Microrecycling of waste flexible printed circuit boards for in-situ generation of O- and N-doped activated carbon with outstanding supercapacitance performance

摘要

There are significant financial and environmental benefits for solid-waste recycling. However, available recycling technologies for electronic waste (e-waste) are limited, as e-waste has the complex intrinsic property of combined metals and non-metals embedded in the same waste stream. In this research, the selective thermal route of microrecycling was utilised to reform plastic from end-of-life flexible printed circuit boards (FPCB) into activated carbon. By employing a thermal disengagement technique, carbonaceous materials were extracted from the waste FPCBs, where similar to 99.6% pure copper co-product was employed as a catalyst for lowtemperature carbonisation. Further thermal activation produced a distorted carbon structure. This distorted structure had a high surface area attributable to the combination of mesopores (similar to 40%) and micropores (similar to 60%) observed through BET analysis. XPS and TEM-EDS analysis showed that the synthesised activated carbon was functionalised in-situ by O- and N-containing groups through thermo-catalytic carbonisation and activation. The carbon electrode of the synthesised porous activated carbon showed excellent electrochemical performance - with a high specific capacitance of 244 F g(-1) at 5 V s(-1) and an ultra-high stability of similar to 97% after 2000 cycles. The results of this study open up new pathways for the recovery and development of high-performance, green materials from waste FPCBs.