Two different silica conformations (Xerogels and Nanoparticles) both formed by the mediation of dendritic poly (ethylene imine) were tested at low pHs on the problematic uranyl cation sorption. The effect of crucial factors i.e., temperature, electrostatic forces, adsorbent composition, accessibility of the pollutant to the dendritic cavities and MW of the organic matrix was investigated to conclude the optimum formulation for water purification under these conditions. This was attained with the aid of UV-Visible and FTIR spectroscopy, dynamic light scattering (DLS), ζ-potential; Brunauer–Emmett–Teller (BET) porosimetry, Thermo Gravimetric Analysis (TG) and Scanning Electron Microscopy (SEM) Results highlighted that both adsorbents have extraordinary sorp-tion capacity. Xerogels are cost-effective since they approximate the performance of na-noparticles with much lesser organic content. Furthermore, they are more practicable materials since they may penetrate the pores of a metal or ceramic solid substrate in the form of a precursor, gel-forming solution.