Polymer membranes are prime candidates for separation and purification processes, with their functionality enhanced by nanoparticle incorporation and diverse polymer structures. Poly(ionic liquids) (PILs), highly charged electrolyte-like polymers, are gaining interest as membrane polymer matrices. Embedding photocatalytic nanoparticles enables water purification through filtration and degradation reactions. Graphitic carbon nitride (g-CN), a metal-free semiconductor with visible-light activity, offers a promising approach for photoredox-based environmental remediation, though its powder form poses separation challenges. This work presents g-CN embedded PIL nanocomposite membranes fabricated via UV curing, characterized by structural, filtration, and surface properties. Photocatalytic performance and reusability under visible light are evaluated using methylene blue (model dye) and sulfadiazine (model antibiotic) under static conditions. A continuous filtration module with integrated light is developed to assess simultaneous filtration, degradation, and antifouling properties, demonstrating the membranes’ potential for advanced water treatment.