Carbonate salts-activated carbon

Due to its advantageous chemical stability, low cost, and extensive porosity, activated carbons (AC) are a crucial material in many industries. The AC precursors, synthetic pathways, activating agents, and synthesis parameters are crucial elements for the best synthesis of AC. Using waste biomass as a precursor for AC has recently increased since it is cheap, readily available, and is a method to fight agricultural waste disposal problems. Physical, chemical, and microwave-induced activation methods and circumstances are reported for producing biomass-derived AC. Recent publications show that biomass-derived AC can be employed as supercapacitor electrodes. Under optimal conditions, active carbons with superior specific capacitance and longer cyclic stability have been reported. The enormous surface area and porous structure of the AC-based electrode materials make them intriguing for supercapacitors, fuel cells, and batteries. Based on the electrolyte ions adsorption at the electrode interface, carbonaceous materials display behavior similar to that of electric double-layer capacitors. Changes in surface chemistry, and introducing certain surface functionalities on ACs, impacted electrochemical qualities more than physiochemical properties. For the purpose of creating high-quality AC for supercapacitor electrodes, carbonate salts have been frequently used. Carbonate salts have various advantages, including being industrial byproducts; they are low-cost and widely available worldwide. Activation with carbonate salts allows special morphologies like hierarchical and composed of micro-, meso-, and macropores for easy penetration of the electrolyte, which shorten the path length and exhibit oxygen functional groups. The development of AC from numerous biomass using carbonate salts as activation agents and their utilization as supercapacitor electrodes are summarized in this chapter.