In situ surface decoration of Fe3C/Fe3O4/C nanosheets: Towards bi-functional activated carbons with supercapacitance and efficient dye adsorption

Abstract

This work reports a bi-functional activated porous carbon (PC) prepared from a biomass tofu, with excellent capacities for charge storage and adsorption of organic dyes, which is enabled by decorating with Fe₃C/Fe₃O₄/C nanosheets. The in-situ growth and self-assembly of the nanosheets on the carbon surface are achieved by a one-step catalytic carbonization of tofu simultaneously with FeCl₃ and ZnCl₂ catalysts. Due to the high surface area and unique iron compounds-containing and sheet-like structures, the PCs exhibit an electrochemical capacitance of 315 F g^-1 at 0.5 A g^-1 as supercapacitor electrodes, and an ultrahigh adsorption capacity of 918 mg g^-1 for methylene blue (MB) and 868 mg g^-1 for Rhodamine B (RhB). This study provides a new perspective for understanding the effects of surface engineering on increasing charge storage and dye adsorption ability of biomass-derived PCs as well as for developing bi-functional PCs with novel magnetic properties.

Keywords: Activated carbon; Dye adsorption; Nanosheets; Supercapacitor.