Capacitive Organic Dye Removal by Block Copolymer Based Porous Carbon Fibers

Abstract

AbstractBlock copolymer based porous carbon fibers (PCFs) have hierarchical pores, high surface areas, and excellent electrical/ion conductivities. Herein, PCF is synthesized from poly(methyl methacrylate)‐block‐poly(acrylonitrile) and utilized for organic dye removal. The PCF contains hierarchical macro‐, meso‐, and micropores with a surface area of 780 m2 g−1. The electrosorptive behavior of PCF is well described by the Langmuir isotherm and the Weber–Morris model. Based on the model, the interconnected hierarchical pores contribute to easy accessibility of dye ions to the inner surface sites within PCF, resulting in a high electrosorption capacity of 1360 mg g−1, reaching ≈87% of the theoretical maximum. The PCF shows a capacity loss of <0.5% over ten cycles during a 240 h operation period. Thanks to the hierarchical pores that allow for rapid ion desorption, the PCF can easily be regenerated. Lastly, depending on the electrode configuration, the PCF can selectively remove anionic dye, cationic dye, or both. The findings herein provide a fundamental understanding of electrosorptive behavior of block copolymer based porous carbon fibers, enabling future development in filtration applications.