Green and size-controllable synthesis of photoluminescent carbon nanoparticles from waste plastic bags

Abstract

We have developed a facile approach for green and size-controllable synthesis of photoluminescent carbon nanoparticles (CNPs) by hydrothermal treatment of various waste plastic bags (WPBs) in low-concentration H₂O₂ solutions (≤5.0 wt%). This approach requires no toxic regents, severe synthetic conditions, or complicated procedures. Fine control over the particle size of the CNPs is achieved by simply changing the H₂O₂ concentration, and higher H₂O₂ concentration leads to smaller particle size of the CNPs. An interesting formation mechanism of the CNPs derived from WPBs has been proposed including thermo-oxidative degradation, polymerization, carbonization, and passivation. It is found that the CNPs can selectively quantify the concentration of Fe³⁺ from 10 to 400 μM with a detection limit as low as 2.8 μM. Moreover, the strong photoluminescence, excellent optical stability, low cytotoxicity, and good water-dispersibility of the CNPs make them suitable candidates for cellular imaging. The simple method developed here presents a new way for effective reuse of WPBs and realizes the encouraging “waste-to-treasure” conversion.