A series of Fe-Co nanoparticles were synthesized via sol-gel route at acidic, neutral and basic condition using rice husk as the silica source. The synthesized nanomaterials were designated as Fe-Co3, Fe-Co7 and Fe-Co9 and characterized by Fourier Transform Infrared (FTIR), Transmission Electron Microscope (TEM) and particle size analyzer. The great effect of pH was clearly evidenced from the shifting in the siloxane bond in the FTIR spectrum. TEM investigation confirmed the existence of discrete and almost sphere like nanoparticles. The particle size decreased with an increase in the pH, registering the smallest average particle size at pH 9. In brief, this study promises a fast, rapid and promising method for the conversion of silica rice husk into nanoscale bimetallic materials.

Silica extracted from rice husk was used as a support to synthesize the monometallic Ag, Co and bimetallic Ag-Co nanoparticles. The nanoparticles were prepared via a sol-gel method by adding glucose as the reducing agent. The prepared nanoparticles were designated as Ag-NP, Co-NP and AgCo-NP. The successful incorporation of Ag/Co onto the silica surface were evidenced by TEM, FT-IR and DR/UV-Vis analysis. The TEM analysis showed the presence of small spherical shape nanoparticles with an average mean size of 3.18-3.57 nm. Through DR/UV-Vis analysis, the presence of Ag+ and cobalt in the oxidation state of +2 and +3 were confirmed, while FT-IR verified the presence of M-O and Si-O-M+ bond.