Mechanically strong and highly luminescent macroporous monolith by crosslinking of carbon nanodots

Abstract

Highly luminescent carbon dots with a fluorescence quantum yield of up to 45% were synthesized by the one step pyrolysis of anhydrous citric acid in diamino-silane. Thanks to surface methoxysilyl groups, the carbon dots are easily polymerized to three dimensional networks in the presence of trace water and under the catalysis of surface secondary amine groups. A remarkable enhancement in mechanical strength is observed after further reaction of the secondary amine with tri-isocyanate or copolymerization with silane. The size of the network mesh of the reinforced carbon dots monolith is around 1.2 μm, with the variation possibility through controlling the gelation step. Due to the advantages of strong luminescence, low cost, thermal stability and macroporous properties, the resulting monolith is expected to hold great technological promise for wide applications.