Nitrogen self-doped activated carbons with narrow pore size distribution from bamboo shoot shells

To prepare the nitrogen self-doped and microporous-rich activated carbons (BNACs), bamboo shoot shells after hydrothermal treatment were activated using KHCO3 under the temperature of 600 ℃, 650 ℃, 700 ℃, 750 ℃ and 800 ℃. The influence of activation temperatures on the properties of BNACs was investigated. Results confirmed that activation temperatures significantly impacted the pore structure, nitrogen groups, and electrochemical properties. The maximum microporosity for the BNACs was 98.8% (SBET) and 89.9% (pore volume) at an activation temperature of 700 ℃, corresponding to the minimum average pore size of 1.29 nm. The nitrogen content of BNAC-700 was 2.05%, with the pyridinic N of 34.1%, pyrrolic N of 27.6%, and graphitic N of 23.4%. Its capacitance values of 166.3 F/g (CV at 5 mV/s) and 178.1 F/g (GCD at 0.5 A/g) were higher than other BNACs, and capacitance retention of 96.3% after 5000 times cycle. This study could greatly benefit the utilization of bamboo shoot shells.