Multiband light emission and nanoscale chemical analyses of carbonized fumed silica

Fumed silica with a specific area of 295 m2/g was carbonized by successive phenyltrimethoxysilane treatments followed by annealing in inert atmosphere up to 650 °C. Emission, excitation, kinetics, and photo-induced bleaching effects were investigated by steady state and time-resolved photoluminescence spectroscopies. The local chemistry was also studied by infrared transmission spectroscopy. Strong ultraviolet and visible photoluminescence was observed in the samples after the chemical treatments/modifications and thermal annealing. It has been shown that ultraviolet photoluminescence in chemically modified fumed silica is associated with phenyl groups, while near ultraviolet and visible em…