Preparation of multi-element doped porous carbon by microwave cross-linking stabilization of disposable surgical masks and its electrochemical properties as sulfur loading

ABSTRACT

Numerous disposable surgical masks (DSMs) were consumed with the development of COVID-19 epidemic. Non-solid products recovered by pyrolysis is more than twenty species with low added value. Therefore, the search for a reasonable carbonization method can not only alleviate the pressure of global plastic pollution, but also produce considerable economic value. Here it is found that microwave cross-linking can promote the substitution of hydrogen atom in the polymer master chain of DSMs by hydrogen atom, which can reorganize the easily cracked DSMs into sp2-hybridized aromatic carbon, it can maintain 51.2% carbon yield at 1000℃. The difference between the DSMs-based porous carbon obtained by in-situ and post-processing N doping was further compared, and it was found that the specific surface area of the activated in-situ doped sample (P-SNO@DSMs) was as high as 2278 m2·g-1, which had rich hierarchical pore structure and high heteroatoms doping rate. Benefiting from the synergistic effect of heteroatoms and hierarchical holes, P-SNO@DSMs sulfur cathode delivers a high specific capacity of 1550 mAh·g-1 at 0.1C and exhibits excellent long-term cycling performance with the smaller capacity decay of 0.13% per cycle after 400 cycles. In this work, clean and efficient microwave cross-linking not only realized the efficient recovery of waste DSMs, but also the application of the prepared materials can be broadened by adding additional heteroatomic sources in the process of microwave cross-linking.