**Abstract**

Activated carbon (AC) is a wonder-material that finds multifarious applications such as catalytic supports, removal of pollutants, electrodes in energy gadgets, gas storage etc. Surface area, chemical constituents and pore structures are a few traits required in the ACs which largely depend on the source of the precursors and processing methodologies adopted. In this context, the idea of recycling phytomass for producing ACs has attracted researchers seeing that the inexpensive and renewable nature of the phytomass can reduce the overall cost of producing ACs with diversified features and that it does not add CO2 to the atmosphere leading to global warming (plants release only the same amount of CO2 as they consumed while growing). Further, phytomass after their life possess no value but their conversion into ACs would be an economically profitable option leading to inexpensive ACs. As a consequent of these advantages this chapter has been planned and designed to provide certain interesting multifunctional aspects of low-cost phytomass derived ACs. The chapter is expected to provide research insights oriented towards identification of unexplored phytomass or wastes which could lead to carbon with novel properties tunable to the applications. Filth-to-wealth or in other words, recycling of wastes provides a strategy categorized under circular-bioeconomy, which is the want of the hour.

**Keywords:** Phytomass, Activated carbon, Adsorbent, Electrocatalysts, Supercapacitor, Antibacterial, Bio-sensors, Circular-bioeconomy, Recycle
