Potassium thiocyanate (KSCN) activation showed great potential to prepare N/S co-doped microporous carbon for environmental remediation, however, predictable preparation for targeted application was a challenge. This study suggested that thermal stabilization effect and oxygen replacement reaction during KSCN activation could together regulate pore formation and N/S co-doping. Results showed that carbonaceous precursor with high thermal stability (expressed by high R50 index) could support stable carbon matrix for KSCN pore-forming. Meanwhile, carbonaceous precursor with high polarity (expressed by high O/C) was more prone to occur oxygen replacement reaction, promoting N/S co-doping. N/S co-doped microporous carbon with high micropore surface area can promote BPA adsorption via the pore-filling mechanism. However, reaction induced by S contained groups can enhance heavy metal (Pb2+) adsorption while prepared material with S doping. In summary, a carbonaceous precursor with high R50 index was conducive to preparing carbon material for organic pollutant adsorption, while the carbonaceous precursor with high O/C was suit to fabricate carbon material with high adsorption capacity for Pb2+ immobilization. This study provided important insights into the directional synthesis of optimized N/S doped microporous carbon. Graphical Abstract

Potassium thiocyanate (KSCN), a highly efficient “three birds with one stone” activator, might work with inorganic activators to produce excellent N/S co-doped porous carbon (NSC) materials for environmental remediation. However, the effects of inorganic activators on cooperative activation are unclear. As a result, the influence of inorganic activators on the synthesis of NSC materials was investigated further. This study shows that the surface areas of the NSC materials acquired through cooperative activation by potassium salts (KOH or K2CO3) were considerably higher than those acquired through KSCN activation alone (1403 m2/g). Furthermore, KSCN could cooperate with K2CO3 to prepare samples with excellent specific surface area (2900 m2/g) or N/S content. The as-prepared NSC materials demonstrated higher adsorption capability for chloramphenicol (833 mg/g) and Pb2+ (303 mg/g) (pore fitting, complexation). The research provides critical insights into the one-step synthesis of NSC materials with a vast application potential.