Fig. 3

The relationship between host structure and photoluminescent (PL) behaviour in folic acid-derived carbon nanodot (FF-CND)/host nanocomposites. Plots of relative room temperature phosphorescence (RTP) intensity values (a, b), fluorescence (\(\tau _1^F\)) lifetimes derived from fluorescence lifetime imaging microscopy (FLIM) decay curves (c, d) and phosphorescence (τP) lifetimes derived from video stroboscopy decay curves (e, f) of F-CND-rich carbonates (black square/solid line), sulphates (red circle/dotted line), and oxalates (blue triangle/dashed line) against cation Z (a, c, e) and density (b, d, f) of the host mineral phase. The background colour in a and b represents approximately the steady-state PL (SS-PL) observed from photographs obtained from composites under UV (365 nm) excitation. Values for \(\tau _1^F\) for F-CND aqueous solution and dried F-CND are given on c and d