Conversion of discarded industrial PPS non-woven fabric into heteroatoms co-doped honeycomb-like hierarchical porous carbon for superior performance supercapacitor

To achieve carbon peaking and carbon neutrality, it is important to develop a circular economy. Among them, the pollution control of solid waste is a key direction. Herein, an environmentally-friendly method has been proposed to convert the discarded industrial polyphenylene sulfide (PPS) non-woven fabric fiber into value-added hierarchical porous carbon (HPC) for superior performance supercapacitor. Pre-treatment by oxidation and nitrification, combined with activation process and carbonization, the well-organized honeycomb-like carbon material ONS-HPC-0.5 is obtained with the ultrahigh specific surface area (3112.2 m2 g−1), abundant heteroatoms oxygen (10.85 atom%), nitrogen (4.93 atom%) and sulfur (5.33 atom%) codoped and hierarchical porous structure. Owing to the structure advantages, the ONS-HPC-0.5 electrode delivers high specific capacitance of 301 F g−1 at 0.5 A g−1, superior rate characteristic and electrochemical stability in alkaline electrolyte. Notably, the assembled ONS-HPC-0.5//ONS-HPC-0.5 symmetric supercapacitor achieves the remarkable energy density of 21.87 Wh kg−1 with power density of 450 W kg−1, which not only demonstrates this material promising application in supercapacitor industry, but also opens up a new circular economy model for the recycling of industrial solid waste.