Enhanced catalyst dispersion and structural control of Co₃O₄-silica nanocomposites by rapid thermal processing

We synthesized cobalt tetroxide (Co₃O₄) silica nanocomposites based on the conventional tetraethyl orthosilicate (TEOS) monomer and ethoxy polysiloxane (ES40) oligomer by sol-gel chemistry coupled with rapid thermal process (RTP). The physicochemical properties and structural formation of cobalt oxide silica nanocomposites were comprehensive characterized. By using ES40, well-controlled, homogeneous nanoparticle dispersion and size of Co₃O₄ with 5 nm within the silica matrix were achieved leading to fractal-like morphology. The concentration of the Co₃O₄ nanocatalyst was also significantly enhanced by more than 50 folds. Fenton-like HCO₃⁻/H₂O₂ catalytic system using acid orange 7 and nanocomposites was examined for organic degradation. 98% AO7 and naphthalene intermediates degradation efficiency was achieved after 20 min with ES40-derived catalyst, which was three to ten folds faster than that of the TEOS-derived catalyst and the commercial Co₃O₄ catalyst. The combined use of ES40 sol-gel and RTP enabled a simple way to nanomaterial preparation and lowers overall processing time.