Efficient removal of a typical dye and Cr(vi) reduction using N-doped magnetic porous carbon

Abstract

N-doped magnetic porous carbon (N-MPC) was prepared by a simple, one-step simultaneous activation-graphitization and activation route. The as-prepared N-MPC had an interconnected hierarchical structure and magnetic properties, with an ultrahigh surface area of ∼2148.42 m² g⁻¹ and a high pore volume of ∼1.26 cm³ g⁻¹. The N-MPC composites had excellent dye removal capacities (1284.09 mg g⁻¹ for methylene blue, 819.39 mg g⁻¹ for rhodamin B, 376.29 mg g⁻¹ for victoria blue and 565.41 mg g⁻¹ for methyl orange) and also had a high reducing ability for Cr(VI). These properties were attributed to the low isoelectric point, high surface area, the aggregation of dyes on N-MPC surface and the metallic Ni(0) embedded in the unique structure. Moreover, the magnetic separation also facilitated its application in wastewater treatment on a large scale. Our results showed that the N-MPC composites have a superb removal capability of Cr(VI) and dyes from water, with important potential practical applications for wastewater clean-up. In addition, the ultrahigh surface area and large pore volume of N-MPC has great potential in many future applications, such as lithium ion batteries, supercapacitors and in photocatalysis.