Extraction and physical characterization of amorphous silica made from corn cob ash at variable pH conditions via sol gel processing

Herein, we disclose a novel approach for the synthesis of nano-silica using corn cob ash (CCA). Also, we identify that silica is amorphous at pH 7 and crystalline at pH 10 at the critical salt concentration for monovalent NaOH. A zeta potential study was used to characterize the surface charge of nanoparticles. The silica nanoparticles were characterized by SEM-EDS, XRD, FTIR, TEM and XRD confirmed the crystalline nature and TEM images showed spherical silica nanoparticles. Brunauer-Emmett-Teller, cation exchange capacity, and N₂ analyses showed excellent support material for catalysis at pH 7. The CCA-mediated synthesized particles showed excellent stability at pH 7.