Functionalization of biosourced silica and surface reactions with mercury in aqueous solutions

This study presents the production of pure silica from rice husk and its stepwise functionalization with triethoxysilane (TES) silver nanoparticles. The derived TES-SiO2 (0.97 mmol TES per g SiO2) Ag0@SiO2 (3.70–21.60 mg Ag materials were used for removal Hg2+ aqueous solutions in presence chloride ions. was rapid equilibrium solid phase loading between 21 101 mg/g. more effective than removing mercury due to highly reactive hydride groups. In case samples is proportional amount Ag0. characterized before after allow insights into interaction mechanism. reaction products sample calomel (Hg2Cl2) AgCl. On surface besides these amalgams Ag1.1Hg0.9 possibly Ag2Hg3 identified. These results show that redox reactions silicon-hydride group, Ag0 take place on materials. coexistence amorphous observed first time while formation heterogeneous systems a rare observation. Also, showed extraordinary efficiency terms Hg:Ag molar ratio (2.28–3.02), considerably higher those reported before. Besides beneficial effect Cl- solution there evidence hyperstoichiometric at nanoscale.