Kysil D. Photoluminescent and structural properties of pyrolytic carbon nanoprecipitates dispersed in fumed silica

It was demonstrated that nanodispersed fumed SiO2 powder can be used as a highly dispersed solid-state matrix for the pyrolytic synthesis of carbon nanoscale luminescent precipitates with a tunable emission spectrum (from the near UV to the visible spectral region). It was found that chemo-thermal treatment of a highly dispersed fumed SiO2 powder using phenyltrimethoxysilane as a carbon precursor leads to the formation of carbon nanoprecipitates (nanodots) dispersed in the aforementioned powder and the appearance of emission bands in the UV and visible spectral regions. It was suggested that during thermal annealing the reconstruction of organosilicon compounds attached to the surface of SiO2 particles occurs, which can be considered as a combination of (1) the formation of polycyclic molecular-like carbon clusters and (2) carbon aggregation into an amorphous structure. It was assumed that radiation of SiO2:C composites in the UV and visible spectral regions is associated with polycyclic carbon molecules/clusters, their excimers and aggregates. The practical potential of the new nanocomposite material as a phosphor for artificial white light sources, as well as for the synthesis of luminescent nanolabels that can be used to visualize biological objects at the subcellular level, was demonstrated.