After liquid exfoliation or direct synthesis, the 2D NMs are incorporated into the membrane polymer matrix, and the thermodynamic instability of introducing NMs onto the membrane dope solution is hypothesized to move the NMs to the surface of the membrane and of the pores during phase inversion. In this study, PSf/SPEEK composite membranes are modified with phosphorene or with h-BN to introduce photocatalytic functionality to the membranes. The SPEEK component contributes ion-exchange properties and enhances hydrophilicity, while the PSf provides the necessary mechanical strength for membrane stability. The strategic incorporation of the 2D NMs is proposed to result in multifunctional membrane systems that not only selectively remove contaminants but also degrade them. The synthesized multifunctional membranes undergo comprehensive surface and structural characterizations, including evaluations of mechanical and chemical stability, to ensure their suitability for water treatment applications. The performance of these membranes for PFAS removal under varying conditions can alter membrane behavior and PFAS rejection. Moreover, the interaction between PFAS molecules and membrane surfaces can be influenced by electrostatic repulsion, size exclusion, and adsorption, all of which can vary depending on PFAS molecule. This research aims to investigate how the functionalization of PSf/SPEEK membranes with 2D NMs can influence the effectiveness of the membranes and guide the optimization of membrane properties to address the urgent issue of water pollution.