Introduction to coconut shell-based activated carbon Coconut shell-based activated carbon is a widely used material in various industrial and commercial applications. It is used for water purification, air filtration, gold recovery, and many more. This material has gained a lot of popularity in recent years due to its environmentally friendly, low-cost, and renewable nature. Activated carbon is produced by heating carbon-rich materials in the absence of oxygen and is then treated with steam or air to create a highly porous surface area.