Mechanism insights for formation of graphene quantum dots from Styrofoam waste and its application as security ink

Abstract

Plastic pollution free environment is the utmost demand of the present day, which arises due to the urgent need of transforming plastic waste into valued materials suitable for wide range of applications. In this context, a single step synthesis of graphene quantum dots (GQDs) from plastic waste might be a promising approach for bulk conversion of plastic waste into value-added high-end products. The acid/base free, cost-effective, rapid synthesis of GQDs has the potential to meet the future demands. More importantly, a crucial aspect lies in comprehending the underlying mechanism for the formation of such nanomaterials which can open new paths for optimization and functionalization, ultimately facilitating the synthesis of cutting edge materials. This study presents an investigation into the synthesis mechanism of GQDs from Styrofoam waste using the microwave pyrolysis method. The research approach combines experimental technique with simulation studies to elucidate the process. The simulation methodology demonstrated the conversion of Styrofoam into a mix of saturated and unsaturated cyclic structures. These structures subsequently interacted to form intermediate species featuring two or more units bonded together. The intermediate species then gave rise to larger graphene like structure which ultimately led to the formation of GQDs. The GQDs synthesized in this study were subsequently transformed into a printable ink formulation in order to evaluate its potential as a practical solution for addressing the concerns associated with counterfeit currencies, fake documents, and tampered or manipulated goods. The synthesis of GQDs based printable ink from nonbiodegradable plastic waste serves the dual benefit of managing plastic waste and its utilization in advanced applications. This approach holds significant promise in providing sustainable solutions for the future.