2D porous carbon nanosheets derived from turnip: Preparation, characterization and its electrochemical performance

摘要

? 2023 Elsevier LtdBiomass-based porous carbon materials have appeal due to their low cost, abundance and sustainability. In this report, a novel kind of heteroatom (N, S) co-doped 2D porous activated carbon using turnip as biomass has been prepared with subsequent non-toxic dual activators. At optimized activation temperature, the activated carbon from turnip-derived using KCl/NaCl (ACTKNa) as activators shows excellent surface area of 1938 m2·g?1 with micro-mesopores distributions. Importantly, ACTKNa as electrode materials for supercapacitors exhibits a superb capacitance value of 570 F·g?1 (0.5 A·g?1) and retains high stability. Interestingly, a symmetric ACTKNa//ACTKNa device can work in the potential window (0–1.5 V) under neutral Na2SO4 solution. Among them, the symmetric device delivers specific energy value 47.5 Wh·kg?1 at specific power of 372 W·kg?1 with outstanding rate capability of 86 after 20,000 cycles. This work opens the way to enhance the specific energy value by increasing the potential window using neutral electrolyte.