Mechanochemical degradation of hazardous pentachloronitrobenzene to in-situ N-doped alkynyl carbon material with high supercapacitor performance

Abstract

Pentachloronitrobenzene (PCNB) as a typical banned POPs has received wide attention for its toxicity, migration and degradation, but its resource utilization has rarely been studied. In this work, hazardous PCNB was efficiently degraded and converted into N-doped alkynyl carbon material (NACM) through a solvent-free mechanochemical strategy. The reaction is mainly due to the substitution reaction of alkynyl groups from CaC2 to organic chlorines in PCNB through mechanochemical activation. This process is environmentally friendly for its high efficiency, mild operating conditions (ball-milling 60 min under 400 rpm at CaC2:PCNB = 10), and superior technological feasibility and economy. The resulting NACM is an unique advanced carbon material with alkynyl-linked benzene ring skeleton, multilayered nanoribbon morphology and in-situ N/O doping, which makes it an excellent electrode material with high specific capacitance (292.9 F cm−3), good electrical conductivity (1718 S m−1), and outstanding cycling stability (>98.1% after 5000 cycles). This work provides a multi-in-one strategy for the PCNB degradation and functional ACMs synthesis, which may be viable for the treatment of other halogenated hazardous chemicals.