Nanoparticles of MgO were synthesized by Aero gel method. These MgO nanoparticles were then mixed with various polymer solutions (poly(vinyl chloride) (PVC), poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF copolymer), polysulfone (PSU)) and then subjected to electrospinning to produce nanocomposite membranes. The hydrolysis of paraoxon, a never agent stimulant, in presence of these membranes was studied using UV. The order of the reactivity of the membranes are found to be PVC-MgO < PVDF < PSU < PVDF-MgO < PSU-MgO. After selecting PSU as the supportive candidate, relative rates of hydrolysis were compared for nanoparticles or charcoal with nanocomposite membranes. The order is as follows; Charcoal (1) < PSU-Al2O3 (1.5) < PSU-MgO (2.1) < Al2O3 nanoparticles (2.8) < MgO nanoparticles (5.4). The amount of hydrolysis of PSU-MgO composite membrane was 60% less when compared to MgO nanoparticles as such usage. The loading percentage of MgO into nanofiber is 35 %. The fabricated composite membrane (containing 5% MgO) was tested for chemical warfare agent stimulant, paraoxon, and found to be about 2 times more reactive than currently used charcoal.