The Critical Role of Oxygen-Containing Functional Groups in the Etching Behavior of Activators to Carbon Materials

Fully activating the carbon matrix to obtain a high specific surface area (SSA) has been a practical approach to enhance the electrochemical performance of carbon materials. Much research mentioned that the activation has a large influence on the oxygen-containing functional groups (OCFGs) of the porous carbon. However, the potential impact of OCFGs ubiquitous in carbon precursors on the etching behavior of activators is rarely studied. Herein, a pitaya peel with a high oxygen content is employed as the carbon matrix and then a series of porous carbon materials are synthesized by a one-step pyrolysis strategy using different activators. We found that the existence of OCFGs in the carbon materials is conducive to enhancing the etching behavior. Theoretical calculations reveal that OCFGs in the carbon matrix could induce the local charge redistributions, thereby improving the binding affinity between the activators and the carbon atoms near OCFGs. Consequently, activators tend to etch carbon atoms around the OCFGs in the carbon precursors. Based on this, the optimized sample exhibits an ultrahigh SSA of 3699 m2 g–1, superior capacitance (373 F g–1 at 1 A g–1), and excellent rate performance. This work contributes to understanding the role of OCFGs in the etching behavior of activators to carbon materials.