Upcycling of lignin waste to activated carbon for supercapacitor electrode and organic adsorbent

We introduce a facile strategy to upcycle lignin waste to valuable activated carbon (AC). Unlike conventional preparation processes of AC, such as high-temperature carbonization above 600 °C followed by chemical or physical activation, we synthesized AC through low-carbonization (∼300 °C), ball-milling, and thermal activation. Low-temperature carbonization effectively led to the formation of the micro-pores and simultaneously high yield. Uniform activated morphology of char lignin is achieved through a ball-milling process. The as-synthesized AC exhibited a large specific surface area of 1075.18 m2 g−1, high specific capacitance of 115.1 F g−1, and excellent adsorbability of 0.23 gtoluene per gactivated carbon. Therefore, we believe that the presented facile strategy could lead to the realization of upcycling of lignin waste to highly useful AC.