Carbon nanodot doped in polymer film: Plasmophore enhancement, catalytic amination and white-light generation

A broader application of carbon nanodot (CD) gets limited due to its feeble emissivity at the red end of the emission spectrum. In this work, we have adopted two-pronged strategies to augment the photoluminescence properties of CD. First, the polymer has been used to avoid aggregation-caused quenching (ACQ). And the further augmentation of the photoluminescence properties of CD by the surface plasmon of silver nanoparticle (Ag-NP). This has been demonstarted by stepwise emission enhancement of emitters present in CD covering the entire visible spectrum. Polymer composite films have been prepared at varying concentrations of Ag-NP for direct observation of metallic nanoparticle-enhanced photoluminescence (MNEP). Such observation has been attributed to the strong bonding interactions of thiol-groups and other functional groups present at the surface of carbon nanodot with the silver nanoparticles. Unprecedentedly, Ag-NP augments nearly 25% of the emission intensity of CD. Interestingly, nanodot is found to exhibit Ag-NP concentration-dependent switching of photoluminescence in composite films and aqueous solutions as well. We show here CD-doped polymer film has the potential to generate white light through LED-down conversion and can effectively catalyze the reductive amination of resazurin and 2,4-dinitrophenol in real-time with relatively high reaction rates.