Effect of phenolic resin infiltration content on the structural and electrochemical properties of hierarchical porous carbons

Abstract

Hierarchical porous (micro-, meso- and macro-porous) carbons (HPCs) are synthesized by a facile replica template method with phenolic resin (PR) as a carbon source and hollow mesoporous silica as a hard template. The morphology of the HPCs can be easily controlled by altering the mass ratio of PR to SiO2 spheres. Structural characterizations reveal that a well-defined HPC with a large surface area of 1141 m(2) g(-1) is formed when PR/SiO2 is 1:1. With further increasing PR infiltration content, macropores of carbons disappear while solid structures appear. A possible formation mechanism for the morphological transformation of HPCs is proposed. The effect of phenolic resin infiltration content on the electrochemical properties of HPCs-based materials as supercapacitor electrodes is further evaluated. The HPCs-1(PR/SiO2 = 1) electrode exhibits the highest specific capacitance of 256 F g(-1) due to its faster diffusion of electrolyte ions and lower charge transfer resistance. The relationship between the morphology and the electrochemical behavior of HPCs is also elucidated.