Silicate-assisted activation of biomass towards N-doped porous carbon sheets for supercapacitors

Biomass-derived carbon has been the focus of research for a long time due to its wide range of sources, rich diversity and low cost. However, it also faces poor pore size distribution, low surface area and inert surface, which leads to its low performance, especially in supercapacitor. Herein, nitrogen enriched porous carbons (N-PC) were synthesized via a simple silica-activation process using carrots biomass as carbon precursor and Na2SiO3 as effective activation agent. Direct grinding for mixing of carrots and Na2SiO3 avoids the utilization of any solvents, leading to the characteristics of easy operation, simplicity and large-scale application. Carrots are rich in vitamins, which makes them serve as excellent carbon and nitrogen precursor. The low-cost Na2SiO3 plays an activating role to create porous structure, realizing the adjustment of mesopore size and increasing surface area for the N-PC. The prepared N-PC exhibits layered morphology, high surface area, rich porous structure, and nitrogen doping, which endow the N-PC with outstanding performance in the field of supercapacitor, indicating its promising for energy storage application.