Luminescence Mechanism of Carbon-Incorporated Silica Nanoparticles Derived from Rice Husk Biomass

In this work, silica-based luminescent materials containing different contents of carbon were synthesized from rice husk biomass. The intrinsic structure, chemical composition, as well as photoluminescent features were investigated. The results suggest that two forms of carbon, i.e., carbon that is chemically bonded and nonbonded with silica, exist in the structure of the as-prepared amorphous silica nanoparticles, which are believed to be responsible for the origin and quenching of photoluminescence, respectively. The generation of successive localized energy levels within the band gap of silica by the chemically bonded carbon is believed to be the luminescent mechanism. The insight into the photoluminescence of rice husk derived carbon-incorporated silica nanoparticles in this work would be valuable for researchers to further modify the luminescent features for practical applications.