Polymer Dehalogenation-Enabled Fast Fabrication of N,S-Codoped Carbon Materials for Superior Supercapacitor and Deionization Applications - Carbon4Energy

Doping carbon materials (DCM) with multiple heteroatoms hold broad interests in electrochemical catalysis and energy storage but require several steps to fabricate, which hinder their practical applications. In this study, a facile strategy was developed to fabricate multiple DCM via room-temperature dehalogenation of polyvinyl dichloride (PVDC) with the presence of dehalogenation agent KOH and different doping sources. N, S-codoped carbon materials (NS-DCM) were demonstratively obtained using two heteroatom doping sources (dimethylformamide for N doping and dimethylsulfoxide for S doping). Afterwards, the precursive room-temperature NS-DCM with intentionally overdosed KOH were submitted to inert annealing in order to obtain large specific surface area and high conductivity for electrochemical applications. Remarkably, NS-DCM annealed at 600 °C (600-NS-DCM), with 3.0 at% N and 2.4 at.% S revealed by XPS measurement, exhibited very high specific capacitance of 427 F g-1 at 1.0 A g-1 in acidic electrolyte and maintained ~60 % of capacitance at ultrahigh working current density of 100.0 A g-1. Furthermore, capacitive deionization (CDI) measurements revealed that 600-NS-DCM possessed an impressive desalination capacity of 32.3 mg g-1 in 40.0 mg L-1 NaCl, and very good cycling stability. Our strategy of fabricating DCM with multiple heteroatoms codoping can be extended to the synthesis of various carbon materials for broad electrochemical applications.