process of dye decolorization, which limits their practical application. Herein, PVDF, mesoporous TiO2 spheres (MTS, similar to 460 nm), and carbon black (CB) are strategically hybridized via a polyvinylpyrrolidone (PVP)-assisted phase inversion method. The fabricated PVDF/CB/TiO2 conductive membrane prepared by optimal low-molecular-weight PVP (10 kDa) shows a highly porous structure with macro-voids, and MTS are firmly incorporated into the PVDF/CB membrane matrix with a morphologically intact structure, rendering the ternary and conductive membranes with excellent PEC properties. The decolorization rate of 0.50 mg/L methylene blue (MB) reaches 98.6% under the condition of 1.0 V bias potential and simulated solar light irradiation in a continuous cross-flow filtration process. The center dot O2- and center dot OH radicals and photogenerated holes (h+) are mainly responsible for MB decolorization in the PEC system. Our work provided a sustainable and efficient method for dye decolorization by combining the PEC system and membrane technology.