Tailoring Ti3CNT MXene via an acid molecular scissor

MXenes are attracting growing attentions from scientific community owing to their decent electric and ionic conductivity, highly accessible surface area, and the presence of redox-active sites. Herein, an acid molecular scissor is proposed to artificially tailor Ti3CNTx MXene at the atomic scale and create defective nanosheets and redox-active sites. The tailored Ti3CNTx MXene exhibits a significantly improved electrochemical performance with the specific capacitance reaching 376 F g−1 and 230.68 mF cm−2, much higher than that of original Ti3CNTx MXene (237 F g−1 and 168.27 mF cm−2). The tailored Ti3CNTx MXene was further assembled into a micro-supercapacitor, which demonstrates a high volumetric capacitance of 250 F cm−3, a high energy density of 12.46 mW h cm−3 at a power density of 0.43 W cm−3. This work offers a new strategy to reinvent MXenes at the atomic scale with largely enhanced redox-active sites for energy storage, catalysis, solid lubricants and electromagnetic interference shielding.