Tailoring texture properties in porous carbon for enhanced capacitive performance: towards investigating the CO2 activation behaviors of carbonaceous matter

Abstract

Regulating texture properties in porous carbon for enhanced capacitive performance and understanding modification processes have been strongly desired. Herein, ordinal H3PO4-CO2 activation, as well as thermal behavior measurements, were applied for obtaining pine sawdust-derived porous carbons (PC-T, T can be 800, 850, 900, 950, and 1000) for boosting specific capacitance and understanding the CO2 activation behaviors of the porous carbon fabricated by H3PO4 activation (PC), respectively. The micropore surface area, microporosity, micropore volume (Vmicro), and specific capacitance of PC-T were all significantly higher than those of PC. For PC, it is optimal to perform CO2 activation above 800 °C, whereby the activation procedure represents a controlled chemical reaction procedure. Alternatively, the specific surface area exhibited a positively linear relationship over the reactivity index. Remarkably, the sample PC-1000 delivered an excellent specific capacitance up to 228.47 F/g upon 0.5 A/ for such a 3-electrode configuration owing to the high specific surface area (1880.64 m2/g) and considerable micro/meso/macropores. Overall, excellent manufacturability and modifiable texture properties afford sequential H3PO4-CO2 activation enabling the manufacture of a range of high-level and multilevel porous carbons.