Poly(m-phenylene isophthalamide) (PMIA) membranes as a support for WO3/g-C3N4 for the degradation of diclofenac in water

Abstract

One of the obstacles hampering large-scale semiconductor photocatalysis is the requirement for the recovery and reuse of photocatalytic nanoparticles. Polymeric membranes are viable and practical support materials for photocatalytic nanoparticles to result in multifunctional photocatalytic membranes. PMIA membranes were applied as support for photocatalytic WO3/g-C3N4 nanoparticles and evaluated for the photodegradation of diclofenac (DFC). The PMIA photocatalytic membranes were prepared using the conventional phase inversion method in which the photocatalyst was embedded into the membranes. SEM, XRD, XPS, and FTIR analysis confirmed the incorporation of WO3/g-C3N4 into PMIA membranes. The contact angle of the PMIA/WGC membranes was reduced from 56.3° for the pure PMIA membrane to 37.5°, and porosity was increased from 74.7 up to 85.3%. The photocatalytic membranes were irradiated in the visible light region. M5, which contains 2% of WO3/g-C3N4 in the PMIA membrane, presented the highest degradation of DFC (85%) after 150 min compared to the other membranes. The degradation performance of DFC using PMIA/WGC was mainly driven by hydroxyl radicals and singlet oxygen. The photodegradation performance within 10 cycles had a difference of less than 5%, indicating the stability of membranes. The PMIA membranes are viable photocatalyst support materials with potential dual functionality in water treatment.