Targeting application of hierarchical porous carbon by facile one-step site-specific activation of wood powder: CO2 adsorption and supercapacitors

Optimization of pore parameters for specific applications is crucial for utilization of hierarchical porous carbon (HPC). In this work, we report a facile method to obtain HPCs for targeting applications in a controlled manner by a one-step site-specific activation method with trace amounts of KOH. For CO2 adsorption applications, the material is optimized to have a pore size consistent with the kinetic diameter of CO2, which facilitates the diffusion of CO2 in the material. The optimized material shows exceptional CO2 adsorption capacity (5.21 mmol g(-1) at 0 degrees C and 3.54 mmol g(-1) at 25 degrees C), and excellent adsorption reversibility (97.6% at 0 degrees C and 98.9% at 25 degrees C). For supercapacitor applications, the pore size of the optimized HPC is multiple of the size of hydrated potassium ions, which enhances the transport of electrolyte ions. The optimized material provides a high specific capacitance of 369 F g(-1) at 0.5 A g(-1), and the assembled symmetric supercapacitor exhibits an extraordinary energy density of 30.51 Wh kg(-1) at a power density of 92.23 W kg(-1). This work provides new insight into tuning of the pore parameters for specific applications of HPCs, and a facile strategy for valueadded utilization of biomass materials.

Automated summary

This study reports a facile method to obtain hierarchical porous carbon (HPC) for specific applications through a one-step site-specific activation method with trace amounts of KOH. The optimized material shows exceptional performance in CO2 adsorption and supercapacitor applications.