**10.2 Fruit shell**

Tamarind shell is used as the carbon precursor for generating the activated carbon (AC) and the resultant AC materials utilized for water purification and supercapacitor applications. Vengatesan et al. [21] studied the tamarind shellderived N-doped carbon for capacitive deionization (CDI) (**Figure 27**).

N-doping is proposed to be an effective method in not only improving the electrical conductivity and wettability of the carbon but also played a crucial role in

**Figure 26.** *Tamarind seed oil.*

**Figure 27.** *Schematic representation of the formation of NTC-800.*

enhancing the electro-sorption performance. As such, the low-cost biomass waste tamarind shell derived N-doped carbon nanosheets developed offer a promising electrode material for conventional high-performance symmetric CDI applications.
